The lunotriquetral joint: kinematic effects of sequential ligament sectioning, ligament repair, and arthrodesis

Outcomes Following Surgical Interventions for Isolated Lunotriquetral Interosseous Ligament Injuries: A Systematic Review

Ulnar-sided wrist pain can be attributed to various bony and ligamentous structures. The purpose of this review is to compare outcomes following surgical interventions for isolated lunotriquetral (LT) interosseous ligament injuries in adults. We assessed 202 procedures from 9 retrospective case series studies of low to moderate quality based on the Structured Effectiveness Quality Evaluation Scale. The comparative outcomes (ie, range of motion, pain, strength, quality of life, complications, return to work, and patient satisfaction) were aggregated and categorized under arthrodesis, capsulodesis, ligament repairs and reconstruction, and ulna shortening osteotomy procedures. Although the comparison of outcomes was largely inconclusive due to the heterogeneity and the omission of preoperative characteristic data, we did observe higher complications and reoperation rates post LT arthrodesis. It is recommended that all outcomes be standardized and presented uniformly with best practices developed to better characterize the injury's severity and integrity in future studies.

Diagnosis and Management of Lunotriquetral Ligament Injuries

PURPOSE OF REVIEW

The standard of care for lunotriquetral ligament injuries is evolving. An understanding of the mechanics of the lunotriquetral ligament and its role in carpal kinematics is critical when deciding how to treat these injuries. Treatment for these injuries varies from nonoperative to wrist arthroscopy with thermal capsulodesis and/or repair to reconstruction or limited arthrodesis. This article provides a review of the anatomy, pathomechanics, evaluation, and ultimately treatment of lunotriquetral ligament injuries.

RECENT FINDINGS

Although lunotriquetral ligament injuries can occur in isolation, injuries to the lunotriquetral ligament are often viewed as a component of other injury patterns to the intrinsic and extrinsic ligaments of the wrist. Static volar intercalated segment instability typically occurs when the dorsal radiocarpal ligament is also compromised. If nonoperative treatment fails, arthroscopy is the gold standard for diagnosis even with improving imaging modalities. Recently, authors have proposed employing the technique of ulnar-shortening osteotomy in those with ulnar negative variance and the absence of an impaction lesion. Other newer techniques included bone-ligament-bone reconstruction for chronic, static instability. LT injuries rarely occur in isolation. Most injuries involving the lunotriquetral ligament can be treated nonoperatively. Those individuals with persistent pain should be treated with a diagnostic wrist arthroscopy. Primary repairs are indicated in those with an acute, complete tear. In chronic, static instability, ligament reconstruction has been shown to improve wrist function and decrease pain.

The Intercalated Segment: Does the Triquetrum Move in Synchrony With the Lunate?

PURPOSE

To quantify the relative motion between the lunate and triquetrum during functional wrist movements and to examine the impact of wrist laxity on triquetral motion.

METHODS

A digital database of wrist bone anatomy and carpal kinematics for 10 healthy volunteers in 10 different positions was used to study triquetral kinematics. The orientation of radiotriquetral (RT) and radiolunate rotation axes was compared during a variety of functional wrist movements, including radioulnar deviation (RUD) and flexion-extension (FE), and during a hammering task. The motion of the triquetrum relative to the radius during wrist RUD was compared with passive FE range of motion measurements (used as a surrogate measure for wrist laxity).

RESULTS

The difference in the orientation of the radiolunate and RT rotation axes was less than 20° during most of the motions studied, except for radial deviation and for the first stage of the hammering task. During wrist RUD, the orientation of the RT rotation axis varied as a function of passive FE wrist range of motion.

CONCLUSIONS

The suggestion that the lunate and triquetrum move together as an intercalated segment may be an oversimplification. We observed synchronous movement during some motions, but as the wrist entered RUD, the lunate and triquetrum no longer moved synchronously. These findings challenge the assumptions behind models describing the mechanical function of the carpals.

CLINICAL RELEVANCE

Individual-specific differences in the amount of relative motion between the triquetrum and lunate may contribute to the variability in outcomes following lunotriquetral arthrodesis. Variation in triquetral motion patterns may also have an impact on the ability of the triquetrum to extend the lunate, affecting the development of carpal instability.

LT Ligament Tears

Lunotriquetral (LT) ligament injuries are uncommon, however, should be considered in patients with ulnar-sided wrist pain. LT injuries are often associated with other injuries but can occur in isolation. Understanding the anatomy and pathomechanics will aid in making the diagnosis. Similar to other injuries, a thorough history and focused physical examination is critical. Radiographs may show normal findings; however, advanced imaging can support the diagnosis. Arthroscopy remains the gold standard for diagnosis. Most patients do well with conservative management; however, injury acuity and severity will direct surgical management. Anatomy, pathophysiology, and treatment options are discussed.

Assessing the scapholunate and lunotriquetral interosseous ligament in MR arthrography: Diagnostic advantages of paraxial reformatting

PURPOSE

The scapholunate (SLIL) and lunotriquetral interosseous ligament (LTIL) function as the main stabilizers of the proximal carpal row. Even with MR arthrography, component assessability is often limited in orthogonal standard planes due to their horseshoe-like shape and resulting partial volume effects. This study aims to investigate the diagnostic value of reformatting isotropic 3D sequences with respect to the anatomical orientation of the intrinsic carpal ligaments.

METHOD

In 110 MR arthrograms of the wrist, we investigated the diagnostic accuracy of two radiologists (R1/R2) for SLIL and LTIL injuries in orthogonal standard planes vs. ancillary angulated reformatting of isotropic 3D dual echo steady state sequence. Component assessability and diagnostic confidence were compared between datasets.

RESULTS

The addition of paraxial reformations improved diagnostic accuracy for lesions of the palmar (R1: 0.87 vs. 0.93; R2: 0.86 vs. 0.93; all p < 0.05) and dorsal LTIL (R1: 0.85 vs. 0.93; R2: 0.82 vs. 0.90; all p < 0.05). No significant increase in accuracy could be ascertained for palmar (R1: 0.92 vs. 0.94, p = 0.50; R2: 0.86 vs. 0.92, p = 0.07) and dorsal (R1: 0.95 vs. 0.95, p = 1.00; R2: 0.90 vs. 0.94, p = 0.29) lesions of the SLIL. Interrater reliability was almost perfect with and without angulated planes for SLIL (κ = 0.88 vs. 0.82) and LTIL assessment (κ = 0.88 vs. 0.86). For the LTIL, observer confidence and component assessability were superior with anatomical reformations available (all p < 0.05).

CONCLUSIONS

In contrast to SLIL injuries, diagnosis of LTIL lesions benefits from ancillary paraxial reformations of 3D sequences in MR wrist arthrography.

Arthroscopic dorsal capsulodesis for isolated lunotriquetral interosseous ligament injuries

We assessed the outcomes of isolated lunotriquetral ligament injuries in ten patients who underwent arthroscopic dorsal capsulodesis. Data from patient records, radiologic images and arthroscopic video records were evaluated. The patients were evaluated for ulnar-sided wrist pain with history and physical examination. Preoperative radiographs and MRIs for pain aetiology were assessed. The patients underwent arthroscopic dorsal capsulodesis and were evaluated 29 months (range 19-45) after surgery. Nine patients returned to their original jobs. In one patient pain was aggravated with heavy activities. Mean scapholunate angle was 44°. There were significant improvements postoperatively in pinch and grip strength and MAYO wrist, patient-reported wrist evaluation and pain scores. The wrist flexion-extension and the radial ulnar deviation were significantly improved compared with the contralateral hand. We conclude that arthroscopic dorsal capsulodesis offers effective management for isolated lunotriquetral interosseous ligament injuries.Level of evidence: IV.

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.

Imaging evaluation of traumatic carpal instability

PURPOSE

To review the epidemiology, pertinent wrist anatomy, classification system, and emergent imaging evaluation of carpal instability with a focus on radiographic assessment of instability.

METHODS

A review of current literature on carpal instability was performed with summary presentation of carpal instability epidemiology, carpal anatomy, imaging evaluation, and classification with imaging evaluation focused on diagnosis in the emergency setting.

RESULTS

Carpal instability is a common pathology in falls on outstretched hand and is likely underdiagnosed due to instability being occult or demonstrating subtle malalignment on static imaging of the wrist. While there is a complex network of intrinsic and extrinsic ligaments contributing to carpal instability, a detailed knowledge of these ligaments is not necessary for radiologists to make an accurate diagnosis in the emergency setting, as identification and classification of carpal instability is based on identification of carpal malalignment patterns on radiography as opposed to identification of specific ligament injuries on advanced imaging. The Mayo classification is the most widely used classification system, which divides carpal instability into four categories: dissociative, non-dissociative, complex, and adaptive. Understanding this classification system allows radiologists to successfully classify almost all carpal instability injuries they will encounter, even in the setting of unusual or rare instability patterns.

CONCLUSION

In working with the treating clinician, it is essential that the emergency radiologist is comfortable with identifying and classifying carpal instability. This will ensure prompt treatment of seemingly benign injuries and those that require intervention, surgical or otherwise, improving the likelihood of a good outcome.

Manual therapy for work-related wrist pain in a manual physical therapist

Introduction: The wrist is a common site for work-related musculoskeletal disorders (WMSD) among physical therapists (PTs), often due to manual therapy. There are limited data on management of wrist injury in PTs. The purpose of this case is to describe the management of a PT with wrist pain.Case Description: The patient was a 28-year-old female with a 6-month history of right ulnar-sided wrist pain, aggravated by performing thoracic/lumbar posterior to anterior (PA) glides. The patient reported 7/10 on the Numeric Pain Rating Scale and 6.5/10 on the Patient-Specific Functional Scale (PSFS). Symptoms were reproduced at the lunotriquetral joint.Outcomes: The patient was seen for two visits. Following anterior to posterior non-thrust mobilization at the triquetrum on lunate, the patient improved inability to perform thoracic/lumbar PA glides. The patient was educated on manual therapy modifications, isometrics, and self-mobilization. At 2-month follow-up, the patient reported 0/10 pain, scored 10/10 on the PSFS, and +7 on the Global Rating of Change.Discussion: This case demonstrates the successful use of education, manual therapy, and exercise in the management of a PT with a wrist-related WMSD. Future research should focus on the prevention/treatment of wrist-related WMSDs in PTs who perform manual therapy.

Intercarpal Ligament Injuries Associated With Distal Radius Fractures

Injuries to the scapholunate (SL) and lunotriquetral (LT) interosseous ligaments occur in approximately one third of distal radius fractures. The diagnosis of these injuries is challenging because plain radiographs are not reliably diagnostic. Wrist arthroscopy may be the most accurate way to examine and diagnose soft-tissue injuries of the carpus adjacent to a distal radius fracture. Treatment options for SL and LT ligament injuries include open repair and/or percutaneous pinning. Because the natural history of these injuries is unclear, the necessity of diagnosing and treating these SL and LT interosseous ligament defects remains speculative.

Wrist cineradiography: a protocol for diagnosing carpal instability

Carpal instability is often related to ruptured or lax carpal ligaments. Wrist cineradiography has been shown to be a good modality for diagnosing carpal instability. To create uniformity in obtaining and assessing wrist cineradiography, a wrist cineradiography protocol is desirable. This protocol will focus on wrist cineradiography for diagnosing carpal instabilities. It describes the pathologic motions of the carpus and correlates these with a clinical diagnosis.

LEVEL OF EVIDENCE

III.

Association of lunate morphology, sex, and lunotriquetral interosseous ligament injury with radiologic measurement of the capitate-triquetrum joint

OBJECTIVE

Radiologic presentation of carpal instability at the radial side of the carpus, e.g. scapholunate diastasis following scapholunate interosseous ligament injury, has been studied extensively. By comparison, presentation at the ulnar-sided carpus has not. The purpose of this study was to assess the effects of lunate morphology, sex, and lunotriquetral interosseous ligament (LTIL) status on the radiologic measurement of the capitate-triquetrum joint (C-T distance). Further, we sought to evaluate the diagnostic accuracy of C-T distance for assessing LTIL injuries.

MATERIALS AND METHODS

We retrospectively identified 223 wrists with wrist radiographs and MR arthrograms with contrast injection. Data collected included sex, lunate morphology and LTIL status from MR arthrography, and C-T distance from radiography. The effects of lunate morphology, sex, and LTIL injury status on C-T distance were evaluated using generalized linear models. Diagnostic performance of C-T distance was assessed by the area under receiver-operator characteristic curve (AUROC).

RESULTS AND CONCLUSION

Lunate morphology, sex, and LTIL injury status all had significant effects on C-T distance; wrists with type II lunates, men, and wrists with LTIL injuries had greater C-T distances than wrists with type I lunates, women, and wrists without LTIL injuries, respectively (p < 0.01). The diagnostic value of the C-T distance for identifying patients with full-thickness LTIL tears was sufficient for women with type I (AUROC = 0.67) and type II lunates (0.60) and good for men with type I (0.72) and type II lunates (0.77). The demonstrated influence of LTIL status on C-T distance supports the use of C-T distance as a tool in assessing for full-thickness LTIL tears.

Lunotriquetral Ligament Reconstruction Utilizing a Palmaris Longus Autograft

Injury to the lunotriquetral ligament can result in midcarpal instability, with resultant alterations in normal wrist kinematics and subsequent arthrosis. We performed a previously undescribed technique of lunotriquetral ligament reconstruction in two patients utilizing a palmaris longus tendon autograft. Average age at presentation was 24 years old with a mean follow up of 10 months. Average range of motion was 62.5° of flexion and 57.5° of extension. Total arc of motion was 83% of the contralateral uninvolved extremity. Average grip strength was 31 kg which was 91% of the contralateral extremity. Average Quick Disability of Arm, Shoulder and Hand score was 12.5 and Modern Activity Subjective Survey of 2007 was 1.5. No complications were noted.

Inside-out method to develop volar arthroscopic portals of the wrist in cadaver specimens

Three direct volar portals for wrist arthroscopy have been described previously: two radiocarpal and one midcarpal. The aim of this study was to systematically describe four volar arthroscopic portals through minimally invasive incisions using an inside-out approach from known dorsal portals. Four volar arthroscopic wrist portals were studied on six hand specimens using an inside-out technique: a radial radiocarpal approach (RRCA), an ulnar radiocarpal approach (URCA), a radial midcarpal approach (RMCA) and an ulnar midcarpal approach (UMCA). Each volar approach corresponded to a dorsal approach: the 3/4 portal for RRCA, 4/5 portal for URCA, dorsal radial midcarpal approach for RMCA, and dorsal ulnar midcarpal approach for UMCA. The average range of motion of the scope through the RRCA was 65° in radial deviation and 72° in ulnar deviation; through the URCA it was 62° in radial deviation and 64° in ulnar deviation; through the RMCA it was 62° in radial deviation and 60° in ulnar deviation, and through the UMCA it was 59° in radial deviation and 68° in radial deviation. No iatrogenic injuries to important anatomical structures were noted. Based on these results, it is possible to perform these four volar portals through an inside-out technique with incisions mirroring the dorsal portals. They were easy to perform, safe and should be useful in ligament or bony intracarpal repair indications.

Carpal Kinematics and Kinetics

The complex interaction of the carpal bones, their intrinsic and extrinsic ligaments, and the forces in the normal wrist continue to be studied. Factors that influence kinematics, such as carpal bone morphology and clinical laxity, continue to be identified. As imaging technology improves, so does our ability to better understand and identify these factors. In this review, we describe advances in our understanding of carpal kinematics and kinetics. We use scapholunate ligament tears as an example of the disconnect that exists between our knowledge of carpal instability and limitations in current reconstruction techniques.

Arthroscopic Classification of the Lesions of the Dorsal Capsulo-Scapholunate Septum (DCSS) of the Wrist

The dorsal capsulo-scapholunate septum (DCSS) is an anatomic structure linking the scapholunate ligament and the dorsal capsule of the wrist. It should be a predynamic scapholunate stabilizer. The authors, using their experience for the extrinsic ligaments testing, suggest an arthroscopic testing of the DCSS. The status could be graded in 4 stages according to the trampoline aspect and to the fiber attachment. They report a preliminary study on a series of 53 arthroscopies made between January 2014 and December 2015 with evaluation of scapholunate ligament instability and DCSS laxity. There is a significant correlation between the lesional stage of the DCSS and the arthroscopic predynamic scapholunate instability stage (P<0.01).

Management of lunotriquetral instability: a review of the literature

Lunotriquetral ligament injury is a relatively common cause of ulnar-sided wrist pain. Injury ranges from partial stable ligament tears to extensive perilunate instability. Clinical decision-making largely depends on the chronicity, instability and cause of the ligament injury. Conservative treatment is generally regarded as first choice of treatment of mild lunotriquetral instability; however, outcome studies on conservative treatment are lacking. Temporary arthroscopic pinning and/or debridement are minimally invasive procedures of preference. In the case of more dissociative injury, surgical interventions may be performed. The literature suggests that soft tissue reconstruction is an effective procedure in this group. Arthrodesis of the lunotriquetral joint is associated with high rates of non-union (up to 57%) and the indications for surgery should therefore be very clear. Methodological issues make it hard to draw firm conclusions from the data. Studies on the effectiveness of conservative management and prospective comparative studies will further improve clinical decision-making in lunotriquetral instability.

LEVEL OF EVIDENCE

N/A.

Diagnosis and Treatment of Acute Lunotriquetral Ligament Injuries

Isolated acute lunotriquetral (LT) injuries are an uncommon diagnosis in hand surgery. Diagnosis is aided by a high index of suspicion when pain is localized over the LT joint. Standard radiographs show typically normal findings, leading to advanced diagnostic investigations, including MRI and wrist arthroscopy. Standard treatment options for acute LT injuries include immobilization, arthroscopy, and direct open LT repair.

Carpal Ligament Anatomy and Biomechanics

A fundamental understanding of the ligamentous anatomy of the wrist is critical for any physician attempting to treat carpal instability. The anatomy of the wrist is complex, not only because of the number of named structures and their geometry but also because of the inconsistencies in describing these ligaments. The complex anatomy of the wrist is described through a review of the carpal ligaments and their effect on normal carpal motion. Mastery of this topic facilitates the physician's understanding of the patterns of instability that are seen clinically.

Carpal Ligament Injuries, Pathomechanics, and Classification

Carpal instability is a complex array of maladaptive and posttraumatic conditions that lead to the inability of the wrist to maintain anatomic relationships under normal loads. Many different classification schemes have evolved to explain the mechanistic evolution and pathophysiology of carpal instability, including 2 of the most common malalignment patterns: volar intercalated segment instability and the more common dorsal intercalated segment instability. Recent classifications emphasize the relationships within and between the rows of carpal bones. Future research is likely to unify the disparate paradigms used to describe wrist instability.

Management of complications of ligament injuries of the wrist

Despite advances in understanding the anatomy and biomechanics of wrist motion, intrinsic carpal ligament injuries are difficult to diagnose and treat. Even when an accurate diagnosis is made, there is no consensus on the most appropriate and reliable treatment. Injury predisposes to a progressive decline in wrist function and a predictable pattern of degenerative arthritis. To prevent inadequate outcomes, many treatment options exist, all having inherent benefits and complications. This article reviews the complications of intrinsic carpal ligament injuries and complications of their treatment. Methods to prevent and principles to manage the complications are discussed.

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.

Anatomical Description of the Dorsal Capsulo-Scapholunate Septum (DCSS)-Arthroscopic Staging of Scapholunate Instability after DCSS Sectioning

Background The dorsal capsuloligamentous scapholunate septum (DCSS) is a confluence of the dorsal capsule, the dorsal intercarpal ligament (DIC), and the scapholunate interosseous ligament (SLIOL). It appears to play a role in the stability of the scapholunate articulation. The purpose of this study was to describe the anatomical basis for this structure and to investigate its role in scapholunate instability through sectioning of this structure followed by an arthroscopic and fluoroscopic analysis. Material and Methods In the anatomical part of the study we dissected 3 fresh cadaver wrists to examine the anatomy of the DCSS. In the arthroscopic part of the study we assessed the EWAS grade of SL instability before and after sectioning the DCSS and measured the scapholunate and radiolunate angles fluoroscopically. Results Sectioning the DCSS increased the EWAS grade of SL instability but did not affect the scapholunate gap, the scapholunate angle or radiolunate angle. Conclusion We have demonstrated that there is a distinct structure that is separate from the dorsal capsule, which we have labeled the Dorsal Capsuloligamentous Scapholunate Septum. We believe that the DCSS is a previously unreported secondary stabilizer of the SL joint which may have therapeutic and prognostic implications.

Immunohistochemical composition of the human lunotriquetral interosseous ligament

PURPOSE

The human lunotriquetral ligament (LTL) is a functionally important intrinsic hand ligament, which is assumedly subjected to insertion angle changes at the entheses during movement. To clarify whether the current model of the ligament's mechanical environment is reflected in its structural composition, we determined the regional distribution of extracellular matrix-related antigens.

METHODS

The extracellular matrix was immunohistochemically investigated in 12 LTLs from both wrists of 6 human donors (Mean age: 60 y).

RESULTS

The dorsal, proximal, and volar portions of the ligament immunolabeled for type I, III collagen and versican. Both entheses labeled strongly for type II collagen, aggrecan, and link protein and were distinctly cartilaginous. The ligament midsubstance was positive for collagen II in 30%, for aggrecan in 40%, and for keratocan and lumican in 100% of specimens. In contrast, keratocan and lumican were absent from the fibrocartilaginous entheses and the articular cartilage. Ligament insertion at a carpal bone occurs either directly through fibrocartilage or indirectly through a bilayered configuration of fibrocartilage and hyaline-like cartilage. The hyaline-like cartilage is continuous with the neighboring articular cartilage.

CONCLUSIONS

The LTL has an extracellular matrix comparable with that of ligaments experiencing a combination of tensile and shear/compressive load at the attachment sites. All regions of the LTL exhibit fibrocartilaginous entheses; purely fibrous attachment sites are rare. The ligament midsubstance shows a more fibrous phenotype than the entheses and expresses keratocan and lumican, which previously have not been recorded in any human hand ligament.

Ulnar-sided wrist pain: evaluation and treatment of triangular fibrocartilage complex tears, ulnocarpal impaction syndrome, and lunotriquetral ligament tears

Ulnar-sided wrist pain is a common cause of upper extremity disability. Presentation can vary from acute traumatic injuries to chronic degenerative conditions. Because of its overlapping anatomy, complex differential diagnosis, and varied treatment outcomes, the ulnar side of the wrist has been referred to as the "black box" of the wrist, and its pathology has been compared with low back pain. Common causes of ulnar-sided wrist pain include triangular fibrocartilaginous complex injuries, lunotriquetrial ligament injuries, and ulnar impaction syndrome.

The mechanism of ulnar-sided perilunate instability of the wrist: a cadaveric study and 6 clinical cases

PURPOSE

To define the mechanism of ulnar-sided perilunate instability using a cadaveric model and correlate these biomechanical findings with 6 clinical cases.

METHODS

We mounted 16 fresh-frozen human cadaver arms and loaded them to failure in extension and radial deviation, recreating our understanding of the injury mechanism leading to ulnar-sided perilunate instability of the wrist. After testing, we examined the wrists clinically and radiographically. We identified, examined, and treated 6 patients with ulnar-sided perilunate instability over a period of 5 years. Based on these data, we propose a 3-stage mechanism for ulnar-sided perilunate instability of the wrist.

RESULTS

In 13 of 16 specimens, we observed failure of ulnotriquetral, ulnolunate, and ulnocapitate ligaments as well as the dorsal scaphotriquetral and dorsal radiotriquetral ligaments. In 11 of these 13, the lunotriquetral interosseous ligament was disrupted, and in 2 of the 11, a dorsal perilunate dislocation occurred. After comparing these laboratory findings with clinical findings in 6 patients with ulnar-sided perilunate instability, we propose the following 3-stage mechanism for ulnar-sided perilunate instability: stage 1, disruption of the lunotriquetral interosseous ligament; stage 2, stage 1 plus disruption of the ulnolunate, ulnotriquetral, and ulnocapitate ligaments as well as the dorsal scaphotriquetral and radiotriquetral ligaments; and stage 3, stage 2 with progression of the injury through the midcarpal joint plus disruption of the scapholunate and radioscapholunate ligaments, potentially resulting in a dorsal perilunate dislocation.

CONCLUSIONS

We describe a 3-stage mechanism of ulnar-sided perilunate ligamentous wrist injury that can lead to dorsal perilunate dislocation. We recommend considering ulnar-sided perilunate instability of the wrist in patients with ulnar wrist pain after a fall on the outstretched wrist.

CLINICAL RELEVANCE

Ulnar-sided wrist injury can lead to subtle forms of perilunate instability.

In vivo length and changes of ligaments stabilizing the thumb carpometacarpal joint

PURPOSE

To investigate the lengths and changes of selected ligaments stabilizing the thumb carpometacarpal (CMC) joint during thumb motion in vivo.

METHODS

We obtained serial computed tomography scans of the thumb CMC joints of 6 healthy volunteers during thumb flexion, abduction, and opposition. We reconstructed the 3-dimensional structures of the bones of the thumb CMC joint using customized software and modeled the paths of fibers of 5 principal ligaments--deep anterior oblique (beak), dorsoradial, posterior oblique, intermetacarpal, and dorsal intermetacarpal--at each of the CMC joint positions studied. We estimated the virtual lengths of these ligaments in neutral position, flexion, abduction, and opposition of the CMC joint by measuring the distances between the origin and the insertion of individual ligaments, and statistically analyzed the length changes.

RESULTS

The estimated length of the CMC joint ligaments underwent significant changes during thumb motion in vivo. Thumb flexion led to the greatest changes in ligament lengths. During flexion, all the ligaments lengthened significantly (p < .05 or p < .01), except for the beak ligament, which shortened significantly (p < .001). The lengths of the ligaments changed similarly during thumb abduction and opposition, except for the dorsoradial ligament. In both motions, the posterior oblique and dorsal intermetacarpal ligaments lengthened and the beak ligament shortened significantly (p < .05 or p < .01). During the 3 thumb motions, the beak ligament underwent marked shortening, while the other measured ligaments lengthened to varied extent.

CONCLUSIONS

The estimated lengths of principal ligaments stabilizing the CMC joint change substantially during thumb motions in vivo. Thumb flexion causes the greatest changes of the ligament lengths; abduction and opposition result in similar changes in the ligament lengths. The beak ligaments shorten while the other ligaments lengthen. This in vivo study suggests that thumb motions expose the CMC joint ligaments to different tensions at these thumb positions, and that the ligaments are under lower tension during thumb opposition and abduction than during flexion.

In vivo length changes of selected carpal ligaments during wrist radioulnar deviation

PURPOSE

To investigate changes in the lengths of selected carpal ligaments during wrist radioulnar deviation in vivo.

METHODS

We studied in vivo changes in the lengths of fibers of 5 palmar and dorsal intracapsular ligaments of the wrist during radioulnar deviation in 6 wrists of healthy volunteers using a noninvasive approach. Using serial computed tomography scans and volume registration techniques, the carpal kinematics were examined at 4 positions, from 40 degrees ulnar deviation to 20 degrees radial deviation, in 20 degrees increments. The 3-dimensional structures of the carpal bones, distal radius and ulna, and metacarpal bones were reconstructed using customized software. We modeled the paths of fibers of 5 palmar and dorsal carpal ligaments: radioscaphocapitate (RSC), long radiolunate (LRL), ulnocapitate (UC), dorsal intercarpal (DIC), and dorsal radiocarpal (DRC) ligaments. We analyzed changes in the lengths of these ligaments during wrist radioulnar deviation.

RESULTS

During wrist ulnar deviation, the RSC, LRL, and DIC ligaments lengthened significantly. During radial deviation, the UC and DRC ligaments lengthened significantly. Compared with their lengths at the neutral position of the carpus, the LRL ligament showed the greatest elongation rate at wrist ulnar deviation, and the DRC ligament showed the greatest elongation rate at wrist radial deviation among the 5 ligaments studied.

CONCLUSIONS

Among ligaments measured, the RSC, LRL, and DIC ligaments are tensed during wrist ulnar deviation. The UC and DRC ligaments are tensed during wrist radial deviation. Results of this in vivo study suggest that radial or ulnar deviation may predispose some carpal ligaments to excessive tensile load. The finding that the ligaments undergo different elongation rates during wrist motion may also indicate their roles in maintaining normal wrist kinematics.

Dorsal radiocarpal ligament capsulodesis for chronic dynamic lunotriquetral instability

PURPOSE

Chronic lunotriquetral (LT) instability (persisting >3 months after injury) can be treated with a variety of surgical methods (LT fusion, ligament repair or reconstruction, or arthroscopic debridement), with varying degrees of success. We retrospectively evaluated the results of dorsal capsulodesis using the dorsal radiocarpal ligament in an attempt to reinforce the dorsal LT interosseous ligament in patients with chronic dynamic LT instability.

METHODS

A total of 11 patients (mean age, 37 years) with persistent posttraumatic wrist pain and weakness were diagnosed with dynamic LT instability (positive LT ballotment test, disruption of Gilula's lines or volar intercalated segment instability deformity on stress radiography, arthroscopic findings of Geissler grade 3, or 4 LT tears). They were treated consecutively with dorsal capsulodesis. We used subjective and functional outcome measures to evaluate the results.

RESULTS

The mean follow-up period was 31 months (range, 12-65 months). The postoperative visual analog pain score and Mayo wrist score were significantly improved compared with their preoperative values. The average grip strength increased by 5 kg, and the average range of wrist flexion was reduced by 3 degrees .

CONCLUSIONS

In this small series, in the short term, dorsal radiocarpal ligament capsulodesis reduced pain and instability and improved function in patients with chronic dynamic LT instability.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Management of wrist injuries

LEARNING OBJECTIVES

After studying this article, the participant should be able to: 1. Understand the anatomy and the biomechanical properties of the wrist. 2. Understand the standard examination process for wrist injuries. 3. Accurately diagnose common wrist conditions. 4. Establish a management plan for wrist problems.

BACKGROUND

Although common, wrist injuries and conditions are difficult to treat if the physician is unfamiliar with their management.

METHODS

Wrist anatomy and kinematics are discussed. Physical and radiographic examinations that are mandatory for diagnosing wrist conditions are presented. Common wrist injuries are reviewed.

RESULTS

Understanding the anatomy and kinematics of the wrist is important in diagnosing and treating wrist conditions and in predicting outcomes after treatment. Physical examination of the wrist requires an understanding of the surface anatomy and a number of specific maneuvers. Physicians should also be familiar with other diagnostic tests, which include radiography, arthrography, computed tomography, magnetic resonance imaging, and arthroscopy.

CONCLUSIONS

Physicians who treat wrist injuries should be able to establish an adequate management plan for common wrist injuries and conditions and be able to predict outcomes based on these treatment plans.

Kinematics of the midcarpal and radiocarpal joint in flexion and extension: an in vitro study

PURPOSE

To apply carpal kinematic analysis using noninvasive medical imaging to investigate the midcarpal and radiocarpal contributions to wrist flexion and extension in a quasidynamic in vitro model.

METHODS

Eight fresh-frozen cadaver wrists were scanned with computed tomography in neutral, full flexion, and full extension. Body-mass-based local coordinate systems were used to track motion of the capitate, lunate, and scaphoid with the radius as a fixed reference. Helical axis motion parameters and Euler angles were calculated for flexion and extension.

RESULTS

Minimal out-of-plane carpal motion was noted with the exception of small amounts of ulnar deviation and supination in flexion. Overall wrist flexion was 68 degrees +/- 12 degrees and extension was 50 degrees +/- 12 degrees. In flexion, 75% of wrist motion occurred at the radioscaphoid joint, and 50% occurred at the radiolunate joint. In extension, 92% of wrist motion occurred at the radioscaphoid joint, and 52% occurred at the radiolunate joint. Midcarpal flexion/extension between the capitate and scaphoid was 0 degrees +/- 5 degrees in extension and 10 degrees +/- 13 degrees in flexion. Midcarpal flexion/extension between the capitate and lunate was larger, with 15 degrees +/- 11 degrees in extension and 22 degrees +/- 19 degrees in flexion.

CONCLUSIONS

The capitate and scaphoid tend to move together. This results in greater flexion/extension for the scaphoid than the lunate at the radiocarpal joint. The lunate has greater midcarpal motion between it and the capitate than the scaphoid does with the capitate. The engagement between the scaphoid and capitate is particularly evident during wrist extension. Out-of-plane motion was primarily ulnar deviation at the radiocarpal joint during flexion. These results are clinically useful in understanding the consequences of isolated fusions in the treatment of wrist instability.

Clinical applications of volar portals in wrist arthroscopy

Volar portals for wrist arthroscopy have certain advantages over the standard dorsal portals for visualizing dorsal capsular structures as well as the palmar aspects of the carpal ligaments. The volar radial portal is relatively easy to use and is an ideal portal for evaluation of the dorsal radiocarpal ligament and the palmar aspect of the scapholunate interosseous ligament. The volar midcarpal portal may be considered as an occasional accessory portal for visualizing the palmar aspects of the capitate and hamate in cases of avascular necrosis or osteochondral fractures. The volar ulnar portal is especially useful for the viewing and debridement of palmar tears of the lunotriquetral ligament.

Tenodesis of the extensor carpi ulnaris for chronic, post-traumatic lunotriquetral instability

We describe a technique of soft-tissue reconstruction which is effective for the treatment of chronic lunotriquetral instability. Part of extensor carpi ulnaris is harvested with its distal attachment preserved. It is passed through two drill holes in the triquetrum and sutured to itself. This stabilises the ulnar side of the wrist.

We have reviewed 46 patients who underwent this procedure for post-traumatic lunotriquetral instability with clinical signs suggestive of ulnar-sided carpal instability. Standard radiographs were normal. All patients had pre-operative arthroscopy of the wrist at which dynamic lunotriquetral instability was demonstrated. A clinical rating system for the wrist by the Mayo clinic was used to measure the outcome. In 19 patients the result was excellent, in ten good, in 11 satisfactory and in six poor. On questioning, 40 (87%) patients said that surgery had substantially improved the condition and that they would recommend the operation. However, six (13%) were unhappy with the outcome and would not undergo the procedure again for a similar problem. There were six complications, five of which related to pisotriquetral problems. The mean follow-up was 39.1 months (6 to 100). We believe that tenodesis of extensor carpi ulnaris is a very satisfactory procedure for isolated, chronic post-traumatic lunotriquetral instability in selected patients. In those with associated pathology, the symptoms were improved, but the results were less predictable.

The effect of ulnar shortening on lunate and triquetrum motion--a cadaveric study

BACKGROUND

Ulnar shortening osteotomy is a widely used procedure for a number of pathologic conditions. However, there is little biomechanical data on its effect on the surrounding soft tissue structures. Therefore, the objective of this study was to determine the effects of progressive ulnar shortening on the distal radioulnar joint and the proximal carpal bones.

METHODS

The kinematics and strain between the ulnar styloid, lunate, and triquetrum were evaluated with varying supination and pronation forces. Six fresh-frozen cadaveric upper extremity specimens were tested after progressive ulnar shortening using a custom jig. Biomechanical measurements including strain and translation were made by evaluating the change in position of the digitizing markers on the carpal bones, radius and ulna.

FINDINGS

There were significant changes in marker positions with respect to intact specimens for each amount of shortening at the ulnar styloid (P<0.001), the lunate (P<0.001), and triquetrum (P<0.001). With progressive ulnar shortening, the strain data demonstrated that there was no significant change in lunato-triquetral strain, but demonstrated a significant increase in both ulno-triquetral and ulno-lunato strain (P<0.04).

INTERPRETATION

Progressive ulnar shortening increases ulno-triquetral and ulno-lunato strains with an ensuing reduction in motion between the carpal bones.

[Ulnar instability of the carpus]

Ulnar instabilities of the carpus are rare findings depending on a dissociation of the lunotriquetral (LT-) junction. They are frequently not recognized or confused with ulnocarpal complaints of other origin due to missing typical clinical or radiological indications. The central structures are the os triquetrum and its connections to the os lunatum, the distal carpal row, radius and ulna. The most important causes are injuries, but degeneration, ulnar impaction syndrome or the ulna plus variant can also be involved. The symptoms are ulnar-sided pain, sensations of instability and weakness as well as "clunking" sensations in the ulnar wrist. Clinical examination may reveal tenderness in the LT-interval, between the ECU- and FCU-tendons, and displacement of the triquetrum on palpation. The LT-interval is rarely extended in conventional X-rays. A VISI position of the os lunatum is found in instabilities of higher degree. A distinct diagnosis is only achieved by arthroscopy. Conservative treatment consists of 4-8 weeks of arm immobilization. Diagnostic arthroscopy can be combined with débridement and/or closed reduction of the LT-interval with consecutive percutaneous k-wire fixation. If a repair of the LT-ligament is not possible, reconstructive methods are indicated. They include extrinsic tenodesis with part of the extensor carpi ulnaris tendon, ligamentoplasty or osteoligamentous autografts. The role of lunotriquetral arthrodesis is considered to be controversial, due to a high rate of non-fusions. Simple correction of the LT-dissociation does not resolve the static instability of the proximal row (VISI-position of the lunatum). In these cases, salvage procedures such as limited arthrodesis of the wrist, proximal row carpectomy or complete arthrodesis are indicated.

The use of a volar ulnar portal in wrist arthroscopy

PURPOSE

The purpose of this study was to quantitatively describe the neurovascular relationships of a volar ulnar (VU) wrist arthroscopy portal. A second purpose was to evaluate whether the use of a VU portal identified additional pathology of the lunotriquetral ligament and ulnar sling mechanism that was not seen through the dorsal portals.

TYPE OF STUDY

This study was an anatomic study and retrospective chart review.

METHODS

Cadaver dissections established the neurovascular anatomy of the VU portal. Measurements were taken from the portal to the ulnar nerve and artery, the palmar cutaneous branch of the ulnar nerve, and the pronator quadratus. A dorsal capsulotomy was performed to assess the ligamentous interval. A chart review was performed of 23 patients in whom a volar ulnar portal was used. Intraoperative pathology that was identified through the VU portal but was not visible through a dorsal portal was recorded. Postoperative neurovascular complications were noted.

RESULTS

The portal was generally > 5 mm radial to the ulnar neurovascular bundle, but no true internervous plane was seen. Tears of the palmar aspect of the lunotriquetral ligament were seen in 7 patients. One patient had a triangular fibrocartilage tear that extended into the dorsal radioulnar ligament.

CONCLUSIONS

This study provides a safe, standardized approach to the volar ulnar aspects of the radiocarpal joint, which is useful for evaluation of the ulnar sling mechanism and the dorsal radioulnar ligament. The VU portal aids in the diagnosis and debridement of tears involving the palmar aspect of the lunotriquetral ligament. The VU portal should be considered for inclusion in the arthroscopic examination of any patient with ulnar sided wrist pain.

LEVEL OF EVIDENCE

Level IV.

In vivo analysis of carpal kinematics and comparative review of the literature

PURPOSE

Techniques have been developed very recently with which it is possible to quantify accurately in vivo 3-dimensional (3-D) carpal kinematics. The aim of this study was to evaluate the feasibility of our novel 3-D registration technique by comparing our data with data found in the literature.

METHOD

The right wrists of 11 healthy volunteers were imaged by spiral computed tomography (CT) during radial-ulnar deviation and 5 of those wrists were imaged also during flexion-extension motion. With a matching technique relative translations and rotations of the carpal bones were traced. We compared our in vivo results with data presented in the literature.

RESULTS

We found our in vivo data largely to concur with in vitro data presented in the literature. In vivo studies revealed only larger out-of-plane motions within the proximal carpal row than described in most in vitro studies. In vivo studies also showed larger interindividual variations.

CONCLUSIONS

A single functional model of carpal kinematics could not be determined. We expect that in vivo 3-D CT studies on carpal kinematics, especially when applied to dynamic wrist motion, will have future diagnostic applications and provide information on long-term results of surgical interventions.

Scaphoid kinematics in vivo

The purpose of this study was to quantify 3-dimensional (3-D) in vivo scaphoid kinematics during flexion-extension motion (FEM) and radial-ulnar deviation (RUD) of the hand. The right wrists of 11 healthy volunteers were imaged by spiral computed tomography during RUD and 5 of those wrists also during FEM. With a matching technique, relative translations and rotations of the scaphoids were traced. Our results showed a broad spectrum of kinematic patterns of the scaphoid during RUD, with small intercarpal motions within the proximal carpal row. Some scaphoids rotated basically around the flexion-extension axis only whereas others rotated almost entirely around the deviation axis during RUD. During FEM we found highly uniform scaphoid motion patterns with large intercarpal motions within the proximal carpal row. These findings suggest that current theories cannot sufficiently explain wrist kinematics and stress the need for more in vivo studies on 3-D carpal kinematics.

Wrist kinetics after luno-triquetral dissociation: the changes in moment arms of the flexor carpi ulnaris tendon

Wrist biomechanics after luno-triquetral (LT) dissociation is important for understanding the clinical sequelae of the disease and for determining its treatment options. The LT interosseous ligament plays an important role in stabilizing the joint and damage to the ligament would be expected to significantly increase moment arms of tendon of the flexor carpi ulnaris (FCU), the principal ulnar wrist flexor. We investigated the changes in moment arms of FCU tendon after various amounts of sectioning of the ligaments proven to be associated with LT dissociation. In six fresh frozen cadaveric upper extremities, excursions of the FCU tendon were recorded simultaneously with wrist joint angulation during wrist flexion-extension and radioulnar deviation. Tendon excursions were measured in intact wrists, in wrists with sectioning of the dorsal portion of the LT interosseous ligament, in wrists with sectioning of the entire LT interosseous ligament, and finally in wrists with further sectioning of the dorsal radiotriquetral and intercarpal ligaments. Moment arms of the tendon were calculated from tendon excursions and joint motion angulations and expressed as percentage changes from those in the intact wrist. During wrist flexion-extension, moment arms of the FCU tendon after sectioning of the entire LT interosseous ligament and after sectioning of the two capsular ligaments were 112 +/- 7% and 114 +/- 8%, respectively; these values were significantly greater than those in the intact wrist. During radioulnar deviation, the moment arms were 114 +/- 11% after sectioning of the dorsal portion of the LT interosseous ligament, 134 +/- 15% after sectioning of the entire ligament, and 153 +/- 18% after sectioning of the capsular ligaments, again being significantly greater than the normal wrist. Increase in moment arms of the FCU tendon after loss of integrity of the LT interosseous ligament and dorsal capsular ligaments may contribute to clinical sequelae of LT dissociation and difficulty in treating this disorder.

Three-dimensional carpal kinematics in vivo

OBJECTIVE

The purpose of this study was to accurately quantify three-dimensional in vivo kinematics of all carpal bones in flexion and extension and radial and ulnar deviation.

DESIGN AND METHODS

The right wrists of 11 healthy volunteers were imaged by spiral CT with rotational increments of 5 degrees during ulnar-radial deviation and of five of them also during flexion-extension motion. One regular-dose scan was used and the subsequent scans during wrist motion were performed with one-tenth of the regular dose. A three-dimensional matching technique using the internal structure of the bones was developed to trace the relative translations and rotations of the carpal bones very accurately.

RESULTS

Most of our results are in concordance with previously published in vitro data. We could, among others, substantiate proof to the statement that there is more than one kinematic pattern of the scaphoid. Furthermore, we could accurately describe small adaptive intercarpal motions in vivo of the distal carpal row.

CONCLUSIONS

To our knowledge, this is the first time the three-dimensional in vivo kinematics of all eight carpal bones is quantified accurately and non-invasively.

RELEVANCE

Kinematics of an injured wrist can be compared to these reference data. It may become possible that in this way a ligament lesion can be detected with high specificity and sensitivity, and that no other diagnostic modality will be needed. With these data we made animations with which the complex movements of the bones during different motions of the wrist can be viewed. In the future it may become possible that this analysis provides valuable information on the long-term results of operative interventions and possibly predicts results of operative techniques.

The effect of sectioning the dorsal radiocarpal ligament and insertion of a pressure sensor into the radiocarpal joint on scaphoid and lunate kinematics

The role of the dorsal radiocarpal wrist ligament has been the subject of several investigations. Several biomechanical studies have used sensors inserted dorsally into the wrist joint to evaluate its pressure distribution. The purpose of this study was to evaluate whether a dorsal capsulotomy that sections the dorsal radiocarpal ligament or insertion of a flexible pressure sensor alters scaphoid or lunate kinematics. Eight cadaver upper extremities were instrumented with motion sensors and placed in a wrist joint simulator. Each arm was moved through continual cycles of wrist flexion/extension and radial/ulnar deviation. Motion data were obtained in the intact state, after a capsulotomy, and after insertion of the sensor. We found that either a dorsal capsulotomy sectioning the dorsal radiocarpal ligament or insertion of the pressure sensor alters scaphoid and lunate kinematics during dynamic wrist motion. This study supports the clinical belief that this dorsal wrist ligament should be spared during surgical approaches to the carpus.

In vivo scaphoid, lunate, and capitate kinematics in flexion and in extension

Carpal kinematics have been previously limited to in vitro models with cadaveric specimens. Using a newly developed markerless bone registration algorithm, we noninvasively studied the in vivo kinematics of the capitate, scaphoid, and lunate during wrist extension and flexion in both wrists of 5 men and 5 women. Computed tomography volume images were acquired in neutral and in 2 positions in both extension and flexion. The 3-dimensional kinematics of the capitate, scaphoid, and lunate relative to the radius were the determined. Scaphoid and lunate rotations differed for flexion and extension but were found to vary linearly with capitate rotation. In flexion the scaphoid contributed 73% of capitate motion and the lunate contributed 46%. In extension the scaphoid contributed 99% of capitate motion and the lunate contributed 68%. Contributions of the scaphoid and lunate to wrist extension were 15% greater than values reported in previous in vitro studies, while scaphoid and lunate contributions to wrist flexion were more similar to previous studies. The findings support a relative "engagement" of the scaphoid, capitate, and lunate during wrist extension. The only difference between male and female kinematics was a more distal location of the rotation axes; we believe this was due to a difference in carpal bone size, not gender. This study reports the 3-dimensional in vivo measurement of carpal motion using a noninvasive technology. This technique may prove useful in the study of more complex motions of the hand and wrist and of the abnormal kinematics that occur following ligamentous injury.

Lunotriquetral instability: diagnosis and treatment

Isolated injury of the lunotriquetral interosseous ligament complex and associated structures is less common and is poorly understood compared with the other proximal-row ligament injury, scapholunate dissociation. The spectrum of injuries ranges from isolated partial tears to frank dislocation, and from dynamic to static carpal instability. The diagnosis may be difficult to establish because of the many possible causes of ulnar-sided wrist pain and the often normal radiographic appearance. The mechanism of injury is variable and includes attrition by age, positive ulnar variance, and perilunate or reverse perilunate injury. Appropriate treatment requires assessment of the degree of instability and the chronicity of the injury. Options include corticosteroid injection, immobilization, ligament repair, ligament reconstruction with tendon grafts, limited intercarpal arthrodesis, and ulnar shortening.