Arthroscopic Debridement for Treatment of Chronic Dynamic Scaphoid Instability.

Background There is a paucity of information on minimal surgical intervention for the treatment of chronic dynamic scaphoid instability (CDSI) that will achieve an acceptable mid-term result. Purpose We hypothesize that by following a debride-first-then-wait protocol, some patients with CDSI can be treated with arthroscopic debridement alone and avoid a reconstructive procedure. Patients and Methods We performed a retrospective, longitudinal study from January 2008 to December 2018 of all patients diagnosed with CDSI and treated with arthroscopic debridement of the scapholunate interosseous ligament. In all cases, a debride-first-then-wait protocol was followed that included a predetermined wait period after arthroscopic debridement, giving the patient a chance to experience possible symptom improvement. This approach integrated the patient's perceived wellness into the decision-making process. All wrists that remained symptomatic or experienced recurrence of symptoms were treated with a reconstructive procedure. The wrists were divided into two groups: arthroscopic debridement only (ADO) and reconstructive procedure (RP). Results Seventy-nine wrists (72 patients) of 191 consecutive wrist arthroscopies met the inclusion criteria. The ADO group consisted of 43 wrists (54%). An average of 6.3 years later (range: 2-11 years), these patients remained satisfied with the results of the arthroscopic debridement and did not want further treatment. The RP group included 36 wrists (46%) with 91.7% of reconstructive surgeries occurring within 6 months of the arthroscopy. With a mid-term follow-up, 75% of Geissler grade II ligament tears, 48% of grade III tears, and 39% of grade IV tears were successfully treated with arthroscopic debridement alone and avoided a reconstructive surgery. Conclusion By adopting a debride-first-then-wait protocol, some patients with CDSI can be treated with a more limited intervention, arthroscopic debridement. In this series, 54% of wrists with CDSI avoided a reconstructive surgery for an average of 6.3 years. Type of Study / Level of Evidence Case Series, Level IV.

Measurement of Scapholunate Joint Space Width on Real-Time MRI-A Feasibility Study.

INTRODUCTION: The scapholunate interosseous ligament is pivotal for wrist stability, and its impairment can result in instability and joint degeneration. This study explores the application of real-time MRI for dynamic assessment of the scapholunate joint during wrist motion with the objective of determining its diagnostic value in efficacy in contrast to static imaging modalities. MATERIALS AND METHODS: Ten healthy participants underwent real-time MRI scans during wrist ab/adduction and fist-clenching maneuvers. Measurements were obtained at proximal, medial, and distal landmarks on both dynamic and static images with statistical analyses conducted to evaluate the reliability of measurements at each landmark and the concordance between dynamic measurements and established static images. Additionally, inter- and intraobserver variabilities were evaluated. RESULTS: Measurements of the medial landmarks demonstrated the closest agreement with static images and exhibited the least scatter. Distal landmark measurements showed a similar level of agreement but with increased scatter. Proximal landmark measurements displayed substantial deviation, which was accompanied by an even greater degree of scatter. Although no significant differences were observed between the ab/adduction and fist-clenching maneuvers, both inter- and intraobserver variabilities were significant across all measurements. CONCLUSIONS: This study highlights the potential of real-time MRI in the dynamic assessment of the scapholunate joint particularly at the medial landmark. Despite promising results, challenges such as measurement variability need to be addressed. Standardization and integration with advanced image processing methods could significantly enhance the accuracy and reliability of real-time MRI, paving the way for its clinical implementation in dynamic wrist imaging studies.

Volar Lunate Dislocation Causing Secondary Carpal Tunnel Syndrome: A Case Report.

Background Failure of carpal tunnel release is an uncommon occurrence with unique pathologies that may impede proper diagnosis and treatment. Symptoms are most often attributed to an inadequate release of the transverse carpal ligament or pathologic scar tissue resultant of the primary decompression. Case Description In this report, we describe the case of a 79-year-old male with a history of scaphoid lunate advanced collapse and a prior carpal tunnel decompression presenting with worsening right wrist function and new right palmar mass. The patient had no significant antecedent trauma, and clinical workup revealed volar dislocation of the lunate. After failed conservative treatment and multiple ultrasound-guided corticosteroid injections, the patient was successfully treated surgically with carpal tunnel release, tenosynovectomy, and lunate excision. Literature Review Volar lunate dislocation without a traumatic mechanism is rare. Progressive carpal destabilization and volar subluxation is not a commonly reported cause of secondary carpal tunnel symptoms. Isolated reports in the literature have been published with nearly identical presentations. Kamihata et al reported a patient, with a history of carpal tunnel decompression, presenting with numbness and tingling in her right hand without traumatic injury. A displaced lunate was found to abut the flexor tendons and median nerve. Ott et al further reported an atraumatic lunate dislocation and palmar swelling 4 weeks after a carpal tunnel release. Clinical Relevance In the setting of existing arthritic degeneration, carpal tunnel release may destabilize the carpus and predispose patients to carpal dislocation. Further research is required to understand the risks associated with this instability leading to lunate dislocations secondary to carpal tunnel release.

Radiocarpal and midcarpal kinematics in scapholunate instability: a four-dimensional CT study in vivo.

The distribution of motion between the radiocarpal and midcarpal joints in scapholunate instability is poorly understood. This has potential implications in predicting degenerative changes and in selecting salvage procedures. We studied 19 healthy wrists and 19 wrists with scapholunate instability using dynamic computed tomography during wrist extension to flexion and ulnar to radial deviation. Radiocarpal and midcarpal kinematics of the scaphoid and the lunate were computed. In scapholunate instability, in the radial column, there was increased motion in the radiocarpal joint when the wrist was radially deviating beyond 10° or moving from 70° to 40° extension. In both groups, the capitolunate joint was the dominant articulation in the central column. In scapholunate instability, there was significantly more capitolunate motion during 70° to 30° extension. These changes may predict the development of radioscaphoid arthritis and enable identifying a kinematically abnormal wrist. The motion distribution in scapholunate instability was abnormal beyond 10° of radial deviation and between 70° and 40° of wrist extension.Level of evidence: III.

Volar Lunate Dislocation: A Case Report.

Introduction: Perilunate dislocations are rare high-energy injuries which may often have the potential to cause lifelong disability of the wrist if not addressed optimally. Hence, early recognition, diagnosis, and intervention are of paramount importance in the restoring function and prevention of morbidity. Lunate dislocations are the fourth and last stage of perilunate dislocations being extremely rare, with volar dislocations representing <3% of perilunate dislocations. Case Report: A 24-year-old man suffered from an alleged history of fall from a bike on an outstretched hand following which he developed complaints of pain and swelling in the right wrist. On examination, the patient has relative sensory loss over the lateral half of the palm with no vascular deficit. An accurate range of motion could not be documented due to severe pain. Standard digital X-rays revealed lunate displaced and angulated volarly with a typical "spilled teacup" appearance along with radial and ulnar styloid fractures. Management: The patient was initially given an attempt of closed reduction which was not successful and was followed with open reduction and internal fixation with both volar and dorsal approach with Kirschner wires. The patient's wrist was immobilized for 6 weeks with below elbow cast with the removal of k wires at 8 weeks after which wrist ROM exercises were started. Results: The patient was followed up for 6 months and now has a functional range of motion of the wrist with no sensory deficit and is able to continue with his profession as a car mechanic. Conclusion: Mayfield progression Stage 4 perilunate dislocations are uncommon with a poor prognosis if not addressed timely. Hence, these injuries need to be identified early and optimally managed with surgical intervention for a favorable outcome.

Ulnar carpal translation following palmar locking plate fixation for distal radius fractures: a retrospective analysis.

BACKGROUND: Concomitant injuries to the radiocarpal ligaments may occur during episodes of distal radius fractures, which may not cause acute subluxation or dislocation but can lead to radiocarpal instability and progress over time. This study aimed to analyze the occurrence of ulnar carpal translation (UCT) after open reduction and internal fixation of distal radius fractures and evaluate the associated factors of UCT. METHODS: The retrospective study has been done now and includes patients treated between 2010 and 2020 who had undergone reduction and locking plate fixation of distal radius fractures. We assessed radiographs taken immediately after the operation and at 3 months post-operation, enrolling patients with UCT for evaluation. In addition to demographic data, we evaluated radiographic parameters, including fracture pattern, fragment involvement, and ulnar variance. We also assessed the palmar tilt-lunate (PTL) angle to determine associated rotatory palmar subluxation of the lunate (RPSL). RESULTS: Among the 1,086 wrists, 53 (4.9%) had UCT within 3 months post-operation. The majority of wrists with UCT exhibited normal to minus ulnar variance (49 wrists; mean: -1.1 mm), and 24 patients (45.3%) had concomitant RPSL. Fracture classification was as follows: 19 type A3 (35.8%), 5 type C1 (9.4%), 11 type C2 (20.8%), and 18 type C3 (34.0%). Radial styloid was involved in 20 wrists (37.7%), palmar rim in 18 wrists (34.0%), dorsal rim in 25 wrists (47.2%), and die-punch fractures in 3 wrists (5.7%). Concomitant ulnar styloid fractures were present in 29 wrists (54.7%). CONCLUSION: This study highlights the potential for UCT to occur following reduction and fixation of distal radius fractures, particularly in cases with a more severe fracture pattern and combined with ulnar minus variance. The high incidence of concomitant RPSL provides further evidence for the possibility of associated radiocarpal ligament insufficiency after distal radius fracture.

Automatic segmentation and labelling of wrist bones in four-dimensional computed tomography datasets via deep learning.

This study developed a deep learning model for fully automatic segmentation and labelling of wrist bones from four-dimensional computed tomography (4DCT) scans. This is a crucial step towards implementing 4DCT for diagnosing wrist ligament lesions, reducing time-consuming analysis of extensive data.

Ligamentoplasty in scapholunate instability: short-term results of the "all dorsal scapholunate repair" technique.

Injury to the scapholunate complex is the cause of scapholunate instability which can lead to radiocarpal and medio-carpal osteoarthritis. Several ligamentoplasty techniques have been reported for the treatment of chronic scapholunate instability before the osteoarthritis stage. The objective of this study was to assess the short-term results of an "all dorsal scapholunate repair" ligamentoplasty. We report the clinical, radiological and functional results of a retrospective study including 21 patients, operated between June 2019 and December 2020 for a stage 3 or 4 scapholunate instability according to the Garcia Elias classification. With a follow-up of 14.2 months, the pain was 0.1/10 according to the VAS at rest and 4/10 during exercise. Wrist strength was measured at 65% of the opposite side. The flexion-extension range of motion was 105°. Radiologically, there was a reduction of the diastasis and scapholunate angle. Osteolysis areas around the anchors were described in 47% of patients. The mean QuickDASH was 29.2/100, PRWE 24/100 and Mayo wrist score 67.8/100. Eighty-one percent of patients were satisfied. Seventeen patients had returned to work 5.2 months postoperatively. In the case of work-related injury, the functional scores were poorer, with a delayed return to work. This technique provides encouraging results in the short term. Most patients were improved compared to preoperative state. The work-related injury appears to be a poor prognostic factor. A longer-term study is imperative to confirm the maintenance over time of the correction of carpal malalignment and the evolution of the osteolysis areas.Level of evidence: Level IV Retrospective study.

Dynamic assessment of scapholunate ligament status by real-time magnetic resonance imaging: an exploratory clinical study.

OBJECTIVE: Clinical-standard MRI is the imaging modality of choice for the wrist, yet limited to static evaluation, thereby potentially missing dynamic instability patterns. We aimed to investigate the clinical benefit of (dynamic) real-time MRI, complemented by automatic analysis, in patients with complete or partial scapholunate ligament (SLL) tears. MATERIAL AND METHODS: Both wrists of ten patients with unilateral SLL tears (six partial, four complete tears) as diagnosed by clinical-standard MRI were imaged during continuous active radioulnar motion using a 1.5-T MRI scanner in combination with a custom-made motion device. Following automatic segmentation of the wrist, the scapholunate and lunotriquetral joint widths were analyzed across the entire range of motion (ROM). Mixed-effects model analysis of variance (ANOVA) followed by Tukey's posthoc test and two-way ANOVA were used for statistical analysis. RESULTS: With the increasing extent of SLL tear, the scapholunate joint widths in injured wrists were significantly larger over the entire ROM compared to those of the contralateral healthy wrists (p<0.001). Differences between partial and complete tears were most pronounced at 5°-15° ulnar abduction (p<0.001). Motion patterns and trajectories were altered. Complete SLL deficiency resulted in complex alterations of the lunotriquetral joint widths. CONCLUSION: Real-time MRI may improve the functional diagnosis of SLL insufficiency and aid therapeutic decision-making by revealing dynamic forms of dissociative instability within the proximal carpus. Static MRI best differentiates SLL-injured wrists at 5°-15° of ulnar abduction.

Anatomical front and back reconstruction sustains radiographic alignment: a comparison to three-ligament tenodesis.

Multiple techniques exist to reconstruct the scapholunate interosseous ligament, though none have demonstrated superiority. This study compares 1-year radiographic outcomes of the three-ligament tenodesis and the anatomical front and back reconstruction. All patients who underwent reconstruction of their scapholunate interosseous ligament at one institution with either anatomical front and back reconstruction or three-ligament tenodesis between 2011 and 2020 were retrospectively reviewed. At 52-week follow-up, anatomical front and back reconstruction maintained a statistically significant improvement in scapholunate gap, corrected radiolunate angle and dorsal scaphoid translation, while three-ligament tenodesis demonstrated no sustained improvement in any parameter. The improvement in dorsal scaphoid translation was significantly greater for patients undergoing anatomical front and back reconstruction compared with three-ligament tenodesis at the 16-weeks postoperative timepoint (-1.0 mm, -0.3 mm). Anatomical front and back reconstruction demonstrates sustained improvement in radiographic outcomes at 1 year when compared with three-ligament tenodesis. By addressing both volar and dorsal critical ligament restraints, adoption of anatomical front and back reconstruction for advanced stage scapholunate interosseous ligament injuries should be considered.Level of evidence: IV.

Carpal instability after partial trapeziectomy, total trapeziectomy and the resection of the distal scaphoid pole: a cadaveric study.

INTRODUCTION: Non-dissociative carpal instability (CIND) may lead to severe functional impairment. Destabilisation of the scapho-trapezial-trapezoidal (STT) ligament complex seems to result in a CIND. MATERIALS AND METHODS: In one group with eight cadaver arms, distal scaphoid pole was resected with the adjacent ligaments. In the other eight cadavers, hemitrapeziectomy was performed followed by total trapeziectomy. CT scans were performed in different wrist positions, and the changed positions of the scaphoid, lunate and capitate were measured in comparison to non-operated wrists. RESULTS: Mainly in clenched fist position, dissociation between proximal and distal row can be determined after total trapeziectomy and resection of distal scaphoid pole. Capitate rotates dorsally up to 24°, the scaphoid up to 17° and the lunate up to 7° compared to the non-operated wrists. Resection of the distal scaphoid pole results in dorsal rotation of capitate and scaphoid of about 14° and the lunate 8°. Relative scapholunate and capitolunate angle increased significantly after total trapeziectomy, especially in clenched fist position. After scaphoid pole resection, significant SL and CL angles changes could be seen in almost every wrist position. CONCLUSION: Destabilisation of the STT ligament complex by total trapeziectomy or distal scaphoid pole resection results in dissociation of the proximal and distal carpal row without instability within the proximal or distal row, corresponding to a CIND. LEVEL OF EVIDENCE: III.

Traumatic Volar Carpal Instability Nondissociative: A Case Series.

Carpal instability nondissociative (CIND) involves disruption between carpal rows from injury to extrinsic and intrinsic wrist ligaments. CIND traumatic (CINDT) highlights the posttraumatic etiology of some of these cases and has been gaining increasing attention in the literature. We present four cases of CINDT-volar intercalated segmental instability (VISI). We diagnosed two adults with distal radius fractures and two adolescents with Galeazzi fractures, all treated surgically, who developed CINDT-VISI with radiolunate angles greater than 15° at 2 weeks after surgery. One adult had progressive deformity but was asymptomatic at 33 months. The other underwent volar capsular release at 1 year to improve alignment. One adolescent with a fixed deformity required soft tissue releases and temporary pinning to restore alignment at 7 months. We treated the other successfully with early physiotherapy. No patient had radiographic signs of arthritis at 1-2 years. This is the first reported association between Galeazzi fractures and CINDT-VISI. Contrary to existing literature, we report successful outcomes with nonsurgical and delayed nonfusion surgery of CINDT-VISI.

Reverse or Ulnar-Sided, Greater Arc Perilunate Injury: Case Report and Systematic Review of Literature.

BACKGROUND: Perilunate injuries of carpal bones are uncommon, high-energy injuries that necessitate early diagnosis and appropriate management to prevent progressive carpal instability and posttraumatic osteoarthritis. A much more uncommon mechanism that starts from the lunotriquetral ligament and proceeds radially in an opposite direction than the classic mechanism may cause a reverse or ulnar-sided perilunate dislocation (PLD). The purposes were: (1) to present an uncommon case of greater arc reverse (ulnar-sided) perilunate fracture-dislocation (REPLFD); and (2) to conduct a systematic review (SR) to evaluate the current evidence on reverse perilunate injuries (REPLIs). METHODS: A novel pattern of injury of REPLFD with fractures of the ulnar styloid, triquetrum, and capitate is presented. A SR was conducted with primary outcome measures of the type of injury (pathoanatomy of lesions) and pathomechanics. Secondary outcome measures were choice of surgery and outcome on follow-up. RESULTS: The Murad's tool and modified Coleman Methodology Score revealed poor methodological quality of the available literature on REPLI. Evidence is lacking in the mechanism of injury and treatment of REPLI, especially regarding REPLFD. CONCLUSIONS: The SR revealed poor methodological quality of the available literature and exposes that not all PLDs can be explained by the current existing pathomechanical injury classifications. However, following the management principles of perilunate injuries, REPLI tends to have good functional results with no major complications. LEVEL OF EVIDENCE: Level V.

The Lateral-W Construct: An Anatomical Variant of the Dorsal Wrist Ligaments.

Background The dorsal intercarpal ligament (DIC) is an elegant dorsal stabilizer of the proximal carpal row, including the scaphoid's proximal pole and scapholunate joint. Along with the dorsal radiocarpal (DRC) ligament, it acts as a dorsal radioscaphoid stabilizer, with dynamism due to its ability to modify its length up to threefold by changing the angles between its V-shaped bundle morphology. The DIC ligament consistently originates from the dorsal tubercle of the triquetrum on the ulnar side. It spans transversely, attaching to the dorsal groove of the scaphoid (97-100%), lunate (75-90%), and proximal rim of the trapezium (12.5-50%), and overlapping the lunotriquetral interosseous ligament and the scapholunate interosseous ligament. Together with the DRC, Viegas et al (Viegas SF, Yamaguchi S, Boyd NL, Patterson RM. The dorsal ligaments of the wrist: anatomy, mechanical properties, and function. J Hand Surg Am 1999;24(3):456-468) proposed that this ligament complex should be called the "lateral-V construct." Anatomical Variant The authors present a unique type C variant of the DIC ligament, showing a distinct thick bundle directed at the dorsal aspect of the second metacarpal base that thus creates a "lateral-W construct." This dorsal triquetro-metacarpal 2 (dTqMC2) ligament acts as restraint to the body of the capitate and will provide enhanced stability of the dorsal midcarpal joint by limiting dorsal translation of the capitate in relation to the lunate. Clinical Relevance Our finding may contribute to the increasing knowledge of the dorsal ligament complex and its role in dorsal midcarpal instability, as well as surgical repair techniques.

Carpal dislocations.

Carpal dislocations result from sequential disruption of the complex relationship between the bones and ligaments of the wrist. Injuries to the carpus occur via predictable mechanisms, an understanding of which is critical to identify and treat these frequently missed patterns of injury and to avoid the sequela of chronic instability. Lunate dislocations are by far the most common, but isolated dislocation of other carpal bones can also occur. Open reduction and internal fixation still remains the gold standard for treatment regardless of the debate around the specific approaches. These high-energy injuries are associated with significant long-term morbidity even when identified promptly and appropriately treated. This review will focus on the evaluation and management of common forms of carpal dislocations.

Scapholunate Instability: Diagnosis and Management - Classification and Treatment Considerations - Part 2.

Intervention for scapholunate instability is aimed at halting the degenerative process by restoring ligament integrity and normalizing carpal kinematics. Part 1 of this Current Concepts article reviewed the anatomy, kinematics, and biomechanical properties of the scapholunate ligament as well as its critical stabilizers. In this section, we provide a foundation for understanding the spectrum of scapholunate ligament instability and incorporate meaningful new anatomical insights that influence treatment considerations. These updates clarify the importance of the critical stabilizers of the scapholunate interval, ligament-specific considerations in scapholunate ligament reconstruction, and the risks of ligament disinsertion when surgically exposing the dorsal wrist. We propose a ligament-based treatment algorithm based on the stage of injury, degree and nature of ligament damage, and presence of arthritic changes.

Scapholunate Instability: Diagnosis and Management - Anatomy, Kinematics, and Clinical Assessment - Part I.

Injuries to the scapholunate joint are the most frequent cause of carpal instability. The sequelae of these injuries account for considerable morbidity, and if left untreated, may lead to scapholunate advanced collapse and progressive deterioration of the carpus. Rupture of the scapholunate interosseous ligament and its critical stabilizers causes dyssynchronous motion between the scaphoid and lunate. Additional ligament injury or attenuation leads to rotary subluxation of the scaphoid and increased scapholunate gap. Intervention for scapholunate instability is aimed at halting the degenerative process by restoring ligament integrity and normalizing carpal kinematics. In the first section of this review, we discuss the anatomy, kinematics, and biomechanical properties of the scapholunate ligament as well as its critical ligament stabilizers. We provide a foundation for understanding the spectrum of scapholunate ligament instability and incorporate meaningful new anatomical insights that influence treatment considerations. The purpose is to provide an update regarding the anatomy of the scapholunate ligament complex, importance of the critical ligament stabilizers of the proximal carpal row, introduction of safe technique to surgically expose the scaphoid and lunate, as well as pathoanatomy as it pertains to the treatment of scapholunate dissociation. In the second section of this review, we propose a novel ligament-based treatment algorithm based on the stage of injury, degree and nature of ligament damage, and presence of arthritic changes.

Scaphoid kinematics in scapholunate instability: a dynamic CT study.

OBJECTIVE: The scaphoid is proposed to be driven by the distal carpal row in scapholunate instability (SLI) as it is dissociated from the proximal row. The aim of this study was to describe the 6 degrees of freedom kinematics of the scaphoid using dynamic CT in the normal and SLI wrists. We hypothesised that the SLI scaphoid would demonstrate kinematic evidence conforming to distal row motion. MATERIALS AND METHODS: We studied dynamic CT scans of 17 SLI and 17 normal wrists during ulnar to radial deviation and extension to flexion. The radio-scaphoid angles in three anatomic planes were calculated in the wrist neutral position and during wrist motion. The centroid position was also calculated in the wrist neutral position and during wrist motion. The scapho-capitate motion index (SCI) was calculated as a ratio between the scaphoid and the capitate motion. RESULTS: In the neutral position of the wrist, the SLI scaphoid was flexed, internally rotated, and radially translated compared to the normal scaphoid. During wrist motion, the SLI scaphoid had more 'in-plane' motion and less 'out-of-plane' motion with a higher SCI during wrist neutral to radial deviation and extension to neutral. CONCLUSION: We have described the malalignment of the SLI scaphoid in the neutral position of the wrist and 6 degrees of freedom kinematics during wrist motion of the SLI scaphoid compared to the normal. The SLI scaphoid conformed more to the distal row motion than the normal scaphoid. This information may help define the surgical reconstruction techniques for SLI.

Scapholunate instability: why are the surgical outcomes still so far from ideal?

The wrist is a universal joint with intrinsic and extrinsic ligaments that function and fail as ligamentous complexes. Those related to scapholunate instability (SLI) include the dorsal scapholunate complex (DSLC), volar radiolunate complex and scaphotrapeziotrapezoid complex. Together the DSLC, scaphoid and lunate create an 'acetabulum' for the capitate, with the dorsal intercarpal ligament being a labrum to contain the capitate. SLI results from failure of the DSLC, typically from its scaphoid attachments. Failure of the lunate and or triquetral attachments increases the instability. DSLC failure leads to radioscaphoid instability, which is the symptomatic clinical problem. SLI reconstruction with open surgery and trans-osseous tendon graft techniques have been challenging. We discuss a biological arthroscopic approach to identify, mobilize and debride the disrupted DSLC. This ligament/capsular/periosteum sheet is then advanced and secured to the debrided footprint. Thereby reconstituting the acetabulum, labrum and scaphoid stability.

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.