Development and stability analysis of carpal kinematic metrics from 4D magnetic resonance imaging.

OBJECTIVE: To develop MRI-derived carpal kinematic metrics and investigating their stability. METHODS: The study used a 4D MRI method to track scaphoid, lunate, and capitate movements in the wrist. A panel of 120 metrics for radial-ulnar deviation and flexion-extension was created using polynomial models of scaphoid and lunate movements relative to the capitate. Intraclass correlation coefficients (ICCs) analyzed intra- and inter-subject stability in 49 subjects, 20 with and 29 without wrist injury history. RESULTS: Comparable degrees of stability were observed across the two different wrist movements. Among the total 120 derived metrics, distinct subsets demonstrated high stability within each type of movement. For asymptomatic subjects, 16 out of 17 metrics with high intra-subject stability also showed high inter-subject stability. The differential analysis of ICC values for each metric between asymptomatic and symptomatic cohorts revealed specific metrics (although relatively unstable) exhibiting greater variability in the symptomatic cohort, thereby highlighting the impact of wrist conditions on the variability of kinematic metrics. CONCLUSION: The findings demonstrate the developing potential of dynamic MRI for assessing and characterizing complex carpal bone dynamics. Stability analyses of the derived kinematic metrics revealed encouraging differences between cohorts with and without wrist injury histories. Although these broad metric stability variations highlight the potential utility of this approach for analyzing carpal instability, further studies are necessary to better characterize these observations.

Exercise-based intervention as a nonsurgical treatment for patients with carpal instability: A case series.

BACKGROUND: Although the important roles of proprioception and neuromuscular control in carpal instabilities under laboratory conditions have been recognized, only a few studies have translated this knowledge into a routine clinical practice. PURPOSE: This study aimed to evaluate the results of a personalized rehabilitation in patients with carpal instability on functionality and pain intensity. STUDY DESIGN: This was a case series study. METHODS: This case series included 39 adults (mean age: 38.2 ± 14.0 years; 16/23 females/males) diagnosed with carpal instability (radial or ulnar) with indication for orthopedic treatment. The disabilities of the arm, shoulder, and hand questionnaire was used to assess upper limb functionality. Pain perception was assessed using a visual analog scale. Exercise-based physiotherapy interventions were performed according to the clinical needs of the patients for at least 6 weeks (2-3 sessions per week). For the treatment of radial instability (n = 13), strengthening exercises of the abductor pollicis longus, extensor carpi radialis longus, flexor carpi radialis, and pronator quadratus muscles were prescribed. For the treatment of ulnar instability (n = 24), extensor carpi ulnaris and pronator quadratus were trained. All patients underwent proprioceptive training in open kinetic chain and closed kinetic chain, as well as strengthening of the unaffected hand. Changes before and after treatment were compared using the nonparametric Wilcoxon signed rank test. RESULTS: A significant improvement with a large effect size in disabilities of the arm, shoulder, and hand (P < .001; d = 2.9) and visual analog scale (P < .001; d = 3.2) scores were obtained after treatment. Moreover, the changes were greater than the minimal clinically important difference of 10.8 and 1.4, respectively. Similar results were found when patients with radial instability and ulnar instability were analyzed separately. CONCLUSIONS: Personalized training with specific proprioception and strengthening exercises produces improvements in functionality and pain perception in our cohort of people with carpal instability. These results highlight the importance of multicomponent exercise in the treatment of wrist instability. Future randomized clinical trials should further investigate the effectiveness of this protocol.

Ligament-Sparing Volar Radiocarpal Arthrotomy During Distal Radius Fracture Repair: Biomechanical Implications on Wrist Stability in a Cadaveric Model.

PURPOSE: Distal radius (DR) fracture fixation with volar locked plating typically uses indirect fracture reduction without direct visualization of the articular surface in an attempt to preserve the volar radiocarpal ligaments and prevent iatrogenic radiocarpal instability. This study assessed the biomechanical stability after a volar radiocarpal arthrotomy for direct articular visualization for DR fracture repair compared to a standard trans-flexor carpi radialis approach without arthrotomy in a cadaver model. METHODS: Ten fresh-frozen upper extremity matched-pair cadaveric specimens were tested. For each pair, one limb underwent trans-FCR approach with a volar arthrotomy that partially sectioned the long and short radiolunate ligaments to visualize the DR articular surface (Group 1). The contralateral limb underwent standard trans-FCR approach without arthrotomy (Group 2). Following capsular repair (Group 1), all specimens (Groups 1 and 2) underwent biomechanical testing, including axial loading (22.2 N, 44.5 N, 89.0 N, 177.9 N), volar translational, and dorsal translation loading (22.2 N, 44.5 N, 89.0 N) to assess carpal stability using both fluoroscopy and motion capture. Ulnar carpal translation was assessed using the Gilula method, measuring radiographic lunate overhang from the ulnar edge of the lunate fossa relative to the full width of the lunate. Dorsal and volar translation were assessed by measuring lunate overhang with respect to the dorsal or volar radial cortex. To simulate fractures with dorsal radiocarpal ligament disruption, the dorsal capsule was sectioned, and the biomechanical comparisons were repeated. RESULTS: Ulnar translation of the lunate remained below 2 mm for both groups in all testing scenarios. No significant differences were identified in ulnar, volar, or dorsal translation with increasing loads between the groups. CONCLUSIONS: This volar ligament-sparing radiocarpal arthrotomy did not cause biomechanical radiocarpal instability. CLINICAL RELEVANCE: This arthrotomy may provide enhanced visualization of the DR articular surface during fracture fixation without causing iatrogenic wrist instability.

Management of Nondissociative Instability of the Wrist.

Nondissociative carpal instability is instability of an entire carpal row and can lead to vague ulnar-sided wrist pain as well as a clunking wrist. The etiology of this process is most often generalized ligamentous laxity; however, it can infrequently occur as a result of trauma or malalignment of the radiocarpal joint. Whereas treatment remains controversial, the literature supports nonsurgical management and includes patient education, dynamic placement of orthoses, proprioceptive therapy, and extensor carpi ulnaris strengthening. If extensive nonsurgical therapy fails, surgical intervention includes soft tissue and bony procedures, all with high complication and failure rates and limited long-term outcome data.

Are adult carpal angle measurements applicable to the pediatric population in the trauma setting?

OBJECTIVE: The aim of this study is to assess the applicability of standard adult carpal angle measurements, specifically the scapholunate and capitolunate angles, in the assessment of the pediatric wrist. MATERIALS AND METHODS: The study cohort comprised male and female children who underwent a wrist radiograph for the evaluation of suspected wrist injuries following trauma. A gender- and indication-matched adult cohort was also assessed. To ensure an accurate carpal angle measurement, only individuals with a sufficiently ossified carpus and an adequately positioned lateral wrist radiograph were included. RESULTS: Carpal angle measurements were performed on the lateral wrist radiographs of 256 individuals between the ages of 5 and 17 years (mean 11.2 years, SD ± 2.5 years) and 256 individuals between the ages of 18 and 40 years (mean 28.8 years, SD ± 6.2 years). The mean pediatric scapholunate angle was 47° (SD ± 8) and the mean pediatric capitolunate angle was 11° (SD ± 7). The mean adult scapholunate and capitolunate angles were 48° (SD ± 8°) and 10° (SD ± 6°) respectively. No statistically significant difference was observed between the scapholunate or capitolunate angle measurements in the two groups (p = 0.26 and p = 0.36). CONCLUSION: The study data supports the applicability of standard adult carpal angle values to the pediatric population provided the carpus is sufficiently ossified.

Force Required to Maintain Reduction of a Preexisting Scapholunate Dissociation.

PURPOSE: To determine the force required to maintain reduction of Geissler grade 4 scapholunate dissociations during physiological wrist motions. METHODS: Fresh-frozen cadaveric wrists with Geissler grade 4 scapholunate dissociations were identified by arthroscopy. Following reduction, a load cell was attached to measure the force across the scapholunate joint at a neutral position and during 4 different wrist motions re-created using a servohydraulic wrist simulator, including a large flexion-extension motion (FEM), small and large dart-thrower's motions (DTMs), and a large DTM with ulnar offset. RESULTS: Five wrists with isolated preexisting scapholunate interosseous ligament (SLIL) tears were analyzed. The force required to maintain reduction was significantly greater in extension than in flexion during the large FEM and large DTM with ulnar offset. The forces were significantly larger in this study of preexisting SLIL dissociations compared with results from a prior study of acutely sectioned SLILs. In addition, forces to maintain reduction during DTMs were significantly less than forces during FEMs. Finally, a set of 3 wrists with preexisting scapholunate and lunotriquetral interosseous ligament (LTIL) tears were identified and had significantly decreased forces to maintain reduction at maximum extension and had decreased maximal forces during a cycle of motion compared with the wrists with isolated SLIL tears. CONCLUSIONS: The forces required to maintain reduction of a Geissler grade 4 wrist are higher than forces after acutely sectioned SLIL. The forces are greater in extension than in flexion and less during the DTM compared with the FEM. Wrists with both SLIL and LTIL tears required less force to maintain reduction than those with isolated SLIL tears. CLINICAL RELEVANCE: This study helps determine the strength of reconstruction required to maintain reduction of a Geissler grade 4 scapholunate dissociation.

Posterior Radioscaphoid Angle as a Predictor of Wrist Degenerative Joint Disease in Patients With Scapholunate Ligament Tears.

OBJECTIVE: The purpose of this study is to determine whether the posterior radioscaphoid angle, a marker of posterior displacement of the scaphoid, is associated with degenerative joint disease in patients with scapholunate ligament tears. MATERIALS AND METHODS: Images from 150 patients with wrist pain who underwent CT arthrography and radiography were retrospectively evaluated. Patients with and without scapholunate ligament ruptures were divided into two groups according to CT arthrography findings. The presence of degenerative changes (scapholunate advanced collapse [SLAC] wrist) was evaluated and graded on conventional radiographs. Images were evaluated by two readers independently, and an adjudicator analyzed the discordant cases. Posterior radioscaphoid angle values were correlated with CT arthrography and radiographic findings. The association between posterior radioscaphoid angle and degenerative joint disease was evaluated. Scapholunate and radiolunate angles were considered in the analysis. RESULTS: The posterior radioscaphoid angle was measurable in all patients, with substantial interobserver agreement (intraclass correlation coefficient, 0.75). The posterior radioscaphoid angle performed better than did the scapholunate and radiolunate angles in the differentiation of patients with and without SLAC wrist (p < 0.02). Posterior radioscaphoid angles greater than 114° presented an 80.0% sensitivity and 89.7% specificity for the detection of SLAC wrist. CONCLUSION: Posterior radioscaphoid angles were strongly associated with degenerative wrist disease, with potential prognostic implications in patients with wrist trauma and scapholunate ligament ruptures.

Midterm Outcome of Bone-Ligament-Bone Graft and Dorsal Capsulodesis for Chronic Scapholunate Instability.

PURPOSE: To assess midterm outcomes of our bone-ligament-bone (BLB) grafts for chronic scapholunate (SL) instability and better define criteria for their use. METHODS: We conducted a retrospective review of 26 patients treated with BLB grafts and dorsal capsulodesis between 1997 and 2009. Twenty-four patients were reviewed. Mean follow-up was 8.2 years. Two patients had dynamic lesions, 7 had SL dissociation, 14 had a dorsal intercalated segment instability lesion, and 1 had SL advanced collapse stage 1. Mean age at surgery was 46 years. All patients presented with pain and 14 had lack of strength. Results were reviewed clinically and radiologically. Images were assessed by 4 surgeons and 1 radiologist for radial styloid, radioscaphoid, radiolunate, midcarpal, and scaphotrapeziotrapezoid degenerative changes. RESULTS: Five patients needed subsequent 4-corner arthrodesis. Of the remaining 19 patients at follow-up, both extension and flexion decreased to 73% of the contralateral side. Postoperative grip strength improved from 78% to 90% of the nonsurgical wrist. Quick Disabilities of the Arm, Shoulder, and Hand score was 10 of 100 and the Patient-Rated Wrist Evaluation score was 10 of 100. Radiologically, the SL gap was improved and maintained at follow-up. The SL angle (mean before surgery, 79°) was initially corrected to 69° but returned to preoperative values at follow-up. Eleven of the 19 cases had signs of midcarpal arthritis. CONCLUSIONS: Bone-ligament-bone grafts with SL dorsal capsulodesis were able to restore and maintain an improved SL interval in all patients. The technique achieved good clinical results and high patient satisfaction, but it did not stop the progression of arthritis, particularly at the midcarpal level. This technique is an option for isolated unrepairable lesion of the dorsal SL ligament with an easily correctable lunate and especially when restoration of grip strength is important. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Scapholunate ligament reconstruction using a flexor carpi radialis tendon graft.

PURPOSE: To review the results of scapholunate ligament reconstruction using a flexor carpi radialis tendon graft. METHODS: We performed a retrospective review of 22 patients with post-traumatic scapholunate instability who were treated with a modification of the Brunelli, a flexor carpi radialis tendon graft. RESULTS: The mean follow-up was 61 months. The average age was 40 years. The average loss of flexion was 23° and of extension was 22° compared with the contralateral side. Grip strength averaged 67% of the nonoperated side. All patients except 2 returned to work. Degenerative changes were seen in 3 patients at the time of revision. Complications occurred in 2 patients and included avascular necrosis of the scaphoid. CONCLUSIONS: Perfect biomechanical reconstruction might not be possible for scapholunate dissociation. Our results show, however, that ligament reconstruction led to satisfactory results from the patient's point of view. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

ACR Appropriateness Criteria® Chronic Hand and Wrist Pain: 2023 Update.

Chronic hand and wrist pain is a common presenting complaint. The intricate anatomy results in a variety of pain generators-multiple bones, articular cartilage, intrinsic ligaments, triangular fibrocartilage complex, joint capsules and synovium, tendons and tendon sheaths, muscles, and nerves-in a compact space. The need for imaging and the choice of the appropriate imaging modality are best determined by the patient's presentation, physical examination, and the clinician's working differential diagnosis. Radiography is usually appropriate as the initial imaging study in the evaluation of chronic hand or wrist pain. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Role of the extensor carpi ulnaris in the stabilization of the lunotriquetral joint. An experimental study.

STUDY DESIGN: Experimental laboratory-based research in biomechanics. INTRODUCTION: The mechanisms by which some lunotriquetral (LTq) ligament disruptions remain stable are not known. PURPOSE OF THE STUDY: To investigate the contribution of muscles in preventing carpal destabilization when the LTq ligaments are torn. METHODS: Ten fresh cadaver wrists, set vertical in a jig, were isometrically loaded through five wrist motor tendons. Changes in carpal alignment secondary to the application of loads were monitored by a Fastrak™ electromagnetic motion tracking device, before and after sectioning the LTq ligaments. RESULTS: After LTq ligaments sectioning, wrist loading forced the triquetrum into flexion (5.4° average) and supination (2.9 ). The only muscle capable of extending and pronating the collapsed triquetrum was the extensor carpi ulnaris (ECU). CONCLUSIONS: Inadequate ECU muscle function is an important destabilizing factor in LTq deficient wrists. Dynamic LTq instabilities may benefit from proprioceptionally training the ECU muscle, while avoiding carpal supination torques.

Current Concepts in Scapholunate Instability Without Arthritic Changes.

Scapholunate instability (SLI) is the most common carpal instability described. SLI leads to a degenerative arthritic pattern known as scapholunate advanced collapse (SLAC). Diagnosis of SLI can be challenging in pre-dynamic and dynamic stages. CT arthrogram, MR arthrogram and dynamic fluoroscopy are helpful in diagnosis while arthroscopy remains the gold standard. SLI is a multi-ligament injury, which involves not only the scapholunate interosseous ligament (SLIL) but also the extrinsic carpal ligaments. Hence, it is better described as an injury compromising the 'dorsal scapholunate(dSLL) complex'. A repair can be attempted for acute SLI presenting within 6 weeks of injury. Reconstruction is the mainstay of treatment for chronic SLI without degenerative changes. Multiple repair techniques have been described which include capsulodesis and tenodesis procedures. The clinical outcomes of the techniques have improved over the years. However, a common problem of all these techniques is the lack of long-term data on the outcomes and deteriorating radiological parameters over time. SLI staging is an important factor to be considered in choosing the reconstruction techniques for a better outcome. Currently, there is a trend towards more biological and less invasive techniques. Regardless of the technique, it is important to preserve the nerve supply of the dorsal capsuloligamentous structures of the wrist. Arthroscopic techniques being minimally invasive have the advantage of less collateral damage to the capsuloligamentous structures. Rehabilitation involves a team approach where a protected dart thrower's motion is allowed after a period of immobilization. Strengthening SL-friendly muscles and inhibiting SL-unfriendly muscles is a key principle in rehabilitation.

Ligament reconstruction with modified suture anchor fixation technique for chronic distal radioulnar joint instability: A case report and literature review.

INTRODUCTION: The chronic instability of the DRUJ should be appropriately treated. Ligament reconstruction in the original technique needs an adequate length of the graft, which needs to be modified in such a case. CASE PRESENTATION: A 27-year-old male presented with right wrist pain accompanied by limited movement that has been felt for the last two months. There was an obvious deformity with tenderness. Palpation revealed a positive ballottement and piano-key sign test. An X-ray examination revealed a union fracture one-third distally on the right radius bone with dorsal dislocation of the right distal radioulnar joint. The result of an MRI confirmed a triangular fibrocartilage complex tear. The patient was diagnosed with chronic DRUJ instability. DISCUSSION: We performed a chronic DRUJ reconstruction using the harvesting palmaris longus tendon. However, the length of the graft is too short. Further, we performed a modified technique with suture anchor fixation for this patient. This technique could be a helpful alternative if the length of the graft is insufficient. As a result, there was an improvement in the DASH score and EQ5D questionnaires. CONCLUSION: Chronic DRUJ instability could be treated by ligament reconstruction with modified suture anchors fixation in the inadequate length of the graft situation.

Scaphoid and Carpal Bone Fracture: The Difficult Cases and Approach to Management.

Scaphoid and carpal bone fractures are challenging injuries to manage and have significant functional implications. Prompt diagnosis is important and relies on systematic evaluation via history, examination, and imaging. Cross-sectional imaging is often helpful for diagnosis and treatment planning. Treatment for nondisplaced fractures is often closed but these injuries typically require prolonged immobilization and may still result in nonunion or avascular necrosis. Displaced carpal bone fractures, and those associated with carpal instability, typically require open reduction internal fixation.

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.

A fluid-structure interaction investigation of intra-articular pressure and ligament in wrist joint.

Understanding the stresses on the scapholunate interosseous ligament (SLIL) and its interaction with synovial fluid pressure could be vital to improve wrist treatment for various wrist conditions such as arthritis, sprains and tendonitis. This study investigated the interaction between the intra-articular pressure, specifically the synovial fluid pressure change and the SLIL stresses in a computational model during wrist radioulnar deviation (RUD). Magnetic resonance imaging (MRI) scans were used to acquire the anatomical model of the carpal bones and ligament, while the kinematics of scaphoid and lunate were obtained through dynamic computerized tomography (CT) scans. A two-way fluid-structure interaction (FSI) was used to model the dynamics between the scaphoid and lunate, the SLIL, and the synovial fluid. The synovial fluid pressure change was found to be small (-4.86 to 3.23 Pa) and close to that simulated in a previous work without the SLIL (-1.68 to 2.64 Pa). Furthermore, peaks of maximum fluid pressure were found to trail the peaks of ligament stress. Therefore, it is suggested that the influence of synovial fluid pressure on the ligament in the SLIL model is negligible and simulations of the scapholunate joint could forego fluid-structure interactions. Future studies can instead explore other structures in the carpus that can possibly contribute to the ligament stresses. Clinically, treatments can be targeted at these areas to help prevent or slow the progression of ligament injuries into serious consequences like the degenerative joint disease.

Negative Ulnar Variance Lessens DRUJ Instability After DRUJ Disruption: A Biomechanical Analysis.

BACKGROUND: The purpose of this study was to perform a biomechanical investigation on the effect of ulnar variance (UV) on the stability of the distal radioulnar joint (DRUJ) prior to and after DRUJ sectioning. METHODS: Ten cadaveric forearm specimens were included in the study and baseline UV was assessed radiographically. Radial motion relative to the ulna was evaluated using Intel real sense cameras and a custom developed program. The forearms were dissected, and a radial osteotomy was performed. Using a custom-made plate, radial stability was assessed with an UV of + 4, 0, and -4 mm by measuring the maximum and minimum radial position relative to the ulna during a simulated Shuck test. The volar radioulnar ligaments and triangular fibrocartilage complex (TFCC) were then sectioned, and testing was repeated at each UV state. RESULTS: Sectioning significantly increased radial translation at neutral (P = .008), +4 mm UV (P = .008), and -4 mm UV (P = .018). There were no significant differences in translation between the 3 UV groups with the DRUJ intact (P = .124). The ulnar negative (-4 mm) state had significantly lower translation compared to the positive (+4 mm) (P < .001) and the neutral (0 mm) (P = .026) UV states. There were no significant differences between the positive and neutral UV groups with the DRUJ sectioned. CONCLUSIONS: Fixating the radius in -4 mm of ulnar negativity significantly decreased radial translation after sectioning the volar radioulnar ligament and TFCC. Ulnar variance had no effect on stability with an intact DRUJ. STUDY TYPE: Biomechanical Study.

Radiological and functional correlation following "SLIC" scapholunate-intercarpal ligamentoplasty at minimum 12 months' follow-up.

We report outcomes for scapholunate-intercarpal ligamentoplasty ("SLIC procedure"), performed in 22 patients (mean age at surgery, 39.7 years), for reducible static scapholunate (SL) instability without repairable stump. Patients were evaluated for pain and active wrist range of motion, grip strength, functional scores (QuickDASH and PRWE) and radiological appearance (SL gap, SL angle, radiolunate angle, capitolunate angle), preoperatively and at a mean 28.3 months' follow-up (range 12-65). A CT scan without injection was performed at follow-up to measure the posterior radioscaphoid angle (PRSA). The objective was to assess radiological-functional correlations after SLIC ligamentoplasty and to analyze postoperative PRSA correction. The hypothesis was that correcting the PRSA improves clinical and functional outcomes. Pain on a visual analog scale improved significantly, from 2.7 to 0.7 at rest and from 7 to 3.2 during hand use. Mean wrist flexion was 46.4° and extension 59.1°. Grip strength reached 82.8% of the contralateral value. Functional scores improved significantly. Mean SL angle decreased significantly from 81.1° to 73.5°, and static scapholunate gap from 4.7 mm to 3.6 mm. Scaphoid subluxation was fully corrected in 15 cases (68%). PRSA angle was significantly corrected, from a mean 112.7° to 104.2°. Patients in whom PRSA was corrected showed a tendency for better clinical and subjective outcomes. There was 1 case of scaphoid necrosis, 7 of recurrent static instability, including 3 early at 4 months, 3 of scaphocapitate osteoarthritis, and 5 of carpal collapse with SLAC wrist. There were no significant correlations between clinical and radiological results in the medium term after SL ligamentoplasty by the SLIC procedure. The results were quite good in the medium term and pointed to the importance of correcting rotatory subluxation of the scaphoid, revealed by the PRSA, more than correcting the scapholunate gap.

Dorsal Bone-Ligament-Bone Reconstruction of Chronic Lunotriquetral Instability: Biomechanical Testing.

Purpose: Lunotriquetral (LT) instability is uncommon and few biomechanical analyses of the condition exist. For chronic LT instabilities, arthrodesis has long been the treatment of choice but has a high risk for nonunion. The aim of this study was to evaluate an alternative treatment option using a bone-ligament-bone graft in a cadaver model and compare it with a conventional arthrodesis. Methods: We used 10 cadaveric forearms with different loading positions. We employed computed tomography scans to evaluate the LT joint. Scans were performed with the joint intact after we sectioned the dorsal LT ligament and the palmar LT ligament. The joints were then reconstructed using a bone-ligament-bone graft from the capitate-hamate joint as well as with a compression screw simulating arthrodesis. The joints were then rescanned and 3-dimensional analysis was performed using specialized 3-dimensional software. Results: Sectioning the dorsal part of LT ligament had little effect on kinematics; however, additional division of the palmar LT ligament resulted in increased mobility. Restoration of physiological kinematics could be partially achieved after bone-ligament-bone reconstruction. Arthrodesis showed increased intercarpal motion in the adjacent scapholunate and lunocapitate joints compared with the bone-ligament-bone reconstruction. Conclusions: The bone-ligament-bone reconstruction displayed physiologic carpal kinematics in the adjacent joints compared with arthrodesis. It provided enough stability but still some mobility in the LT joint to be able to use it as a treatment modality for chronic LT instability without the risk for nonunion. Decreased intercarpal motion was not statistically significant although there appeared to be a trend toward it. Type of study/level of evidence: Therapeutic IV.

Intercarpal ligamentoplasty for scapholunate dissociation: comparison of two techniques.

We modified our original surgical technique of scapholunate intercarpal ligamentoplasty for treating chronic scapholunate dissociation. The aim of this study was to compare the outcomes in patients treated by the same surgical team with the original method and the modified method over two different time periods. Nineteen patients with a mean age of 40 years were treated with the original method (mean follow-up of 34 months, range 12-54), and 21 patients with a mean age of 38 years were treated with the modified method (mean follow-up of 27 months, range 13-40). In both groups, we found a significant improvement in pain levels, grip strength, functional scores in terms of QuickDASH and Patient-Rated Wrist Evaluation, and radiographic scapholunate gap and scapholunate angle after surgery. There were no significant differences between the two groups in outcome measures except the scapholunate gap, which was significantly better controlled by the modified procedure. Between the immediate postoperative period and the last follow-up, there was a significant increase in the scapholunate gap and scapholunate angle after the original method, while there only a small increase after the modified method. We conclude that both versions of the scapholunate intercarpal ligamentoplasty yield satisfactory clinical and radiological results in the short to mid-term. The modified method makes the triquetral surgical step easier and seems to better optimize the tension across the ligamentoplasty, thus maintaining the intercarpal correction.Level of evidence: III.