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For: Nelitz M, Lippacher S, Reichel H, Dornacher D. Evaluation of trochlear dysplasia using MRI: correlation between the classification system of Dejour and objective parameters of trochlear dysplasia. Knee Surg Sports Traumatol Arthrosc 2014. [PMID: 23196644 DOI: 10.1007/s00167-012-2321-y] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]

For:	Nelitz M, Lippacher S, Reichel H, Dornacher D. Evaluation of trochlear dysplasia using MRI: correlation between the classification system of Dejour and objective parameters of trochlear dysplasia. Knee Surg Sports Traumatol Arthrosc 2014. [PMID: 23196644 DOI: 10.1007/s00167-012-2321-y] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]

Number

Cited by Other Article(s)

Bi AS, Triana J, Li ZI, Kaplan DJ, Campbell KA, Alaia MJ, Strauss EJ, Jazrawi LM, Gonzalez-Lomas G. More negative sagittal tibial tuberosity-trochlear groove distances are correlated with larger patellofemoral chondral lesion size. Knee Surg Sports Traumatol Arthrosc 2025;33:1569-1578. [PMID: 39189127 DOI: 10.1002/ksa.12444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 08/07/2024] [Accepted: 08/09/2024] [Indexed: 08/28/2024]

Abstract

PURPOSE

The purpose of this study is to assess the association between sagittal tibial tuberosity-trochlear groove (sTT-TG) distance and patellofemoral chondral lesion size in patients undergoing cartilage restoration procedures.

METHODS

A retrospective cohort analysis of patients who underwent an osteochondral allograft transplantation or matrix-induced autologous chondrocyte implantation in the patellofemoral compartment, from 2010 to 2020, were included if they had patellofemoral high-grade lesions, magnetic resonance imaging (MRI) and minimum 2-year follow-up. The preoperative sTT-TG distance was measured independently on axial T2-weighted MRI sequences by two authors, each at least two weeks apart. Intraoperative lesion size was reported according to operative report measurements by the attending surgeon. An interclass correlation coefficient (ICC) was calculated to assess intra- and inter-rater reliability, and categorical data analysis and linear regression models were used to assess the relationship between sTT-TG and lesion size.

RESULTS

A total of 80 patients (50 females) with a mean age of 31.5 ± 10.4 years, body mass index of 27.0 ± 5.9 kg/m2 and follow-up of 61.5 ± 21.4 months were included. A total of 107 lesions were present: 63 patients with unipolar (patella = 41, trochlea = 22) and 22 with bipolar lesions. The mean MRI defect size was 1.6 ± 1.0 cm2 and the mean intraoperative defect size was 3.8 ± 2.4cm2. Intra- (ICC: 0.99,0.98) and inter-rater reliability (ICC: 0.96) were excellent for both MRI defect size and sTT-TG measurements. The mean sTT-TG was -4.8 ± 4.9 mm and was significantly inversely related to MRI defect size (-0.45, p < 0.01), intraoperative patellar lesion size (-0.32, p = 0.01), total lesion area (-0.22, p = 0.04), but not trochlear lesion size (-0.09, p = 0.56). Multivariable regression demonstrated a more negative sTT-TG remained an independent variable correlated with larger MRI-measured patellofemoral defect sizes and intraoperative patellar lesions.

CONCLUSION

A more negative sTT-TG was an independent variable correlated with larger patellofemoral lesions in patients undergoing patellofemoral cartilage restoration.

LEVEL OF EVIDENCE

Level III, Diagnostic.

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Rab P, Vieider RP, Fritsch L, Cotic M, Imhoff FB, Siebenlist S, Achtnich A, Hinz M. Distal femoral osteotomy for the treatment of chronic patellofemoral instability improves gait patterns. Arch Orthop Trauma Surg 2025;145:176. [PMID: 40056196 PMCID: PMC11890233 DOI: 10.1007/s00402-025-05788-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2024] [Accepted: 02/21/2025] [Indexed: 03/10/2025]

Abstract

PURPOSE

The purpose of this study was to evaluate pre- to postoperative changes in clinical and functional outcomes as well as gait patterns in patients who underwent surgery for chronic patellofemoral instability (PFI).

METHODS

Patients who underwent surgery for the treatment of recurrent PFI according to an individual risk factor analysis were included. Pre- and minimum 12 months postoperatively, patient-reported outcome measures (PROM; Kujala score, Lysholm score, Tegner Activity Scale [TAS] and Visual Analog Scale for pain) as well as gait (dynamic Q-angle) and function (dynamic valgus and dynamic Trendelenburg during single-leg squat) via videography were evaluated. Subgroup analysis was performed based on whether or not patients underwent concomitant distal femoral osteotomy (DFO) due to coronal and/or torsional malalignment.

RESULTS

Twenty-three patients were included (follow-up: 12.5 [12.1-13.0] months), of which 60.9% patients underwent a concomitant DFO. All PROM improved significantly (p < 0.05). Overall, dynamic Q-angle (p = 0.016) and dynamic valgus (p = 0.041) were observed significantly less frequently postoperatively when to compared to preoperatively. Subgroup analysis showed that only the group that underwent DFO had a significant improvement of dynamic Q-angle (p = 0.041). Dynamic Trendelenburg did not improve (p > 0.05). Regression analysis showed that the presence of a postoperative dynamic Q-angle was associated with a worse postoperative Kujala score (p = 0.042) and TAS (p = 0.049).

CONCLUSION

Patient-individualized surgery for PFI improved gait patterns and functional testing, especially in patients who also underwent DFO. The presence of dynamic Q-angle postoperatively was associated with significantly worse functional outcome and sporting ability.

LEVEL OF EVIDENCE

Level III.

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Orellana KJ, Lee J, Yang D, Kell D, Nguyen J, Lawrence JT, Williams BA. Trochlear Morphological Changes in Skeletally Immature Patients Across Consecutive MRI Studies. Am J Sports Med 2025;53:690-698. [PMID: 39849996 DOI: 10.1177/03635465241312168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2025]

Abstract

BACKGROUND

Trochlear dysplasia is a consistent risk factor for recurrent patellofemoral instability (PFI), but there is limited understanding of how the trochlea develops during growth. The aim of this study was to evaluate serial magnetic resonance imaging (MRI) studies performed in skeletally immature patients with and without PFI to characterize changes in trochlear anatomy over time.

HYPOTHESIS

PFI leads to progressive worsening of trochlear dysplasia over time.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective case-control study was conducted on pediatric patients (<18 years of age) with and without a diagnosis of PFI who had multiple ipsilateral MRI studies of the knee at least 6 months apart. Inclusion criteria were patients with open distal femoral physes at the initial MRI study and no intervening surgery between MRI studies. All patients with PFI were included, and 30 patients without PFI were identified for comparison. MRI scans were retrospectively reviewed to evaluate trochlear morphology using the Dejour and Oswestry-Bristol classifications and to measure the sulcus angle, trochlear depth index, medial condylar trochlear offset, and lateral trochlear inclination (LTI). Univariate and bivariate statistics were performed to evaluate differences in morphology between MRI studies and between groups.

RESULTS

A total of 128 patients were identified (98 in the PFI group, 30 in the non-PFI group) with a mean age of 12.3 ± 2.4 years and mean time between MRI studies of 2.3 ± 1.5 years (range, 0.5-6.5 years). Among patients with PFI, rates of moderate to severe (Dejour grades B-D and Oswestry-Bristol classification flat or convex) trochlear dysplasia increased from the initial to most recent imaging study (67% vs 89%; P < .001), and statistically significantly more dysplastic LTI and sulcus angle were observed on follow-up (P < .05). Among the non-PFI group, the percentage of patients with normal trochlear morphology increased from 53% to 87% (P < .001), and less dysplastic measures of trochlear depth index, LTI, and sulcus angle were seen on follow-up imaging (P < .05). When comparing rates of change, trochlear metrics changed toward a more shallow and dysplastic direction in the PFI cohort and toward a deeper and less dysplastic direction in the non-PFI group.

CONCLUSION

Skeletally immature patients with untreated PFI have trochlear dysplasia that progressively worsens over time. Conversely, those without PFI have trochlear characteristics that appear to normalize with growth.

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Jian-Lüssi N, Pfirrmann CWA, Buck FM, Frauenfelder T, Rosskopf AB. A novel adapted MRI-based scheme for Dejour classification of trochlear dysplasia. Skeletal Radiol 2025;54:437-445. [PMID: 39042200 PMCID: PMC11769863 DOI: 10.1007/s00256-024-04748-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Revised: 07/03/2024] [Accepted: 07/07/2024] [Indexed: 07/24/2024]

Abstract

PURPOSE

To elaborate an optimized scheme for the Dejour classification of trochlear dysplasia based on axial and sagittal MR images and to evaluate its intra- and inter-reader reliability.

MATERIAL AND METHODS

Over a period of 20 months patients with a knee MRI and the diagnosis of trochlear dysplasia were retrospectively included. Exclusion criteria were incomplete examination, qualitatively non-diagnostic examination, post trochlear surgery, missing informed consent for research purposes. Three independent evaluations were performed by two radiologists: first using an established description of the Dejour classification (types A-D) and then two evaluations using a new adapted scheme (types A-D). The adapted scheme includes a shallow trochlea, in type A no spur/no cliff, in type B with spur/no cliff, in type C no spur/with cliff, and in type D with spur/with cliff.

RESULTS

One hundred seventy-one knee MRIs (female:65.5%; left side:52.6%) were included with a median age of 34.3 years (range:11.3-79.2). Inter-reader reliability using the established description was fair for the four-type-classification (kappa(k) = 0.23; 95%CI:0.11-0.34), fair for differentiation low-grade versus high-grade dysplasia (k = 0.28;0.13-0.43), slight for differentiation spur versus no-spur types (k = 0.20;0.05-0.34). Inter-reader reliability using the adapted scheme was substantial (k = 0.79;0.75-0.83) for the four-type-classification, substantial for differentiation low-grade versus high-grade dysplasia (k = 0.80;0.75-0.85), substantial for differentiation spur versus no-spur presence (k = 0.76;0.71-0.81). Intra-reader reliability was almost perfect for the adapted scheme (k-values: 0.88-0.95; 95%CIs: 0.84-0.98).

CONCLUSION

The novel adapted scheme for Dejour classification shows an almost perfect intra-reader reliability and a substantially higher inter-reader reliability. It may become a helpful tool in the daily diagnostic work of radiologists.

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Mazy D, Angelelli L, Cance N, Giovannetti de Sanctis E, Dejour DH. Medial orientation of the trochlear groove is a strong indicator of high-grade trochlear dysplasia. Knee Surg Sports Traumatol Arthrosc 2025;33:926-934. [PMID: 39105459 DOI: 10.1002/ksa.12418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 07/27/2024] [Accepted: 07/28/2024] [Indexed: 08/07/2024]

Chokshi S, Gangatirkar R, Kandi A, DeLeonibus M, Kamel M, Chadalavada S, Gupta R, Munigala H, Tappa K, Kondor S, Burch MB, Ravi P. Medical 3D Printing Using Material Jetting: Technology Overview, Medical Applications, and Challenges. Bioengineering (Basel) 2025;12:249. [PMID: 40150713 PMCID: PMC11939548 DOI: 10.3390/bioengineering12030249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2025] [Revised: 02/26/2025] [Accepted: 02/26/2025] [Indexed: 03/29/2025] Open

Affiliation(s)

Shivum Chokshi Department of Radiology, College of Medicine, University of Cincinnati, Cincinnati, OH 45221, USA; (S.C.); (R.G.); (A.K.); (S.C.); (S.K.); (M.B.B.)
Raghav Gangatirkar Department of Radiology, College of Medicine, University of Cincinnati, Cincinnati, OH 45221, USA; (S.C.); (R.G.); (A.K.); (S.C.); (S.K.); (M.B.B.)
Anish Kandi Department of Radiology, College of Medicine, University of Cincinnati, Cincinnati, OH 45221, USA; (S.C.); (R.G.); (A.K.); (S.C.); (S.K.); (M.B.B.)
Maria DeLeonibus Department of General Surgery, Division of Oral and Maxillofacial Surgery, College of Medicine, University of Cincinnati, Cincinnati, OH 45221, USA;
Mohamed Kamel Department of Urology, College of Medicine, University of Cincinnati, Cincinnati, OH 45221, USA;
Seetharam Chadalavada Department of Radiology, College of Medicine, University of Cincinnati, Cincinnati, OH 45221, USA; (S.C.); (R.G.); (A.K.); (S.C.); (S.K.); (M.B.B.)
Rajul Gupta Department of Orthopedics, College of Medicine, University of Cincinnati, Cincinnati, OH 45221, USA;
Harshitha Munigala Department of Biomedical Engineering, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH 45221, USA;
Karthik Tappa Department of Breast Imaging, Division of Diagnostic Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
Shayne Kondor Department of Radiology, College of Medicine, University of Cincinnati, Cincinnati, OH 45221, USA; (S.C.); (R.G.); (A.K.); (S.C.); (S.K.); (M.B.B.)
Michael B. Burch Department of Radiology, College of Medicine, University of Cincinnati, Cincinnati, OH 45221, USA; (S.C.); (R.G.); (A.K.); (S.C.); (S.K.); (M.B.B.)
Prashanth Ravi Department of Radiology, College of Medicine, University of Cincinnati, Cincinnati, OH 45221, USA; (S.C.); (R.G.); (A.K.); (S.C.); (S.K.); (M.B.B.)

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Yuan M, Chen Y, Li J, Yang H, Yu F, Lv F. Abnormal patellar sagittal spatial kinematics in patients with patellofemoral pain: an in vivo dynamic CT study. J Orthop Surg Res 2025;20:193. [PMID: 39994699 PMCID: PMC11849214 DOI: 10.1186/s13018-025-05610-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2024] [Accepted: 02/14/2025] [Indexed: 02/26/2025] Open

Abstract

BACKGROUND

Patellofemoral joint kinematics is a complex three-dimensional(3D) motion, involving shift and rotation in the coronal, sagittal, and axial directions. Quantifying patellar tracking only at the axial level of the patella or with two-dimensional(2D) parameters may not be comprehensive. The current study sought to explore the spatial kinematics characteristics of the patella in three directions, especially the sagittal plane in patients with patellofemoral pain (PFP) based on Four-dimensional computed tomography (4D-CT).

METHODS

A total of 35 knees with PFP and 35 controls from March 2023 to May 2024 were evaluated. 3D shift and tilt of the patella were measured in the patellofemoral joint coordinate system established by MIMICS. The 3D shift and tilt of the patella in three directions (coronal, sagittal, and axial) were evaluated. Differences between groups were analyzed using two-way repeated measures ANOVA.

RESULTS

The 3D tiltsagittal and 3D tiltaxial trends differed between the two groups (P = 0.020, 0.018, respectively). The 3D shiftsagittal at knee flexions of 50° to 70° was significantly increased in the PFP group compared to the control group (P = 0.009, 0.015, respectively). The 3D tiltsagittal was significantly greater in the PFP group than in the control group at -10° to 10° and 50° to 70° of knee flexion (P = 0.004, 0.005, 0.046, 0.007, respectively). The 3D tiltaxial was significantly greater in the PFP group than in the control group at -10° to 0° and 40° to 70° of knee flexion (P = 0.033, 0.011, 0.004, 0.015, respectively). The 3D shiftcoronal at knee flexions of -10° to 20° were significantly decreased in the PFP group compared to the control group (P = 0.002, < 0.001, 0.018, respectively).

CONCLUSION

It is necessary to evaluate the spatial position characteristics of the patellofemoral joint and the stability of the patella from multiple planes and angles at the dynamic level. Analyzing the spatial multi-plane kinematic characteristics of the patellofemoral joint may help in determining the etiology of PFP.

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Dippmann C, Lavard P, Kourakis AH, Siersma V, Hansen P, Talibi M, Krogsgaard MR. Good 5-year results and a low redislocation rate using an à la carte treatment algorithm for patellofemoral instability in patients with severe trochlea dysplasia. Knee Surg Sports Traumatol Arthrosc 2025;33:401-412. [PMID: 39171406 PMCID: PMC11792106 DOI: 10.1002/ksa.12432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 06/19/2024] [Accepted: 06/28/2024] [Indexed: 08/23/2024]

Abstract

PURPOSE

Trochlear dysplasia is a major risk factor for recurrent patellar instability, reduced quality of life and osteoarthritis of the patellofemoral joint. Patellar instability in patients with trochlear dysplasia can be treated by trochleoplasty, usually in combination with medial patellofemoral ligament reconstruction (MPFL-R). An à la carte treatment algorithm, which also addresses patella alta, lateralisation of the tibial tuberosity and valgus or torsional malalignment when present has been standard in one clinic for treatment of patellar instability patients since 2009, based on the hypothesis that it results in optimal subjective and clinical outcome, normalisation of the lateral trochlea inclination (LTI) angle and a low rate of patellar redislocation.

METHODS

This prospective study reports the 5-year results for consecutive patients with high-grade trochlea dysplasia operated according to the algorithm 2010-2017, evaluated preoperatively and 1, 2 and 5 years postoperatively. Clinical information on previous surgery and postoperative patellar stability, range-of-motion (ROM) and subsequent surgery were registered. Subjective outcome was evaluated by four patient-reported outcome measures (PROMs): Kujala, Lysholm, International Knee Documentation Committee and Knee injury and Osteoarthritis Outcome Score. The LTI angle was measured pre- and postoperatively on magnetic resonance imaging scans.

RESULTS

There were 131 patients (87 females) with a median age of 22 years (range: 14-38). All had a trochleoplasty and an MPFL-R. Additional procedures (tibial tuberosity medialisation/distalisation and/or femoral/tibial osteotomy) were performed in 52%. All PROM scores improved from preoperatively to 1-year follow-up with further improvement at 2 and 5 years after surgery (p < 0.05). Three patients (2%) had a traumatic patellar dislocation 9, 12 and 24 months postoperatively and 38% underwent subsequent surgery (hardware removal, arthroscopically assisted brisement force, knee arthroscopy). A normalisation of the LTI angle (≥11°) was achieved in 76%.

CONCLUSIONS

Treatment according to the à la carte algorithm for patients with patellar instability and high-grade trochlear dysplasia resulted in significant clinical and subjective improvement in all PROM scores and a very low redislocation rate (2%) 5 years after surgery.

LEVEL OF EVIDENCE

Level II.

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Chen Y, Tian W, Li J, Sheng B, Lv F, Nie S, Lv F. Decreased Association Between Patellar Axial Malalignment and Patellar Height and Increased Association Between Patellar Axial Malalignment and Tibial Tubercle-Trochlear Groove During Weightbearing. Clin Orthop Relat Res 2025:00003086-990000000-01863. [PMID: 39842005 DOI: 10.1097/corr.0000000000003357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2024] [Accepted: 12/03/2024] [Indexed: 01/24/2025]

Abstract

BACKGROUND

Nonweightbearing preoperative assessments avoid quadriceps contraction that tends to affect patellar motion and appear to be inaccurate in quantifying anatomic factors, which can lead to incorrect corrections and postoperative complications.

QUESTIONS/PURPOSES

(1) Does the relationship of patellar axial malalignment and other anatomic factors change during weightbearing? (2) What anatomic factor was most strongly correlated with recurrent patellar dislocation during weightbearing?

METHODS

This prospective, comparative, observational study recruited participants at our institution between January 2023 and September 2023. During this time, all patients with recurrent patellar dislocations received both weightbearing and nonweightbearing CT scans; control patients who received unilateral CT scans because of injuries or benign tumors received both weightbearing and nonweightbearing CT scans. Between January 2023 and September 2023, 52 patients were treated at our institution for patellar dislocation. We included those who had experienced at least two dislocations. The exclusion criteria were as follows: (1) traumatic dislocation, (2) prior knee surgery, (3) osteoarthritis (≥ Kellgren-Lawrence Grade 3), and (4) abnormal walking and standing postures confirmed by the orthopaedic surgeon and an inability to complete weightbearing CT with their body in a neutral position (meaning their body weight was evenly placed on both knees) because of severe pain. After applying prespecified exclusions, 63% (33 patients) of the original number were included, and data for 33 patients (65 knees) with weightbearing CT data and 28 patients (52 knees) with nonweightbearing CT data were obtained. Because of ethical requirements, the control group included patients who underwent unilateral CT scanning (for an injury or a benign tumor), and weightbearing CT and nonweightbearing CT covered both knees. Control knees were confirmed to have normal patellofemoral function by physical examination by an orthopaedic surgeon involved with the study. The control group consisted of the normal knees (52 knees underwent both weightbearing CT and nonweightbearing CT) and the affected but uninvolved knees (47 knees underwent weightbearing CT and 6 knees underwent nonweightbearing CT), and a total of 52 patients (99 knees) with weightbearing CT data and 31 patients (58 knees) with nonweightbearing CT data were included. There were no differences between the recurrent patellar dislocation and control groups in terms of gender, side, and BMI. Although the patients in the control group were older than those in the study group, most patients in both groups were at or at least near skeletal maturity. Patellofemoral measurements were evaluated with the Insall-Salvati ratioextension, Blackburne-Peel ratioextension, Caton-Deschamps ratioextension, bisect offset index, lateral patellar tilt angle, tibial tubercle-trochlear groove, lateral trochlear inclination, sulcus depth, and sulcus angle. Intraclass correlation coefficients (ICCs) for all these measurements were greater than or equal to 0.70 and so were considered adequate for reliability. The correlations between patellar axial malalignment and other anatomic factors during weightbearing and nonweightbearing were compared, and anatomic factors between weightbearing and nonweightbearing were compared to investigate the relationship of patellar axial malalignment and anatomic factors during weightbearing. The correlation between anatomic factors and recurrent patellar dislocation and the diagnostic performance of each factor for recurrent patellar dislocation were reported to find the anatomic factor that most strongly correlated with recurrent patellar dislocation during weightbearing.

RESULTS

We observed several changes in axial malalignment measurements that occurred with weightbearing. The correlation between bisect offset index and Blackburne-Peel ratioextension decreased with weightbearing compared with the nonweightbearing state (r = 0.12 [95% confidence interval (CI) -0.12 to 0.35] with weightbearing versus r = 0.58 [95% CI 0.36 to 0.75]; p = 0.003). The correlation between bisect offset index and Caton-Deschamps ratioextension decreased with weightbearing compared with the nonweightbearing state (r = 0.25 [95% CI 0.03 to 0.47] versus r = 0.68 [95% CI 0.49 to 0.82]; p = 0.002). The correlation between bisect offset index and tibial tubercle-trochlear groove distance increased with weightbearing compared with the nonweightbearing state (r = 0.63 [95% CI 0.43 to 0.78] versus r = 0.38 [95% CI 0.05 to 0.62]; p = 0.04). The correlation between lateral patellar tilt angle and Blackburne-Peel ratioextension decreased with weightbearing compared with the nonweightbearing state (r = 0.05 [95% CI -0.17 to 0.28] versus r = 0.44 [95% CI 0.21 to 0.63]; p = 0.02). The correlation between the lateral patellar tilt angle and Caton-Deschamps ratioextension decreased with the weightbearing compared with the nonweightbearing state (r = 0.16 [95% CI -0.09 to 0.40] versus r = 0.46 [95% CI 0.19 to 0.66]; p = 0.04). The correlation between lateral patellar tilt angle and tibial tubercle-trochlear groove distance increased with weightbearing compared with the nonweightbearing state (r = 0.64 [95% CI 0.48 to 0.76] versus r = 0.41 [95% CI 0.13 to 0.64]; p = 0.048). Several parameters changed with weightbearing. In both recurrent patellar dislocation and control groups, the Insall-Salvati ratioextension and the tibial tubercle-trochlear groove distance were lower with weightbearing compared with nonweightbearing (recurrent patellar dislocation/control: p = 0.001/p < 0.001 versus p = 0.006/p < 0.001); bisect offset index was higher with weightbearing compared with nonweightbearing (recurrent patellar dislocation/control: p < 0.001/p < 0.001). In the control group, the Blackburne-Peel ratioextension and the Caton-Deschamps ratioextension were lower with weightbearing compared with nonweightbearing (p = 0.01, p = 0.007). The anatomic factor most strongly correlated with recurrent patellar dislocation during weightbearing was the bisect offset index (r = 0.73 [95% CI 0.65 to 0.79]; p < 0.001). The anatomic factor most strongly correlated with recurrent patellar dislocation during nonweightbearing was the sulcus depth (r = -0.70 [95% CI -0.78 to -0.59]; p < 0.001). The ROC analysis showed that during weightbearing, the bisect offset index had the best diagnostic ability for recurrent patellar dislocation (area under the curve [AUC] 0.93 [95% CI 0.89 to 0.97]), whereas when the patient was nonweightbearing, sulcus depth was the best predictor (AUC 0.91 [95% CI 0.85 to 0.96]).

CONCLUSION

Evaluations based on nonweightbearing examinations underestimated the interaction between the tibial tubercle-trochlear groove and patellar axial alignment, thus surgeons could consider weightbearing preoperative assessments for tibial tuberosity osteotomy to avoid failing to restore normal patellar axial alignment. Bisect offset index was an important indicator to improve detecting possible recurrent patellar dislocation in the state of functional activation of soft tissues and can estimate patellar tilt to simplify the preoperative evaluation procedure. For patients who are at high risk but who have not yet developed a patellar dislocation, assessing the risk of recurrent patellar dislocation with the bisect offset index during weightbearing can inform them about the intensity and manner of their daily exercise.

LEVEL OF EVIDENCE

Level III, prognostic study.

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Chen Y, Yu F, Rong F, Lv F, Lv F, Li J. Analysis of spatial patellofemoral alignment using novel three-dimensional measurements based on weight-bearing cone-beam CT. Insights Imaging 2025;16:1. [PMID: 39747790 PMCID: PMC11695510 DOI: 10.1186/s13244-024-01883-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2024] [Accepted: 12/06/2024] [Indexed: 01/04/2025] Open

Abstract

OBJECTIVES

To propose a reliable and standard 3D assessment method to analyze the effect of weight-bearing (WB) status on the location of patella and clarify the diagnostic performance of 3D parameters for recurrent patellar dislocation (RPD) in WB and non-weight-bearing (NWB) conditions.

METHODS

Sixty-five knees of RPD patients and 99 knees of controls were included. Eight landmarks, two lines and a coordinate system were defined on 3D bone models of knees based on weight-bearing CT and non-weight-bearing CT. The shift and tilt of patella in three orthogonal axes (Xshift, Yshift, Zshift, Xtilt, Ytilt, Ztilt) were evaluated.

RESULTS

Xshift and Yshift were significantly higher, Zshift, Xtilt and Ytilt were significantly lower in WB condition than NWB condition (p < 0.001, p < 0.001, p = 0.001, p = 0.002, p = 0.010). In both WB and NWB conditions, Xshift, Yshift and Ztilt were significantly higher, and Xtilt was significantly lower in the RPD group than the control group (WB/NWB: p < 0.001/p = 0.002, p < 0.001/p = 0.001, p < 0.001/p < 0.001, p < 0.001/p = 0.009). In WB condition, Zshift and Ytilt were significantly higher in the RPD group than the control group (p = 0.011, p < 0.001). Ztilt had the best diagnostic performance for RPD in both WB and NWB conditions, with AUC of 0.887 (95% CI: 0.828, 0.946) and 0.885 (95% CI: 0.822, 0.947), respectively.

CONCLUSIONS

The 3D measurement method reliably and comprehensively reflected the relative spatial position relationship of the patellofemoral joint. It can be applied to the 3D preoperative planning of patellofemoral procedures. In addition, patellofemoral evaluation under the WB condition was essential to detect subtle underlying risk factors for RPD, with axial lateral patellar tilt being the best predictor.

CRITICAL RELEVANCE STATEMENT

This 3D measurement method under weight-bearing conditions contributes to comprehensively describing the relative spatial position of the patellofemoral joint in a standardized way and can be applied to preoperative evaluation for recurrent patellar dislocation.

KEY POINTS

Patellofemoral alignment is a 3D problem, and the accuracy of 2D parameters has been questioned. 3D measurement was reliable and comprehensively reflected relative spatial relationships of the patellofemoral joint. 3D measurements under weight-bearing condition help preoperative evaluation for RPD.

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Schneble CA, Yu K, Venkadesan M, Cooperman D, Beitler B, Sieberer J, Fulkerson J. Three-Dimensional Imaging of the Patellofemoral Joint Improves Understanding of Trochlear Anatomy and Pathology and Planning of Realignment. Arthroscopy 2025;41:130-140. [PMID: 38697330 DOI: 10.1016/j.arthro.2024.04.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Revised: 04/07/2024] [Accepted: 04/09/2024] [Indexed: 05/04/2024]

Frings J, Janssen E, Krause M, Frosch KH, Vettorazzi E, Weiler A, Schmeling A. Thin flap sulcus-deepening trochleoplasty in patellar instability yields good functional outcomes without progressive cartilage deterioration in the short-term follow-up-A retrospective single-surgeon cohort study. Knee Surg Sports Traumatol Arthrosc 2024. [PMID: 39720939 DOI: 10.1002/ksa.12566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2024] [Revised: 12/03/2024] [Accepted: 12/07/2024] [Indexed: 12/26/2024]

Abstract

PURPOSE

Sulcus-deepening trochleoplasty (TP) effectively treats patellofemoral (PF) instability (PFI) caused by high-grade trochlear dysplasia (TD), but current evidence is based on small case series. We hypothesised, that TP would result in significant functional improvements and a low re-dislocation rate but would not accelerate the progression of PF cartilage deterioration.

METHODS

We retrospectively reviewed all TP cases performed by a single surgeon between 2015 and 2021. Inclusion criteria were postoperative Magnetic resonance imaging (MRI) >6 and >12 months and a clinical follow-up >12 months. Patients with simultaneous cartilage repair, open physes or incomplete records were excluded. Clinical outcomes were assessed using pre- and postoperative scores, postoperative Banff Patellofemoral Instability Instrument (BPII) 2.0 and Knee Injury and Osteoarthritis Outcome Score (KOOS), re-dislocation rate and patient satisfaction. PF cartilage was evaluated via Area Measurement and Depth & Underlying Structures (AMADEUS) scores preoperatively, at 6 months and at the final follow-up.

RESULTS

We included 113 patients (25.8 ± 8.3 years) with high-grade TD (Dejour B-D; mean lateral inclination angle: -2.9 ± 9.1°), 85% of whom had advanced cartilage lesions. All underwent TP, lateral retinacular lengthening (LRL) and medial patellofemoral ligament reconstruction (MPFL-R). After 34.8 ± 20.9 months, function, pain levels and Tegner scores improved significantly (p < 0.001). KOOS dimensions were: symptoms 79.9 ± 13.5, pain 86.4 ± 12.1, activity 91.9 ± 8.3, sports 71.7 ± 22.2 and quality-of-life 58.1 ± 23.8. BPII 2.0 was 64.3 ± 31.4. Preoperative AMADEUS scores (55.2 ± 17.4) remained stable at 6 months (p = 0.343) but improved to 58.4 ± 16.0 at 28.6 (12-89) months (p = 0.004). Complication and re-dislocation rates were 5.3% and 1.8%, with 93% patient satisfaction.

CONCLUSION

Sulcus-deepening TP with MPFL-R and LRL yields good to excellent short-term results without progressive chondral deterioration, enabling patients to return to their prior or higher activity levels despite advanced preoperative chondral lesions. TP can be considered a safe, joint-preserving technique for PF stabilisation.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

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Giovannetti de Sanctis E, Toanen C, Guarino A, Pineda T, Deroche E, Dejour DH. The role of the most cranial trochlear orientation in patellar maltracking to better characterise trochlear morphology. Knee Surg Sports Traumatol Arthrosc 2024;32:2909-2918. [PMID: 38923584 DOI: 10.1002/ksa.12314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/23/2024] [Accepted: 06/02/2024] [Indexed: 06/28/2024]

Abstract

PURPOSE

The purpose of our study is to describe a magnetic resonance imaging quantitative parameter to assess the morphology of the trochlea that could be measurable from normal to high-grade trochlear dysplasia while evaluating the most proximal slice with trochlear cartilage.

METHODS

Two groups of patients have been compared: patients with no patellofemoral pain, no previous trauma and undergoing surgery for a suspected isolated meniscal tears (group A) and patients with objective patellar instability (group B). The cranial trochlear orientation (CTO) angle is defined as the angle between the posterior bicondylar line and the most lateral and most medial points on the subchondral bone covered by cartilage digitised on the first and most cranial image with the trochlear cartilage clearly visible.

RESULTS

The final cohort included 253 patients (109 in group A and 144 in group B). CTO was significantly higher in group B (-2.5 ± 8.4 vs. -10.8 ± 5,1; p < .001). Moreover, 75% of knees in group B had a CTO > -7°, while 75% of knees in group A had a CTO < -7°. CTO was measurable in all 253 knees, whereas the lateral trochlear inclination and the sulcus angle were measurable in only 202 knees. The entire cohort was also divided into knees with CTO ≤ 0° and CTO > 0°. All knees with a CTO > 0 were in group B, and 49% of knees with CTO < 0 were in group B. CTO was positively correlated with lateral patellar tilt.

CONCLUSIONS

CTO is the only parameter that can be measured on the most cranial slice, in every patient, even in high-grade trochlear dysplasia. According to this new system, the axial trochlear shape may be divided into two types: a positive CTO and a negative CTO, with the trochlea serving, respectively, as a medial and lateral barrier.

LEVEL OF EVIDENCE

Level III.

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De Leeuw A, Abidi S, Scarciolla L, Petersbourg D, Putman S, Cotten A. Patellar Instability: Imaging Findings. Semin Musculoskelet Radiol 2024;28:257-266. [PMID: 38768591 DOI: 10.1055/s-0044-1785538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]

Lee JY, Kim SE, Kwon OH, Kim Y, Son TG, Han HS, Ro DH. Shallow trochlear groove and narrow medial trochlear width at the proximal trochlea in patients with trochlear dysplasia: A three-dimensional computed tomography analysis. Knee Surg Sports Traumatol Arthrosc 2024;32:1434-1445. [PMID: 38563648 DOI: 10.1002/ksa.12166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 03/05/2024] [Accepted: 03/10/2024] [Indexed: 04/04/2024]

Abstract

PURPOSE

Although the Dejour classification is the primary classification system for evaluating trochlear dysplasia, concerns have been raised about its reliability owing to its qualitative criteria and challenges associated with obtaining accurate radiographs. This study aimed to quantify trochlear dysplasia using three-dimensional (3D) computed tomography (CT) reconstruction with novel parameters related to the transepicondylar axis (TEA).

METHODS

Sixty patients were enrolled, including 20 with trochlear dysplasia and 40 healthy controls. The 3D CT model was generated using the Materialise Interactive Medical Image Control System software. The following six parameters were measured in eight consecutive planes at 15° intervals (planes 0-105): the distance from the TEA to the most cortical point of the lateral condyle ('LP-TEA', where LP stands for lateral peak), medial condyle ('MP-TEA', MP for medial peak) and deepest point of the trochlea ('TG-TEA', TG for trochlear groove). The distances from the medial epicondyle (MEC) to the corresponding TEA points were measured ('LP-MEC', 'MP-MEC' and 'TG-MEC').

RESULTS

In the dysplasia group, TG-TEA (planes 0, 15 and 30) and MP-MEC (planes 0, 15 and 30) were significantly greater than those in the control group (all p < 0.05 for planes of TG-TEA and MP-MEC). For type A dysplasia, LP-MEC (plane 0) was greater than that in the control group. For type B dysplasia, the MP-MEC (planes 0 and 15) and TG-TEA (planes 0 and 15) were greater than those of the control group. For type D dysplasia, MP-MEC (planes 0, 15 and 30) and TG-TEA (planes 0 and 15) were elevated.

CONCLUSION

The 3D CT reconstruction analysis established a reproducible method for quantifying osseous trochlear morphology. Patients with trochlear dysplasia had a shallow TG and narrow medial trochlear width at tracking angles of 0°-30°. This finding corroborates the clinical manifestations of recurrent patellar instability that occur during early flexion.

LEVEL OF EVIDENCE

Level III.

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Martinez-Cano JP, Tuca M, Gallego A, Rodas-Cortes Y, Post WR, Hinckel B. The Dejour classification for trochlear dysplasia shows slight interobserver and substantial intraobserver reliability. Knee Surg Sports Traumatol Arthrosc 2024;32:1363-1369. [PMID: 38532466 DOI: 10.1002/ksa.12158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 03/07/2024] [Accepted: 03/12/2024] [Indexed: 03/28/2024]

Ferreira B, Gomes E, Figueiredo I, Ribeiro R, Valente C, Delgado D, Sánchez M, Andrade R, Espregueira-Mendes J. Derotational high tibial osteotomy in cases of anterior knee pain and/or patellofemoral instability: a systematic review. J ISAKOS 2024;9:401-409. [PMID: 38430984 DOI: 10.1016/j.jisako.2024.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/09/2024] [Accepted: 02/25/2024] [Indexed: 03/05/2024]

Zhou Y, Yu A, Wu X, Yao J, Tan H, Wang H, Lian C, Zhou A. Evaluating the reliability of the lateral femoral condyle measuring methods by different modalities for patients with lateral patellar dislocation. BMC Musculoskelet Disord 2024;25:388. [PMID: 38762738 PMCID: PMC11102213 DOI: 10.1186/s12891-024-07495-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 05/06/2024] [Indexed: 05/20/2024] Open

Hinz M, Weyer M, Brunner M, Fritsch L, Otto A, Siebenlist S, Achtnich A. Varus osteotomy as a salvage procedure for young patients with symptomatic patellofemoral arthritis and valgus malalignment at short- to mid-term follow-up: a case series. Arch Orthop Trauma Surg 2024;144:1667-1673. [PMID: 38386061 PMCID: PMC10965738 DOI: 10.1007/s00402-024-05212-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 01/24/2024] [Indexed: 02/23/2024]

Abstract

PURPOSE

The purpose of the study was to report the clinical, functional and radiological outcome following varus osteotomy as a salvage procedure in young to middle-aged patients with patellofemoral arthritis (PFA) and associated valgus malalignment. It was hypothesized that a significant improvement in knee function and reduction in pain would be achieved. Moreover, no conversion to patellofemoral joint arthroplasty could be observed.

MATERIAL AND METHODS

Patients (< 50 years of age) that underwent varus osteotomy between 08/2012 and 01/2020 for the treatment of symptomatic PFA and associated valgus malalignment were consecutively included (minimum follow-up: 24 months). Patient-reported outcome measures (PROM; International Knee Documentation Committee subjective knee form [IKDC]), Visual Analog Scale [VAS] for pain, Tegner Activity Scale [TAS], and satisfaction with the postoperative results (1-10-scale, 10 = highest satisfaction) and weight-bearing whole-leg anteroposterior radiographs were conducted pre- and postoperatively. The change in PROM and femorotibial angle (FTA) were tested for statistical significance.

RESULTS

In total, 12 patients (14 knees) were included (66.7% female; mean age: 33.8 ± SD 6.6 years). In ten cases, lateral opening-wedge distal femoral osteotomies (DFO) were performed, of which three cases included a concomitant femoral derotation. Three medial closing-wedge DFO and one medial closing-wedge high tibial osteotomy were performed. At follow-up (55.3 ± 29.3 months), a significant improvement in knee function (IKDC: 56.4 ± 14.4 to 69.1 ± 11.2, p = 0.015) and reduction in pain (VAS for pain: 3.5 [interquartile range 2.3-5.8] to 0.5 [0-2.0], p = 0.018) were observed. Patients were able to reach their preoperative sporting activity level (TAS: 3.0 [3.0-4.0] to 3.5 [3.0-4.0], p = 0.854) and were highly satisfied with the postoperative result (9.0 [6.5-10]). Additionally, a significant correction of valgus malalignment was observed (5.0° ± 2.9° valgus to 0.7° ± 3.2° varus, p < 0.001). Regarding complications, two re-osteosyntheses were performed due to loss of correction and delayed union. No conversion to patellofemoral arthroplasty occurred.

CONCLUSION

In patients with symptomatic PFA and associated valgus malalignment, varus osteotomy as a salvage procedure achieved a significant improvement in knee function and reduction in pain. No conversion to patellofemoral joint arthroplasty occurred at short- to mid-term follow-up.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.

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Pence KB, Sen S, Ormeci T, Caliskan M, Sakul BU. Evaluation of femoral condyle volumes in patients with trochlear dysplasia: a pilot study. Clin Radiol 2024;79:e475-e481. [PMID: 38145924 DOI: 10.1016/j.crad.2023.11.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 11/07/2023] [Accepted: 11/18/2023] [Indexed: 12/27/2023]

Pineda T, Dejour D. Inconsistent repeatability of the Dejour classification of trochlear dysplasia due to the variability of imaging modalities: a systematic review. Knee Surg Sports Traumatol Arthrosc 2023;31:5707-5720. [PMID: 37919443 DOI: 10.1007/s00167-023-07612-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 09/28/2023] [Indexed: 11/04/2023]

Abstract

PURPOSE

The purpose of this systematic review was to critically assess the quality of papers that report on the intra- and inter-observer repeatability of the Dejour classification for trochlear dysplasia, and to identify the possible causes for poor repeatability.

METHODS

Two authors independently conducted an electronic search (four databases) on 8 February 2023 for studies (English or French) that assessed trochlear dysplasia classifications on imaging of skeletally mature participants. Exclusion criteria were reviews of clinical studies, conference proceedings, or editorials. After title, abstract, and full-text screening, characteristics of eligible studies were tabulated (author, year, journal, study design, cohort characteristics, and intra- and/or inter-observer agreement coefficients). The methodological quality of studies was assessed using the Joanna Briggs Institute (JBI) checklist for analytical cross-sectional studies. Authors analysed three components of the included studies: (1) classifications based on true lateral radiographs and slice imaging; (2) dysplasia graded into Type A vs B vs C vs D and 3) coefficients of intra- and/or inter-observer agreement.

RESULTS

The electronic search returned 3,178 references, and after removal of duplicates and irrelevant studies, ten were eligible for data extraction. A second search (31 July 2023) yielded one additional study. Eight studies did not include lateral radiographs, two studies did not explicitly state if radiographs were true lateral views, and one used true lateral radiographs in isolation. Classification of trochlear dysplasia into A vs B vs C vs D using different imaging modalities resulted in moderate to near-perfect intra-observer agreement, and slight to near-perfect inter-observer agreement. Studies distinguished between moderate and severe dysplasia using a variety of combinations: A vs B/C/D, A/B vs C/D and A/C vs B/D.

CONCLUSION

This systematic review revealed that the Dejour classification remains the most widely used to assess trochlear dysplasia and that the majority of studies that assessed the reliability of the Dejour classification, reported moderate to near-perfect inter-observer agreement; however, pooling of results for comparison among the included studies was inappropriate due to substantial variation in imaging protocols and non-standardised criteria to distinguish severe from moderate dysplasia.

LEVEL OF EVIDENCE

Level IV.

TRIAL REGISTRY

The PROSPERO registration number is CRD42023386731.

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Chen J, Li X, Feng Y, Li Q, Xu Z, Wang L, Zhang J, Quan Z, Zhou A. Lateral trochlear inclination measured by the transepicondylar axis holds potential for evaluating trochlear dysplasia in patients with lateral patellar dislocation. Knee Surg Sports Traumatol Arthrosc 2023;31:5611-5620. [PMID: 37851025 DOI: 10.1007/s00167-023-07614-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 09/29/2023] [Indexed: 10/19/2023]

Tarchala M, Kerslake S, Hiemstra LA. Sulcus-Deepening Trochleoplasty for High-Grade Trochlear Dysplasia: Demystifying the Procedure-a Review of the Current Literature. Curr Rev Musculoskelet Med 2023;16:538-549. [PMID: 37698757 PMCID: PMC10587046 DOI: 10.1007/s12178-023-09868-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/29/2023] [Indexed: 09/13/2023]

Abstract

PURPOSE OF REVIEW

The most common and biomechanically influential pathoanatomic risk factor for recurrent patellofemoral instability is trochlear dysplasia. Sulcus-deepening trochleoplasty is a procedure developed to address high-grade trochlear dysplasia in the setting of patellofemoral instability. The purpose of this paper is to outline the current classification and surgical management of trochlear dysplasia as well as to review the current literature on the clinical outcomes and complications of sulcus-deepening trochleoplasty.

RECENT FINDINGS

This review outlines the most recent literature reporting evidence behind the decision-making to perform a trochleoplasty in the setting of patellofemoral instability and high-grade trochlear dysplasia. Critical parameters include grade of trochlear dysplasia, severity of symptoms, pertinent physical examination findings, surgical techniques, modifications for skeletally immature patients, and considerations for the revision setting. Historic studies have elicited concerns regarding high reported complication rates for trochleoplasty; however, recent studies consistently report good clinical outcomes and acceptable complication rates, similar to those of other patellar stabilizing procedures. The addition of a trochleoplasty in patients with high-grade dysplasia results in a lower re-dislocation rate, significant improvements in patient-reported outcome measures (PROMs) as well as high levels of patient satisfaction and return to sport. The use of sulcus-deepening trochleoplasty for the treatment of high-grade dysplasia and recurrent patellofemoral instability is a well-established technique with good outcomes and an acceptable complication profile. In patients with high-grade dysplasia, trochleoplasty results in lower re-dislocation rates, high patient satisfaction scores, and good clinical and functional outcomes. An understanding of trochleoplasty and its indications should be in the armamentarium of surgeons treating patellofemoral instability.

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Fithian AT, Richey AE, Sherman SL, Shea KG, Pun SY. Association of Hip Dysplasia With Trochlear Dysplasia in Skeletally Mature Patients. Orthop J Sports Med 2023;11:23259671231200805. [PMID: 37822419 PMCID: PMC10563471 DOI: 10.1177/23259671231200805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Accepted: 05/19/2023] [Indexed: 10/13/2023] Open

Abstract

Background

Developmental dysplasia of the hip (DDH) and trochlear dysplasia (TD) are distinct pathologies with several important features in common. In addition to shared risk factors, both forms of dysplasia cause abnormal joint kinematics and force transmission, predisposing patients to pain, injuries to cartilage and soft tissue stabilizers, and ultimately arthritis.

Purpose

To evaluate for an association between hip dysplasia and TD in skeletally mature patients with symptomatic hip dysplasia.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

A total of 48 patients with DDH who underwent periacetabular osteotomy were compared with 48 sex-matched patients who underwent hip arthroscopy for femoroacetabular impingement (FAI) between July 2014 and February 2021. All patients were skeletally mature. The Tönnis angle and lateral center-edge angle were measured on preoperative pelvis radiographs. Femoral version, trochlear depth, lateral trochlear inclination (LTI), tibial tubercle-trochlear groove distance (TTTG-d), and posterior lateral condylar angle (PLCA) were measured on preoperative magnetic resonance imaging scans of the symptomatic hip and ipsilateral knee. Continuous variables were compared between the patient groups using 2-sample t tests. Interobserver reliability was measured using the intraclass correlation coefficient.

Results

Patients with DDH demonstrated a reduced trochlear depth compared with patients with FAI (3.6 vs 4.6 mm; P < .001). There were no differences between groups in femoral anteversion, LTI, TTTG-d, or PLCA. Two (4.2%) patients with FAI and 17 (35.4%) patients with DDH had a trochlear depth <3 mm (P < .001). One (2.1%) patient with FAI and 7 (14.6%) patients with DDH had an LTI <11° (P = .027). There was no difference between groups in frequency of a convex proximal trochlea, patient-reported ipsilateral knee pain, or ipsilateral knee procedures.

Conclusion

Patients with DDH had reduced trochlear depth compared with patients with FAI, demonstrating a higher incidence of dysplastic trochlear features that may predispose patients to patellofemoral joint disease. Further research is needed to determine whether screening at-risk patients and treating TD will help to prevent symptomatic patellofemoral disease.

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Roy KD, Joshi P, Ali I, Shenoy PM, Malek I, Barlow D, Syed A, Joshi Y. A comparative analysis of interobserver reliability and intraobserver reproducibility of the Oswestry-Bristol Classification and the Dejour Classification for trochlear dysplasia of the knee. Bone Jt Open 2023;4:532-538. [PMID: 37470126 PMCID: PMC10357325 DOI: 10.1302/2633-1462.47.bjo-2023-0048] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/21/2023] Open

Abstract

Aims

Classifying trochlear dysplasia (TD) is useful to determine the treatment options for patients suffering from patellofemoral instability (PFI). There is no consensus on which classification system is more reliable and reproducible for the purpose of guiding clinicians' management of PFI. There are also concerns about the validity of the Dejour Classification (DJC), which is the most widely used classification for TD, having only a fair reliability score. The Oswestry-Bristol Classification (OBC) is a recently proposed system of classification of TD, and the authors report a fair-to-good interobserver agreement and good-to-excellent intraobserver agreement in the assessment of TD. The aim of this study was to compare the reliability and reproducibility of these two classifications.

Methods

In all, six assessors (four consultants and two registrars) independently evaluated 100 axial MRIs of the patellofemoral joint (PFJ) for TD and classified them according to OBC and DJC. These assessments were again repeated by all raters after four weeks. The inter- and intraobserver reliability scores were calculated using Cohen's kappa and Cronbach's α.

Results

Both classifications showed good to excellent interobserver reliability with high α scores. The OBC classification showed a substantial intraobserver agreement (mean kappa 0.628; p < 0.005) whereas the DJC showed a moderate agreement (mean kappa 0.572; p < 0.005). There was no significant difference in the kappa values when comparing the assessments by consultants with those by registrars, in either classification system.

Conclusion

This large study from a non-founding institute shows both classification systems to be reliable for classifying TD based on axial MRIs of the PFJ, with the simple-to-use OBC having a higher intraobserver reliability score than that of the DJC.

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Tanaka MJ, Sodhi A, Wadhavkar I, Kane K, Velasquez Hammerle MV, Mangudi Varadarajan K, Tornetta P. Redefining Trochlear Dysplasia: Normal Thresholds Vary by Measurement Technique, Landmarks, and Sex. Am J Sports Med 2023;51:1202-1210. [PMID: 36942723 DOI: 10.1177/03635465231158099] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]

Abstract

BACKGROUND

Trochlear dysplasia is a known risk factor for patellar instability. Multiple radiographic measurements exist to assess trochlear morphology, but the optimal measurement technique and threshold for instability are unknown.

PURPOSE

To describe the optimal measurements and thresholds for trochlear dysplasia on magnetic resonance imaging (MRI) that can identify knees with patellar instability in male and female patients.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 3.

METHODS

Knee MRI scans of patients with patellar instability were compared with those of age- and sex-matched controls. Measurements of the sulcus angle, lateral trochlear inclination (LTI), and trochlear depth were performed on axial images using bony and cartilaginous landmarks. Receiver operating characteristic curve analysis was performed, with the area under the curve (AUC) describing the accuracy of each diagnostic test. Optimal cutoff values were calculated to distinguish between knees with and without patellar instability. AUC and cutoff values were reported for each measurement as well as for male and female subgroups.

RESULTS

A total of 238 knee MRI scans were included in this study (138 female, 100 male; age range, 18-39 years). Trochlear depth measurements had the greatest diagnostic value, with AUCs of 0.79 and 0.82 on bone and cartilage, respectively. All measurements (sulcus angle, LTI, trochlear depth) on bone and cartilage had an AUC ≥0.7 (range, 0.70-0.86), with optimal cutoff values of 145° (bone) and 154° (cartilage) for the sulcus angle, 17° (bone) and 13° (cartilage) for LTI, and 4 mm (bone) and 3 mm (cartilage) for trochlear depth. Optimal cutoff values in female patients varied from those in male patients for all measurements except for cartilaginous trochlear depth.

CONCLUSION

Normal thresholds for trochlear dysplasia varied based on the use of bony versus cartilaginous landmarks. Cartilaginous trochlear depth measurements had the greatest ability to identify knees with patellar instability. Furthermore, optimal cutoff values for all measurements except for cartilaginous trochlear depth differed between female and male patients. These findings suggest that sex-specific parameters of normal values may be needed in the assessment of risk factors for patellofemoral instability.

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Vranken K, Doring S, Buls N, Vanlauwe J, Germonpré S, Provyn S, De Smet A, De Maeseneer M. Influence of medial and lateral imaging plane inclination on assessment of trochlear depth, sulcus angle, and facet asymmetry in the setting of trochlear anatomy: a cadaveric study. SURGICAL AND RADIOLOGIC ANATOMY : SRA 2023;45:207-213. [PMID: 36651995 DOI: 10.1007/s00276-022-03069-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 12/20/2022] [Indexed: 01/19/2023]

Arthroscopic Anatomical Double-Bundle Medial Patellofemoral Complex Reconstruction Improves Clinical Outcomes in Treating Recurrent Patellar Dislocation Despite Trochlear Dysplasia, Elevated Tibial Tubercle-Trochlear Groove Distance, and Patellar Alta. Arthroscopy 2023;39:102-111. [PMID: 35840069 DOI: 10.1016/j.arthro.2022.06.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 06/25/2022] [Accepted: 06/26/2022] [Indexed: 02/02/2023]

Abstract

PURPOSE

To evaluate the clinical outcomes of arthroscopically assisted double-bundle medial patellofemoral complex reconstruction (MPFC-R).

METHODS

A retrospective review was carried out among adult patients who experienced at least 2 patellar dislocations and underwent primary arthroscopically assisted MPFC-R between January 2014 and November 2019. Dejour classification, tibial tubercle-trochlear groove (TT-TG) distance, and patellar height (with Insall-Salvati index) were measured. Pre- and postoperative patellar tilt were compared. Information on outcome scores, ability to return to sports, postoperative recurrent dislocations, and complications was recorded.

RESULTS

A total of 42 MPFC-Rs in 39 patients were included. Mean age at surgery was 22.2 ± 7.6 years; 69.2% of patients were female. Mean follow-up was 47.3 ± 20.2 months. Seventy-four percent of cases had Dejour B (19.0%), C (33.3%), and D (21.4%) trochlear dysplasia; mean TT-TG distance was 19.6 ± 3.5 mm, and mean Insall-Salvati index was 1.21 ± 0.17. Mean patellar tilt decreased from 27.6 ± 11.6° to 9.4 ± 6.5° (P < .001). All patients had statistically significant (P < .001) improvement in mean International Knee Documentation Committee (IKDC) (44.9 ± 18.2 to 87.5 ± 6.9), Lysholm (61.4 ± 16.6 to 94.1 ± 6.4), Kujala (56.0 ± 16.8 to 92.9 ± 5.3), and Tegner score (2.7 ± 1.3 to 4.6 ± 1.4). The majority of patients (96.9%) returned to sports, with 90.3% returning to the same or greater level of activity. No postoperative dislocations or subluxations were reported.

CONCLUSIONS

Arthroscopically assisted double-bundle MPFC-R is a promising procedure to treat recurrent patellar instability at 2- to 7-year mid-term follow-up, despite the presence of trochlear dysplasia, elevated TT-TG distance and patellar alta. The improvement of IKDC score exceeded the minimal clinically important difference in 95.2% patients, and 66.7% surpassed the patient acceptable symptomatic state based on postoperative IKDC score with no redislocations being reported at latest follow-up.

LEVEL OF EVIDENCE

Level IV, case series, retrospective.

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O'Malley O, Choudhury A, Biggs A, Humdani AJ, Brown O, Smith TO, Ejindu V, Hing CB. Association between Patellofemoral Anatomy and Chondral Lesions of the Knee in Patellofemoral Instability. J Knee Surg 2023;36:153-158. [PMID: 34187065 DOI: 10.1055/s-0041-1731351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]

Chen J, Li Q, Liu S, Fan L, Yin B, Yang X, Wang L, Xu Z, Zhang J, Quan Z, Zhou A. Prediction of Subsequent Contralateral Patellar Dislocation after First-Time Dislocation Based on Patellofemoral Morphologies. J Clin Med 2022;12:jcm12010180. [PMID: 36614981 PMCID: PMC9820933 DOI: 10.3390/jcm12010180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/03/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open

Abstract

The subsequent dislocation of a contralateral patellofemoral joint sometimes occurs after a first-time lateral patellar dislocation (LPD). However, the anatomic risk factors for subsequent contralateral LPD remain elusive. This study included 17 patients with contralateral LPD and 34 unilateral patellar dislocators. The anatomic parameters of the contralateral patellofemoral joints were measured using CT images and radiographs that were obtained at the time of the first dislocation. The Wilcoxon rank-sum test was performed, and a binary regression model was established to identify the risk factors. The receiver operating characteristic curves and the area under the curve (AUC) were analyzed. The tibial tubercle-Roman arch (TT-RA) distance was significantly different between patients with and without contralateral LPD (24.1 vs. 19.5 mm, p < 0.001). The hip−knee−ankle (HKA) angle, patellar tilt, congruence angle, and patellar displacement were greater in the study group than in the control group (p < 0.05). The TT-RA distance revealed an OR of 1.35 (95% CI (1.26−1.44]), p < 0.001) and an AUC of 0.727 for predicting contralateral LPD. The HKA angle revealed an OR of 1.74 (95% CI (1.51−2.00), p < 0.001) and an AUC of 0.797. The Patellar tilt, congruence angle, and patellar displacement had AUC values of 0.703, 0.725, and 0.817 for predicting contralateral LPD, respectively. In conclusion, the contralateral patellofemoral anatomic parameters were significantly different between patients with and without subsequent contralateral LPD. Increased TT-RA distance and excessive valgus deformity were risk factors and could serve as predictors for contralateral LPD. At first-time dislocation, the abnormal position of the patella relative to the trochlea may also be an important cause of subsequent LPD.

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Affiliation(s)

Jiaxing Chen Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China Orthopedic Laboratory, Chongqing Medical University, Chongqing 400016, China
Qiaochu Li Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China Orthopedic Laboratory, Chongqing Medical University, Chongqing 400016, China
Sizhu Liu Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
Lin Fan Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China Orthopedic Laboratory, Chongqing Medical University, Chongqing 400016, China
Baoshan Yin Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China Orthopedic Laboratory, Chongqing Medical University, Chongqing 400016, China
Xinyu Yang Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China Orthopedic Laboratory, Chongqing Medical University, Chongqing 400016, China
Linbang Wang Department of Orthopedics, Peking University Third Hospital, Beijing 100191, China
Zijie Xu Sports Medicine Department, Beijing Key Laboratory of Sports Injuries, Peking University Third Hospital, Beijing 100191, China
Jian Zhang Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China Orthopedic Laboratory, Chongqing Medical University, Chongqing 400016, China
Zhengxue Quan Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China Orthopedic Laboratory, Chongqing Medical University, Chongqing 400016, China Correspondence: (Z.Q.); (A.Z.)
Aiguo Zhou Department of Orthopedics, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China Orthopedic Laboratory, Chongqing Medical University, Chongqing 400016, China Correspondence: (Z.Q.); (A.Z.)

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Frodl A, Lange T, Siegel M, Meine H, Taghizadeh E, Schmal H, Izadpanah K. Individual Influence of Trochlear Dysplasia on Patellofemoral Kinematics after Isolated MPFL Reconstruction. J Pers Med 2022;12:jpm12122049. [PMID: 36556269 PMCID: PMC9786691 DOI: 10.3390/jpm12122049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/05/2022] [Accepted: 12/07/2022] [Indexed: 12/14/2022] Open

Abstract

INTRODUCTION

The influence of the MPFL graft in cases of patella instability with dysplastic trochlea is a controversial topic. The effect of the MPFL reconstruction as single therapy is under investigation, especially with severely dysplastic trochlea (Dejour types C and D). The purpose of this study was to evaluate the impact of trochlear dysplasia on patellar kinematics in patients suffering from low flexion patellar instability under weight-bearing conditions after isolated MPFL reconstruction.

MATERIAL AND METHODS

Thirteen patients were included in this study, among them were eight patients with mild dysplasia (Dejour type A and B) and five patients with severe dysplasia (Dejour type C and D). By performing a knee MRI with in situ loading, patella kinematics and the patellofemoral cartilage contact area could be measured under the activation of the quadriceps musculature in knee flexion angles of 0°, 15° and 30°. To mitigate MRI motion artefacts, prospective motion correction based on optical tracking was applied. Bone and cartilage segmentation were performed semi-automatically for further data analysis. Cartilage contact area (CCA) and patella tilt were the main outcome measures for this study. Pre- and post-surgery measures were compared for each group.

RESULTS

Data visualized a trending lower patella tilt after MPFL graft installation in both groups and flexion angles of the knee. There were no significant changes in patella tilt at 0° (unloaded pre-surgery: 22.6 ± 15.2; post-surgery: 17.7 ± 14.3; p = 0.110) and unloaded 15° flexion (pre-surgery: 18.9 ± 12.7; post-surgery: 12.2 ± 13.0; p = 0.052) of the knee in patients with mild dysplasia, whereas in patients with severe dysplasia of the trochlea the results happened not to be significant in the same angles with loading of 5 kg (0° flexion pre-surgery: 34.4 ± 12.1; post-surgery: 31.2 ± 16.1; p = 0.5; 15° flexion pre-surgery: 33.3 ± 6.1; post-surgery: 23.4 ± 8.6; p = 0.068). CCA increased in every flexion angle and group, but significant increase was seen only between 0°-15° (unloaded and loaded) in mild dysplasia of the trochlea, where significant increase in Dejour type C and D group was seen with unloaded full extension of the knee (0° flexion) and 30° flexion (unloaded and loaded).

CONCLUSION

This study proves a significant effect of the MPFL graft to cartilage contact area, as well as an improvement of the patella tilt in patients with mild dysplasia of the trochlea. Thus, the MPFL can be used as a single treatment for patient with Dejour type A and B dysplasia. However, in patients with severe dysplasia the MPFL graft alone does not significantly increase CCA.

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Chen J, Ye Z, Wu C, Zhang X, Zhao J, Xie G. Sulcus depth, congruence angle, Wiberg index, TT-TG distance, and CDI are strong predictors of recurrent patellar dislocation. Knee Surg Sports Traumatol Arthrosc 2022:10.1007/s00167-022-07245-3. [PMID: 36463567 DOI: 10.1007/s00167-022-07245-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 11/21/2022] [Indexed: 12/07/2022]

Abstract

PURPOSE

To characterize patellofemoral morphology, determine radiological cutoff values based on computed tomography (CT) images, and clarify predominant anatomic risk factors in young patients with recurrent patellar dislocation (RPD).

METHODS

A total of 212 knees (age 23.0 ± 5.3 years, female: male = 110:102) with CT-confirmed RPD were enrolled for analysis. The control group was matched by age and sex (2:1). Patellofemoral and trochlear morphology, patellofemoral alignment, and other parameters were assessed by CT. Standardized methods were used for measurements. Receiver operating characteristic (ROC) curves and the areas under the ROC curve (AUCs) were used to assess accuracy in diagnosing RPD. The index of union (IU) was employed to identify a cutoff value for risk. A binary logistic regression model (Forward, LR) was constructed, and standardized coefficients were calculated to compare the relative strength of different predictors. Factors included in the model were employed to calculate distributions in the studied population.

RESULTS

The majority of measurements showed a significant difference between the RPD and control groups when comparing mean values. The AUC value was favorable for sulcus depth and significantly better than that for other trochlear morphology parameters (P < 0.0001). Cutoff values were 0.58 for the Wiberg index, 153.3° for the sulcus angle, 3.6 mm for the sulcus depth, 1.94 for the trochlear width ratio, 16.2° for the lateral trochlear inclination, 17.2° for the patellar lateral tilt, 25.5° for the congruence angle, 1.2 for the patellar height [Caton-Deschamps index (CDI)], 6.1° for the knee rotation, and 16.4 mm for the tibial tubercle-trochlear groove (TT-TG) distance. A binary logistic regression model (χ² = 20.826, P = 0.008) including the Wiberg index, sulcus depth, congruence angle, patellar height (CDI), and TT-TG distance was constructed for RPD (P ≤ 0.015), which showed excellent diagnostic performance, as indicated by an AUC of 0.989 (95% CI, 0.979 to 0.998). Sulcus depth showed the strongest relationship with RPD, followed by the congruence angle and Wiberg index, as indicated by the standardized coefficients - 1.43, 1.02, and 0.97, respectively. Eighty-seven percent of the RPD population had sulcus depth ≤ 3.6 mm.

CONCLUSIONS

This study provides a systematic reference of cutoff values based on CT data. The combination of five anatomic risk factors (sulcus depth, congruence angle, Wiberg index, TT-TG distance, and CDI) may be an excellent predictor of RPD as initial risk assessment. Sulcus depth, as the most frequently observed anatomic risk factor, showed the best diagnostic performance among trochlear morphological parameters and the strongest relationship with RPD, followed by the congruence angle and Wiberg index. In clinical practice, the sulcus depth, congruence angle, Wiberg index, TT-TG distance, and CDI with the proposed cutoff values can be used in combination to evaluate RPD. When assessing trochlear morphology, sulcus depth is recommended as the best radiological parameter.

LEVEL OF EVIDENCE

Level III.

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The pathologic double contour sign and the trochlea shape patterns can diagnose trochlea dysplasia. J ISAKOS 2022;8:74-80. [PMID: 36435430 DOI: 10.1016/j.jisako.2022.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 06/12/2022] [Accepted: 11/10/2022] [Indexed: 11/25/2022]

Abstract

OBJECTIVES

The goal of this study is to describe the distinct morphologic patterns of the normal and dysplastic trochleae, the trochlear shape patterns (TSP) seen on the axial views of MRI scans.

METHOD

Two cohorts of patients were used for comparison. Cohort 1: MRI scans of 100 patients with no history of patella instability. Cohort 2: MRI scans of 66 patients diagnosed with severe trochlea dysplasia and patella instability. The presence of the pathologic double contour (PDC) sign and the type of TSP were identified in the axial views at the level of three specific anatomical references: Trochlear Specific Zone 0 (TSZ 0), posterior femoral condyle line (PFCL) and transverse distal femoral physis line (tv-DFPL). The pathologic double contour sign is an area of flat or convex lateral trochlea which is elevated over the contour of the medial femoral condyle. Three basic morphologic patterns of trochlear shape were identified. TSP type 1 (normal trochlea): There is no PDC. There is a clearly defined sulcus delineating the lateral and medial trochlear facets (sulcus angle <165°). TSP type 2 (normal but shallow trochlea): There is no PDC. The trochlear groove is shallow (sulcus angle >165°), but the lateral and medial facets are present. TSP type 3: This pattern is characterised by the presence of a PDC. The chi-square test was used to determine whether the distribution of the TSP was the same between the two cohorts at the anatomical reference lines.

RESULTS

The differences observed in distribution of the TSP between the two cohorts were statistically significant. There was a strong positive correlation between the morphology of the trochlea (TSP) and patella instability. All patients in the patella instability cohort showed a PDC.

CONCLUSION

Normal trochleae show TSP type 1 and 2 proximal to the tv-DFPL. The presence of the pathologic double contour sign and trochlea shape pattern type 3 (TSP 3) proximal to the tv-DFPL (PFCL or TSZ 0) are diagnostic of trochlea dysplasia.

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The severity of patellar and trochlear dysplasia are correlated. Knee Surg Sports Traumatol Arthrosc 2022;30:3438-3443. [PMID: 35347377 DOI: 10.1007/s00167-022-06945-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 03/10/2022] [Indexed: 10/18/2022]

Li J, Yuan M, Qiu L, Sheng B, Yu F, Yang H, Lv F, Lv F, Huang W. The SP-ET index is a new index for assessing the vertical position of patella. Insights Imaging 2022;13:152. [PMID: 36153385 PMCID: PMC9509501 DOI: 10.1186/s13244-022-01289-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 08/24/2022] [Indexed: 11/10/2022] Open

Orellana KJ, Batley MG, Lawrence JTR, Nguyen JC, Williams BA. Radiographic Evaluation of Pediatric Patients with Patellofemoral Instability. Curr Rev Musculoskelet Med 2022;15:411-426. [PMID: 35932425 DOI: 10.1007/s12178-022-09780-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/21/2022] [Indexed: 11/25/2022]

Orfanos G, William Glover A, Sharma N, Barnett A. Trochleoplasty for severe trochlear dysplasia significantly improves the quality of life of patients with symptomatic patellar instability. Knee 2022;37:95-102. [PMID: 35752140 DOI: 10.1016/j.knee.2022.06.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/13/2022] [Accepted: 06/09/2022] [Indexed: 02/02/2023]

Two-type classification system for femoral trochlear dysplasia in recurrent patellar instability based on three-dimensional morphology. Knee Surg Sports Traumatol Arthrosc 2022;31:1790-1797. [PMID: 35906412 DOI: 10.1007/s00167-022-07077-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 07/18/2022] [Indexed: 10/16/2022]

Abstract

PURPOSE

Radiographic and two-dimensional (2D) CT/MRI analysis of femoral trochlear dysplasia play a significant role in surgical decision-making for recurrent patellar instability. However, the three-dimensional morphology of dysplastic trochlea is rarely studied due to the limitations of conventional imaging modalities. This study aimed to (1) develop a 3D morphological classification for trochlear dysplasia based on the concavity of the trochlear groove and (2) analyze the interrater reliability of the classification system.

METHODS

The 3D trochleae of 132 knees with trochlear dysplasia and recurrent patellar instability were reconstructed using CT scan data and classified using the innovative classification criteria between January 2016 and June 2020. A concave trochlear sulcus with sloped medial and lateral trochlear facets was classified as Type I trochlea. The trochlear groove with no concavity is classified as Type II. Furthermore, in Type II, the trochlea with the elevated trochlear floor at the proximal part was identified as IIa and the trochlea with the hypoplastic trochlear facets as IIb. The intra- and inter-rater reliability was examined using kappa (κ) statistics.

RESULTS

The 3D classification system showed substantial intra-rater agreement and moderate interrater agreement (0.581 ~ 0.772). The intra- and interrater agreement of Dejour's four-grade classification was fair-to-moderate (0.332 ~ 0.633). Eighty-one trochleae with concave trochlear sulcus were classified as Type I, and fifty-one without concavity as Type II. Twenty-five non-concave trochleae were classified as type IIa due to the elevated trochlear floor and 26 trochleae into IIb with the hypoplasia of trochlear facets.

CONCLUSION

This study developed a 3D classification system to classify trochlear dysplasia according to trochlear concavity and morphology of the trochlear facets. On CT/MRI scans or 3D reconstructions, the interpretation of features of dysplastic trochleae may vary, especially for the flat and convex trochleae. The novel system provides morphological evidence for when to consider trochleoplasty according to the different types of trochlear sulcus.

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Elias JJ, Rezvanifar SC, Koh JL. Groove-deepening trochleoplasty reduces lateral patellar maltracking and increases patellofemoral contact pressures: Dynamic simulation. J Orthop Res 2022;40:1529-1537. [PMID: 34559438 DOI: 10.1002/jor.25181] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 08/10/2021] [Accepted: 09/07/2021] [Indexed: 02/04/2023]

Abstract

Groove-deepening trochleoplasty is performed to restore patellar stability by increasing the lateral constraint applied to the patella by the trochlear groove. Multibody dynamic simulation of knee function was used to characterize the influence of groove-deepening trochleoplasty on patellar tracking and patellofemoral contact pressures. Computational models were created to represent seven knees with trochlear dysplasia, indicated by a flat trochlear groove and supratrochlear spur. The models were manipulated to remove the spur and deepen the trochlear groove to represent the average shape following a trochleoplasty. Knee squatting was simulated for the preoperative and postoperative conditions. Statistically significant (p < 0.05) differences in output parameters were identified with repeated measures comparisons at every 5° of knee flexion. Trochleoplasty significantly decreased lateral patellar tracking, particularly at low knee flexion angles. Trochleoplasty decreased the peak lateral shift of the patella (bisect offset index) with the knee extended from 0.87 ± 0.14 to 0.75 ± 0.12. Trochleoplasty also significantly decreased the contact area and increased the maximum contact pressure at multiple flexion angles. Trochleoplasty decreased the average contact area by approximately 10% in mid-flexion, with a corresponding increase in the average maximum contact pressure of 13%-23%. Decreased contact area and increased contact pressures are related to altered patellofemoral congruity due to reshaping the femur without a corresponding change to the patella. Clinical significance: The results indicate groove-deepening trochleoplasty decreases lateral patellar maltracking, reducing the risk of patellar dislocations, but can elevate patellofemoral contact pressures, which could contribute to long-term degradation of cartilage.

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Geraghty L, Zordan R, Walker P, Chao TW, Talbot S. Patellar dislocation is associated with increased tibial but not femoral rotational asymmetry. Knee Surg Sports Traumatol Arthrosc 2022;30:2342-2351. [PMID: 34850247 DOI: 10.1007/s00167-021-06813-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/17/2021] [Indexed: 11/27/2022]

Abstract

PURPOSE

Patellar dislocation is associated with a range of anatomical abnormalities affecting the trochlea, extensor mechanism and the tibia. The relationship between patellofemoral instability and rotational abnormalities of the posterior condyles, trochlear groove and proximal tibia has not been adequately determined. This study aimed to identify the frequency and severity of anatomical risk factors to determine their relative contribution to patellofemoral instability.

METHODS

A retrospective morphological study was undertaken comparing multiple anatomical measurements with magnetic resonance imaging of 50 patients with patellofemoral instability to an age- and gender-matched Control group (n = 50). Several techniques were assessed measuring both femoral and tibial axial asymmetry. A new measurement, tibial rotational asymmetry, comparing a line between the midpoints of the collateral ligaments to the axis between the patellar tendon and posterior cruciate ligament, was assessed for its association with patellofemoral instability.

RESULTS

Compared to the controls, the patellofemoral instability group demonstrated a significant difference in tibial rotational asymmetry, with a mean of 2.9° (SD 3.2°) externally rotated vs - 1.6° (SD 2.2°) in the control group. Significant differences were also demonstrated regarding the sulcus angle, tibial tubercle-trochlear groove distance, tibial tubercle-posterior cruciate ligament distance, patellar size and the Insall-Salvati ratio. There were no differences between groups regarding the lengths of the posterior condyles, the heights of the trochlear ridges or lateralisation of the trochlear groove. Further analysis of the patellofemoral instability group revealed a subgroup of males with normal anatomy (7/50) and a subgroup of females with isolated patella alta (7/50).

CONCLUSION

Patellofemoral instability is associated with tibial rotational asymmetry due to lateralisation of the tibial tubercle. It is also associated with patella alta and reduced trochlear groove depth. The femoral axial shape is otherwise unchanged.

LEVEL OF EVIDENCE

III.

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Dong C, Zhao C, Kong L, Piao K, Hao K, Wang F. Medialization of trochlear groove was correlated with extended lateral trochlear in trochlear dysplasia: a transverse CT analysis. J Orthop Surg Res 2022;17:276. [PMID: 35570290 PMCID: PMC9107703 DOI: 10.1186/s13018-022-03166-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 05/08/2022] [Indexed: 11/10/2022] Open

Abstract Abstract Purpose To investigate the difference of trochlear width between normal and dysplastic trochlear and to analyze whether the medialization of trochlear groove was correlated with abnormal width of trochlear facets in trochlear dysplasia. Methods This study involved CT scans of fifty knees with trochlear dysplasia (TD group) and fifty knees without obvious trochlear dysplasia (Normal group). The linear distance from the medial femoral epicondyle to the various reference points was measured on axial CT images which included the medial edge of medial trochlear facet (dMTE), trochlear groove (dTG), and the lateral edge of lateral trochlear facets (dLTE). The medial and lateral trochlear width was calculated and standardized by the width of the anatomical epicondylar axis. Pearson’s correlation analysis was performed between the dTG and the width of the medial and lateral trochlear. Results The reliability of the results was good. Intraclass correlation coefficient (ICC) ranged from 0.89 to 0.97. The dMTE was significantly greater in the TD group than the normal group (32.7 ± 5.1% vs. 29.6 ± 3.5%, p = 0.009). There was no significant difference in the dLTE between groups. The dTG was reduced in the TD group compared with the normal group (45.2 ± 4.1% vs. 49.1 ± 3.9%, p = 0.019). In the TD group, there was a significant reduction in the medial trochlear width (13.9 ± 4.1% vs. 19.4 ± 2.9%, p < 0.001) and a significant increase in the lateral trochlear width (31.3 ± 4.0% vs. 26.9 ± 3.6%, p < 0.001) compared with the normal group. The dTG was significantly correlated with the lateral trochlear width (r value = − 0.693, p < 0.001) and not correlated with the medial trochlear width (r value = 0.044, p = 0.766) in trochlear dysplasia. Conclusions This study demonstrated that dysplasia of trochlear morphology was related to the reduction of medial trochlear width and increase in lateral trochlear width. The medialization of trochlear groove was significantly correlated with the increased lateral trochlear width. Collapse

Ormeci T, Turkten I, Sakul BU. Radiological evaluation of patellofemoral instability and possible causes of assessment errors. World J Methodol 2022;12:64-82. [PMID: 35433342 PMCID: PMC8984217 DOI: 10.5662/wjm.v12.i2.64] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 10/27/2021] [Accepted: 02/10/2022] [Indexed: 02/06/2023] Open

Krishnan H, Eldridge JD, Clark D, Metcalfe AJ, Stevens JM, Mandalia V. Tibial tuberosity-trochlear groove distance: does it measure up? Bone Jt Open 2022;3:268-274. [PMID: 35321559 PMCID: PMC8965791 DOI: 10.1302/2633-1462.33.bjo-2021-0107] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open

Ormeci T, Sen S, Turkten I, Gulabi D, Avcı CC, Sakul BU. The relationship between patellar volume and trochlear volume in patients with patellofemoral instability. Clin Radiol 2022;77:e329-e336. [PMID: 35144768 DOI: 10.1016/j.crad.2022.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 01/06/2022] [Indexed: 11/19/2022]

Fuchs A, Feucht MJ, Dickschas J, Frings J, Siegel M, Yilmaz T, Schmal H, Izadpanah K. Interobserver reliability is higher for assessments with 3D software-generated models than with conventional MRI images in the classification of trochlear dysplasia. Knee Surg Sports Traumatol Arthrosc 2022;30:1654-1660. [PMID: 34423397 PMCID: PMC9033701 DOI: 10.1007/s00167-021-06697-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 08/10/2021] [Indexed: 11/11/2022]

Abstract

PURPOSE

Trochlear dysplasia is a significant risk factor for patellofemoral instability. The severity of trochlear dysplasia is commonly evaluated based on the Dejour classification in axial MRI slices. However, this often leads to heterogeneous assessments. A software to generate MRI-based 3D models of the knee was developed to ensure more standardized visualization of knee structures. The purpose of this study was to assess the intra- and interobserver agreements of 2D axial MRI slices and an MRI-based 3D software generated model in classification of trochlear dysplasia as described by Dejour.

METHODS

Four investigators independently assessed 38 axial MRI scans for trochlear dysplasia. Analysis was made according to Dejour's 4 grade classification as well as differentiating between 2 grades: low-grade (types A + B) and high-grade trochlear dysplasia (types C + D). Assessments were repeated following a one-week interval. The inter- and intraobserver agreement was determined using Cohen's kappa (κ) and Fleiss kappa statistic (κ). In addition, the proportion of observed agreement (po) was calculated for assessment of intraobserver agreement.

RESULTS

The assessment of the intraobserver reliability with regard to the Dejour-classification showed moderate agreement values both in the 2D (κ = 0.59 ± 0.08 SD) and in the 3D analysis (κ = 0.57 ± 0.08 SD). Considering the 2-grade classification, the 2D (κ = 0.62 ± 0.12 SD) and 3D analysis (κ = 0.61 ± 0.19 SD) each showed good intraobserver matches. The analysis of the interobserver reliability also showed moderate agreement values with differences in the subgroups (2D vs. 3D). The 2D evaluation showed correspondences of κ = 0.48 (Dejour) and κ = 0.46 (high / low). In the assessment based on the 3D models, correspondence values of κ = 0.53 (Dejour) and κ = 0.59 (high / low) were documented.

CONCLUSION

Overall, moderate-to-good agreement values were found in all groups. The analysis of the intraobserver reliability showed no relevant differences between 2 and 3D representation, but better agreement values were found in the 2-degree classification. In the analysis of interobserver reliability, better agreement values were found in the 3D compared to the 2D representation. The clinical relevance of this study lies in the superiority of the 3D representation in the assessment of trochlear dysplasia, which is relevant for future analytical procedures as well as surgical planning.

LEVEL OF EVIDENCE

Level II.

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Spang RC, Jahandar A, Meyers KN, Nguyen JT, Maher SA, Strickland SM. Dysplastic Patellofemoral Joints Lead to a Shift in Contact Forces: A 3D-Printed Cadaveric Model. Am J Sports Med 2021;49:3344-3349. [PMID: 34415194 DOI: 10.1177/03635465211031427] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]

Abstract

BACKGROUND

The distribution of contact forces across the dysplastic patellofemoral joint has not been adequately quantified because models cannot easily mimic the dysplasia of both the trochlea and the patella. Thus, the mechanical consequences of surgical treatments to correct dysplasia cannot be established.

PURPOSE/HYPOTHESIS

The objective of this study was to quantify the contact mechanics and kinematics of normal, mild, and severely dysplastic patellofemoral joints using synthetic mimics of the articulating surfaces on cadavers. We tested the hypothesis that severely dysplastic joints would result in significantly increased patellofemoral contact forces and abnormal kinematics.

STUDY DESIGN

Controlled laboratory study.

METHOD

Patellofemoral dysplasia was simulated in 9 cadaveric knees by replacing the native patellar and trochlear surfaces with synthetic patellar and trochlear implants. For each knee, 3 synthetic surface geometries (normal, showing no signs of dysplasia; mild, exemplifying Dejour type A; and severe, exemplifying Dejour type B) were randomized for implantation and testing. Patellar kinematics and the sum of forces acting on the medial and lateral patellar facets were computed for each knee and for each condition at 10° increments from 0° to 70° of flexion.

RESULTS

A pronounced lateral shift in the weighted center of contact of the lateral facet occurred for severely dysplastic knees from 20° to 70° of flexion. Compared with normal geometries, lateral patellar facet forces exhibited a significant increase only with mild dysplasia from 50° to 70° of flexion and with severe dysplasia at 70° of flexion. No measurable differences in medial patellar facet mechanics or joint kinematics occurred.

CONCLUSION

Our hypothesis was rejected: Severely dysplastic joints did not result in significantly increased patellofemoral contact forces and abnormal kinematics in our cadaveric simulation. Rather, severe dysplasia resulted in a pronounced lateral shift in contact forces across the lateral patellar facet, while changes in kinematics and the magnitude of contact forces were not significant.

CLINICAL RELEVANCE

Including dysplasia of both the patella and trochlea is required to fully capture the mechanics of this complex joint. The pronounced lateralization of contact force in severely dysplastic patellofemoral joints should be considered to avoid cartilage overload with surgical manipulation.

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Sharma N, Rehmatullah N, Kuiper JH, Gallacher P, Barnett AJ. Clinical validation of the Oswestry-Bristol Classification as part of a decision algorithm for trochlear dysplasia surgery. Bone Joint J 2021;103-B:1586-1594. [PMID: 34587807 DOI: 10.1302/0301-620x.103b10.bjj-2020-1984.r1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]

Abstract

AIMS

The Oswestry-Bristol Classification (OBC) is an MRI-specific assessment tool to grade trochlear dysplasia. The aim of this study is to validate clinically the OBC by demonstrating its use in selecting treatments that are safe and effective.

METHODS

The OBC and the patellotrochlear index were used as part of the Oswestry Patellotrochlear Algorithm (OPTA) to guide the surgical treatment of patients with patellar instability. Patients were assigned to one of four treatment groups: medial patellofemoral ligament reconstruction (MPFLr); MPFLr + tibial tubercle distalization (TTD); trochleoplasty; or trochleoplasty + TTD. A prospective analysis of a longitudinal patellofemoral database was performed. Between 2012 and 2018, 202 patients (233 knees) with a mean age of 24.2 years (SD 8.1), with recurrent patellar instability were treated by two fellowship-trained consultant sports/knee surgeons at The Robert Jones and Agnes Hunt Orthopaedic Hospital. Clinical efficacy of each treatment group was assessed by Kujala, International Knee Documentation Committee (IKDC), and EuroQol five-dimension questionnaire (EQ-5D) scores at baseline, and up to 60 months postoperatively. Their safety was assessed by complication rate and requirement for further surgery. The pattern of clinical outcome over time was analyzed using mixed regression modelling.

RESULTS

In all, 135 knees (mean age 24.9 years (SD 9.4)) were treated using a MPFLr. Ten knees (7.4%) required additional surgery. A total of 50 knees (mean age 24.4 years (SD 6.3)) were treated using MPFLr + TTD. Ten (20%) required additional surgery. A total of 20 knees (mean age 19.5 years (SD 3.0)) were treated using trochleoplasty + TTD. Three patients (15%) required additional surgery. In each treatment group, there was a significant improvement in Kujala, IKDC, and EQ-5D at one year postoperatively (p < 0.001) with a recognized level of overall complication rate.

CONCLUSION

The OBC is a valid assessment tool to grade patients with trochlear dysplasia and, when used as part of the OPTA, helps to determine treatments that are safe and effective. This fulfils the requirements for its application in mainstream clinical practice. Cite this article: Bone Joint J 2021;103-B(10):1586-1594.

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McCrum E, Cooper K, Wittstein J, French RJ. Imaging of Patellofemoral Instability. Clin Sports Med 2021;40:693-712. [PMID: 34509206 DOI: 10.1016/j.csm.2021.05.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]

Ipsilateral patellofemoral morphological abnormalities are more severe than those of contralateral joints in patients with unilateral patellar dislocation. Knee Surg Sports Traumatol Arthrosc 2021;29:2709-2716. [PMID: 33834257 DOI: 10.1007/s00167-021-06539-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 03/16/2021] [Indexed: 10/21/2022]

Abstract

PURPOSE

To determine the differences in anatomic parameters between ipsilateral dislocated knees and contralateral non-dislocated knees in patients with unilateral patellar dislocation and to identify any variations in ipsilateral knees contributing to contralateral anatomic abnormalities.

METHODS

A total of 82 patients with unilateral patellar dislocation from 2016 to 2019 were retrospectively evaluated. Bilateral anatomic factors, including the tibial tubercle to trochlear groove (TT-TG) distance, lower limb rotational deformities, trochlear dysplasia, patella tilt, and patellar height, were assessed by CT.

RESULTS

The study included 46 patients (32 females and 14 males, mean age ± SD 20.5 ± 6.8). The interobserver reliability of each parameter showed excellent agreement. The ipsilateral TT-TG distance (P = 0.004), patella tilt (P = 0.001), and patellar height (P = 0.01) were greater in the ipsilateral knees than in the contralateral knees. The lateral trochlea inclination (LTI) in the contralateral knees was larger than that in the ipsilateral knees (P = 0.022). There was a significant difference in the distribution of trochlear dysplasia of Dejour between the ipsilateral knees (dislocated side) and the contralateral knees (P = 0.036). However, bilateral femoral and/or tibial torsion, and bilateral knee joint rotation did not differ significantly. Binary logistic regression showed that only ipsilateral LTI revealed significant ORs of 8.83 (P = 0.016) and 7.64 (P = 0.018) with regard to contralateral abnormal tibial torsion and LTI, respectively.

CONCLUSION

In patients with unilateral patellar dislocation, the ipsilateral TT-TG distance, patella tilt, and patellar height values were larger in the ipsilateral knees than in the contralateral knees, and trochlear dysplasia was more severe in the ipsilateral joints. The risks of contralateral pathological tibial torsion and LTI were 8.8- and 7.6-fold higher, respectively, in patients with abnormal ipsilateral LTI.

LEVEL OF EVIDENCE

Level IV.

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Outcomes of MPFL reconstruction with tibial tubercle transfer for recurrent patellar instability with high grade trochlear dysplasia in Indian population. J Clin Orthop Trauma 2021;20:101490. [PMID: 34290957 PMCID: PMC8274292 DOI: 10.1016/j.jcot.2021.101490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/27/2021] [Accepted: 06/27/2021] [Indexed: 11/20/2022] Open

Abstract

BACKGROUND

Patellar instability is a painful condition which affects the quality of life and mobility of young individuals. The aim of this study is to observe the results of medial patello-femoral ligament reconstruction with hamstring autograft along with a modified Fulkerson osteotomy, for recurrent instability of patella with high-grade trochlear dysplasia in Indian population.

MATERIALS & METHODS

We conducted a prospective observational study of 26 knees (21 patients) who attended our outpatient department from June 2014 to February 2019, with recurrent instability of the patella and high-grade trochlear dysplasia. All knees were treated with MPFL reconstruction with hamstring autograft and modified Fulkerson osteotomy.

RESULTS

The mean follow-up period was 30 months (range: 24-50). The mean Lysholm scores improved from 49.9 (range: 30-63) preoperatively to 82.5 (range: 51-100) (p < 0.05), Kujala scores from 55.5 (36-67) to 85.9 (55-100) and International Knee Documentation Committee (IKDC) scores from 50.2 (31.6-62.3) to 82.9 (54.7-98.3) (p < 0.05) at 2 years follow-up. TT-TG distance decreased from 21.2 mm (18-25) to 11.6 mm (10-13) (p < 0.05) and patellar tilt angle decreased from 24.2° (18°-35°) to 7.2° (5°-10°) (p < 0.05). One knee had superficial skin infection in immediate post-operative period. Three knees had postoperative stiffness, which improved on manipulation under anesthesia. Six knees had implant irritation from the osteotomy screws which were removed after bony union was achieved. Functional scores were low in two knees due to patello-femoral pain, but they did not have recurrent instability.

CONCLUSION

MPFL reconstruction with tibial tubercle transfer gives good functional outcomes in 92.3% patients with recurrent patellar instability, associated with high-grade trochlear dysplasia in Indian population.

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