Ulnar-sided perilunate instability: an anatomic and biomechanic study

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.

Midcarpal Instability

Midcarpal instability (MCI) of the wrist represents multiple distinct clinical entities that all have in common abnormal force transmission across the midcarpal joint. This can be asymptomatic but can also result in painful wrist motion, a characteristic catch-up clunk, and symptoms of instability. The carpus is stabilized by numerous extrinsic and intrinsic ligaments. Dynamic joint reactive forces between the proximal and distal carpal rows help create reciprocal motion, which results in smooth, physiologic wrist mechanics. Diagnosis of MCI requires a thorough history, physical examination, and adequate imaging. MCI can be managed nonsurgically with activity modification, physical therapy, specialized orthotics, medications, and corticosteroid injections. A variety of surgical treatment options exists to treat symptomatic MCI. These include arthroscopic thermal capsulorrhaphy, ligament repair or reconstruction, radial osteotomies, and limited radiocarpal or intercarpal fusions. Capsulorrhaphy or ligament repair is favored for mild to moderate cases; osteotomies can be used for the correction of bony deformities contributing to instability, whereas partial wrist arthrodesis is indicated for severe or recurrent instability and fixed deformities.

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.

Chronic Isolated Dorsal Dislocation of the Lunate. A Rare Presentation of Carpal Instability

Isolated dorsal lunate dislocation is a rare injury. Only one case has been reported previously in which the treatment was performed in the chronic stage. In this report, we present the case of a 49-year-old handworker male who presented a dorsal dislocation of the lunate after a traffic accident. He was referred to our clinic 2.5 months later due to an initial misdiagnosis. Surgical treatment was performed and consisted of an open reduction using a nerve-sparing dorsal approach. A complete rupture of the perilunate ligaments and a marked instability of the lunate were detected. Stabilisation of the scapholunate, lunotriquetral and scaphocapitate spaces with a compression screw and Kirschner wires, respectively, was performed. The persistence of pain and functional limitation after the surgery along with an insufficient reduction of the scapholunate space on the X-ray and the development of a fistula on the ulnar edge of the carpus prompted reintervention. A hardware-free total wrist arthrodesis was preferred over other procedures, such as proximal row carpectomy, owing to the important articular damage. At the 3-month follow-up, he was clinically stable, consolidation of arthrodesis was documented and he had returned to his previous activities. Isolated dorsal dislocation of the lunate is a rare lesion. There is no consensus on the management of isolated chronic dislocations of the lunate. The frequent delay in the diagnosis compromises the final outcome of reconstructive techniques and introduces the risk of residual instability, increasing the incidence of chronic pain associated with post-traumatic osteoarthritis. In the case of chronic lesions, treatment with palliative techniques, such as proximal carpectomy or joint arthrodesis, should be considered.

Reverse Perilunate Injuries-The "Extended Scaphoid" Sign

Background  Reverse perilunate injuries (REPLI) are rare variants of the classic radial-sided perilunate injuries (PLI) whose mechanism was described by Mayfield in 1980. Classic radial-sided nontranscaphoid dorsal PLI invariably display a flexed, foreshortened position of the scaphoid on their initial posteroanterior (PA) and lateral radiographs. We observed that some dorsal perilunate dislocations displayed an extended position of the scaphoid on their initial radiographs. Our hypothesis is that this extended position of the scaphoid was associated with a REPLI pattern. Methods  The PA and lateral initial emergency radiographs of our specialized wrist surgery series of 114 dorsal pure ligamentous PLI (within a 186 cases series of PLI treated between 2004 and 2020) were reviewed as well as the available figures of the current REPLI literature. Results  A total of seven cases of cases within our dorsal PLI series displayed an extended position of the scaphoid on their initial PA and lateral radiographs, while 107 cases displayed a flexed, foreshortened position. The PA and lateral radiographs available in the REPLI literature displayed an extended position of the scaphoid, a lunotriquetral dissociation, and a dorsal dislocation of the capitate with respect to the lunate. Discussion  This study confirms our hypothesis. By contrast to the dorsal classic radial-sided pure ligamentous PLI pattern of scaphoid displacement (scaphoid flexed and foreshortened with scapholunate gap), the dorsal REPLI pattern displays an extended position of the scaphoid with scapholunate step-off and overlap rather than a gap. The combination of a lunotriquetral dissociation with a dorsal dislocation of the capitate from the lunate yet an extended position of the scaphoid with almost normal radioscaphoid relationships should raise a high suspicion for REPLI.

Traumatic Nondissociative Carpal Instability: A Case Series

PURPOSE

We report 8 cases of acute or subacute unilateral nondissociative carpal instability (CIND) in the context of nondisplaced scaphoid fractures.

METHODS

Eight patients from 3 centers developed abnormal volar intercalated segment instability (VISI) or dorsal intercalated segment instability (DISI) following the diagnosis of a nondisplaced scaphoid fracture. An operative inspection in each patient confirmed intact scapholunate and lunotriquetral interosseous ligaments. We outline the demographic characteristics of our patient cohort, radiologic and operative findings of CIND-DISI and CIND-VISI, and the outcomes of acute and delayed treatment.

RESULTS

Two patients were diagnosed with CIND-DISI and 6 with CIND-VISI associated with ipsilateral nondisplaced scaphoid fractures. The average time from injury to diagnosis of CIND was 11 weeks, and the mean clinical and radiographic follow-up was 18 months. Rapid healing of the scaphoid fractures was achieved in all patients (4 open reduction internal fixation, 4 cast). All patients underwent surgery to improve proximal carpal row alignment: in 3 of the 4 patients who were diagnosed and treated surgically within 12 weeks of injury, the radiolunate angle (RLA) was successfully restored. A contracture release and ligament repair or reconstruction with tendon graft 12 or more weeks following injury was unsuccessful in restoring proximal row alignment in all 4 patients. Two patients in the delayed treatment group required secondary surgery for partial fusion.

CONCLUSIONS

Based on the arthroscopic, imaging, and operative findings, we propose that the ligamentous restraints to CIND-VISI are dorsal at the radiocarpal joint and volar at the midcarpal joint. Conversely, the ligamentous restraints to CIND-DISI are dorsal at the midcarpal joint and volar at both the radiocarpal and midcarpal joints. In our series, a delayed diagnosis and late reconstructive surgery were associated with no improvement in RLA. We recommend early recognition of traumatic CIND and prompt treatment of injured ligaments prior to the development of a fixed deformity.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Arthroscopic Lunotriquetral Ligamentoplasty, from the Cadaver Lab to the Clinical Practice

Introduction There has been an increase in the diagnosis of injuries to the intrinsic ligaments of the wrist due to the more widespread use of arthroscopy in the treatment of patients with musculoskeletal wrist pain, and arthroscopy is particularly very helpful to determine the etiology of these lesions at the ulnar level. The treatment of lunotriquetral ligament injuries encompasses different techniques with results that are little reproducible. Ligament reconstruction through tendon grafting has shown favorable results, but it involves extensive open approaches that lead to a slower recovery a lower range of joint motion due to the excess of scar tissue. The objective of the present study is to describe the performance, in a cadaver, of a minimally-invasive lunotriquetral and secondary-stabilizer ligamentoplasty and its application in a representative clinical case.

Material and Methods A preliminary study of six specimens in which a lunotriquetral and secondary-stabilizer ligamentoplasty was performed consecutively through a free tendon graft with arthroscopic assistance. We proceeded to recreate the complete ligament injury, and to perform an assessment of lunotriquetral instability according to the Geissler classification and an arthroscopic ballottement test. We describe the surgical technique, ligament stability after the ligamentoplasty, and the subsequent anatomical dissection, assessing the anatomical structures susceptible to iatrogenic injury. We also describe the application of the technique in one case, comparing the clinical parameters before and after the procedure: range of motion of the joint, strength, pain and the shortened version of the Disabilities of the Arm, Hand, and Shoulder (QuickDASH) questionnaire.

Results The ligamentoplasties performed showed recovery of the stability of the lunotriquetral interval assessed according to the Geissler classification and the arthroscopic ballottement test. In the dissection of the specimens, no iatrogenic lesions were found in the tendons or the surfaces of the mediocarpal and radiocarpal joints. The average distances between the nearest bone tunnels and nerves were of 7.3 mm for the sensory branch of the ulnar nerve, of 3.6 mm for the posterior interosseous nerve, and of 4.5 mm for the ulnar neurovascular bundle. No fractures were observed in the tunnelled bones. In the clinical case herein presented, six months after the intervention, there was an improvement in strength and preoperative pain, with a slight decrease in the joint range of motion (15% compared to the contralateral joint).

Conclusions The lunotriquetral ligamentoplasty herein described could contribute to the biomechanical restoration of the carpus and be an option for recosntruction in selected cases. Its performance through minimally-invasive techniques, and the use of a free tendon graft together with specific rehabilitation should be considered to optimize the outcomes.

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.

Avascular necrosis of the lunate secondary to perilunate fracture dislocation: Case report and review of the literature

This is a 39-year-old male, fell from a bike, left wrist with trans-styloid perilunate fracture dislocation that underwent open reduction internal fixation, 20 months after surgery the patient developed avascular necrosis of the lunate, final wrist fusion was performed secondary to the arthritic changes on the wrist. Anatomic dissection was performed and vascularity of the lunate was identified, its origin is from the volar palmar arch, when dislocated palmarly and more than 90 degrees the vessel is still intact. More than 512 patients with perilunate dislocation and perilunate fracture dislocation are included we identified in the literature transient avascular necrosis of the lunate in nine and seventeen of pure avascular necrosis of the lunate. Concluding that avascular necrosis of the lunate after perilunate dislocation or perilunate fracture dislocation is an infrequent finding especially when the volar ligaments are intact.

Carpal Instability: I. Pathoanatomy

The pathoanatomy of carpal instability is multifactorial and usually complex. A thorough medical history and clinical examination are essential, as well as profound knowledge of the specific instability patterns. The stability of the wrist is ensured by the carpal joint surfaces, by intact intra-articular (particularly the scapholunate interosseous ligament) and intracapsular ligaments, and by crossing extensor and flexor tendons, the latter making the proximal carpal row an "intercalated segment." An important classification feature is the distinction between dissociative and nondissociative forms of carpal instability. Among others, scapholunate dissociation, lunotriquetral dissociation, midcarpal instability, and ulnar translocation are the most common entities. Early forms of instability are considered dynamic. In the natural course, static instability of the wrist and osteoarthritis will develop. This review focuses on the pathoanatomical fundamentals of the various forms of carpal instability.

Volar Tilt of the Lunate After Open Reduction Internal Fixation of a Distal Radius Fracture

The pathophysiology of carpal adaptations after fracture of the distal radius is incompletely understood. We report 5 patients who had normal carpal alignment on injury radiographs that developed marked volar angulation of the lunate during recovery from volar plate fixation of a fracture of the distal radius. There were no signs of alteration of the carpal ligaments. Two patients had similar volar tilt on the contralateral side. The cause and optimal treatment of carpal malalignment after restoration distal radial alignment are unclear.

Demystifying Palmar Midcarpal Instability

Palmar midcarpal instability is an uncommon condition diagnosed clinically with a painful pathognomonic clunk on terminal ulnar deviation of the wrist. Various causes have been described, but congenital laxity of the carpal ligaments is thought to be a key contributor. Treatment commences with conservative measures. This includes proprioceptive training based on more recent concepts on the sensorimotor function of the wrist. When these measures plateau, surgery is considered. The lack of high-level evidence and consensus on its cause continue to hamper our understanding and knowledge of this condition. The purpose of this review is to examine the current evidence to conceptualize this mysterious, yet infrequent phenomenon, and to provide an algorithm on its management.

Reduction and Association of the Lunotriquetral Ligament for Reverse Perilunate Dislocation

Background  Reverse perilunate injuries are rare. Contrary to perilunate injuries, the violent force would start from the lunotriquetral ligament, go reversely toward the radial side, and cause the reverse or ulnar-sided perilunate dislocation. Case Description  We describe a 31-year-old man with a reverse perilunate dislocation, who presented to our institution 3 weeks after a motorcycle accident. The patient was successfully treated with the reduction and association of the lunate and triquetrum (RALT) procedure by using closed maneuver and percutaneous headless compression screw fixation. The patient can obtain a good radiographic result and satisfactory function at the 30-month follow-up. Literature Review  Many case series were reported concerning the perilunate injuries. However, few cases of reverse perilunate dislocation have been reported in the literature. No cases of reverse perilunate dislocation treated 3 weeks after the injury with the RALT procedure have been reported. Clinical Relevance  In this case, we found that the dislocation could still be reduced with the closed maneuver. With the RALT procedure, the carpal alignment can be maintained and the stability can be regained. Also, the functional outcomes are good.

Treatment of Carpal Instability and Distal Radioulnar Joint Instability

Carpal instability and distal radioulnar joint instability represent an important set of conditions responsible for pain and disability in the wrist. Either condition can occur as a result of ligamentous failure or loss of articular congruity from fractures or a combination of both. Instability itself is a clinical diagnosis supported by relevant imaging modalities. Carpal and distal radioulnar joint instability needs to be considered according to its stage and severity as well as other factors like etiology and chronicity to determine the optimal treatment option. This article summarizes the conditions most relevant to the practice of a hand surgeon, with emphasis divided equally between assessment and diagnosis, staging, and treatment. The 3 most common carpal instability conditions are outlined in this article together with a review on acute and chronic distal radioulnar joint instability.

Anatomy and injuries of the pediatric wrist: beyond the basics

Ligamentous injuries of the pediatric wrist, once thought to be relatively uncommon, are increasingly recognized in the context of acute high-energy mechanism trauma and chronic axial loading, including those encountered in both recreational and high-performance competitive sports. Recent advances in MR-based techniques for imaging the pediatric wrist allow for sensitive identification of these often radiographically occult injuries. Detailed knowledge of the intrinsic and supportive extrinsic ligamentous complexes, as well as normal developmental anatomy and congenital variation, are essential to accurately diagnose injuries to these structures. Early identification of ligamentous injury of the pediatric wrist is essential within the conservative treatment culture of modern pediatric orthopedics because treatment of these lesions often necessitates surgery, and outcomes often depend on early and sometimes aggressive intervention. In this article, we review MR arthrogram technique and pediatric wrist anatomy, and correlate appearances on MR and selected ligamentous pathologies of the pediatric wrist.

Biomechanical Analysis of Palmar Midcarpal Instability and Treatment by Partial Wrist Arthrodesis

PURPOSE

To create a biomechanical model of palmar midcarpal instability by selective ligament sectioning and to analyze treatment by simulated partial wrist arthrodesis.

METHODS

Nine fresh-frozen cadaver arms were moved through 3 servohydraulic actuated motions and 2 passive wrist mobilizations. The dorsal radiocarpal, triquetrohamate, scaphocapitate, and scaphotrapeziotrapezoid ligaments were sectioned to replicate palmar midcarpal instability. Kinematic data for the scaphoid, lunate, and triquetrum were recorded before and after ligament sectioning and again after simulated triquetrohamate arthrodesis (TqHA) and radiolunate arthrodesis (RLA).

RESULTS

Following ligament sectioning, the model we created for palmar midcarpal instability was characterized by significant increases in (1) lunate angular velocity, (2) lunate flexion-extension, and (3) dorsal/volar motion of the capitate during dorsal/volar mobilizations. Simulated TqHA caused significantly more scaphoid flexion and less extension during the wrist radioulnar deviation motion. It also increased the amount of lunate and triquetral extension during wrist flexion-extension. Simulated RLA significantly reduced scaphoid flexion during both wrist radioulnar deviation and flexion-extension.

CONCLUSIONS

Both simulated arthrodeses eliminate wrist clunking and may be of value in treating palmar midcarpal instability. However, simulated RLA reduces proximal row motion whereas simulated TqHA alters how the proximal row moves. Long-term clinical studies are needed to determine if these changes are detrimental.

CLINICAL RELEVANCE

Palmar midcarpal instability is poorly understood, with most treatments based on pathomechanical assumptions. This study provides information that clinicians can use to design better treatment strategies for this unsolved condition.

Lack of experience is a significant factor in the missed diagnosis of perilunate fracture dislocation or isolated dislocation

OBJECTIVE

The aim of this study was to analyze the risk factors contributing to the misdiagnosis of perilunate injuries.

METHODS

The study included patients who had perilunate dislocation or fracture dislocation correctly or incorrectly diagnosed on initial examination between 2008 and 2014. Data related to the length of time until correct diagnosis of the perilunate injury; cause of injury; presence of associated fractures, polytrauma or concomitant trauma in the ipsilateral upper extremity; time between injury and first presentation; first treatment applied; presence of ligamentous perilunar injuries only or fracture and dislocation; inadequate radiographic assessment; and experience of the physicians were recorded and analyzed.

RESULTS

A total of 44 wrists were included in the study. Of those, 10 (22.7%) wrists (mean patient age: 44.4 years [28 ± 58 years]) with perilunate injuries were misdiagnosed in the initial evaluation. All of the risk factors were found to be similar between the group of patients with correct initial diagnosis and missed diagnosis group, except for the experience of the orthopedic surgeon assessing the injury (p = 0.0001). Of the surgeons who missed the diagnosis, 70% reported that it was their first encounter with a perilunate injury.

CONCLUSION

The results of this study indicated that lack of experience was the most important factor in the misdiagnosis of perilunate fracture dislocation or isolated dislocation.

LEVEL OF EVIDENCE

Level IV, diagnostic study.

Palmer Midcarpal Instability: An Algorithm of Diagnosis and Surgical Management

Background  Palmar midcarpal instability (PMCI) is an uncommon form of nondissociative carpal instability. However, it is an important cause of chronic ulnar wrist pain. Diagnosis can be difficult and high index of suspicion is mandatory. Pathomechanics and optimal treatment of PMCI remain uncertain. We propose an algorithm of clinical diagnosis and evaluate the outcome of our management. Materials and Methods  Between 2000 and 2011, 16 patients, including 7 males and 9 females, of a mean age of 33.9 diagnosed with PMCI were reviewed for their clinical, radiologic, and arthroscopic features. All patients presented with ulnar wrist pain in their dominant hands except in one. Initial management included a disease-specific anticarpal supination splint. Refractory cases were evaluated by arthroscopy and treated by arthroscopic thermal shrinkage using radiofrequency appliance as an interim or definite surgical intervention. Shrinkage was targeted at the ulnocarpal ligament at the radiocarpal joint and triquetrohamate ligament at the midcarpal joint. Nonresponsive or recurrent cases were managed by a novel technique of dorsal radiocarpal ligament reconstruction procedure using a pisiform-based split flexor carpi ulnaris (FCU) tendon graft. Results  In all cases, the midcarpal clunk test was positive with pain. Other common clinical features included lax ulnar column, carpal supination, volar sagging of the wrist, increased pisostyloid distance, wrist pain aggravated by passive hand supination and not by passive forearm supination, and increased wrist pain upon resisted pronation, which could be partially alleviated by manually supporting the pisostyloid interval. Common arthroscopic findings were excessive joint space at triquetrohamate interval and reactive synovitis over the ulnar compartments. Nine patients (56.3%) responded well to splinting alone at an average follow-up of 3.3 years. Arthroscopic thermal shrinkage was performed in five patients with recurrence in two patients. Five patients received split FCU tendon graft for ligament reconstruction. All patients showed improvement in the wrist performance score (preop 21.0, postop 36.6 out of 40) and pain score (preop 10.0, postop 2.2 out of 20) at the final follow-up of average 86 months (range: 19-155 months). Grip strength improved from 66.9 to 82.0% of the contralateral side. Wrist motion slightly decreased from a flexion/extension arc of 132 to 125 degrees. Three patients were totally pain free, one had mild pain, and one had moderate fluctuating pain. All patients returned to their original works. X-ray showed no arthrosis. Conclusion  PMCI is an uncommon but significant cause of chronic ulnar wrist pain. We have developed a clinical algorithm for diagnosis of the condition. The natural history seems to favor a benign course. Conservative treatment with an anticarpal supination splint is recommended as the initial management. Surgical options for resistant cases include arthroscopic thermal shrinkage or soft tissue reconstruction. The reconstruction of the dorsal radiocarpal ligament using a pisiform-based split FCU tendon graft provides reliable restoration of the carpal stability with good long-term outcome and few complications. This should be considered a viable alternative to limited carpal fusion.

Inestabilidad lunopiramidal

Históricamente, la inestabilidad en el lado radial de la muñeca ha recibido mucha más atención que la inestabilidad en el lado ulnar, a pesar de ser una patología relativamente frecuente. Como consecuencia de ello, suele darse un retraso en el diagnóstico correcto y el tratamiento apropiado. Las lesiones del ligamento lunopiramidal pueden ser parciales o completas, y estas últimas pueden estar asociadas a lesión de los estabilizadores secundarios. Cuando se lesionan estos estabilizadores es cuando se produce una inestabilidad estática del carpo conocida como Volar Intercalated Segmentary Instability (VISI). Entre los test clínicos más utilizados para detectar una inestabilidad del ligamento lunopiramidal están el Ballottement test, descrito por Reagan, y el Shear test, descrito por Kleinman, aunque ambos poseen una sensibilidad y una especificidad bajas. Para el diagnóstico de estas lesiones se emplean técnicas como la radiografía simple (que suele ser normal si no hay una inestabilidad estática del carpo), la artrografía y la RMN, entre otras, aunque el gold standard lo constituye la artroscopia de muñeca. No existe un consenso en cuanto al tipo de tratamiento óptimo, ya que la mayoría de los estudios publicados son retrospectivos de nivel iv sin medidas objetivas estandarizadas mediante instrumentos validados. Además, en su mayoría describen los resultados del tratamiento tardío, ya que no se suelen diagnosticar en la fase aguda. Dentro de los tratamientos descritos se encuentran el tratamiento artroscópico (desbridamiento/termocoagulación asociados o no a estabilización con agujas de Kirscher), la reparación abierta, la reconstrucción del ligamento y la artrodesis del ligamento lunopiramidal.

Arthroscopic Electrothermal Collagen Shrinkage for Symptomatic Laxity of the Scapholunate Interosseous Ligament

The medical records, radiographs and operative reports of ten consecutive patients of average age 37 (range 19–67) years with wrist pain secondary to structural disruption of the scapholunate interosseous ligament (Geissler Type 2 injuries) who were treated with wrist arthroscopy and electrothermal collagen shrinkage of the scapholunate interosseous ligament were reviewed. Functional outcomes were assessed using the DASH scoring system at an average follow-up of 28 (range 12–44) months. At latest follow-up, nine patients (90%) were asymptomatic and had returned to their pre-injury functional level. The mean score on the DASH questionnaire was 20 (range 11–48). One patient developed wrist discomfort and mechanical symptoms 7 months postoperatively and required revision surgery. Our preliminary findings suggest that this may be a viable treatment option in the management of patients with symptomatic scapholunate interosseous ligament laxity without complete ligament disruption. Additional study is needed to better understand the role of this treatment modality.

Understanding carpal instability: a radiographic perspective

The wrist is disposed to a variety of instability patterns owing to its complex anatomical and biomechanical properties. Various classification schemes have been proposed to describe the different patterns of carpal instability, of which the Mayo classification is the most commonly used. Understanding the concepts and pertinent terminology of this classification scheme is important for the correct interpretation of images and optimal communication with referring physicians. Standard wrist radiographs are the first line of imaging in carpal instability. Additional information may be obtained with the use of stress radiographs and other imaging modalities.

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.

Isolated or predominant capitolunate osteoarthritis is the consequence of lunotriquetral dissociation. X-ray analysis of 22 consecutive cases

Secondary osteoarthritis due to a scapholunate malalignment is well known, but is debatable in cases of lunotriquetral malalignment. It has been shown that lunotriquetral malalignment can lead to midcarpal osteoarthritis. The hypothesis of this retrospective study was that a relationship exists between the presence of midcarpal osteoarthritis and the presence of lunotriquetral malalignment. All patients with midcarpal osteoarthritis, isolated or predominant, treated between 1981 and 2013 were reviewed. Intracarpal angles were measured and the relative position of the carpal bones was analyzed by two examiners. Osteoarthritis of the wrist's joints was quantified in three stages. Diagnosis of static dissociative ligament lesion was made and correlated with the location of osteoarthritis. Twenty-two wrists in 20 patients (13 men and 7 women; mean age of 59 years) were included. The lunocapitate osteoarthritis was moderate in 6 cases and severe in 16 cases. The radioscaphoid osteoarthritis was moderate in 5 cases and severe in 1 case. Lunotriquetral malalignment was present in all cases; it was isolated in 8 cases and associated with scapholunate malalignment in 14 cases. In isolated lunotriquetral malalignment cases, midcarpal osteoarthritis was isolated or associated with degenerative lesions of lunotriquetral interval. Cases of perilunate instability in which the osteoarthritis is more severe in the midcarpal joint than in the radioscaphoid joint likely resulted from an injurying mechanism with ulnar beginning (ulnar-sided perilunate instability).

Midcarpal instability

Midcarpal instability is a collective term for a number of conditions where the instability of the wrist is predominantly between the proximal and distal carpal rows. It has been regarded as relatively rare and infrequently requires surgical treatment. Palmar midcarpal instability is the most commonly found type of midcarpal instability and can be responsible for causing a clunking and painful wrist. The diagnosis is made on clinical grounds using the midcarpal instability provocative tests. Standard imaging and arthroscopic inspection do not usually confirm a definite diagnosis, but are important in excluding other pathologies. The classification and staging has been described using the extent of palmar translocation of the distal carpal row, which is elicited on passive stress tests. As this is a functional instability, it may be that a functional staging description might be better, and a proposed scheme is described. Treatment options including partial wrist fusions, tenodesis stabilizations and arthroscopic capsular shrinkage have been described in small case series with limited follow-up. There are no comparative series or randomized studies because of the relative rarity of this condition.

[Ligament reconstruction for lunotriquetral instability using a distally based strip of the extensor carpi ulnaris tendon]

OBJECTIVE

Stabilization of the lunotriquetral junction.

INDICATIONS

Dynamic and static chronic instability without fixed dislocation of the carpals.

CONTRAINDICATIONS

Chronically fixed dislocation of the carpals, ulnar impaction syndrome, osteoarthritis of the joint between hamate and triquetrum and other parts of the wrist joint, rheumatoid arthritis, chondrocalcinosis.

SURGICAL TECHNIQUE

Restoration of the palmar portion of the lunotriquetral ligament using a distally based strip of the extensor carpi ulnaris tendon with temporary fixation of the lunotriquetral junction with K-wires.

POSTOPERATIVE MANAGEMENT

Immobilization for 8 weeks with a radial cast that includes the first metacarpophalangeal joint. Removal of the K-wires after 8 weeks and exercise.

RESULTS

The procedure with rare complications reliably restores stability of the lunotriquetral junction. Reduction of grip strength, pain during exercise, and a reduced range of motion persist. Overall, the results are predominantly good and excellent.

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.

Physical Examination of the Wrist: Useful Provocative Maneuvers

Chronic wrist pain resulting from partial interosseous ligament injury remains a diagnostic dilemma for many hand and orthopedic surgeons. Overuse of costly diagnostic studies including magnetic resonance imaging, computed tomography scans, and bone scans can be further frustrating to the clinician because of their inconsistent specificity and reliability in these cases. Physical diagnosis is an effective (and underused) means of establishing a working diagnosis of partial ligament injury to the wrist. Carefully performed provocative maneuvers can be used by the clinician to reproduce the precise character of a patient's problem, reliably establish a working diagnosis, and initiate a plan of treatment. Using precise physical examination techniques, the examiner introduces energy into the wrist in a manner that puts load on specific support ligaments of the carpus, leading to an accurate diagnosis. This article provides a broad spectrum of physical diagnostic tools to help the surgeon develop a working diagnosis of partial wrist ligament injuries in the face of chronic wrist pain and normal x-rays.

Soft tissue stabilization for palmar midcarpal instability using a palmaris longus tendon graft

PURPOSE

To report the results of a technique of soft tissue stabilization for palmar midcarpal instability using a palmaris longus graft.

METHODS

In patients' symptomatic wrists with palmar midcarpal instability that had failed conservative management, we used a dorsal approach and stabilized the hamate and triquetrum by reconstructing the dorsal triquetrohamate ligament. The palmaris longus tendon graft was fixed with bone anchors. Seven wrists in 6 patients were available for follow-up at a mean of 28 months (range, 17-37 mo).

RESULTS

There was an overall meaningful improvement in function (mean preoperative Disabilities of the Arm, Shoulder, and Hand score, 49 preoperatively, 28 postoperatively). There was a significant increase in grip strength from 15 to 21 kg. At final follow-up, 2 patients had moderate pain. The others had mild or no pain. Four patients returned to their previous occupation or activity. Patients retained full pronation and supination. When compared with the normal side, flexion was reduced to 71%, extension to 81%, radial deviation to 90%, and ulnar deviation to 65% of the opposite side. Although the mean results show an improvement, one patient had a poor result with deterioration in Disabilities of the Arm, Shoulder, and Hand score in spite of a clinically stable wrist, and another had clinical evidence of recurrent instability during pregnancy. One patient had residual symptoms from a prominent bone anchor.

CONCLUSIONS

Overall, this technique showed good medium-term results in most of our patients. It retained some midcarpal mobility, eliminated clunking in most patients, and provided a noteworthy improvement in grip strength and function. We continue to use this technique for patients with symptomatic midcarpal instability, but it requires further evaluation with larger patient numbers and a longer follow-up to assess its overall value.

Isolated lunotriquetral ligament tears treated with ulnar shortening osteotomy

PURPOSE

To evaluate outcomes in a single-surgeon series of ulnar shortening osteotomy for the treatment of traumatic isolated tears to the lunotriquetral interosseous ligament (LTIL).

METHODS

This study includes 53 consecutive cases of posttraumatic isolated LTIL tears treated with ulnar shortening osteotomy with minimum 1-year follow-up (range, 1.0-10.6 y). We confirmed all LTIL tears via arthroscopy before performing a precision 2.5-mm oblique osteotomy using a modified Rayhack technique. We assessed outcomes using grip strength measurements and Chun and Palmer's modified Gartland Werley wrist scoring system, which includes subjective and objective outcome measures.

RESULTS

Preoperatively, 45 cases were graded as fair (28%; n = 15) or poor (57%; n = 30) on the modified Gartland Werley score. There were insufficient data to calculate grades in 8 cases (15%). At final follow-up, most patients exhibited excellent (51%; n = 27) or good (32%; n = 17) scores, some scored fair (17%; n = 9), and none scored as poor. All subjective and objective variables significantly improved over a mean follow-up of 36 months (range, 12-127 mo). Mean grip strength increased from a value of 23 kg before surgery to 33 kg over the same period, a 41% increase. All patients achieved clinical and radiographic union by 10 months. Osteotomy plates were removed routinely in most cases (89%; n = 47) at a mean of 17 months.

CONCLUSIONS

Ulnar shortening osteotomy reduced symptoms of posttraumatic isolated LTIL tears in this single-surgeon series.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The role of MDCT arthrography in the follow-up of scapholunate stabilisation

PURPOSE

The aim of this study was to assess outcomes in a group of patients with scapholunate dissociation treated with stabilisation surgery (Brunelli-Stanley) and to compare arthrography with multidetector computed tomography (MDCT) with conventional radiography, the gold standard in the follow-up of wrist surgery.

MATERIALS AND METHODS

Twelve patients (13 wrists) underwent surgery for scapholunate dissociation and were followed up with clinical (visual analogue scale, Mayo Wrist Score, Patient-Rated Wrist Evaluation, and Disabilities of the Arm, Shoulder, and Hand) and radiological assessment (conventional radiography and CT arthrography). Conventional radiography was assessed for: the scapholunate gap, scapholunate angle, radiolunate angle, capitate-lunate angle, and carpal height index; the CT arthrography images were also evaluated for: the distance between the dorsal exit hole of the bone tunnel and the proximal scaphoid pole, the thickness and tension of the flexor carpi radialis (FCR) strip, and any signs of joint degeneration.

RESULTS

Analysis of the data from conventional radiography and MDCT arthrography demonstrated a significant statistical correlation among the measurements obtained on the radiograms and multiplanar CT reconstructions and the patients' clinical outcome.

CONCLUSIONS

Our results show that MDCT arthrography has the same value as conventional radiography in the evaluation of standard parameters (scapholunate gap, scapholunate angle, radiolunate angle, capitolunate angle, carpal height index), but in addition provides an accurate delineation of the FCR tendon graft, allowing differentiation of its thickness, direction and degree of tension.

Fracture-dislocations of the carpus: perilunate injury

The progressive perilunar instability model described by Mayfield is still used to predict the pattern of injury. Diagnosis of injury and clinical and radiographic findings depend on the pattern of injury. Open procedures are preferred for anatomic reduction after initial closed reduction is performed for acute injuries. A dorsal, volar, or combined dorsal/volar approach may be necessary and is often decided by surgeon preference. Loss of motion and diminished grip strength are common consequences despite appropriate treatment. Successful outcomes depend on time to treatment, open or closed nature of injury, extent of chondral damage, residual instability, and fracture union.

Antipronation spiral tenodesis--a surgical technique for the treatment of perilunate instability

Perilunate dislocations involve avulsion or rupture of both intrinsic and extrinsic ligaments around the lunate. If inadequately treated, these ligaments may not heal properly, inducing a particular type of carpal instability characterized by the loss of the ability of the carpus to resist pronation torques. Six ligaments protect the carpus against excessive intracarpal pronation: long radiolunate, palmar and dorsal lunotriquetral, dorsal scapholunate, dorsal intercarpal, and palmar scaphocapitate ligaments. Collectively, these antipronation ligaments have a spiral configuration around the carpus. This article describes a technique to reconstruct this spiral arrangement of ligaments using a strip of flexor carpi radialis. To illustrate the technique, we describe 1 clinical case with a follow-up of 34 months. The so-called antipronation spiral tenodesis is only indicated if the instability is easily reducible, without cartilage damage.

Perilunate dislocations and fracture dislocations

Perilunate dislocations and fracture dislocations are high-energy injuries that can result in pain, stiffness, weakness, or disability if inappropriately treated. Prompt recognition and surgical treatment with anatomic reduction of carpal malalignment improve the likelihood of optimal, long-term clinical success and patient satisfaction. The progressive development of radiographic evidence of arthrosis is common but has not been shown to consistently correlate with worse patient function and outcomes.

Percutaneous screw and axial Kirschner wire fixation for acute transscaphoid perilunate fracture dislocation

PURPOSE

In this retrospective, nonrandomized study, we evaluated the clinical outcomes of percutaneous screw and K-wire fixation in the treatment of acute transscaphoid perilunate fracture dislocation.

METHODS

Between 2004 and 2009, we studied 24 patients treated by fixation with a 2.0-mm (0.078-in) axial K-wire across the capitolunate joint and a percutaneous screw (3.0-mm AO cannulated screws were used in 13 patients, and Herbert-Whipple screws were used in 11 patients) within 7 days of the injury. We performed a comparative radiographic assessment of the scapholunate angle, radiolunate angle, capitolunate angle, revised carpal height ratio, and gap between the scapholunate joint between the injured wrist and the contralateral, healthy wrist. Clinical outcomes were evaluated on the basis of range of motion, pain, functional status, and Mayo scores.

RESULTS

Twenty-three patients (96%) achieved scaphoid union at a mean union time of 18 weeks (range, 14-28 wk). Radiographic assessments revealed no statistically significant difference between the injured wrist and the contralateral, healthy wrist. However, significant differences were noted in the mean range of motion during flexion and forearm supination between the injured wrist and contralateral healthy wrist. The mean wrist function results were encouraging, and the average Mayo score was 83.

CONCLUSIONS

A percutaneous procedure involving screw fixation for the scaphoid fracture and an axial K-wire fixation for intercarpal dislocation is a successful treatment for acute transscaphoid perilunate fracture dislocation.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic III.

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.

Midcarpal instability: a radiological perspective

Midcarpal instability (MCI) is the result of complex abnormal carpal motion at the midcarpal joint of the wrist. It is a form of non-dissociative carpal instability (CIND) and can be caused by various combinations of extrinsic ligament injuries that then result in one of several subtypes of MCI. The complex patterns of injury and the kinematics are further complicated by competing theories, terminology and classifications of MCI. Palmar, dorsal, ulna midcarpal instability, and capitolunate or chronic capitolunate instability are all descriptions of types of MCI with often overlapping features. Palmar midcarpal instability (PMCI) is the most commonly reported type of MCI. It has been described as resulting from deficiencies in the ulna limb of the palmar arcuate ligament (triquetrohamate-capitate) or the dorsal radiotriquetral ligaments, or both. Unstable carpal articulations can be treated with limited carpal arthrodesis or the ligamentous defects can be treated with capsulorrhaphy or ligament reconstruction. Conventional radiographic abnormalities are usually limited to volar intercalated segment instability (VISI) patterns of carpal alignment and are not specific. For many years stress view radiographs and videofluoroscopy have been the methods of choice for demonstrating carpal instability and abnormal carpal kinematics respectively. Dynamic US can be also used to demonstrate midcarpal dyskinesia including the characteristic triquetral "catch-up" clunk. Tears of the extrinsic ligaments can be demonstrated with MR arthrography, and probably with CT arthrography, but intact yet redundant ligaments are more difficult to identify. The exact role of these investigations in the diagnosis, categorisation and management of midcarpal instability has yet to be determined.

Surgical treatment of pediatric posttraumatic palmar midcarpal instability: case report

We treated a 6-year-old child able to extend her wrist only to within 30 degrees of the neutral position secondary to posttraumatic palmar midcarpal instability with palmar and dorsal capsulodesis and pinning. More than 8 years after surgery, she has no complaints referable to her wrist and has 30 degrees of active wrist extension. Although unpredictable in adults, soft-tissue reconstruction is a treatment option in the pediatric patient with posttraumatic palmar midcarpal instability.

Ulnar-sided wrist pain. II. Clinical imaging and treatment

Pain at the ulnar aspect of the wrist is a diagnostic challenge for hand surgeons and radiologists due to the small and complex anatomical structures involved. In this article, imaging modalities including radiography, arthrography, ultrasound (US), computed tomography (CT), CT arthrography, magnetic resonance (MR) imaging, and MR arthrography are compared with regard to differential diagnosis. Clinical imaging findings are reviewed for a more comprehensive understanding of this disorder. Treatments for the common diseases that cause the ulnar-sided wrist pain including extensor carpi ulnaris (ECU) tendonitis, flexor carpi ulnaris (FCU) tendonitis, pisotriquetral arthritis, triangular fibrocartilage complex (TFCC) lesions, ulnar impaction, lunotriquetral (LT) instability, and distal radioulnar joint (DRUJ) instability are reviewed.

Wrist anatomy and biomechanics

Anatomic and biomechanical research of the wrist has yielded a substantial amount of information that improves our basic knowledge of carpal morphology and function of the wrist and provides information to better assess and improve treatment(s) for various problems of the wrist joint. A precise knowledge of the anatomy and biomechanics of the wrist is useful not only for diagnosis of traumatic ligamentous injuries or degenerative change of the wrist joint but also for treatment for wrist dysfunction.

The floating lunate: arthroscopic treatment of simultaneous complete tears of the scapholunate and lunotriquetral ligaments

Carpal instabilities continue to be a controversial topic in hand surgery. Accurate diagnosis of the ligament injuries is usually difficult without an arthroscopic evaluation. Few studies have focused on the diagnosis and proper management of simultaneous scapholunate (SL) and lunotriquetral (LT) ligament tears. This is an uncommon injury that leads to marked disability and chronic wrist pain. This is essentially a "floating lunate" and indicates a severe ligamentous lesion. Thirteen patients (six female and seven male) with complete SL and LT tears and with gross arthroscopic dynamic carpal instability were included in the present study. None of the patients showed radiographic evidence of lunate dislocation. One patient presented acutely and was operated on 3 days after the injury. The average time from the initial injury to the arthroscopy for the other 12 patients was 13.5 months (range 1.5-84 months). All patients underwent arthroscopic debridement of the SL and LT ligaments coupled with percutaneous pinning (two 0.045-in. Kirschner wires) in both joints. At the final follow-up, the average range of motion was 50 degrees of flexion, 54 degrees of extension, 77 degrees of pronation, 80 degrees of supination, 25 degrees of ulnar deviation, and 15 degrees of radial deviation. The average final grip strength was 67% from the non-affected side. All patients had negative shifting tests at final follow-up. Furthermore, there was no evidence of any static or dynamic instability in all the patients except for one patient who developed a volar intercalated segment instability 8 months after the surgery. At the final follow-up, ten patients had no pain, one had mild pain, and two experienced moderate pain.