Palmar midcarpal instability: results of surgical reconstruction

Radial Midcarpal Instability Treated with Radioscaphocapitate Ligament Recession: A Case Report

Background  Midcarpal instability is an uncommon entity characterized by pain and clunking as the wrist moves from radial deviation to ulnar deviation. Management is primarily nonoperative. In patients with persistent symptoms, operative treatments are divided into soft tissue reconstruction and limited midcarpal arthrodesis. Case Description  We present a rare case of radial midcarpal instability associated with radioscaphocapitate (RSC) ligament injury. A 20-year-old man presented with radial-sided wrist pain and clunking with radial deviation after a fall. Wrist arthroscopy confirmed the pathology of an RSC ligament injury resulting in an extended posture of the scaphoid and a catch-up clunk from sudden flexion of the scaphoid in radial deviation. His RSC ligament was recessed and he had excellent outcome at 1 year follow-up. Literature Review  Midcarpal instability was reported by Lichtman et al as a painful wrist click in ulnar deviation and classified according to the direction of the subluxation. Radial midcarpal instability was later described by Caputo et al in patients with rotatory subluxation of the scaphoid. We present a previously unreported form of radial midcarpal instability as it does not quite fit into the type III midcarpal instability with ligament laxity of the scaphotrapeziotrapezoid joint and type IV with scapholunate ligament disruption. The painful wrist click occurs in radial deviation as the result of an RSC ligament injury. Clinical Relevance  We performed arthroscopic thermal capsulorrhaphy of the ulnar arcuate ligaments and dorsal capsule and an open proximal recession of the RSC ligament. The elimination of pain and clunking accompanied by the restoration of scaphoid flexion and return to load-bearing activities validates the pathology and suggests the potential of this soft tissue procedure in the treatment of radial midcarpal instability.

Palmar midcarpal instability a narrative review of the literature: Have we reached a consensus on a treatment?

Palmar midcarpal instability (PMCI) is a wrist condition that requires treatment through non-surgical rehabilitation programs or surgical stabilization. This condition's natural history is poorly understood, and the optimal treatment approach remains unknown. Non-surgical treatments are initially implemented, followed by surgical stabilization if necessary. Arthrodesis and soft tissue stabilization are the two main surgical options for PMCI, with no established gold standard for treatment. A systematic review of 12 articles comparing arthrodesis and soft tissue stabilization was conducted to identify the optimal treatment approach for PMCI. Arthrodesis techniques, such as lunotriquetral arthrodesis, showed high functional outcomes but also high reintervention rates due to nonunion. Soft tissue stabilization techniques showed superior functional outcomes with less mobility loss and lower reintervention rates compared to arthrodesis. However, more studies are required to determine the optimal soft tissue technique. Based on this review we created a treatment algorithm for PMCI starting with non-surgical treatment first, followed by surgical stabilization if needed. Soft tissue stabilization techniques are preferred over arthrodesis due to better functional outcomes and lower reintervention rates. However, each patient's treatment approach should be individualized and evaluated independently to determine the best course of action. PMCI is a rare wrist condition, and further research is needed to better understand its natural history and establish a gold standard for treatment. The lack of literature comparing the two surgical options underscores the need for further research to determine the optimal treatment approach. Nonetheless, the current evidence suggests that soft tissue stabilization is a promising alternative to arthrodesis, providing superior functional outcomes and lower reintervention rates.

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.

Arthroscopic Capsular Shrinkage Is Safe and Effective in the Treatment of Midcarpal Instability in a Pediatric Population: A Single-Center Experience of 51 Cases

Objective  Treatment of palmar midcarpal instability (PMCI) remains controversial and children can develop PMCI from asymptomatic hypermobility. Recently, case series have been published regarding the use of arthroscopic thermal shrinkage of the capsule in adults. Reports of the use of the technique in children and adolescents are rare, and there are no published case series. Methods  In a tertiary hand center for children's hand and wrist conditions, 51 patients were treated with arthroscopy for PMCI between 2014 and 2021. Eighteen out of 51 patients carried additional diagnosis of juvenile idiopathic arthritis (JIA) or a congenital arthritis. Data were collected including range of movement, visual analog scale (VAS) at rest and with load, and grip strength. Data were used to determine the safety and efficacy of this treatment in pediatric and adolescent patients. Results  Mean follow-up was 11.9 months. The procedure was well tolerated and no complications were recorded. Range of movement was preserved postoperatively. In all groups VAS scores at rest and with load improved. Those who underwent arthroscopic capsular shrinkage (ACS) had significantly greater improvement in VAS with load, compared with those who underwent arthroscopic synovectomy alone ( p  = 0.04). Comparing those treated with underlying JIA versus those without, there was no difference in postoperative range of movement, but there was significantly greater improvement for the non-JIA group in terms of both VAS at rest ( p  = 0.02) and VAS with load ( p  = 0.02). Those with JIA and hypermobility stabilized postoperatively, and those with JIA with signs of early carpal collapse and no hypermobility achieved improved range of movement, in terms of flexion ( p  = 0.02), extension ( p  = 0.03), and radial deviation ( p  = 0.01). Conclusion  ACS is a well-tolerated, safe, and effective procedure for PMCI in children and adolescents. It improves pain and instability at rest and with load, and offers benefit over open synovectomy alone. This is the first case series describing the usefulness of the procedure in children and adolescents, and demonstrates effective use of the technique in experienced hands in a specialist center. Level of Evidence  This is a Level IV study.

Midcarpal Instability: A Historical and Etymological Review

Although midcarpal instability was first described almost 45 years ago, this uncommon condition is still poorly understood by most clinicians today. Adding to the confusion, it is known by 2 different names: midcarpal instability and carpal instability nondissociative. In this article, we describe the history of the recognition of instability of the midcarpal joint, including its pathomechanics, classification, and treatment. We hope that a more complete understanding of the etymology and kinematics of the disorder will facilitate its future recognition and assist in appropriate treatment decision making.

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.

Four-Corner Fusion with Locking Dorsal Circular Plate versus Headless Compression Screws: A Clinico-Radiological Comparative Study

Introduction Four-corner fusion is a technique for the treatment of carpal advanced collapse. It consists of scaphoid excision and arthrodesis of the lunate, triquetrum, hamate, and capitate bones. This can be accomplished with different kinds of osteosynthesis. In the first reports of the use of a circular plate, poor outcomes are described, with high rates of non-union, which decreased in later studies, which highlight certain aspects of the surgical technique.

Objective To report our experience with four-corner fusion with the use of a dorsal locking plate (Xpode, Trimed Inc., Santa Clarita, CA, US), and compare it with another traditional fixation method (3.0-mm headless compression screws [HCSs], Synthes, Slothurn, Switzerland), with an emphasis on union, an assessment of the fincitonal outcomes, and the presence of complications.

Material and Methods A comparative study of two prospective series of patients operated on through two fixation techniques for four-corner fusion using autologous bone graft from the iliac crest.

The first group of patients, evaluated between 2010 and 2012, underwent osteosynthesis with 2 HCSs, with a minimum follow up of 18 months. The second group, evaluated between 2011 and 2014, underwent osteosynthesis with a dorsal locking plate, with a minimium foloow up of 12 months. The patients were operated on by four different surgeons in four centers.

The patients were evaluated with radiographs to establish the presence of union and the time it took to occur. In case of doubt, union was confirmed through a computed tomography (CT) scan at 8 weeks postoperatrively. We also assessed the range of motion, the presence of complications, and function through the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and a grip strength score.

Results We achieved a union rate of 100% in both groups at similar times. In the dorsal locking plate group, we obtained better full range of motion, particularly in wrist extension, which was statistically significant (p = 0.0016), as well as lower DASH scores, which was also statistically significant (p = 0.0066). Complications were only present in two patients in the HCS group.

Conclusion Both techniques are valid and reproducible for the treatment of wrists with scapholunate advanced collapse (SNAC) and scaphoid non-union advanced collapse (SLAC). Based on the outcomes, with the Xpode plate, the patients presented better ranges of motion and DASH scores; therefore it may be an excellent fixation option in the open four-corner fusion surgical technique. The entry point and configuration of the HCS are fundamental variables to analyze.

The union rate of 100% obtained in the present study contrasts with the high rates of non-union reported in the literature published in the early 2000s.

Carpal Instability: II. Imaging

Beyond clinical examination, the various forms of carpal instability are assessed with radiologic methods and arthroscopy. For this purpose, the imaging demand for spatial and contrast resolution is particularly high because of the small ligamentous structures involved. The entities of carpal instability are classified into degrees of severity. Early (dynamic) forms of instability can either be indirectly detected with X-ray stress views and cineradiography or by direct visualization of ruptured ligaments in high-resolution magnetic resonance (MR) imaging and MR or computed tomography (CT) arthrography, with the latter the standard of reference in imaging. Advanced (static) forms of carpal instability are sufficiently well detected on radiographs; visualization of early carpal osteoarthritis is superior on CT. To prevent disability of the hand, the radiologist has to provide an early and precise diagnosis. This case-based review highlights the imaging procedures suitable for detection and classification of carpal instability.

Extrinsic and Intrinsic Ligaments of the Wrist

Carpal stability depends on the integrity of both intra-articular and intracapsular carpal ligaments. In this review, the role of the radial-sided and ulnar-sided extrinsic and intrinsic ligaments is described, as well as their advanced imaging using magnetic resonance arthrography (MRA) and contrast-enhanced magnetic resonance imaging (MRI) with three-dimensional (3D) scapholunate complex sequences and thin slices. In the last decade, the new concept of a so-called "scapholunate complex" has emerged among hand surgeons, just as the triangular ligament became known as the triangular fibrocartilage complex (TFCC).The scapholunate ligament complex comprises the intrinsic scapholunate (SL), the extrinsic palmar radiocarpal: radioscaphocapitate (RSC), long radiolunate (LRL), short radiolunate (SRL) ligaments, the extrinsic dorsal radiocarpal (DRC) ligament, the dorsal intercarpal (DIC) ligament, as well as the dorsal capsular scapholunate septum (DCSS), a more recently described anatomical structure, and the intrinsic palmar midcarpal scaphotrapeziotrapezoid (STT) ligament complex. The scapholunate (SL) ligament complex is one of the most involved in wrist injuries. Its stability depends on primary (SL ligament) and secondary (RSC, DRC, DIC, STT ligaments) stabilizers.The gold standard for carpal ligament assessment is still diagnostic arthroscopy for many hand surgeons. To avoid surgery as a diagnostic procedure, advanced MRI is needed to detect associated lesions (sprains, midsubstance tears, avulsions and chronic fibrous infiltrations) of the extrinsic, midcarpal and intrinsic wrist ligaments, which are demonstrated in this article using 3D and two-dimensional sequences with thin slices (0.4 and 2 mm thick, respectively).

Posttraumatic Carpal Instability Nondissociative

Background  Posttraumatic midcarpal instability nondissociative (CIND) is an exceptional rare condition, therefore the outcome after different treatment options remains unknown. Questions  The purpose of this study was to investigate the different treatment options for posttraumatic CIND. We also describe the different radiological and magnetic resonance imaging (MRI) findings in this patient cohort. Patients and Methods  We present outcomes of 10 patients who developed CIND following acute wrist trauma between 2007 and 2018, 3 with dorsal intercalated segment instability pattern (CIND-DISI) and 7 with volar intercalated segment instability (CIND-VISI) radiographically. Results  Three patients with CIND-VISI had satisfactory outcomes with conservative treatment. Two patients with irreducible CIND-DISI and one with CIND-VISI underwent proximal row carpectomy (PRC), two with reducible CIND-VISI had radiolunate fusion, and two with secondary osteoarthritis had total wrist fusion. All patients with CIND-DISI needed surgery, whereas only four of the seven patients with CIND-VISI needed surgery. On MRI, all three patients with CIND-DISI had rupture of the radiolunate ligament. Conclusions  The data collected in this study may provide the first step toward better understanding of the pathology for this exceptionally rare finding. In CIND-VISI, we have not seen any ligament injury in four patients. Therefore, conservative therapy is more likely to be the first step. In CIND-DISI, we recommend an operative procedure: if detected early, with ligament suture, otherwise by radiolunate fusion, PRC, or total wrist fusion. Level of Evidence  This is a Level IV study.

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.

Long-Term Results of Arthroscopic Capsular Shrinkage for Palmar Midcarpal Instability of the Wrist

Background  Midcarpal instability is a term for a collection of poorly understood conditions where the proximal row of the carpus is unstable. The most common type of midcarpal instability is palmar midcarpal instability (PMCI). Treatment for PMCI includes nonoperative proprioceptive retraining of the wrist, splints, and strengthening. If this fails, various authors have suggested several different fusions, tenodesis procedures, or capsular shrinkage. There are no long-term case series in the literature. Objective  The aim of this study is to assess the long-term results of arthroscopic capsular shrinkage when used for PMCI of the wrist. Methods  A prospective cohort study of patients who underwent arthroscopic capsular shrinkage for PMCI was performed. Ethical board approval was given for this study. All patients were followed up and reviewed independently from the operating surgeon. Assessment included a structured questionnaire, disabilities of the arm, shoulder and hand (DASH) questionnaire, and clinical examination using a goniometer. PMCI was assessed objectively with the anterior drawer test and radiological imaging was only performed if clinically relevant to the residual symptoms. Results  Thirteen patients (15 wrists) underwent arthroscopic capsular shrinkage for PMCI. Twelve patients (14 wrists) were available for clinical review with a follow-up rate of 92.3%. The mean time from index procedure to final review was 12 years (range: 10-14years). The symptoms of instability had completely resolved in nine wrists (7 patients). Only 2 of the 14 wrists had symptoms that were reproduced with a positive anterior drawer test. All other wrists were stable on objective assessment. The mean DASH score had improved from pre op of 34 to post op of 12.1 and at 12-year follow-up this had deteriorated minimally to 15.3. Assessment of the range of motion showed an average increase in range of flexion/extension by 22 degrees. Patient satisfaction was excellent. The patients rated that nine wrists were much better than presurgery, three as better, one unchanged, and one worse. Discussion/Conclusion  There are no studies looking at the long-term natural history of treatments for PMCI. The lead author proposes a grading system for symptomatic PMCI that has been retrospectively applied to this cohort. It is a grading system from 1 to 4 and is based on a treatment algorithm. This is the first long-term study from any joint, where the results of capsular shrinkage have been maintained over time. In this series, we have not seen any deleterious effect from possible mechanoreceptor injury. We suspect that functioning mechanoreceptors are more relevant in the unstable joint, than the structurally stable joint. The authors propose that thermal capsular shrinkage is an effective and durable option for use in mild-to-moderate forms of PMCI.

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.

Management of Nondissociative Instability of the Wrist

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

Scapholunate Ligament Injury and the Effect of Scaphoid Lengthening

Objective  We hypothesized that lengthening the scaphoid in a model of scapholunate ligament injury (SLI) will result in correction of radiographic markers of dorsal intercalated segment instability (DISI) deformity. Materials and Methods  An SLI with DISI deformity was created by sectioning the SL ligament, the palmar radiocarpal ligaments, and scapho-trapezio-trapezoid ligaments of a cadaveric upper extremity ( n  = 5). The wrist was radiographed in both anteroposterior and lateral planes to confirm creation of SLI and DISI. The scaphoid was then osteotomized at its waist. A series of grafts (1-8 mm) were then placed at the osteotomy site. Radiographs were completed at each length. The main outcome measures were scapholunate interval (SL, mm), scapholunate angle (SLA, degrees), and radiolunate angle (RLA, degrees). These values, measured following the insertion of varying graft lengths, were compared with baseline measurements taken "post-injury" status. Results  The ability to create an SLI with DISI was confirmed in the postinjury group with a statistically significant change in RLA, SLA, and SL compared with preinjury. With osteotomy and progressive insertion of spacers, the values improved into the accepted normal ranges for RLA (6 mm) and SLA (4 mm) with scaphoid lengthening. Conclusions  In this cadaveric model of SL injury, radiographic markers of DISI were returned to within normal ranges with scaphoid osteotomy and lengthening. Clinical Relevance  The results of this study add insight into wrist kinematics in our injury model and may represent a potential future direction for surgical treatment of SLI.

Palmar Capsuloligamentous Plication in Dorsal Capitolunate Instability: Technique and Preliminary Results

Midcarpal instability (MCI) is a form of the carpal instability nondissociative pattern and can be differentiated into dorsal, palmar, or extrinsic MCI. Dorsal MCI can frequently be observed in adolescent or adult patients due to trauma or hyperlaxity of the palmar intrinsic carpal ligaments. Clinical stress tests and cinematography are capable to depict the ligamentous instability centered around the capitolunate area. We describe a novel technique which aims to address palmar ligamentous hyperlaxity by plication of the radioscaphocapitate, radiolunotriquetral, and arcuate ligaments, thus closing the so-called space of Poirier. This palmar technique has been used in several cases in isolated form or in conjunction with other concomitant procedures. After the floor of the carpal tunnel and thus the palmar ligaments are exposed and the weak spot meticulously verified, 2 or rarely 3 deep FibreWire pulley sutures are used for capsuloligamentous plication. Among 11 patients, 4 cases (5 operated wrists) with isolated capitolunate capsuloligamentous plication were followed at an average of 2.6 years after surgery. The results were excellent with a mean postoperative Disabilities of the Arm, Shoulder and Hand Score of 9.7 (range, 6.9 to 15.0), mean numerical rating scale of 0 at rest and 1 (range, 0 to 2) during stress. All cases stated that they were very satisfied with the result and all would definitely elect to choose the surgery again. Palmar capsuloligamentous plication has been shown to be a quick, relatively easy and reliable procedure to reduce dorsal MCI in our patient cohort.

Long-Term Functional Results of a Wrist Exercise Program for Patients with Palmar Midcarpal Instability

Background  Patients with palmar midcarpal instability have symptoms of pain, combined with clinical signs of abnormal mobility on stressing the joint, an unpredictable blockade feeling, and a noticeable clunk, in the absence of an underlying trauma. No data are available on the effect of conservative treatment for these patients. Purpose  The purpose of this study was to evaluate the effect and the long-term functional outcomes of a wrist exercise program in patients with palmar midcarpal instability. Patients and Methods  All patients diagnosed with palmar midcarpal instability between 2005 and 2011 were included. Patients completed the Patient-Rated Wrist and Hand Evaluation (PRWHE) and the Short Form-36 health (SF-36) questionnaires, scaled their perceived pain before and after treatment, and indicated the effect of the received treatment. Results  A total of 119 patients diagnosed with palmar midcarpal instability were included. The median follow-up time was 6 years (IQR 4.5-7.0). The median PRWHE score after hand therapy was 35.5 and the median mental component of the SF-36 score was 53.9 and the physical component was 45.2. The median perceived pain reduced from eight to four and the median therapeutic effect of the wrist exercise program was five. Conclusion  Although palmar midcarpal instability remains to be a chronic disease, the effectiveness of our wrist exercise program is promising with acceptable long-term functional results and a good quality of life. Level of Evidence  Level IV, retrospective cohort study.

Dorsal Wrist Plication for Midcarpal Instability

PURPOSE

Midcarpal instability (MCI) is a cause of chronic wrist pain for which treatment remains controversial. This study's purpose was to determine the outcome of a treatment algorithm for MCI that included immobilization and surgical interventions.

METHODS

We prospectively enrolled 23 consecutive patients (12 males, average age 27 years) with 27 symptomatic wrists. All had generalized wrist pain with an average duration of 22 months. All had MCI and a catch-up clunk that reproduced the symptoms. Initial treatment was full immobilization for 6 weeks. When necessary, recurrence after immobilization was treated with an anatomically based surgical procedure to plicate the dorsal capsule and extrinsic ligaments to stabilize the midcarpal joint. Failure of surgical plication was followed by 4-corner intercarpal arthrodesis when necessary. Patients were observed for instability, grip strength, wrist motion, and Patient-Rated Wrist Evaluation.

RESULTS

For 22 wrists there was partial relief of symptoms with full-time cast or orthosis immobilization; however, symptoms quickly returned with mobilization. The other wrists had previously been immobilized and patients refused further nonsurgical care. All patients underwent surgical plication of the dorsum of the wrists. Postoperative follow-up (35 months) showed statistically significant improvements in grip strength and Patient-Rated Wrist Evaluation scores. All patients had improved pain at final follow-up. Most improvement was in female patients aged under 25 years, with hypermobility and without major traumatic or work-related injuries. This contrasted with poorer outcomes in men aged over 25years who had moderate or severe trauma that was mostly work-related. Instability recurred in 2 patients who then had a 4-corner arthrodesis.

CONCLUSIONS

Immobilization was not successful in controlling pain and recurrence of instability in patients with MCI. Surgical midcarpal capsular plication was less effective in men with posttraumatic instability. The capsular plication procedure was successful in young female patients with ligament laxity and a history of only minor or repetitive trauma and no history of major trauma.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

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.

[Mediocarpal instability of the wrist]

Typical lesions of the carpal ligaments are mostly found after a fall on the wrist in hyperextension or as complex injuries after severe trauma, e. g. after a fall from a significant height, motorcycle accident or as accompanying lesions in multiple trauma. The typical mechanisms, patterns and diagnostic algorithms are well known for the common ligamentous injuries (e.g. scapholunate, lunotriquetral and perilunate); therefore, consistent diagnostic procedures and adequate therapy are increasingly performed after such lesions, e. g. by early ligament repair or by ligament reconstruction through augmentation. Within appropriate operative treatment, accompanying fractures are also treated and instabilities are addressed by transfixation of joints by Kirschner wires. If followed by immobilization with a cast or stable brace, healing can be achieved in most cases; however, more problems occur if ligamentous lesions or instabilities are not clearly due to a trauma mechanism and more the result of laxity or hypermobile situations due to a congenital predisposition. In such cases, wrist pain is often described and misdiagnosed as the result of overload or tenovaginitis.

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.

Midcarpal Instability: The Role of Wrist Arthroscopy

The evidence behind management options for midcarpal instability (MCI) is scarce, relying solely on case series. Established treatments cause significant loss of wrist motion. As understanding of the condition has progressed, surgeons have been trying soft tissue techniques. The treatment option should be chosen for the appropriate type and grade of MCI. The Hargreaves grading system for palmar MCI aids treatment decision-making. A possible role for arthroscopy in treatment of MCI has been developed using arthroscopic thermal capsular shrinkage, appropriate for cases with dynamic instabilities. Static deformities require a soft tissue reconstruction or a partial wrist fusion.

Imaging in carpal instability

Carpal instability is a complex and heterogeneous clinical condition. Management requires accurate identification of structural injury with an understanding of the resultant movement (kinematic) and load transfer (kinetic) failure. Static imaging techniques, such as plain film radiography, stress views, ultrasound, magnetic resonance, MR arthrography and computerized tomography arthrography, may accurately depict major wrist ligamentous injury. Dynamic ultrasound and videofluoroscopy may demonstrate dynamic instability and kinematic dysfunction. There is a growing evidence base for the diagnostic accuracy of these techniques in detecting intrinsic ligament tears, but there are limitations. Evidence of their efficacy and relevance in detection of non-dissociative carpal instability and extrinsic ligament tears is weak. Further research into the accuracy of existing imaging modalities is still required. Novel techniques, including four-dimensional computerized tomography and magnetic resonance, can evaluate both cross-sectional and functional carpal anatomy. This is a narrative review of level-III studies evaluating the role of imaging in carpal 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.

Midcarpal Instability: A Comprehensive Review and Update

Midcarpal instability has been well described as a clinical entity but the pathokinematics and pathologic anatomy continue to be poorly understood. This article presents a comprehensive review of the existing knowledge and literature-based evidence for the diagnosis and management of the various entities comprising midcarpal instability. It discusses the limitations of the current understanding of midcarpal instability and proposes new directions for furthering knowledge of the causes and treatment of midcarpal instability and wrist pathomechanics in general.

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.

A new technique for the treatment of midcarpal instability

Extensor carpi radialis brevis (ECRB) transfer to the hamate bone is a novel procedure that offers a new surgical treatment option for select patients with midcarpal instability (MCI) who do not respond to conservative treatment. We present our early experience with this procedure. In total, 12 patients (13 wrists) were reviewed with a follow-up duration ranging from 1 to 6 years. Complications and changes in active range of motion (AROM) were noted. Patient related outcome was measured using the Patient Rated Wrist/Hand Evaluation (PRWHE) questionnaire, amongst others. Two patients failed to show a positive response to the surgery. ECRB transfer to the ulnar side of the wrist is a new procedure that offers a potential option for the surgical treatment of MCI in select patients; however, further biomechanical and clinical studies are required. The level of evidence for this study is IV (therapeutic).

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.

[Wrist arthroscopy : challenging procedure of modern hand surgery]

Arthroscopy of the wrist has developed in the shadow of arthroscopy of the large joints. Nowadays, wrist arthroscopy has a relevant importance in the diagnostics and therapy in hand surgery and is indispensable for serious surgery of the wrist. Special equipment and extensive knowledge of the surgeon are necessary for carrying out the procedure.

Surgical Techniques for the Management of Midcarpal Instability

Palmar midcarpal instability (PMCI) is an uncommon and poorly understood disorder. Its etiology is believed to be due to traumatic or congenital laxity of the ligaments (volar and dorsal) that stabilize the proximal row. This laxity results in hypermobility of the proximal carpal row and unphysiologic coupling of the midcarpal joint. Clinically, the condition is manifested by a painful clunk with ulnar and radial wrist deviation. The purpose of this article is to chronicle our personal experience with this condition and to review our current treatment recommendations and outcomes.

A carpal ligament substitute part II: polyester suture for scapho-lunate and triqueto-lunate ligament reconstruction

Carpal ligaments are commonly injured and may lead to pain and disability. These ligaments are very difficult to repair, and the results are unpredictable; as a result, treatment options abound. A novel approach is presented here using a polyester suture, aiming to substitute these ligaments' function, rather than to repair them.

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.

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.

Physical examination of the wrist

Physical examination of the wrist requires knowledge of wrist anatomy and pathology to make a diagnosis or narrow the differential diagnosis. Symptoms are provoked by palpation and signs are produced by manipulation. Negative findings elsewhere in the wrist are important. Final diagnosis may require diagnostic imaging. By having all three methods of assessment agree one is assured of correct diagnosis. The physical examination of the wrist is not unlike that of other joints, in that a systematic approach includes observation, range of motion, palpation, and special tests.

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.

Extensor retinaculum capsulorrhaphy for ulnocarpal and distal radioulnar instability: the Herbert sling

Wrist pain and instability are challenging problems that may be the result of pathology at the distal radioulnar (DRUJ) or ulnocarpal joints or both. Instability of the wrist can often be attributed to a compromise of the integrity of the triangular fibrocartilage complex (TFCC), a key soft tissue stabilizer of the DRUJ and ulnocarpal articulations. Subsequently, when surgical reconstruction is indicated, techniques should strive to restore the biarthrodial function of the TFCC. Although anatomic reconstruction of the DRUJ ligaments provides successful stabilization of the radioulnar articulation, those patients who present with concomitant ulnocarpal instability require an alternative technique that addresses both the DRUJ- and ulnocarpal-stabilizing functions of the TFCC. The Herbert sling, which is an extensor retinaculum capsulorrhaphy, is an effective method of creating a strong tether among the distal radius, ulna, and ulnar carpus. Preliminary biomechanical and clinical results have been encouraging.

The non-dissociative clunking wrist: a personal view

Clunking of the wrist is often the result of a combined radiocarpal and midcarpal ligament insufficiency, coupled with inadequate neuromuscular coordination. When symptomatic, these wrists may benefit from splinting, isometric exercising of specific muscles and advice on activity modification. Failing this, different surgical strategies have been proposed, depending on the location of dysfunction. When the clunking derives from an isolated injury of one joint, reconstruction of its inadequate ligaments may be an effective solution. However, soft tissue procedures tend to fail when clunking results from multilevel instability. In these cases, partial carpal arthrodesis is an alternative. Although effective in eliminating the clunking, midcarpal fusion is associated with alteration of the so-called "dart-throwing" motion, the most common rotation in daily activities, and hence is not recommended. Radiolunate fusion, by contrast, appears to be a less morbid alternative, with the benefit of eliminating the painful clunking while preserving a good range of dart-throwing motion.

Four-corner arthrodesis: influence of the position of the lunate on postoperative wrist motion: a cadaveric study

PURPOSE

Evaluate the influence of the position of the lunate on postoperative wrist motion in four-corner arthrodesis.

METHODS

Six upper cadaveric limbs were evaluated, comparing the total arc of motion in each wrist after simulating four-corner arthrodesis. The lunate was fixed in 3 different positions: neutral (0 degrees ), extended (30 degrees ), and flexed (20 degrees ). Statistical analyses (ANOVA and Bonferroni tests) were carried out to establish the significance of differences in articular motion in these 3 positions.

RESULTS

Significant statistical differences were observed in full wrist extension. No significant differences, however, were found in flexion-extension total arc of motion, radial deviation, or ulnar deviation.

CONCLUSIONS

According to our results in this cadaveric model, the position of the lunate affects postoperative wrist flexion and extension after four-corner arthrodesis. The flexed lunate position increases postoperative wrist extension and restrains wrist flexion. Inversely, the extended lunate position improves articular flexion and limits extension. Total arc of motion of the fused wrist does not vary in the 3 lunate positions.

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.

Delayed post-traumatic midcarpal dislocation

We report a case of delayed post-traumatic volar midcarpal dislocation in a 39 year-old woman. The dislocation was a gradual process starting from the time of injury. Initial X-rays showed a normal midcarpal joint. By 6 weeks, lunocapitate subluxation was apparent radiologically and by the 18 week X-ray, midcarpal dislocation had occurred. This type of wrist injury has not been previously reported. Because of advanced degenerative changes in the lunocapitate joint, a partial wrist fusion was performed with a successful outcome.

Arthroscopic thermal capsulorrhaphy for palmar midcarpal instability

Midcarpal instability is an uncommon problem in which deficient static and dynamic wrist stabilisers cause sudden, uncontrolled movement of the proximal carpal row. We studied 15 wrists prospectively in 13 patients who underwent arthroscopic thermal capsulorrhaphy for palmar midcarpal instability. Capsulorrhaphy was performed using standard wrist arthroscopic techniques and a small diameter monopolar radiofrequency probe. One hundred percent follow-up was achieved at a mean of 42 (range 14 - 67) months. With regards to instability, all wrists showed improvement or resolution of instability. Functional improvement was confirmed by an improvement in the mean DASH score from 38 pre-operatively to 17 at final follow-up. Our early results show that thermal capsulorrhaphy is effective in reducing the instability symptoms of palmar midcarpal instability.