Treatment of Dynamic Scaphoid Instability

Comparison of Outcomes of Scapholunate Ligament Reconstruction Techniques

Introduction  Injury to the scapholunate interosseous ligament (SLIL) is a common cause of carpal instability, yet surgical management of chronic SLIL disruption remains challenging with no optimal technique identified. Purpose  The purpose of this meta-analysis was to comparatively review the available evidence of clinical, radiographic, and patient-reported outcome measures among popular techniques of SLIL reconstruction (capsulodesis, tenodesis, and bone-tissue-bone graft) to better guide management of SLIL injuries. Methods  A total of 1,172 patients from 42 included studies were assessed. Standardized data extraction and analysis were performed. The mean of postoperative outcome assessments with standard deviation was used to calculate pooled standardized mean difference with 95% confidence interval. Results  Visual Analog Scale (VAS) score for postoperative pain was lowest in bone-tissue-bone patients at 0.9 ( p  = 0.0360). Bone-tissue-bone patients had the highest percentage of "excellent" functional outcomes at 64.5% ( p  < 0.0001). Disabilities of the Arm, Shoulder, and Hand (DASH)/QuickDASH score was best in bone-tissue-bone patients at 9.7 ( p  < 0.0001). Patient-Rated Wrist Evaluation (PRWE) score was best in tenodesis patients at 37.8 ( p  = 0.0255). There were no statistically significant differences in grip strength, range of motion, or radiographic outcomes among the techniques. Conclusion  Existing data demonstrate some benefit of bone-tissue-bone reconstruction over capsulodesis and tenodesis in pain reduction and functional improvement of the injured wrist. No statistically significant differences among radiographic outcomes could be ascertained, possibly attributable to the heterogeneity of procedures. This review provides an updated reference and highlights the need for multicenter trials with longer term follow-up and more standardized outcome measures.

Long-term Results of the Treatment of Scapholunate Instability with Dynamic Extensor Carpi Radialis Brevis Tenodesis

Scapholunate dissociation is the most common form of carpal instability. This retrospective case series aimed to assess long-term results obtained by treating scapholunate instability with dynamic tenodesis using the entire extensor carpi radialis brevis tendon, which is detached from the base of the third metacarpal, rerouted in the third extensor compartment, and fixed at the distal portion of the scaphoid to maintain reduced rotatory subluxation.

Methods

Nine patients with scapholunate instability were treated. We reviewed eight patients with a mean follow-up of 12 years. One subgroup of four patients was affected by static scapholunate instability, and the other by dynamic scapholunate instability. Disability of the Arm, Shoulder, and Hand score, Patient Rated Wrist Evaluation score, modified Mayo score, and radiographs were used to determine functional and anatomical outcomes.

Results

Excellent functional results did not correlate with radiological outcome in patients with static scapholunate instability. In this subgroup, scapholunate angle and gap and radiolunate angle improved in average but remained in the pathologic range. In only one of these patients, osteoarthritis was observed. In the subgroup of patients affected by dynamic instability, very good functional outcomes correlate with radiological results, except in one patient who developed arthritic changes.

Conclusions

Dynamic tethering of the scaphoid with the extensor carpi radialis brevis tendon might be indicated in the treatment not only in patients affected by dynamic scapholunate instability but also in patients with static instability. Prospective studies with a larger number of patients are required to evaluate this method.

Dynadesis for Treatment of Dynamic Scaphoid Instability with 20-Year Results

Background  Even though the scapholunate interosseous ligament is the most common wrist ligament injury, its treatment remains a challenge for hand surgeons. We report on a surgical treatment (Dynadesis) for dynamic scaphoid instability (DSI) with a 20-year follow-up period. Description of Technique  Dynadesis utilizes antagonist forearm muscles in order to synergistically provide dynamic stabilization to the scaphoid when the wrist is loaded. It is a tendon-to-tendon transfer with the following two components: 1) Dorsal-The extensor carpi radialis longus (ECRL) is passed through a hole in the reduced, distal scaphoid, providing the scaphoid with an independent extension force. 2) Volar-A dynamic checkrein is created by tension-locking the ECRL tendon around the flexor carpi radialis (FCR) tendon. The portion of the FCR distal to the scaphoid tethers and tightens with contracture of the ECRL and FCR muscles. Patients and Methods  Twenty patients (21 wrists) were treated with Dynadesis and reevaluated 20 years later (range: 20-27 years). Results  Average grip strength improved by 8 kg. The average wrist flexion-extension arc decreased by 3 ° . Wrist X-rays showed no radiocarpal arthritis. On the Mayo wrist score, 81% reported excellent to good results (average: 89). Pain levels improved by 90%, with 76% of patients reporting no pain. All patients (100%) were satisfied with their results and would recommend the procedure. Conclusions  Dynadesis is specifically designed for the treatment of DSI. It avoids the eventual complication of osteoarthritis and does not sacrifice wrist motion. A predictable and satisfactory long-term result is obtainable with correct patient selection based on clinical staging and arthroscopic findings.

Management of chronic scapholunate ligament injury

Scapholunate ligament is the most commonly injured ligament in the wrist and requires accurate diagnosis and treatment. It presents with pain, stiffness and can lead to carpal instability as well as degenerative arthritis if left untreated, with subsequent loss of function and disability. There are several management options currently available but there is no consensus on how best to manage a wrist with chronic sequelae of scapholunate ligament injury. This review explores available evidence in the literature on optimal treatment options including non-operative and operative procedures, relevant surgical techniques and their associated outcomes. A summary of the current concepts in the management of Chronic Scapholunate ligament injury is presented.

Surgical outcomes of chronic isolated scapholunate interosseous ligament injuries: a systematic review of 805 wrists

Background

Management of chronic isolated scapholunate interosseous ligament (SLIL) injuries has generated a substantial volume of low-quality literature with descriptions of multiple new surgical techniques, and the impact of instability pattern and the optimal surgical technique remain unclear. The primary goal of this review was to compare clinical, radiographic and patient-rated outcomes between current surgical techniques.

Methods

We performed a systematic literature search using multiple databases. We analyzed clinical, radiographic and patient-reported outcomes. We used a fixed-effects model weighted by sample size with combined outcomes estimated via least squares means with 95% confidence intervals. We also performed a subgroup analysis of static versus dynamic instability.

Results

We assessed 805 procedures from 37 study groups, with 429 procedures used in subgroup analysis. There were no statistically significant differences in outcomes between surgical techniques or in subgroup analysis. Overall, postoperative wrist flexion and pain scores decreased, and grip strength and patient-rated outcomes improved.

Conclusion

Compared to overall preoperative values, modest improvements in pain score, grip strength and functional outcome scores were obtained from a range of reconstructive procedures performed for chronic isolated SLIL injuries. No significant differences could be ascertained between surgical techniques, potentially owing to the low quality of evidence and procedure heterogeneity. This study provides accurate preoperative reference values for future studies, highlights the controversial clinical impact of instability classification, and the need for higher-quality multicentre or collaborative trials to improve our understanding and management of this common injury.

Optimal management of scapholunate ligament injuries

Scapholunate ligament (SLL) injuries are a common cause of wrist pain and instability. Treatment of SLL injuries requires intricate understanding of wrist anatomy and biomechanics. Mindful physical exam and appropriate diagnostic studies can orient the surgeon to the defined stage of injury. Review of the literature on each treatment by stage can prepare the upper extremity surgeon to provide the best evidence-based care. The optimal management of SLL injuries should result in a stable, painless wrist.

Combined Tenodesis-Capsulodesis for Scapholunate Instability: Minimum 2-Year Follow-Up

Background The aim of this study is to evaluate the clinical and radiological midterm results of a combined dorsal tenodesis-capsulodesis for static and reducible scapholunate dissociation (SLD). Patients and Methods We evaluated 20 of 22 consecutive patients with static SLD minimum with follow-up of 2 years operated between 2003 and 2012. The mean age was 40 years (range: 23-65 years). Seventeen were men. Final evaluation included comparative wrist range of motion (ROM) and grip strength, pre- and postoperative pain and function by visual analog scale, and QuickDASH and Wrightington scores. Radiographs included preoperative, early postoperative, and final X-rays. Scapholunate space (SLS) and scapholunate and radioscaphoid angles (SLA and RSA) were measured. Statistical significance was evaluated with Student t-test, considered significant when p < 0.05. Results Mean follow-up was 67 months (range: 24-126 months). Mean final ROM was: flexion 55 degrees (73%), extension 62 degrees (90%), radial deviation 19 degrees (82%), and ulnar deviation 44 degrees (90%). Mean grip strength was 44 kg (92%). Pain at rest improved from 3.4 to 0.5 (p < 0.05). Pain in activity improved from 7 to 1.7 (p < 0.05). Final function was 8.5 (preoperative, 5.2; p < 0.05). Mean QuickDASH score improved from 38 to 8 (p < 0.05). Functional Wrightington score was as follows: 13 excellent, 3 good, 1 regular, and 3 poor. There were three postoperative minor complications. Radiological results (preoperative/early postoperative/final follow-up) were as follows: SLS, 4.7/1.6/1.8 mm; and SLA, 60/50/62 degrees; RSA, 39/45/37 degrees. Four patients showed arthritic changes (two SLAC wrist). Conclusion The clinical and radiological results with more than 2-year follow-up suggest that this technique may be effective, reproducible, and safe for symptomatic static and reducible SLD. Level of Evidence Level IV, case series.

The role of arthroscopy in carpal instability

Carpal instability is predominantly caused by trauma and presents as a painful wrist with signs and symptoms of weakness, clicking, clunking and a sense of giving way. Wrist arthroscopy is widely regarded as the 'gold standard' in diagnosing and understanding carpal instability. This article is based on an extensive literature search to evaluate the evidence behind the use of wrist arthroscopy in the assessment and management of these patients. There is convincing evidence supporting the role of arthroscopy in diagnosis and assessment of factors involved in the development of carpal instability, but weak evidence for the effectiveness of arthroscopic techniques in the actual treatment of this condition. The article reviews mechanisms behind, and the role for arthroscopy in the management of scapholunate, lunotriquetral, midcarpal and radiocarpal instability. It also presents how the author incorporates the 'evidence-base' into an 'experience-based' clinical practice.

Assessment of scapholunate instability and review of evidence for management in the absence of arthritis

Scapholunate ligament tear is a common wrist injury and may lead to degenerative arthritis of the wrist in the long term. We review the assessment and classification of scapholunate instability and discuss the findings from our search for evidence for the management of scapholunate instability in the absence of arthritis. Strong evidence (level 1 or 2) for management is lacking and published recommendations are largely experience-based. The choice of procedure in the absence of arthritis depends on the extent of the tear, quality of the ligament remnants, and reducibility of the joint. Prospective, randomized studies with validated outcome measures are needed to establish the efficacy of intervention on symptoms and function and its effect on the risk of future arthritis.

Scapholunate ligament reconstruction using an acellular dermal matrix: a mechanical study

PURPOSE

Numerous surgical techniques have been described for the treatment of chronic scapholunate ligament instability. We hypothesized that scapholunate ligament reconstruction using an acellular dermal matrix was biomechanically comparable to previously described surgical reconstructions.

METHODS

The scaphoid and lunate with the entire scapholunate ligament were harvested from 15 cadaveric specimens. The scapholunate ligament was transected and reconstructed using an acellular dermal matrix (Arthroflex; LifeNet Health, Virginia Beach, VA) and 4 micro suture anchors in 10 specimens. Five specimens were kept with the native scapholunate ligament intact. Five other specimens were reconstructed using a 1.0-mm-thick dermal matrix, and a second cohort of 5 specimens was reconstructed using a 1.5-mm-thick matrix. Tensile testing of all specimens was performed using a servohydraulic material testing system and data acquisition software. The tensile test apparatus applied a distractive load of 10 mm/min (0.17 mm/s) until the specimens reached ultimate failure. Failure force, failure displacement, stiffness, and energy to failure were calculated.

RESULTS

All 5 specimens in the intact group failed at the scapholunate ligament midsubstance. The mean ultimate failure force was 172 N, with mean stiffness of 74 N/mm. In the reconstruction group with 1.0-mm dermal matrices, the mode of failure was at the suture-matrix interface in all specimens, whereas the 1.5-mm dermal matrix reconstruction cohort all failed at the bone-suture anchor interface. In the 1.0-mm reconstruction group, the mean ultimate failure force was 77 N, with mean stiffness of 24 N/mm. In the 1.5-mm dermal matrix reconstruction cohort, the mean ultimate failure force was 111 N, with mean stiffness of 30 N/mm.

CONCLUSIONS

Scapholunate ligament reconstruction using acellular dermal matrix and suture anchors demonstrated similar biomechanical properties to previously described reconstruction techniques.

CLINICAL RELEVANCE

Scapholunate ligament reconstruction using acellular dermal matrix warrants clinical investigation as a potential treatment alternative for chronic scapholunate instability.

Scaphoid kinematics before and after scaphotrapeziotrapezoidal ligament section. Assessment by radiostereometric analysis and computed tomography in a cadaver study

The purpose of this study was to measure changes in scaphoid kinematics after division of scaphotrapeziotrapezoidal ligaments, with the intention of determining a clinical measure that could be detected by computed tomography. Twelve freshly frozen cadaver upper extremities were marked with tantalum beads and fixed in positions of neutral, 30° extension, and 40° ulnar deviation. Stereoradiographs for bone migration analysis by radiostereometric analysis and computed tomography scans for visible assessment were obtained before and after scaphotrapeziotrapezoidal ligament section. After ligament resection there was a scaphoid supination of 5° and a small (less than 1 mm) radial, distal, and dorsal translation of the distal pole in 30° of wrist extension. In computed tomography reconstructions, the ligament section appeared as a 1 to 2 mm gap in the scaphotrapeziotrapezoidal corner, with loss of articulation between the distal scaphoid pole and the trapezoid bone and increased scaphoid flexion.

Long-term outcomes of dorsal intercarpal ligament capsulodesis for chronic scapholunate dissociation

PURPOSE

Chronic scapholunate dissociation is the most common cause of symptomatic wrist instability. In an attempt to restore normal carpal mechanics and prevent wrist arthrosis, we developed and tested biomechanically the dorsal intercarpal ligament capsulodesis (DILC). Previously, we reported good early clinical results for this procedure at an average follow-up period of 25 months. Here, we report on the functional and radiographic outcomes at a longer follow-up period of a minimum of 5 years.

METHODS

Records of patients undergoing the DILC for chronic (greater than 6 weeks), flexible, static scapholunate dissociation were reviewed. Only patients with follow-up evaluation of greater than 60 months were included. Physical examination, radiographs, and validated outcome instruments were used to evaluate the patients.

RESULTS

Twenty-one patients (22 wrists) met the inclusion criteria. Fifteen of 21 patients (16 wrists) were available for follow-up evaluation. Average follow-up period was 86 months. Physical examination revealed average wrist flexion and extension of 50 degrees and 55 degrees , respectively, radial and ulnar deviation of 17 degrees and 36 degrees , respectively, and grip strength of 43 kgf. Disabilities of the Arm, Shoulder and Hand, Short Form-12, and Mayo wrist scores averaged 19, 78, and 78, respectively. Radiographs revealed an average scapholunate angle and gap of 62 degrees and 3.5 mm, respectively. Eight of the 16 wrists in our study demonstrated arthritic changes on radiographs.

CONCLUSIONS

The DILC does not consistently prevent radiographic deterioration and the development of arthrosis in the long-term; however, the level of functionality and patient satisfaction remained relatively high in 58% of our patients, suggesting a lack of correlation between the radiographic findings and development of arthrosis and the functional outcomes and patient satisfaction. We believe that the DILC is still a reasonable option for treating flexible static scapholunate dissociation in patients without radiographic signs of arthritis presenting with wrist pain despite conservative treatment. Prevention of radiographic deterioration and arthrosis remains an unsolved problem.

Arthroscopic debridement and closed pinning for chronic dynamic scapholunate instability

PURPOSE

For chronic dynamic scapholunate (SL) instability (>3 months after injury) open procedures (capsulodesis, limited intercarpal fusions, tenodesis, SL ligament reconstruction) have become popular in recent years but their long-term results have been suboptimal. We evaluated retrospectively the results of aggressive arthroscopic debridement of the SL ligament to bleeding bone in an effort to induce scar formation and closed pinning of the SL joint in patients unwilling to have an open procedure.

METHODS

Eleven patients (mean age, 37 y) presenting with persistent posttraumatic pain and weakness to the wrist were diagnosed with dynamic SL instability (positive Watson scaphoid shift test result, SL gapping on grip-view radiographs, arthroscopic findings of a Geissler grade III or IV SL tear) and treated. Range of motion, grip strength, radiographic measurements, and the Mayo wrist score were used to evaluate the results.

RESULTS

The mean follow-up period was 33 months (range, 12-76 mo). Three patients had subsequent surgery 9 to 11 months after the procedure. Subsequent surgeries included a dorsal capsulodesis, a four-corner fusion, and a wrist arthrodesis. Of the 8 remaining patients there were 2 excellent, 4 good, 1 fair, and 1 poor result based on the Mayo wrist score. In these patients the mean range of motion was 65 degrees of extension to 59 degrees of flexion and the mean grip strength was 82% of the uninjured contralateral extremity. Although persistent radiographic SL gapping in grip views was noted in all 8 patients none progressed to static instability or dorsal intercalated segment instability.

CONCLUSIONS

The results of this technique are suboptimal; however, it may be an option for patients unwilling to have more than an arthroscopic procedure or those requiring maintenance of wrist motion, provided they understand the risks and benefits of this approach.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic, Level IV.