• femoral shortening
• high hip dislocation
• hip
• hip arthroplasty
• type IV DDH

• Developmental dysplasia of the hip
• Magnetic resonance imaging
• Muscles
• Osteotomy

• Humans
• Magnetic Resonance Imaging/methods
• Male
• Female
• Developmental Dysplasia of the Hip/diagnostic imaging
• Developmental Dysplasia of the Hip/surgery
• Muscle, Skeletal/diagnostic imaging
• Muscle, Skeletal/pathology
• Child, Preschool
• Infant
• Child
• Follow-Up Studies
• Hip/diagnostic imaging

Hip arthroplasty in patients with a history of paediatric hip disorders presents a significant challenge for orthopaedic surgeons. These patients are typically younger and have greater functional demands. Therefore, achieving optimal biomechanical conditions is crucial, involving placement of the acetabulum at the ideal centre of rotation and securing a stable femoral component with good offset to preserve abductor muscle function and restore leg length. The altered anatomy in these cases makes total hip arthroplasty more complex, necessitating thorough preoperative imaging and an individualised surgical approach. Various techniques may be employed to optimise biomechanical outcomes. We propose a modified lateral hip approach, offering exceptional visualisation of the acetabulum and femur while preserving the continuity of the abductor muscles without requiring trochanteric osteotomy. To achieve the most biomechanically advantageous acetabular position, cotyloplasty is our preferred method.

• Total hip arthroplasty
• Pediatric hip sequelae
• Center of rotation
• Cotyloplasty
• Hip abductor muscles

• Extra-small femoral stem
• Hypoplastic femur
• Total hip arthroplasty

• Humans
• Arthroplasty, Replacement, Hip/methods
• Femur/surgery
• Femur/diagnostic imaging
• Male
• Female
• Adult
• Hip Prosthesis
• Middle Aged
• Young Adult
• Prosthesis Design

• Seoul National University Hospital

• developmental hip dysplasia
• intramedullary distraction
• leg length discrepancy
• telescopic rod
• total hip arthroplasty

• avascular necrosis
• girdle-stone
• orthopaedic
• sickle cell disease
• total hip replacement

• Crowe IV
• complications
• direct anterior approach
• femoral osteotomy
• hip dysplasia
• total hip arthroplasty

• Humans
• Retrospective Studies
• Arthroplasty, Replacement, Hip
• Radiography
• Acetabulum
• Muscle, Skeletal

• Osteonecrosis of the femoral head
• Pre-operative leg length discrepancy
• Proximal femoral shape
• Unilateral total hip arthroplasty

• Female
• Humans
• Middle Aged
• Arthroplasty, Replacement, Hip/adverse effects
• Retrospective Studies
• Femur Head/surgery
• Leg
• Risk Factors
• Leg Length Inequality/diagnostic imaging
• Leg Length Inequality/epidemiology
• Leg Length Inequality/etiology
• Osteonecrosis/complications

• 06-2003-0630 Seoul National University Hospital Research Fund

• Developmental dysplasia of the hip
• soft-tissue balance
• total hip arthroplasty

• Arthroplasty, Replacement, Hip/adverse effects
• Arthroplasty, Replacement, Hip/methods
• Contracture/etiology
• Contracture/surgery
• Femur/surgery
• Follow-Up Studies
• Hip Dislocation, Congenital/complications
• Hip Dislocation, Congenital/diagnostic imaging
• Hip Dislocation, Congenital/surgery
• Humans
• Muscles/surgery
• Retrospective Studies

• avascular necrosis (AVN)
• balance
• developmental dysplasia of the hip
• gait
• kinematics
• motion analysis

• Chang Gung Memorial Hospital, Linkou
• Ministry of Science and Technology, Taiwan

Performing a total hip arthroplasty for a high hip dislocation is technically demanding and presents several challenges, with appropriate evaluation of the bone morphology of the hip and proper implant selection being critical for successful outcomes.

The purpose of our study was to evaluate the clinical and radiographic outcomes of cementless modular total hip arthroplasty for the treatment of high hip dislocations with sub-trochanteric transverse shortening osteotomy.

Sixty-eight hips with a high hip dislocation, were treated using a sub-trochanteric transverse shortening osteotomy and cementless modular total hip arthroplasty, retrospectively reviewed. Hip function was assessed using the Harris hip score, with hip abduction strength evaluated using the Trendelenburg test. Radiographic assessment included the measurement of leg length discrepancy, identification of implant loosening, localization of the hip center, and union at the osteotomy site.

The mean follow-up period was 12.9 (range 5.2–16.8) years. The mean Harris hip score improved from a pre-operative score of 48.6 ± 3.6 to 82.4 ± 4.2 (p < 0.05). The hip was within the true acetabulum in all patients, postoperatively. Osteotomy union was achieved in 67 of the 68 hips (98.5%) in a mean latency of 12.5 ± 0.6 weeks. The mean length of femoral shortening was 66.5 ± 4.5 mm, with a mean pull-down length of the proximal part of 35.5 ± 3.5 mm.

For the treatment of high hip dislocations with satisfactory clinical outcomes, the modular stem offers an adjustable anteversion angle to restore sufficient rotational stability and the transverse osteotomy provides sufficient compression pressure across the osteotomy site to facilitate union.

Trial registration It was a retrospective study and approved by Istanbul Research and Training Hospital institutional Ethics Review Board (772-05/02/2016).

• High hip dislocation
• Modular
• Transverse osteotomy

The reconstruction of the hip joint in patients suffering from developmental hip dysplasia (DDH) is a demanding procedure and presents many challenges to the reconstructive surgeon. Higher rates of mechanical complications are present in this group of patients. The results of cemented and uncemented implants used in DDH patients are very promising, according to recent outcomes. However, the surgeon has to be aware of several complications, in order to establish an uneventful surgical management of DDH. The specific article investigates the technical challenges and clinical results of total hip arthroplasty in patients with DDH.

• congenital hip dysplasia
• developmental hip disease
• hip arthritis
• total hip arthroplasty
• total hip replacement

The purpose of this study was to determine whether dislocation height can predict the use of subtrochanteric osteotomy in patients with Crowe type IV hip dysplasia.

We retrospectively included 102 patients affected by unilateral Crowe type IV developmental dysplasia who underwent primary total hip arthroplasty with modular cementless stem from April 2008 to May 2019 in our institution. Based on radiographs and operative notes, we found 62 hip arthroplasties were performed with subtrochanteric osteotomy and 40 without subtrochanteric osteotomy, which were named as the (subtrochanteric osteotomy) STO group and non-STO group, respectively. The predictive values of height of greater trochanter, height of femoral head/neck junction, and distalization of greater trochanter were analyzed using receiver operating characteristic (ROC) curves.

The ROC curves showed that distalization of greater ntrochanter had the highest areas under the ROC curve (AUC), at 0.998. This was followed by height of greater trochanter and height of head/neck junction, which had AUCs of 0.937 and 0.935, respectively. The optimal thresholds of these three indicators were 4.84 cm, 6.05 cm, and 4.26 cm. At the last follow-up, six dislocations occurred (five in the STO group and one in the non-STO group). Four hips were treated by closed reduction and two by open reduction. Three patients (all in STO group) developed femoral nerve palsy with skin numbness on the frontal thigh or tibia and all recovered in a year. At outpatient visit, the limb length was measured. LLD was <1 cm in 83/102, 1–2 cm in 18/102, and >2 cm in 1/102.

This study reveals that indicators of dislocation height are useful in predicting the use of subtrochanteric osteotomy during total hip arthroplasty for Crowe type IV hip dysplasia. However, a comprehensive, multivariate analysis may be required to validate these results.

• developmental dysplasia of the hip
• dislocation height
• subtrochanteric osteotomy
• total hip arthroplasty

• Childhood pyogenic infection
• Developmental dysplasia of the hip
• High hip dislocation
• Subtrochanteric shortening osteotomy
• Total hip arthroplasty

This study aims to report the physiological and radiological long-term results of total hip arthroplasty (THA) combined with or without subtrochanteric osteotomy in a group of developmental dysplasia of hip (DDH) patients.

This retrospective study included 90 hips of 59 patients (3 males, 56 females; mean age 45.7±10.9 years; range, 24 to 67 years) who underwent THA between January 1979 and March 2006. Thirteen patients needed subtrochanteric shortening. The evaluation was performed through Harris hip scores, physical examination, and radiological imaging.

The follow-up period ranged from 5 to 32 years, and the mean follow-up period was 10.3±6.4 years. Revision was required in 17 hips out of 90. Twelve revisions were needed because of aseptic loosening of femoral or acetabular component, three were for fracture of the femoral stem, and two for protrusio acetabuli. Four patients had transient nerve palsy, and one had permanent nerve function loss. In one patient, nonunion was observed around the femoral osteotomy site. Harris hip score was remarkably improved compared to top preoperative values (48 vs. 88.2, p<0.01).

Although revision rates tend to increase in long-term follow-up, THA is one of the best treatment options in DDH patients to relieve pain, improve daily activity levels, and minimize the damage of the knee and lumbar region.

To restore rotation center exactly in revision hip arthroplasty is technically challenging, especially in Paprosky type III. The technical difficulty is attributable to the complicated acetabular bone defect. In this study, we discussed the method of restoring rotation center in revision hip arthroplasty and reported the clinical and radiological outcome of mid-term and long-term follow-up.

This study retrospectively reviewed 45 patients (48 hips) who underwent revision hip arthroplasty, in which 35 cases (35 hips) were available for complete follow-up data. During the operation, the acetabular bone defect was reconstructed by impaction morselized bone graft, and the hip rotation center was restored by using remnant Harris fossa and acetabular notches as the marks. The clinical outcome was assessed using the Harris hip score. Pelvis plain x-ray was used to assess implant migration, stability of implants, and incorporation of the bone graft to host bone.

The average follow-up duration was 97.60 months (range 72–168 months). The average Harris hip score improved from 29.54 ± 10.87 preoperatively to 83.77 ± 5.78 at the last follow-up. The vertical distance of hip rotation center measured on pelvis x-ray was restored to normal, with the mean distance (15.24 ± 1.31) mm (range 12.4~17.3 mm). The mean loss of vertical distance of hip rotation center was (2.21 ± 0.72) mm (range 1.1 ~ 5.3 mm) at the last follow-up.

Satisfactory clinical and radiological outcome can be obtained through restoring hip rotation center by using remnant Harris fossa and acetabular notches as the anatomical marks in revision hip arthroplasty.

• Acetabular defects
• Follow-up
• Revision hip arthroplasty
• Rotation center

To measure the factors that affect functional leg length of Crowe type IV Developmental dysplasia of the hip (DDH) patients and to review our own methods to balance leg length discrepancy (LLD) in Crowe type IV DDH patients.

This was a prospective observational study which started in June 2017 and ended in August 2019. Inclusion criteria included: (i) Crowe type I or Crowe type IV hip dysplasia patients who underwent total hip arthroplasty (THA) in the Department of Orthopaedics at our institution between July 2017 and June 2018; (ii) the patients were treated with our specific leg length balance strategy; and (iii) the related outcomes of patients were completely recorded. Finally, 18 consecutive Crowe type I patients (20 hips) and 14 consecutive Crowe type IV patients (18 hips) were selected and divided into two groups according to Crowe types. All patients received THA, and patients with a longer affected side and inferior anatomical acetabular positions in Crowe type IV group also received subtrochanteric osteotomy. During operation and after hip reduction, leg lengths were compared while two legs were in an extended position and the operative leg was on top of the non‐operative one. Additional leg length adjustment was applied when leg length was considered to be unequal. Prior to surgery, subluxation height of the femoral head on the affected side, functional LLD, bony length of lower limbs, and distance from teardrops to the lowest point line of the sacroiliac joint were recorded. After surgery, cup sizes, functional LLD, and height of hip rotational centers were measured. Clinical evaluations, such as Harris Hip Score (HHS) and SF‐12 scale, were also obtained before and after surgery for all patients.

At the last follow‐up, functional LLD and clinical measurements of both Crowe type IV group and Crowe type I group were significantly improved. Compared with Crowe type I patients, Crowe type IV patients had a significantly lower MCS, a significantly longer leg lengthening length and a significantly lower hip center height after surgery. Significant differences of tibia length, leg length, and teardrop position were found between affected side and healthy side of Crowe type IV patients. Only three of 14 Crowe type IV patients remained under 1 cm functional LLD. Five patients in the Crowe type IV group developed lower limb numbness immediately following surgery, and they all recovered within 6 months. The average follow‐up period for either group was 14 months, and all patients were followed‐up at 1, 3, 6, and 12 months then yearly after surgery until the final follow‐up.

After detailed leg length balance process, THA combined with transverse sub‐trochanter osteotomy could be an effective method to achieve equal function leg length with most Crowe type IV patients.

• Hip dislocation
• Leg length inequality
• Osteotomy
• Skeletal deformity
• Total hip replacement

• classification of dislocation
• complication
• high-riding hips
• subtrochanteric osteotomy

• Adult
• Aged
• Female
• Humans
• Male
• Middle Aged
• Arthroplasty, Replacement, Hip/methods
• Femur/diagnostic imaging
• Femur/surgery
• Hip Dislocation, Congenital/classification
• Hip Dislocation, Congenital/diagnosis
• Hip Dislocation, Congenital/surgery
• Operative Time
• Osteotomy/methods
• Retrospective Studies

Total hip arthroplasty (THA) of Crowe type IV developmental dysplasia of the hip (DDH) is challenging. Although traditional (lateral, posterolateral, and posterior) THA approaches have been used with great anatomic success, they damage periarticular muscles, which are already quite weak in type IV DDH. The recently developed direct anterior approach (DAA) can provide an inter‐nerve and inter‐muscle approach for THA of type IV dysplasia hips. However, femur exposure with the DAA could be difficult during surgery and it is hard to apply femoral shortening osteotomy. THA techniques used for type IV DDH include anatomic hip center techniques (true acetabular reconstruction) and high hip center techniques, wherein an acetabulum is reconstructed above the original one. Although anatomic construction of the hip center is considered “the gold standard” treatment, it is impossible if the anatomical acetabular is too small and shallow. Procedures used to support type IV DDH reduction with anatomic hip center techniques include greater trochanter osteotomy, lesser trochanter osteotomy, and subtrochanteric osteotomy. However, these techniques have yet to be standardized, and it is unclear which is best for type IV DDH. One‐state and two‐state non‐osteotomy reduction techniques have also been introduced to treat type IV DDH. Potential complications of THA performed in patients with type IV DDH include leg length discrepancy (LLD), peri‐operative femur fracture, nonunion of the osteotomy site, and nerve injury. It is worth noting that nowadays an increasing number of Crowe type IV DDH patients are more sensitive to postoperative LLD.

• Acetabular reconstruction
• Hip dislocation
• Osteotomy
• Postoperative complications
• Total hip replacement

• Dysplastic hip
• Modular stem
• South Asia
• Total hip arthroplasty

• childhood pyogenic arthritis
• clinical outcomes
• high dislocation
• limb length discrepancy
• total hip arthroplasty

• developmental dysplasia of the hip
• direct leverage
• femoral head reduction
• high hip dislocation
• total hip arthroplasty

• Crowe classification
• Total hip arthroplasty
• developmental dysplasia of the hip
• subtrochanteric osteotomy

• comparison study
• developmental dysplasia of the hip
• femoral shortening osteotomy
• high hip dislocation
• total hip arthroplasty

• Knee joint
• Neglected developmental dysplasia of the hip
• Radiographic changes

Adult patients with developmental dysplasia of the hip develop secondary osteoarthritis and eventually end up with total hip arthroplasty (THA) at younger age. Because of altered anatomy of dysplastic hips, THA in these patients represents technically demanding procedure. Distorted anatomy of the acetabulum and proximal femur together with conjoined leg length discrepancy present major challenges during performing THA in patients with developmental dysplasia of the hip. In addition, most patients are at younger age, therefore, soft tissue balance is of great importance (especially the need to preserve the continuity of abductors) to maximise postoperative functional result. In this paper we present a variety of surgical techniques available for THA in dysplastic hips, their advantages and disadvantages. For acetabular reconstruction following techniques are described: Standard metal augments (prefabricated), Custom made acetabular augments (3D printing), Roof reconstruction with vascularized fibula, Roof reconstruction with pedicled iliac graft, Roof reconstruction with autologous bone graft, Roof reconstruction with homologous bone graft, Roof reconstruction with auto/homologous spongious bone, Reinforcement ring with the hook in combination with autologous graft augmentation, Cranial positioning of the acetabulum, Medial protrusion technique (cotyloplasty) with chisel, Medial protrusion technique (cotyloplasty) with reaming, Cotyloplasty without spongioplasty. For femoral reconstruction following techniques were described: Distraction with external fixator, Femoral shortening through a modified lateral approach, Transtrochanteric osteotomies, Paavilainen osteotomy, Lesser trochanter osteotomy, Double-chevron osteotomy, Subtrochanteric osteotomies, Diaphyseal osteotomies, Distal femoral osteotomies. At the end we present author’s treatment method of choice: for acetabulum we perform cotyloplasty leaving only paper-thin medial wall, which we break during acetabular cup impacting. For femoral side first we peel of all rotators and posterior part of gluteus medius and vastus lateralis from greater trochanter on the very thin flake of bone. This method allows us to adequately shorten proximal femoral stump, with possibility of additional resection of proximal femur. Furthermore, several advantages and disadvantages of this procedure are also discussed.

• Hip
• Arthroplasty
• Dysplasia
• Reconstruction
• Techniques
• Acetabulum
• Femur
• Osteoarthritis
• Developmental dysplasia of the hip

Hip reduction in total hip arthroplasty for high dislocated hips is difficult. Various femur osteotomy procedures have been used for hip reduction, but these methods increase operative time and risk of nonunion. We investigated the efficacy of a novel partial greater trochanter osteotomy technique for hip reduction in total hip arthroplasty for patients with high hip dislocation.

Twenty-one patients (23 hips) with high dislocated hip were treated with total hip arthroplasty that included partial greater trochanter osteotomy, i.e., the upper 2/3 greater trochanter was resected, and the gluteus medius muscle attachment was spared. The clinical outcome was evaluated by comparing the Harris hip scores and radiographic exam results, obtained before surgery and at follow-ups.

Follow-ups of 21 patients ranged from 13 to 56 months. The mean Harris hip score increased from preoperative 55.0 (36–69) to postoperative 86.1 (71–93; P = 0.00). The average preoperative leg length discrepancy in patients with unilateral high hip dislocation was 46 mm (28–65 mm); postoperatively leg length discrepancy was less than 1 cm in 11 patients, between 1 and 2 cm in 8 patients, and more than 2 cm in 2 patients. The average leg lengthening at the time of surgery was 36 mm (24–54 mm). Trendelenburg’s gait changed from positive to negative in 20 hips by the last follow-up. No nerve injury occurred postoperative.

Partial greater trochanter osteotomy is an effective method to render hip reduction in total hip arthroplasty for patients with high dislocation of the hip.

The online version of this article (doi:10.1186/1471-2474-15-293) contains supplementary material, which is available to authorized users.