Ulnar-sided wrist pain can be caused by a number of problems, including ulnar impaction syndrome (UIS) and triangular fibrocartilage complex (TFCC) injury. Multiple studies have described the diagnostic criteria for UIS and TFCC injuries, and excellent surgical outcomes have been reported for each condition. Few studies have examined the extent to which the two independent conditions cooccur, and little is known about their relationship. Based on theories in the literature and clinical experience, we propose the possibility of TFCC injury as the cause and result of UIS in this review.

This study evaluates the outcomes of arthroscopic triangular fibrocartilage complex (TFCC) foveal reattachment using an inside-out suture passing through the TFCC at specific ulnocarpal anatomical landmarks to grasp the radioulnar ligaments. Thirty-eight patients with a mean age of 36 years (range 19-54), diagnosed with TFCC injury with distal radioulnar joint (DRUJ) instability, underwent arthroscopic inside-out TFCC foveal reattachment using designated suture sites. At a mean follow-up of 32 months (range 26-44), pain score, range of motion, grip strength, Disabilities of the Arm, Shoulder and Hand (DASH) score, and Modified Mayo Wrist Score all showed significant improvement after surgery. The DRUJ stability was restored and the minimal clinically important difference threshold for the DASH score was achieved in all patients. Arthroscopic TFCC foveal reattachment using the inside-out technique at specific ulnocarpal anatomical landmarks provided reliable outcomes and could be considered as another straightforward procedure for treating TFCC injuries with DRUJ instability.Level of evidence: IV.

Triangular fibrocartilage complex (TFCC) peripheral tears with persistent wrist pain can be treated with arthroscopic surgical repair owing to vascularization of the peripheral region. The safety and efficacy of all-inside repair has been shown in prior case series. The purpose of this study was to compare two methods of arthroscopic peripheral TFCC repair: all-inside vertical mattress and outside-in horizontal mattress.

A 5-year retrospective review was performed on patients treated from 2016 to 2021 with wrist arthroscopy and TFCC repair for Palmer 1B tears. Patients with ulnar extrinsic ligament repair, distal radioulnar joint instability, concomitant ulnar shortening osteotomy, and extensor carpi ulnaris instability were excluded. Patient therapy and office visit records were reviewed. Outcomes including Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH); range of motion; grip strength; immobilization time; complications; and need for revision procedures were compared.

Fifty-two patients were included in the study, 32 in the outside-in group and 20 in the all-inside group. The average follow-up length was 24.8 weeks, with similar range of motion and strength in both groups. The average postoperative QuickDASH score was 13 in the outside-in group and 9 in the all-inside group at 43.5 months, compared with the preoperative QuickDASH scores of 47 and 50, respectively. Mean immobilization time was longer for outside-in than for all-inside (5.25 vs 2.0 weeks, respectively).

All-inside arthroscopic peripheral TFCC repair showed range of motion, grip strength, complications, revisions, and postoperative improvement in QuickDASH scores similar to those with the outside-in technique.

Therapeutic IV; retrospective comparative study.

The triangular fibrocartilage complex (TFCC) is crucial for stability and acts as a shock absorber and load transmitter at the distal radioulnar joint (DRUJ). It is often injured in wrist trauma, particularly in young athletes. Clinical assessment involves patient history, physical examination, and imaging modalities like MRI, with wrist arthroscopy as the gold standard for diagnosing TFCC tears. Multiple classification systems categorize TFCC tears based on location and arthroscopic appearance, guiding treatment decisions. Surgical options are recommended for tears refractory to conservative management or severe tears. Despite numerous arthroscopic treatments available in the literature, this article aims to simplify the approach. It presents the authors' surgical algorithm for managing acute traumatic TFCC tears arthroscopically. The choice of technique depends on the lesion's location, with various options for peripheral and foveal tears. Post-operative rehabilitation is crucial for optimal recovery. This article provides a comprehensive review of acute traumatic TFCC injuries, covering anatomy, classification, assessment, and treatment options. Emphasis is placed on accurate diagnosis and appropriate arthroscopic management through a structured approach.

An unstable distal radioulnar joint can cause ulnar-sided wrist pain. Stability of the distal radioulnar joint, which varies among individuals, is dependent on the bony structure of the sigmoid notch and the surrounding soft tissues, such as the interosseous membrane, the extensor carpi ulnaris tendon, the pronator quadratus, and the deep radioulnar ligaments. In particular, avulsions of the deep radioulnar ligaments lead to instability and disturbed wrist proprioception. In patients with ulnar-sided pain, a distiction must always be made between clinical instability and generalized laxity. Treatment of instability, in most cases, is open or arthroscopically assisted repair of the triangular fibrocartilage complex. Postoperatively, while a degree of instability can return, symptoms typically do not. Symptom recurrence may be related to generalized joint laxity. Need for reoperation, with a goal of inducing stabilizing scar tissue, is based on severity of symptoms, and experience shows that cases with early onset of recurrent symptoms are more likely to require revision.

There are many techniques that address triangular fibrocartilage complex foveal injuries, which are typically performed with an outside to inside technique. In this article, we describe an inside to outside triangular fibrocartilage complex repair technique that may result in more accurate suture passage and mitigate the risk of fracture from ulna tunnels.

Triangular fibrocartilage complex (TFCC) changes on wrist magnetic resonance imaging (MRI) may occur in patients without corresponding symptoms and examination consistent with TFCC pathology. This study aims to define the rate of asymptomatic TFCC changes in patients undergoing wrist MRI for indications other than ulnar-sided wrist pain and to compare this with the rate in ulnar-sided wrist pain patients.

Patients who underwent wrist MRI at a single large orthopedic practice over a 2-year period were identified by Current Procedural Terminology (CPT) code 73221. Patients with an associated diagnosis, including "hand," "wrist," "radius," "radial," "scaphoid," "navicular," or "De Quervain," were retrospectively reviewed for demographics, symptoms, examination, trauma, and MRI findings. Patients with ulnar-sided wrist pain were used as the comparison group.

Wrist MRIs were available for 132 patients, with 92 in the primary cohort and 40 forming the comparison group. The MRI indications included wrist pain (other than ulnar-sided; 64%), hand/thumb pain (21%), mass (12%), and numbness/tingling (2%). The TFCC MRI changes were seen in 44% of the patients and abnormal TFCC was positively associated with age. In contrast, 80% of the 40 patients with ulnar-sided wrist pain had abnormal TFCC on MRI.

There is a high rate of abnormal TFCC identified on MRI in patients without corresponding ulnar-sided wrist symptoms. This highlights the importance of not treating MRI imaging in isolation without correlating with the patient's symptoms while also preparing patients for a high likelihood of asymptomatic TFCC changes on routine wrist MRI.

Retrospective case series; Level IV.

Elbow stability arises from a combination of bony congruity, static ligamentous and capsular restraints, and dynamic muscular activation. Elbow trauma can disrupt these static and dynamic stabilizers leading to predictable patterns of instability; these patterns are dependent on the mechanism of injury and a progressive failure of anatomic structures. An algorithmic approach to the diagnosis and treatment of complex elbow fracture-dislocation injuries can improve the diagnostic assessment and reconstruction of the bony and ligamentous restraints to restore a stable and functional elbow. Achieving optimal outcomes requires a comprehensive understanding of pertinent local and regional anatomy, the altered mechanics associated with elbow injury, versatility in surgical approaches and fixation methods, and a strategic rehabilitation plan.

This study compared the biomechanical stability of transosseous repair and transosseous combined with capsular repair techniques to reattach the triangular fibrocartilage complex (TFCC) for distal radioulnar joint instability.

Eight adult cadaveric upper-extremity specimens were studied. Each underwent peripheral ulnar-sided detachment of the deep and superficial TFCC fibers and repair. Four groups were prepared sequentially: intact TFCC, disrupted TFCC, transosseous repair, and combined transosseous with capsular repair. Forearm rotational torque was measured in three wrist positions: 60° flexion, neutral position, and 60° extension. Maximum dorsal and palmar ulnar translations in response to a 20-N traction load were measured at nine wrist positions after stabilizing the humerus and radius. Measurements were taken before and after TFCC disruption and following repair.

Clear instability of the radius relative to the ulna was observed after sectioning the deep and superficial fibers of the TFCC, and stability was markedly improved after reconstruction in all positions. Compared with the normal group, rotational torque was similar between the two repair methods. In the pronation palmar flexion and supination dorsal extension positions, dorsal-palmar translation was smaller in the combined transosseous with capsular repair group than in the transosseous repair-alone group.

Triangular fibrocartilage complex deep fibers are the primary stabilizing structure of the distal radioulnar joint. In this cadaveric study, the combined transosseous with capsular repair technique demonstrated less dorsal-palmar translation compared with the transosseous-alone repair technique.

Combined transosseous with capsular repair is expected to provide improved postoperative stability for patients with peripheral TFCC tears and distal radioulnar joint instability.

Lunotriquetral coalitions are the most common form of carpal coalition wherein the cartilage between the lunate and triquetrum ossification centers failed to undergo apoptosis. This technical case report examines the arthrokinematics of bilateral lunotriquetral coalitions with dissimilar Minnaar types in one participant with one asymptomatic wrist and one wrist with suspected distal radioulnar joint injury. Static and dynamic (four-dimensional) CT images during pronosupination were captured using a photon-counting detector CT scanner. Interosseous proximity distributions were calculated between the lunotriquetral coalition and adjacent bones in both wrists to quantify arthrokinematics. Interosseous proximity distributions at joints adjacent to the lunotriquetral coalition demonstrate differences in median and minimum interosseous proximities between the asymptomatic and injured wrists during resisted pronosupination. Altered kinematics from lunotriquetral coalitions may be a source of ulnar-sided wrist pain and discomfort, limiting the functional range of motion. This case report highlights potential alterations to wrist arthrokinematics in the setting of lunotriquetral coalitions and possible associations with ulnar-sided wrist pain, highlighting anatomy to examine in radiographic follow-up. Furthermore, this case report demonstrates the technical feasibility of four-dimensional CT using photon-counting detector technology in assessing arthrokinematics in the setting of variant wrist anatomy.

Triangular fibrocartilage complex (TFCC) injuries are a common cause of ulnar-side wrist pain and may progress to persistent pain, instability of the distal radioulnar joint, and arthritis if left untreated. Diagnosis and management of these injuries requires a nuanced understanding of features pertinent to the clinical presentation, imaging, and arthroscopic findings for accurate management. Arthroscopic-assisted repair techniques have revolutionized surgical management, providing detailed visualization and facilitating the repair of TFCC injuries and associated pathologies with minimally invasive techniques. In this review, we discuss the anatomy of the TFCC, history and examination of ulnar-sided pathology, imaging findings, and classification schemes and review surgical techniques for the treatment of TFCC injuries. We also touch on pearls and pitfalls of the techniques, complications, and results of treatment.

Cartilage injuries of the hand and wrist can be debilitating in the athlete. Diagnosis is difficult given the broad spectrum of presenting symptomatology. History and physical examination is crucial to achieve the correct diagnosis, and advanced imaging can offer helpful assistance to the clinician as well. TFCC injuries and ulnar impaction syndrome are among the most common conditions in athletes with hand and wrist pain. Treatment of these injuries is initially nonoperative, but elite athletes may elect to bypass nonoperative treatment in favor of earlier return to sport. Surgical treatment varies but can include open and arthroscopic methods. The clinician should tailor treatment plans to each athlete based on level of competition, type of sport, and individual preferences and goals.

Background: This study compared clinical outcomes between arthroscopic and open repair of triangular fibrocartilage complex (TFCC) foveal tears in chronic distal radioulnar joint (DRUJ) instability patients. Methods: A total of 79 patients who had gone through foveal repair of TFCC using arthroscopic technique (n = 35) or open technique (n = 44) between 2016 and 2020 were retrospectively analyzed. The visual analog scale (VAS) score for pain, active range of motion (ROM), grip strength, Mayo Modified Wrist Score (MMWS), Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire score, and Patient-Rated Wrist Evaluation (PRWE) score at 2-4-6-12-24 months postoperatively were compared between two groups. Results: Two years after the operation, clinical parameters (VAS, MMWS, DASH, and PRWE), grip strength, and ROM showed significant advancement in the two groups in comparison to their values measured preoperatively (p < 0.001). Nonetheless, we could not identify any statistically significant differences in the above clinical factors between the two groups. The arthroscopic group showed a better flexion-extension arc at 2 months and supination-pronation arc at 2 and 4 months than the open group (p < 0.001). There were no significant differences between the two groups at 2 years postoperatively. Ten patients (12.6%) had recurrent instability (three in the arthroscopic group and seven in the open group, p = 0.499). Similarly, both groups showed no significant difference in the return to work period. Conclusions: Arthroscopic foveal repair of TFCC provided similarly favorable outcomes and early recovery of pain and ROM compared to open repair.

To qualitatively and quantitatively analyze the anatomic features of the insertion of deep radioulnar ligaments (RULs) and provide an anatomic basis for further studies.

The anatomic features of deep RUL insertion were observed macroscopically in 26 cadaveric wrists, after which the size of the deep RUL footprint and distance from the center of the footprint to the ulnar-sided margin of articular cartilage of the ulnar head were each measured. Five specimens were analyzed histologically to examine the attachment of the RUL on the ulna. In addition, we evaluated 21 asymptomatic wrists from healthy volunteers using 3.0 T magnetic resonance imaging.

The insertion of the deep RUL was located mainly on the radial aspect of the ulnar fovea from the foveal center to the articular cartilage. The footprint of the deep RUL appeared in 3 different shapes. The maximal width, length, and area of the footprint of the deep RUL were 3.7 (95% confidence interval [CI], 3.3-4.0) mm, 8.4 (95% CI, 7.9-8.9) mm, and 26.3 (95% CI, 23.4-29.1) mm2, respectively. Histologic analyses showed the attachment of the deep RUL on the radial wall of the fovea exhibited a direct insertion with typical 4-layer structures. The deep RUL fibers formed an acute angle with the distal component of the triangular fibrocartilage complex.

The deep RUL was inserted on the radial side of the ulnar fovea and not the foveal center; it had direct insertion on the radial wall continuous with articular cartilage, and the fibers in the direct insertion formed an acute angle with the distal component of the triangular fibrocartilage complex.

Understanding the quantitative anatomy of the deep RUL insertion may help guide surgeons to perform an anatomic foveal repair of the triangular fibrocartilage complex in its native footprint.

Traumatic foveal tears of the triangular fibrocartilage complex lead to ulnar-sided wrist pain and instability, resulting in painful motion and loss of grip strength with a severe impact on the overall function of the upper limb. Surgical repair is nothing new and has traversed through the realm of open repair to arthroscopic assisted to all arthroscopic repair techniques over the many decades, with arthroscopic repairs showing better visualization, lesser trauma, and equally favorable patient outcomes. Techniques had varied from using trans osseous tunnels to bone anchors, with or without the usage of special jigs. Here, we describe a simple and fast 3 portal arthroscopic technique of repairing the torn foveal insertion of the triangular fibrocartilage complex using a bone anchor inserted under arthroscopic and fluoroscopic guidance into the fovea. Both the dorsal and volar limbs of the triangular fibrocartilage complex are repaired arthroscopically, resulting in a strong anatomic repair resulting in a stable and pain-free wrist.

Triangular fibrocartilage complex injuries are common in amateur and professional sports. These injuries are mainly caused by acute or chronic repetitive axial loads on the wrist, particularly on the ulnar side and in association with rotations or radial/ulnar deviations. In order to treat professional athletes, a detailed specific knowledge of the pathology is needed. Moreover, the clinician should fully understand the specific and unique environment and needs of the athletes, their priorities and goals, the type of sport, the time of the season, and the position played. An early diagnosis and appropriate management with the quickest possible recovery time are the uppermost goals for both the athlete and the surgeon. A compromise between conservative vs surgical indications, athletes' needs and expectations, and financial implications should be achieved. Arthroscopic procedures should be timely planned when indicated as they could allow early diagnosis and treatment at the same time. Conservative measures are often used as first line treatment when possible. Peripheral lesions are treated by arthroscopic repair, whilst central lesions are treated by arthroscopic debridement. Further procedures (such as the Wafer procedure, ulnar osteotomies, etc.) have specific indications and great implications with regard to rehabilitation.

Distal radius fractures are common injuries. Satisfactory outcomes are typically achieved with appropriate nonoperative or operative treatment. A proportion of these injuries develop symptomatic malunions, which may be treated surgically with distal radius corrective osteotomy. A thorough understanding of the anatomy, biomechanics, radiographic parameters, and indications is needed to provide appropriate treatment. Factors, including surgical approach, osteotomy type, use of bone graft, fixation construct, management of associated tendon and/or nerve conditions, soft tissue contracture releases, and need for ulnar-sided procedures, should be considered. A comprehensive evaluation is necessary to guide understanding for when salvage procedures may be preferred.

Background  Traumatic disruption of the triangular fibrocartilage complex (TFCC) is commonly present in various wrist traumas. A variation of surgical techniques is previously developed for different injury patterns. To our knowledge, only a few studies have investigated the fixation of combined foveal and capsular TFCC injuries using the ulnar tunnel technique. Purpose  This prospective cohort study of 21 patients aimed to evaluate the clinical and patient-reported outcome at 2 years of follow-up after arthroscopic TFCC of combined, foveal, and capsular reattachment by modified ulnar tunnel technique. Methods  Pain, grip strength, wrist motion, inclusive rotation, and patient-reported outcomes were assessed pre- and postoperatively at 2 years of follow-up. Results  No complications occurred preoperatively. Pain and patient-reported outcomes improved significantly ( p  < 0.0001 and 0.004). Grip strength improved, but not significantly ( p  = 0.088). The range of motion remained unchanged. All the patients achieved full stability of the distal radioulnar joint. Two patients sustained a new TFCC injury due to a wrist trauma and underwent a reoperation successfully. Two patients experienced complications: one patient experienced tenderness caused by cyst occurrence after PushLock ankers and the second had subluxation of the extensor carpi ulnaris tendon subsheet. Both patients were successfully treated and reoperated on with curettage of the cyst, and reconstruction of the extensor carpi ulnaris retinaculum. All the patients ended with good or excellent satisfaction scores. Conclusion  The ulnar tunnel technique for combined foveal and capsular injuries shows promising short-term follow-up results and high satisfaction scores in the patients. Level of Evidence  II (Prospective Corhorte).

Ulnar styloid fractures commonly occur in the setting of distal radius fractures and often progress to asymptomatic nonunion. Displaced basilar ulnar styloid fractures involving the deep radioulnar ligament attachments may cause distal radioulnar joint (DRUJ) instability. A careful clinical history, physical examination, review of imaging studies, and selected diagnostic interventions are important for confirming the relationship of the ulnar styloid nonunion with ulnar-sided wrist symptoms and/or DRUJ instability. Improved functional and symptomatic outcomes can be achieved with nonunion repair or fragment excision with or without triangular fibrocartilage complex repair, depending on the location and size of the ulnar styloid fracture.

Triangular fibrocartilage complex injuries can cause distal radioulnar joint (DRUJ) instability, which can be evaluated clinically with the DRUJ ballottement test. However, the reliability and validity of the test are unclear. This study aimed to analyze the reliability and validity of the test using a tracking device on healthy participants and patients with triangular fibrocartilage complex injuries.

In this cross-sectional study, three orthopedic hand surgeons performed the DRUJ ballottement test using a technique of holding the carpal bones to the radius on 25 healthy participants (50 hands; 10 men and 15 women; mean age, 33 years; range, 20-51 years) and eight patients with triangular fibrocartilage complex injuries (16 hands; six men and two women; mean age, 43 years; range, 27-59 years). We used a three-dimensional electromagnetic tracking device to quantify the movement of the DRUJ and verify the reliability and validity of the test.

The intrarater and interrater intraclass correlation coefficients for DRUJ movement were 0.77 and 0.61, respectively, and the kappa coefficient for grading of DRUJ instability was 0.79. The correlation coefficient between DRUJ movement measured using the tracking device and instability judged clinically was 0.77. A comparison of healthy participants and the patients showed significantly greater DRUJ movement in the patients.

The test showed substantial intrarater and interrater reliability for assessing DRUJ movement and instability. The significant positive correlation between DRUJ movement and instability indicates the concurrent validity of the test. Moreover, the test showed discriminative validity in identifying mild or moderate DRUJ instability.

The DRUJ ballottement test using the holding technique has a relatively high diagnostic accuracy and can be used to assess DRUJ instability.

Chronic distal radioulnar joint (DRUJ) instability is a complex clinical condition that is difficult to treat. Currently, there is no gold standard treatment. We present a novel technique using Arthrex Mini Tightrope for DRUJ stabilization. In this case series, a 1.6 mm K-wire was passed transversely through the distal ulna and radius. The Mini Tightrope was inserted into the end of the K-wire and pulled through the bone tunnels. Appropriate tension was achieved to stabilize the joint according to individual laxity comparable to the contralateral side. Five patients (3 males and 2 females) comprised this pilot series, with a mean age of 27.1 years. All sustained a traumatic injury at an average of 12.4 months before surgery (range: 5 to 32 mo). In addition, 3 patients had central triangular fibrocartilage complex tears treated with arthroscopy at the time of Mini Tightrope placement. While one patient was lost to follow-up after 7 weeks postoperative due to incarceration, 4 patients demonstrated coronal and sagittal stability in the context of DRUJ motion and a satisfactory range of motion. The mean time for the return to work for the two patients who were laborers or normal activity postoperatively was 5.2 weeks (range: 1 to 16.4 wk). Unrestricted activity was generally allowed 8 weeks postoperatively but varied by patient. The same 4 patients underwent hardware removal at an average of 31 weeks (range: 15 to 44 wk). Although this is only a pilot series, this suggests that temporary Mini Tightrope stabilization of the DRUJ may be a viable solution while upholding the benefits of minimally invasive surgery.

Distal radioulnar joint (DRUJ) instability is a common postoperative complication of distal radius fractures, seriously impacting patients' quality of life. This study investigated its possible influencing factors to determine prognosis and to guide treatment better. We retrospectively included a series of patients with distal radius fractures that underwent volar locking plate fixation. Basic patient information and imaging parameters were collected. The incidence of DRUJ instability during follow-up was recorded, and factors associated with DRUJ instability were determined using univariate analysis and multifactorial logistic regression analysis. A total of 159 patients were enrolled in this study. At 6 months of follow-up, 54 patients (34.0%) had DRUJ instability, and multivariate analysis showed coronal plane displacement (OR, 1.665; 95% CI, 1.091-2.541), fracture classification (OR, 0.679; 95% CI, 0.468-0.984) and DRUJ interval (OR, 1.960; 95% CI, 1.276-3.010) were associated with DRUJ instability after volar locking plate. DRUJ interval, coronal plane displacement, and fracture classification are associated with DRUJ instability during follow-up. Therefore, preoperative risk communication and intraoperative attention to recovering relevant imaging parameters are necessary for these patients.

Isolated distal radioulnar joint (DRUJ) dislocations are referred to as dorsal or volar of neglected isolated volar DRUJ dislocation which was detected at the second dislocations concerning the position of the ulnar head in relationship to the radius. In contrast to large joint dislocations such as a shoulder dislocation, the clinical picture may mimic a simple soft tissue injury and the dislocation may be missed. In this article, we aimed to present a case presentation to the emergency department. Our patient who had no complaint other than wrist pain was diagnosed with volar dislocation on lateral radiography and closed reduction was performed in the emergency department with sedation. There was no recurrence in the follow-up and we achieved a satisfactory result with a painless and unrestricted wrist joint at six months. DRUJ and the ligaments stabilize the joint work in anatomical coordination and play an important role in forearm rotation movement. Traumatic injuries to these structures range from isolated tears to severe fractured dislocations. Isolated DRUJ dislocations are rare. Initial treatment of this injury is closed reduction, post-reduction stability is important and fixation is required in case of instability. Although surgical treatment is performed in cases that cannot be closed reduced and in the presence of instability after reduction, it is possible to obtain successful results in acute cases with closed reduction performed with sedation in emergency departments. For this reason, a conservative approach should be tried before making a surgical decision in these injuries that require special attention in diagnosis.

A 41-year-old female patient sought medical attention due to a malunited distal radius fracture with a positive ulnar variance, experiencing wrist pain and limited range of motion. The patient was successfully treated with an isolated ulnar osteotomy and bone grafting, resulting in significant alleviation of symptoms and improved wrist mobility. Various surgical methods have been proposed to address malunited radius fractures, and ulnar osteotomy has shown promise as an effective technique for such cases.

When evaluating the available literature on the diagnosis and management of triangular fibrocartilage complex tears (TFCC), ulnar tears comprise the major focus of TFCC literature. Radial-sided (Class 1D) tears are seldom researched or discussed. The purpose of this study was to review the methods for identifying and treating radial-sided TFCC lesions, by examining the anatomy of the TFCC, the pathology of its radial portion, diagnostic techniques, and both surgical and nonoperative treatments. The avascular nature of the radial TFCC may influence its healing potential. Magnetic resonance arthrogram is the gold standard for non-invasively diagnosing a radial-sided tear. Non-operative management should be exhausted prior to surgical intervention, which commonly involves an inside-out repair involving radial trans-osseous sutures. Still, the literature is limited by patient sample size and therefore requires a greater population of class 1-D tears to confirm optimal diagnostic and treatment methods.

The triangular fibrocartilage complex (TFCC) is composed of dorsal and palmar radioulnar ligaments (RULs). A common injury pattern of the RUL is the avulsion of the ulnar insertion, which can be treated by arthroscopic or open repair. Although the general method of TFCC reconstruction is a tendon graft with a bone tunnel, detailed information regarding the radial attachment of the RUL is unclear. This study aimed to clarify the morphology of the radial attachments of the palmar radioulnar ligament (PRUL), dorsal radioulnar ligament (DRUL), and short radiolunate ligament (SRL) using three-dimensional imaging.

A total of 29 upper limbs (16 formalin-fixed and 13 embalmed by Thiel's embalming method) of Japanese cadavers were used. After gross observation, we marked the attachments of the PRUL, DRUL, and SRL using 0.7-mm diameter pins. We created three-dimensional images of the radius, outlining the PRUL, DRUL, and SRL attachments. The software application calculated the centers of the PRUL and DRUL attachments.

The PRUL attachment was horizontally shaped. The center of the PRUL was 1.5 mm proximal and 5.8 mm radial to the tip of the palmar pyramid formed by the palmar cortex and the radioulnar and radiocarpal joint surfaces. The DRUL attachment was vertically shaped. The center of the DRUL was 2.0 mm proximal and 1.7 mm radial from the tip of the dorsal pyramid formed by the dorsal cortex and the radioulnar and radiocarpal joint surfaces. The length of the SRL was 9.2 mm. The SRL and PRUL were strongly conjoined.

The anatomical center on the RUL attachment of the radius can be determined from osseous landmarks.

The findings of this study contribute to the understanding of RUL attachment to the distal radius and may assist surgeons in performing anatomical reconstruction of TFCC.

Most partial hand amputees experience limited wrist movement. The limited rotational wrist movement deteriorates natural upper limb system related to hand use and the usability of the prosthetic hand, which may cause secondary damage to the musculoskeletal system due to overuse of the upper limb affected by repetitive compensatory movement patterns. Nevertheless, partial hand prosthetics, in common, have only been proposed without rotational wrist movement because patients have various hand shapes, and a prosthetic hand should be attached to a narrow space.

We hypothesized that partial hand amputees, when using a prosthetic hand with a wrist rotation module, would achieve natural upper limb movement muscle synergy and motion analysis comparable to a control group. To validate the proposed prototype design with the wrist rotation module and verify our hypothesis, we compared a control group with partial hand amputees wearing hand prostheses, both with and without the wrist rotation module prototype. The study contained muscle synergy analysis through non-negative matrix factorization (NMF) using surface electromyography (sEMG) and motion analyses employing a motion capture system during the reach-to-grasp task. Additionally, we assessed the usability of the prototype design for partial hand amputees using the Jebsen-Taylor hand function test (JHFT).

The results showed that the number of muscle synergies identified through NMF remained consistent at 3 for both the control group and amputees using a hand prosthesis with a wrist rotation module. In the motion analysis, a statistically significant difference was observed between the control group and the prosthetic hand without the wrist rotation module, indicating the presence of compensatory movements when utilizing a prosthetic hand lacking this module. Furthermore, among the amputees, the JHFT demonstrated a greater improvement in total score when using the prosthetic hand equipped with a wrist rotation module compared to the prosthetic hand without this module.

In conclusion, integrating a wrist rotation module in prosthetic hand designs for partial hand amputees restores natural upper limb movement patterns, reduces compensatory movements, and prevent the secondary musculoskeletal. This highlights the importance of this module in enhancing overall functionality and quality of life.

Following injury to the Triangular Fibrocartilage Complex (TFCC), foveal repair surgery may be indicated to restore joint stability and function. Protection of the repaired ligament is a clinical consideration during post-surgical rehabilitation, although no "gold standard" rehabilitation protocol currently exists.

To describe the professional opinions of Accredited Hand Therapists (AHT) regarding post-operative rehabilitation recommendations following TFCC foveal repair surgery.

Cross-sectional descriptive study.

All Australian AHTs were invited to complete a quantitative, online, 10-item survey between December 2019 and March 2020. The survey included questions regarding clinical recommendations for wrist and forearm immobilization, range of motion and exercise methods, and timeframes. AHT characteristics and experience of patients sustaining a TFCC re-rupture were also collected. Categorical and nominal survey responses were reported descriptively and effects of AHT characteristics on survey responses were assessed using Pearson Chi2, with significance set to <0.05.

Survey responses were received from 135 AHTs or approximately 37% of the available population at the time of completion (March 2020). Recommendations for post-surgery immobilization ranged from "not required" to 8 weeks, 6 weeks representing the most common answer. Wrist and forearm range of motion commencement time ranged from "immediately" to "later than 8 weeks," with 6 weeks also the most common answer. When asked whether post-surgery rupture had been experienced in their respective patient groups, 15 therapists (11%) indicated "Yes." The most recommended thermoplastic orthosis was a Sugartong orthosis (41%) followed by a Muenster orthosis (30%), both of which immobilizes the wrist and forearm.

Rehabilitation varied widely between AHTs. Further prospective research is recommended to explore whether patient-related or rehabilitation factors influence outcomes following TFCC repair.

Triangular fibrocartilage complex (TFCC) injuries are categorized most commonly by the Palmer and the Atzei and Luchetti classifications. Combined tears are reported less frequently, and the classification of these tears is unclear. In this study, we present a series of patients with combined central disc and foveal TFCC tears that do not fit into either of these classifications.

Seventeen patients from 2 institutions presented with a combined central and foveal TFCC tear, confirmed by wrist arthroscopy between September 2017 and December 2020. Patient demographics, injury mechanism, associated injuries, clinical findings, magnetic resonance imaging results, surgeon description of tears, and treatment rendered were evaluated.

Patients were predominantly female (76%). Mean age was 40 years with a bimodal age distribution (7/17 patients <35 and 10/17 >45 years). Eleven patients (65%) sustained the injury from a fall. All had some degree of distal radioulnar joint (DRUJ) instability on clinical examination and almost half (8/17) had a history of a distal radius or ulnar styloid fracture during the initial injury. The foveal tear was confirmed by direct visual assessment and a positive hook test result; a suction test result commonly was positive as well. All patients underwent debridement of the central tear, and 16 of 17 underwent foveal TFCC repair with 1 having an irreparable tear.

We present a series of patients with combined central disc and foveal TFCC tears, a pattern that does not fit current classification schemes. All patients exhibited some degree of instability of the DRUJ and almost half had a history of distal radius or ulnar styloid fracture. Identification of a central tear of the TFCC, together with even subtle DRUJ instability, should lead to consideration of a coexistent foveal tear.

Diagnostic IV.

The ulnar shortening osteotomy (USO) is a common procedure used to treat ulnar impaction syndrome secondary to static or dynamic ulnar-positive variance. There are many described techniques for the USO. The distal metaphyseal ulnar shortening osteotomy (DMUSO) with retrograde cannulated screw fixation was described to reduce complications seen with other techniques. Biomechanical analysis of fixation constructs demonstrates 2-screw constructs are significantly stiffer than 1 screw and antegrade constructs have similar or greater stiffness when compared with retrograde constructs. Here, we describe a technique of antegrade cannulated screw fixation for DMUSO that obviates the need for the disruption of the distal radioulnar joint for intra-articular exposure of the ulnar head. Similar to the traditional retrograde DMUSO technique, this construct may also decrease the risk of delayed union, symptomatic implants associated with diaphyseal osteotomies, and disruption of triangular fibrocartilaginous complex in wafer procedures.

The purpose of this agreement was to establish evidence-based consensus statements on imaging of distal radioulnar joint (DRUJ) instability and triangular fibrocartilage complex (TFCC) injuries by an expert group using the Delphi technique.

Nineteen hand surgeons developed a preliminary list of questions on DRUJ instability and TFCC injuries. Radiologists created statements based on the literature and the authors' clinical experience. Questions and statements were revised during three iterative Delphi rounds. Delphi panelists consisted of twenty-seven musculoskeletal radiologists. The panelists scored their degree of agreement to each statement on an 11-item numeric scale. Scores of "0," "5," and "10" reflected complete disagreement, indeterminate agreement, and complete agreement, respectively. Group consensus was defined as a score of "8" or higher for 80% or more of the panelists.

Three of fourteen statements achieved group consensus in the first Delphi round and ten statements achieved group consensus in the second Delphi round. The third and final Delphi round was limited to the one question that did not achieve group consensus in the previous rounds.

Delphi-based agreements suggest that CT with static axial slices in neutral rotation, pronation, and supination is the most useful and accurate imaging technique for the work-up of DRUJ instability. MRI is the most valuable technique in the diagnosis of TFCC lesions. The main indication for MR arthrography and CT arthrography are Palmer 1B foveal lesions of the TFCC.

MRI is the method of choice for assessing TFCC lesions, with higher accuracy for central than peripheral abnormalities. The main indication for MR arthrography is the evaluation of TFCC foveal insertion lesions and peripheral non-Palmer injuries.

• Conventional radiography should be the initial imaging technique in the assessment of DRUJ instability. CT with static axial slices in neutral rotation, pronation, and supination is the most accurate method for evaluating DRUJ instability. • MRI is the most useful technique in diagnosing soft-tissue injuries causing DRUJ instability, especially TFCC lesions. • The main indications for MR arthrography and CT arthrography are foveal lesions of the TFCC.

Background  Wrist arthroscopy has become increasingly popular for diagnosing and treating traumatic wrist injuries. How wrist arthroscopy has influenced the daily practice of wrist surgeons remains unclear. The objective of this study was to evaluate the role of wrist arthroscopy for the diagnosis and treatment of traumatic wrist injuries among members of the International Wrist Arthroscopy Society (IWAS). Methods  An online survey was conducted among IWAS members between August and November 2021 with questions regarding the diagnostic and therapeutic importance of wrist arthroscopy. Questions focused on traumatic injuries of the triangular fibrocartilage complex (TFCC) and scapholunate ligament (SLL). Multiple-choice questions were presented in the form of a Likert scale. The primary outcome was respondent agreement, defined as 80% answering similarly. Results  The survey was completed by 211 respondents (39% response rate). The majority (81%) were certified or fellowship-trained wrist surgeons. Most respondents (74%) had performed over 100 wrist arthroscopies. Agreement was reached on 4 of the 22 questions. It was agreed that the outcomes of wrist arthroscopy strongly depend on surgeons' experience, that there is sufficient evidence for the diagnostic purposes of wrist arthroscopy, and that wrist arthroscopy is better than magnetic resonance imaging (MRI) for diagnosing TFCC and SLL injuries. No agreement was reached on the preferred treatment of any type of TFCC or SLL injury. Conclusion  There is agreement that wrist arthroscopy is superior to MRI for diagnosing traumatic TFCC and SLL injuries, yet experts remain divided on the optimal management. Guidelines need to be developed for the standardization of indications and procedures. Level of Evidence  This is a Level III study.

Key step of arthroscopic triangular fibrocartilage complex (TFCC) foveal reattachment is to suture dorsal and palmar deep components of radioulnar ligaments (RULs) to the fovea of ulnar head to ensure distal radioulnar joint stability. However, the deep components are covered and cannot be identified arthroscopically from standard radiocarpal joint view. Suturing sites described in previous studies have not been proved gasping of the deep components. The purpose of this study was to investigate our TFCC suture locations using relevant landmarks on securing the RULs' deep components for arthroscopic TFCC foveal reattachment.

Wrist arthroscopy and horizontal mattress suture was performed in 20 fresh-frozen cadaver wrists. Based on close proximity of the ulnocarpal ligaments to the palmar RUL and fovea, palmar suture location was designated at the junction between ulnolunate, ulnotriquetral ligaments and palmar border of TFCC disc, whereas dorsal suture location was at dorsal border of TFCC disc, opposite the palmar location, at same distance between prestyloid recess and palmar location. The radiocarpal and ulnocarpal joint was subsequently opened to evaluate grasping of RULs' deep components and evaluate the relevant landmarks.

Thirty-nine of 40 (97%) RULs' deep components were successfully grasped by the sutures. With 0.98-0.99 interobserver agreement for the measurements, mean distance between sigmoid notch to suture and suture to ulnar capsule were 5.6 ± 1.1 and 4.0 ± 0.9 mm, respectively. Whereas, the dissecting point of deep component from the superficial component of the RULs was detected immediately radial to the midpoint between the sigmoid notch and the ulnar capsule (4.5 ± 0.9 mm from sigmoid notch).

We determined the relevant anatomical landmarks to navigate the TFCC suture locations, which reliably secure the deep components of the radioulnar ligaments for the arthroscopic TFCC foveal reattachment.

The ulnar positive variance (UPV) can be observed on simple radiography due to a triangular fibrocartilage complex (TFCC) foveal tear. This study investigated to identify how much radiographic UPV occurs due to a TFCC foveal tear, which may be misdiagnosed as an ulnar impaction syndrome (UIS).

One hundred forty patients who underwent arthroscopic transosseus TFCC foveal repair from March 2013 to March 2019 in our institution were enrolled in this study. Ulnar variances were measured in preoperative, postoperative 6 weeks, 1-year follow-up wrist posteroanterior (PA) radiograph, and power grip PA radiograph of the affected wrist and were compared with those of the same patient's unaffected wrist.

In the neutral wrist PA radiograph, ulnar variance increased by 0.56 mm (p < 0.001) after TFCC foveal tear compared to the unaffected side. In the power grip view, ulnar variance also increased by 0.39 mm (p < 0.001) in the affected wrist. The preoperative ulnar positive variance was reduced after an arthroscopic transosseous TFCC foveal repair from 0.56 to 0 mm (p < 0.001). No significant statistical difference was observed between an Atzei class 2 and 3 TFCC tear (0.56 mm vs. 0.41 mm, p = 0.263).

This study revealed that TFCC foveal tear induces 0.56 mm of radiologic UPV, which was successfully corrected after arthroscopic transosseous TFCC foveal repair. Therefore, UPV associated with TFCC foveal tear should not be misdiagnosed as an UIS. Also, when ulnar shortening osteotomy is planned in case of UIS combined with TFCC foveal tear, the amount of UPV induced by TFCC foveal tear should be considered to prevent over-shortening.

Arthroscopically assisted techniques for the treatment of foveal triangular fibrocartilage complex (TFCC) injuries offer a less invasive option. Reports of the ulnar tunnel technique on a larger patient population are needed. This prospective cohort study of 44 patients aimed to evaluate the clinical and patient-reported outcome after arthroscopic foveal re-attachment using a novel, modified ulnar tunnel technique. Furthermore, preoperative magnetic resonance imaging findings were compared with the findings from the arthroscopic evaluation. History of ulnar sided wrist pain, positive fovea-sign at the clinical examination and positive hook test at the surgery were the main inclusion criteria for the study. Pain, grip strength, wrist motion and patient-reported outcomes were assessed pre-and postoperatively. The follow-up of this study was 31 months (range 18-48). No complications occurred during the surgery. All outcomes improved besides the range of motion, which remained unchanged. Pain on a visual analogue scale was 63 before, and 14 after the surgery (p = .0004). Pre- and postoperative values of Disability of Arm, Shoulder and Hand Questionnaire were 41/6, respectively (p = .007). Grip strength, measured in Kilogram-force were 29 and 36, pre-and postoperatively (p = .0004). Conspicuously, all patients achieved stability. Six patients needed re-operation, three for renewed injury. Thirty-nine of 44 patients scored excellent or good on the satisfaction score. We found the devised method to be with fewer complications and with favourable results compared with other techniques for the treatment of TFCC injuries. Level of evidence: III.

Injury to the triangular fibrocartilage complex (TFCC) may result in ulnar wrist pain with or without instability. One component of the TFCC, the radioulnar ligaments, serve as the primary soft-tissue stabilizer of the distal radioulnar joint (DRUJ). Tears or avulsions of its proximal, foveal attachment are thought to be associated with instability of the DRUJ, most noticed during loaded pronosupination. In the absence of detectable instability, injury of the foveal insertion of the radioulnar ligaments may be overlooked. While advanced imaging techniques such as MRI and radiocarpal arthroscopy are well-suited for diagnosing central and distal TFCC tears, partial and complete foveal tears without instability may be missed without a high degree of suspicion. While technically challenging, DRUJ arthroscopy provides the most accurate method of detecting foveal abnormalities. In this annotation the spectrum of foveal injuries is discussed and a modified classification scheme is proposed.Cite this article: Bone Joint J 2023;105-B(1):5-10.

To determine whether clinical outcomes of arthroscopic one-tunnel wrist triangular fibrocartilage complex (TFCC) transosseous suture repair are not diminished in cases of ulnar styloid process fracture nonunion (USPFN).

Patients who underwent arthroscopic 1-tunnel transosseous suture repair of Palmer 1B foveal TFCC tear (with/without superficial fiber tear; Atzei class 2 or 3 TFCC tear) from 2015 to 2020 were retrospectively reviewed. Group I was the TFCC foveal tear repair group with USPFN. Group II was the TFCC foveal tear repair group without USPFN. In group I, no additional treatment for USPFN was made. Functional preoperative and postoperative outcomes were compared by Modified Mayo Wrist Score (MMWS); Quick Disabilities of the Arm, Shoulder, and Hand (Quick-DASH) score; grip strength; pain visual analog scale (VAS); and distal radioulnar joint (DRUJ) stability. Wrist posteroanterior, lateral, and both oblique views of the wrist were used to assess the ulnar styloid process before and after operation.

This study consisted of 66 patients: group I (n = 22) and group II (n = 44). No differences were found between the 2 groups preoperatively in MMWS, Quick-DASH, grip strength, and VAS (MMWS: P = .94, Quick-DASH: P = .23, grip strength: P = .69, VAS: P = .45). No differences were found between the 2 groups with respect to outcome measures postoperatively in MMWS, Quick-DASH, grip strength, and VAS (MMWS: P = .59, Quick DASH: P = .82, grip strength: P = .15, VAS: P = .84). All of the enrolled patients achieved restored function with negative ballottement test and maintained DRUJ stability on follow-up. Of the 22 USPFN cases in group I, 11 (50%) showed spontaneous union after transosseous TFCC foveal repair without any additional USPFN treatment. The proportion of patients achieving a minimal clinically important difference for the Quick-DASH was similar between the 2 groups.

Although this current study has insufficient statistical power, the available data suggest that patients with TFCC foveal tear combined with USPFNs treated with arthroscopic transosseous repair surgery could experience similar functional improvement compared with those with TFCC foveal tear without USPFNs. The presence of USPFN accompanied by Palmer 1B type TFCC foveal tear may not affect the clinical results, including MMWS, Quick-DASH, grip strength, VAS, and DRUJ stability of patients who undergo arthroscopic 1-tunnel transosseous suture repair.

Level III, retrospective comparative study.

Scoping review.

Rehabilitation guidelines following triangular fibrocartilage complex (TFCC) foveal repair surgery have been inconsistently reported in the published literature, with no consensus regarding wrist or forearm range of motion (ROM) commencement time.

To scope the available literature to identify the extent and strength of the evidence supporting the clinical guidelines for wrist and forearm ROM commencement time following primary TFCC foveal repair surgery.

A systematic search produced 26 studies (3 retrospective cohort studies, 1 prospective cohort study, 1 retrospective comparative study, and 21 retrospective case series) that described specific rehabilitation protocols following TFCC foveal repair surgery.

No supporting evidence was identified regarding rehabilitation protocol recommendations across all the included studies. Postsurgery wrist ROM commencement ranged from 2 to 8 weeks; forearm ROM commencement ranged from 2 to 12 weeks. ROM commencement times did not appear to systematically influence the rate of adverse events, although adverse events were poorly reported.

TFCC rehabilitation protocols were poorly reported and varied widely between the included studies. Additional research is recommended to comprehensively evaluate the association between wrist and/or forearm ROM and the rate of adverse events for this complex and multifaceted condition.

We performed ordinary ulnar shortening osteotomy (USO) in patients younger than 18 years old with secondary ulnar impaction syndrome (UIS) after traumatic events. Here, we report the clinical and radiologic outcomes with a review of the previous literature through a retrospective case series.

Twenty-two adolescents treated by USOs from 2006 to 2018 were investigated. The amount of shortening was classified into three categories. The first category was for a still open physis on the medial half of the radius in those younger than 15. In this category, we osteotomized the ulna for the physis level to be left neutral or negative by 1-2 mm. The second category had no growth potency in the radius. If the patient was younger than 15, we considered only residual growth of the ulna, thus performing USO for the ordinary UV to be negative by 2-3 mm. For patients aged 15-18 years old, if growth potency was nearly absent in the ulna, we performed traditional USO with a neutral ulnar variance (UV).

Categories 1, 2, and 3 for the amount of USO were determined for 4, 4, and 14 patients, respectively. All USOs properly healed without substantial complications. The mean preoperative UV was 2.91 mm, and the final value decreased to 0.23 with statistical significance (p < 0.001). The range of wrist motion was improved after USO from 133.86° and 132.73° to 154.77° and 160.68° (all, p < 0.001 in flexion-extension and pronation-supination arcs, respectively). The preoperative VAS and MMWS scores also improved from 2.77 to 75.00 to 0.18 and 88.86, respectively, at the final follow-up (all, p < 0.001).

UIS in adolescent populations after trauma in their children/younger adolescents could be properly treated by USO. Even with an open physis at the ulna, neutral UVs could be achieved, and the clinical outcomes were satisfactory. However, long-term follow-up is still needed regarding TFCC and DRUJ status.

Level IV, retrospective case series.

Distal oblique bundle (DOB) reinforcement for treatment of post-traumatic bidirectional instability of the distal radioulnar joint (DRUJ) has previously been reported. The objective of the current study was to assess the incidence of symptomatic graft failure and the need for secondary wrist procedures at a longer follow-up in an updated patient cohort of 27 patients with 28 DOB reinforcement procedures. Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) and patient-rated wrist/hand evaluation (PRWHE) outcome measures were also evaluated. At median 82 months follow-up, pre- to postoperative QuickDASH score improved from a mean of 62 (SD 14) to 31 (SD 22) (p < 0.01) and PRWHE score from a mean of 67 (SD 17) to 34 (SD 23) (p < 0.01). Symptomatic graft failure with resultant painful DRUJ instability occurred in four out of 28 procedures, which was better than the published results of alternative surgical options for DRUJ instability. DOB reinforcement presents a relatively safe, effective and durable method for treatment of post-traumatic DRUJ instability.Level of evidence: III.

Arthroscopic and open surgical procedures are commonly used to repair distal radioulnar joint (DRUJ) instability. Both may result in patient dissatisfaction and recurrence of DRUJ instability. An alternative treatment that yields improved outcomes is a limited open approach using a bone anchor to support the DRUJ.

A retrospective chart review of 58 patients (59 extremities) aged 18 to 60 years with type 1B Palmer rupture (3 months or more after injury) of the triangular fibrocartilage complex (TFCC) without distal radius fracture was conducted. Inclusion criteria are: 3 to 12 months after injury, clinical DRUJ instability, and minimum of 6 months of postoperative follow-up. Operative fixation with Stryker Sonic or Depuy Mitek anchor was done by the same surgeon using a limited open procedure. Preoperative and postoperative assessments included Disability of the Arm, Shoulder, and Hand; Brief Pain Inventory; Wong-Baker FACES Pain Rating Scale; Numeric Pain Scale; range of motion; and recurrence of instability. A multivariate analysis of variance model was fit to imputed data to assess the effect of both anchors.

Clinical and statistical differences were found in preoperative and postoperative assessments for either the Stryker Sonic or the Depuy Mitek anchor but not between anchor types. There was no recurrence after 3 years with either anchor.

Patients requiring TFCC repair using the Stryker Sonic or Depuy Mitek anchor experienced: (1) significant clinical and statistical improvement in postoperative assessments; (2) patient satisfaction; and (3) corrected DRUJ instability. Consequently, major determinants in deciding which bone anchor to use may be based on cost or surgeon's preference.

This study aimed to investigate the optimal tension for the reconstruction of the distal radioulnar ligaments (DRULs) in the treatment of the distal radioulnar joint (DRUJ) instability.

A total of eight human cadaver upper extremities were used. First, the Tekscan sensor film system was used to measure the contact characteristics of the intact DRUJ. Following this, the DRULs were resected, and the measurement was repeated. The DRULs were then reconstructed according to Adams' procedure, and the contact forces under different initial tension were compared with that of the intact group to obtain the optimal tension. At that point, the contact force of the DRUJ was close to normal. The reliability of the obtained tension was verified by translational testing, which reflected the stability of the DRUJ.

In the neutral position, the contact force, area, and pressure inside DRUJ were 0.51 ± 0.10 N, 64.08 ± 11.58 mm², and 8.33 ± 2.42 kPa, respectively. After the DRULs were resected, they were 0.19 ± 0.02 N, 41.75 ± 5.01 mm², and 4.86 ± 1.06 kPa, respectively. The relationship between the tension and contact force was linear regression (Y = 0.0496x + 0.229, R² = 0.9575, P < 0.0001). According to the equation, when the tension was 3.64-7.68 N, the contact force was close to normal. There was no statistical difference in the stability of the reconstructed DRUJ under this tension compared with the intact group (P = 0.08).

By comparing the contact forces under different reconstruction tensions with the normal value, we obtained the optimal tension, which can provide the theoretical basis for the clinical treatment of chronic DRUJ instability.

Clinical studies suggest that even untreated basal ulnar styloid fractures may not affect patient outcomes. This may be due to the remaining parts of the distal radioulnar ligament still attached providing sufficient residual stability of the distal radioulnar joint. We tested this hypothesis in a biomechanical cadaveric model. Dorsopalmar translation of the distal radioulnar joint and forearm rotation were measured. Seventeen specimens were tested after a simulated ulnar styloid fracture including the fovea, followed by transection of the remaining palmar (n = 9) or dorsal (n = 8) portions of the distal radioulnar ligament and finally with all remnants transected. Rotation and translation both increased significantly after the final transection compared with the foveal fracture. The increase in translation was larger after transection of the dorsal remnants. We conclude that in an ulnar styloid fracture including the fovea, some ligament components are still attached to the ulnar head, giving residual stability to the distal radioulnar joint.

To compare the clinical outcomes of arthroscopically-assisted suture anchor repair and transosseous sutures for repair of foveal triangular fibrocartilage complex tears in patients with distal radioulnar joint (DRUJ) instability.

Sixty patients with triangular fibrocartilage complex foveal detachment associated with DRUJ instability were prospectively recruited and randomized into 2 equal groups-the anchor repair group and the transosseous repair group. The primary outcome was DRUJ function after 2 years, which was assessed by the DRUJ evaluating system. The secondary outcomes were grip strength, visual analog scale for pain, Mayo Modified Wrist ScorePatient-Rated Wrist Evaluation score, and the Disabilities of the Arm, Shoulder, and Hand score.

There were no significant differences between the groups for any of the outcome measures. Good-to-excellent outcomes (according to the DRUJ evaluation system) were achieved in 27 (90%) patients in the anchor repair group and 26 (86.7%) patients in the transosseous repair group. Fewer complications were observed in the anchor repair group.

Both techniques yielded good and comparable outcomes with a lesser incidence of early complications in the anchor repair group.

Therapeutic II.

To evaluate the outcomes of "tent form" triangular fibrocartilage complex (TFCC) repair combined with dorsal distal radioulnar joint (DRUJ) capsule imbrication for posttraumatic chronic DRUJ instability.

All patients treated with arthroscopic "tent form" TFCC repair and DRUJ capsule imbrication from 2016 to 2019 were retrospectively reviewed. The inclusion criteria were symptomatic chronic DRUJ instability for >6 months and dorsal DRUJ subluxation on magnetic resonance imaging. The Disabilities of the Arm, Shoulder, and Hand score, Patient-Rated Wrist Evaluation, grip strength, Modified Mayo Wrist Score, range of motion, and distal radioulnar joint stability were assessed for a minimum of 2 years postoperatively.

Thirty-eight patients were included in the final analysis. The average follow-up duration was 35.6 months (range, 24-48 months). The 24-month postoperative grip strengths and 3-dimensional motions of wrist were not significantly different from that of the nonoperated wrist. Compared with their preoperative status, Disabilities of the Arm, Shoulder, and Hand score, Patient-Rated Wrist Evaluation, and Modified Mayo Wrist Score indicated the significant improvement with P values of .001, .001, and .002, respectively.

In chronic DRUJ instability with a loosening dorsal capsule, "tent form" TFCC transcapsular repair combined with DRUJ capsule imbrication restored the integrity of TFCC and dorsal DRUJ capsule and achieved a promising outcome. We recommend this procedure as an option of treatment for patients with posttraumatic chronic DRUJ instability.

IV, case series.

The purpose of this study was to investigate whether a watch-shaped external wrist band brace improves distal radioulnar joint (DRUJ) stability. Seven fresh cadaveric arms were used. Using a customized testing system, volar and dorsal translation forces were applied to the radius externally while the ulna was fixed. The test was performed with the forearm in neutral, 60° pronated, and 60° supinated positions, once without the brace and once with the brace applied. In each condition, the amount of translation was measured. Then, the triangular fibrocartilage complex (TFCC) was detached from the ulnar styloid process and the fovea ulnaris, and the same tests were performed again. Detachment of the TFCC significantly increased volar and dorsal translations in all forearm rotations compared to the intact condition (p < 0.05), except for the pronated dorsal translation of the radius (p = 0.091). Brace application significantly reduced volar and dorsal translations in all forearm rotations both in intact specimens and in TFCC-detached specimens (p < 0.05), except for pronated volar and dorsal translations in TFCC-detached specimens (p = 0.101 and p = 0.131, respectively). With the brace applied, the TFCC-detached specimens showed no significant difference in volar or dorsal translation in all forearm rotations compared to the intact specimens (p > 0.05). The external wrist band brace improved DRUJ stability in both normal and TFCC-torn wrists and reduced the DRUJ instability caused by TFCC tear to a near-normal level.

Background: Symptomatic ulnar styloid non-union can be treated by excision of the ulnar styloid fragment. For combined triangular fibrocartilage complex (TFCC) tears, several repair techniques such as arthroscopic repair, open repair to the fracture site or reconstruction using a tendon graft have been introduced. This study reports the technique and outcomes of open foveal repair of the TFCC with excision of the ulnar styloid fragment in patients with symptomatic ulnar styloid non-union and distal radioulnar joint (DRUJ) instability. Methods: Consecutive patients with symptomatic ulnar styloid non-union with TFCC tears and DRUJ instability who underwent excision of the ulnar styloid fragment and open foveal repair of the TFCC were retrospectively reviewed. After excising the ulnar styloid fragment, a capsular window was created between the triquetrum and TFCC, followed by attaching the TFCC to the fovea using three sutures through a bone tunnel from the ulnar cortex to the fovea. Additional ulnar shortening osteotomies were performed in patients with positive ulnar variance and ulnar impaction test. The outcomes were evaluated in terms of DRUJ stability and the Quick Disabilities of the Arm, Shoulder and Hand (DASH) scores. Results: In total, 21 patients with a mean age of 40 were enrolled in the study. All patients demonstrated DRUJ stability at a mean follow-up duration of 14 months. The mean Quick DASH score significantly improved from 18.9 ± 11.7 to 2.5 ± 4.1 (p < 0.05). Eleven patients underwent combined ulnar shortening osteotomies, and no difference in the Quick DASH score was found between patients who underwent ulnar shortening osteotomy and those who did not. Conclusions: This study demonstrates that open foveal repair of the TFCC with ulnar styloid fragment excision is an effective strategy to surgically treat patients with symptomatic ulnar styloid non-union with TFCC tear and DRUJ instability. Level of Evidence: Level III (Therapeutic).