The effect of rotatory subluxation of the scaphoid on radio-scaphoid contact

A novel classification of Kienbock's disease based on magnetic resonance imaging

PURPOSE

We devised a classification system for Kienbock's disease using magnetic resonance imaging (MRI). Moreover, we compared it with the modified Lichtman classification and evaluated the inter-observer reliability.

METHODS

Eighty-eight patients diagnosed with Kienbock's disease were included. All patients were classified using the modified Lichtman and MRI classifications. MRI staging was based on factors including partial marrow oedema, cortical integrity of the lunate, and dorsal subluxation of the scaphoid. The inter-observer reliability was evaluated. We also evaluated the presence of a displaced coronal fracture of the lunate and investigated its association with the presence of a dorsal subluxation of the scaphoid.

RESULTS

Seven patients were categorized into stage I, 13 into II, 33 into IIIA, 33 into IIIB, and two into IV using the modified Lichtman classification. Six patients were categorized into stage I, 12 into II, 56 into IIIA, ten into IIIB, and four into IV using the MRI classification. The greatest shift between the stages was observed in stages IIIA and IIIB when the results of the two classification systems were compared. The inter-observer reliability of the MRI classification was greater than that of the modified Lichtman classification. Fifteen cases with a displaced coronal fracture of the lunate were identified, and a dorsal subluxation of the scaphoid was significantly more present in these patients.

CONCLUSION

The MRI classification system is more reliable than is the modified Lichtman classification. MRI classification reflects carpal misalignment with higher fidelity and is more appropriate for classification into stages IIIA and IIIB.

Dynadesis for Treatment of Dynamic Scaphoid Instability with 20-Year Results

Background  Even though the scapholunate interosseous ligament is the most common wrist ligament injury, its treatment remains a challenge for hand surgeons. We report on a surgical treatment (Dynadesis) for dynamic scaphoid instability (DSI) with a 20-year follow-up period. Description of Technique  Dynadesis utilizes antagonist forearm muscles in order to synergistically provide dynamic stabilization to the scaphoid when the wrist is loaded. It is a tendon-to-tendon transfer with the following two components: 1) Dorsal-The extensor carpi radialis longus (ECRL) is passed through a hole in the reduced, distal scaphoid, providing the scaphoid with an independent extension force. 2) Volar-A dynamic checkrein is created by tension-locking the ECRL tendon around the flexor carpi radialis (FCR) tendon. The portion of the FCR distal to the scaphoid tethers and tightens with contracture of the ECRL and FCR muscles. Patients and Methods  Twenty patients (21 wrists) were treated with Dynadesis and reevaluated 20 years later (range: 20-27 years). Results  Average grip strength improved by 8 kg. The average wrist flexion-extension arc decreased by 3 ° . Wrist X-rays showed no radiocarpal arthritis. On the Mayo wrist score, 81% reported excellent to good results (average: 89). Pain levels improved by 90%, with 76% of patients reporting no pain. All patients (100%) were satisfied with their results and would recommend the procedure. Conclusions  Dynadesis is specifically designed for the treatment of DSI. It avoids the eventual complication of osteoarthritis and does not sacrifice wrist motion. A predictable and satisfactory long-term result is obtainable with correct patient selection based on clinical staging and arthroscopic findings.

Postoperative Pain Is Correlated with Scaphoid Dorsal Translation following Scapholunate Interosseous Ligament Reconstruction

Background  Dorsal scaphoid translation (DST) has been demonstrated to occur in patients with complete scapholunate interosseous ligament (SLIL) tears. Radiographs and magnetic resonance imaging (MRI) have demonstrated ability to detect DST in patients with documented complete scapholunate (SL) disruption, but the relevance of this parameter to outcomes of reconstruction has not been determined. Purpose  The purpose of this article is to determine how radiographic parameters of SL dissociation correlate with postoperative pain and functional outcomes of SLIL reconstruction. Methods  We performed a retrospective review of prospectively collected data on a cohort of 14 patients who underwent SLIL repair or reconstruction. Preoperative data included radiographic measurements of carpal posture and alignment (SL angle, radiolunate [RL] angle, SL gap, and DST), self-reported measure of average pain on a numerical rating scale (NRS) of 0 to 10, and the patient rated wrist evaluation (PRWE) survey. Postoperatively, the same data were collected at each follow-up visit. Radiographic parameters were statistically compared with postoperative NRS pain score and PRWE scores. Statistical correlations were calculated using Spearman's correlation coefficient, and mean NRS pain scores were compared using Wilcoxon's rank-sum tests, with an α value of p  = 0.05. Results  Mean NRS pain scores improved significantly after surgery. Mean DST improved significantly after surgery. The presence of postoperative dorsal scaphoid translation (DST) correlated strongly with postoperative pain. SL angle, RL angle, and SL gap showed no correlation with patient reported pain. There was no correlation with any radiographic parameter and PRWE. Conclusions  Our study demonstrates that the presence of DST in postoperative radiographs has a strong correlation with patient reported pain following SLIL reconstruction. We conclude that correction of dorsal translation of the scaphoid is a more sensitive predictor of postoperative pain relief than SL gap, RL angle, or SL angle. Level of evidence  This is a Level IV study.

Kinetic dysfunction of the wrist with chronic scapholunate dissociation. A cadaver study

BACKGROUND

Most laboratory studies investigating scapholunate dissociations are based on normal cadaver arms with serially sectioned ligaments. It is assumed that the kinetic behavior of a ligament-sectioned wrist is similar to a scapholunate dissociation. We tested five cadaver wrists with real injuries. The goal of this research was to evaluate the biomechanical behavior of scapholunate advanced collapse wrists compared to an experimental group with simulated injuries.

METHODS

Using a magnetic 6-degree of freedom motion tracking device, changes in scaphoid alignment induced by isometric loading 5 wrist motor tendons in two groups of specimens were monitored. Twelve fresh cadaver wrists in which scapholunate injury was simulated by sectioning the scapholunate ligament were compared to 5 arms with chronic scapholunate dissociation.

FINDINGS

The behavior of the scaphoid is the same in both groups, but the magnitude of displacement is greater in chronic scapholunate dissociation wrists, although not statistically significant. The extensor carpi ulnaris is the only muscle that provokes scaphoid pronation; all other muscles induce its supination.

INTERPRETATION

Different factors may play a role in the amount of scaphoid rotation observed in wrists with chronic scapholunate dissociation. Ligament sectioning alone in the experimental setup can only partially replicate the behavior of real scapholunate dissociations. The extensor carpi ulnaris has a major role in destabilizing scapholunate advanced collapse wrists; therefore, isometric contraction of this muscle should be avoided in the conservative treatment. The experimental setup designed is useful to evaluate the biomechanical behavior of the carpus under traction load.

The Use of Contact Biomechanics to Study the Intact, Proximal Row Carpectomy and Scaphoid Excision, Four Bone Fusion Wrist

The study of contact biomechanics of the wrist is a challenge. This is partly due to the relatively small size of the joint as well as the lack of space in the radiocarpal joint which makes the delivery of investigative materials such as pressure sensitive film without causing artifact, difficult. Fortunately, a number of authors have studied the intact wrist, the scapholunate ligament injured wrist, the proximal row carpectomy and the scaphoid excision, four bone fusion. Despite some contrasting findings, there are some general concepts that we understand about wrist mechanics.

Treatment of chronic scapholunate dissociation with tenodesis: A systematic review

Scapholunate (SL) instability is the most common dissociative carpal instability condition. It is the most frequent cause of wrist osteoarthritis, defined as scapholunate advanced collapse or SLAC wrist. Familiarity with the SL ligament complex is required to understand the various features of SL instability. Damage to the SL interosseous ligament is the main prerequisite for SL instability; however the extrinsic, palmar and dorsal ligaments of the carpus also come into play. When more than 6 weeks has passed since the initial injury event, SL instability is considered chronic because ligament healing is no longer possible. Before osteoarthritis sets in and when the SL instability is still reducible (scaphoid can be reverticalized), ligament reconstruction surgery is indicated. Since the end of the 1970s, various ligament reconstruction or tenodesis techniques have been described. These techniques are used in cases of chronic, dynamic or static reducible SL instability, when no repairable ligament stump and no chondral lesions are present. The aim is to correct the SL instability using a free or pedicled tendon graft to reduce pain while limiting the loss of mobility and protecting against osteoarthritis-related collapse in the long-term. We will perform a systematic review of the various tenodesis techniques available in the literature.

Equivalent Clinical Outcomes Following Favored Treatments of Chronic Scapholunate Ligament Tear

BACKGROUND

Optimal treatment of chronic scapholunate (SL) instability remains controversial. Many surgical techniques have been proposed with varied results in subsequent case series; however, there is limited evidence demonstrating the relative effectiveness of the different treatment options.

QUESTIONS/PURPOSES

We conducted a systematic review of the English literature to compare outcomes from capsulodesis and ligament reconstruction for treatment of chronic scapholunate instability.

METHODS

An electronic database search using keywords associated with scapholunate ligament instability was performed. A total of 511 studies were identified. All studies with scapholunate ligament tears >4 weeks after the initial injury were included in the review. Data extracted included patient demographics, wrist range of motion, and radiographic outcome measures.

RESULTS

A total of 308 patients from 11 studies met the inclusion criteria and were included in the study. The average time to surgery from initial injury was 11 months. There was no significant difference in wrist flexion or extension after capsulodesis or reconstruction. The weighted mean for postoperative wrist extension/flexion was 56°/45.6° in the capsulodesis group and 40.9°/47.3° in the reconstruction group. Pooled means of SL angle and SL gap were 60.3° and 3.44 mm after capsulodesis and 56.5 and 2.72 mm after reconstruction, respectively.

CONCLUSIONS

This systematic review failed to demonstrate any significant difference in outcomes from capsulodesis or reconstruction for treatment of chronic scapholunate instability. However, the retrospective studies examined were notably heterogeneous in design with high estimates of variance. Further prospective trials are necessary to determine an ideal treatment strategy.

Optimal detection of scapholunate ligament tears with MRI

Background Scapholunate interosseous ligament (SLIL) injuries can often be difficult to detect using magnetic resonance imaging (MRI), especially with older 1.0 and 1.5 Tesla magnets. Wrist arthroscopy is the gold standard for diagnosis of SLIL injuries, but is an invasive procedure with associated risks. Purpose To assess whether SLIL injuries can be more accurately detected using axial MRI sequences instead of coronal sequences. Material and Methods An institutional review board approved retrospective analysis of arthroscopic wrist surgeries performed at our institution. Patients that had a preoperative MRI performed at our university center using a 1.5 Tesla scanner with a dedicated wrist coil were included in the study. Three fellowship-trained musculoskeletal radiologists reviewed the axial sequences and coronal sequences independently. The accuracy of the coronal and axial sequences was compared with the arthroscopic/surgical findings. Result Twenty-six patients met the inclusion criteria. The sensitivity for SLIL tears was 79% and 65% for the axial and coronal sequences, respectively. The specificity was 82% for the axial and 69% for the coronal sequences, respectively. The positive and negative predictive values for the axial sequences were 76% and 84% respectively, compared to 68% and 71% for the coronal sequences, a statistically significant difference. Conclusion SLIL tears are more readily detectable on axial MRI sequences than coronal. Clinically, patients with radial-sided wrist pain and suspicion for SLIL tears should have the axial sequences scrutinized carefully. An otherwise normal study with the axial sequence being degraded by motion or other MRI artifacts might need repeat imaging.

Factors associated with improved outcomes following proximal row carpectomy: a long-term outcome study of 144 patients

We conducted a review of 144 consecutive patients who underwent proximal row carpectomy from 1967 to 2010 for the diagnosis of wrist arthritis. At a mean follow-up of 13.4 years, patients experienced good pain relief with preservation (but not improvement) of wrist motion. A total of 17 patients (12%) required revision surgery at an average of 44.6 months. Improved pain, function, and survival outcomes were seen in those who underwent proximal row carpectomy after the age of 40, had a preoperative diagnosis of Kienbock's disease, who underwent a concomitant neurectomy procedure, patients who were non-labourers, and patients who underwent surgery after 1990. Although 45% of patients developed moderate to severe radiocapitate arthrosis postoperatively, these findings did not correlate with clinical outcomes or risk of revision surgery. Patients with type II lunate and type II and III capitate shapes had higher rates of postoperative radiocapitate arthrosis.

LEVEL OF EVIDENCE

III, Prognostic.

Management of complications of ligament injuries of the wrist

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

In vivo 3-dimensional analysis of stage III Kienböck disease: pattern of carpal deformity and radioscaphoid joint congruity

PURPOSE

To examine 3-dimensional carpal alignment and radioscaphoid joint (RSJ) congruity among normal wrists and those with Lichtman stage III Kienböck disease or scapholunate dislocation (SLD).

METHODS

We conducted 3-dimensional analysis based on computed tomographic data to compare 10 wrists of stage III Kienböck disease (5 IIIa and 5 IIIb) with 5 normal wrists and 3 wrists with SLD. A markerless bone registration technique was used to investigate the 3-dimensional position of the scaphoid relative to the radius. To evaluate RSJ congruency, the inferred contact area between the scaphoid proximal pole and the distal radius was calculated from 3-dimensional bone models.

RESULTS

The scaphoid position was not significantly different from normal wrists in stage IIIa Kienböck disease. Stage IIIb Kienböck disease was meaningfully associated with a flexed scaphoid and proximal translation of the centroid, but not dorsal translation of the scaphoid proximal pole, where RSJ congruity was preserved. With SLD, the scaphoid flexed to the same extent as that in stage IIIb Kienböck disease, and the proximal pole translated dorsally together with the capitate, producing RSJ incongruity.

CONCLUSIONS

The patterns of carpal collapse differed between stage IIIb Kienböck disease and SLD in terms of RSJ congruity. Our study showed that stage IIIb Kienböck disease did not involve dorsal subluxation of the scaphoid proximal pole and that RSJ congruity was retained, unlike SLD.

CLINICAL RELEVANCE

Our results suggest that carpal collapse in Kienböck disease is not associated with RSJ incongruity, which may explain why there are asymptomatic patients with Kienböck disease and carpal collapse.

[Standard wrist arthroscopy: technique and documentation]

OBJECTIVE

Minimally invasive approach to the wrist in order to diagnose and treat different wrist pathologies.

INDICATIONS

Diagnosis of unclear chronic pain syndromes, cartilage status, intra-articular ligament structures as well as post-traumatic and inflammatory conditions of the wrist. Treatment of ulnar impaction syndrome, dorsal ganglia and also in fracture treatment and various different wrist interventions.

CONTRAINDICATIONS

Soft tissue infections around the wrist, severe scarring may impede access to the joint.

SURGICAL TECHNIQUE

Supine position with the forearm upright and in neutral position, the elbow flexed by 90°, axial traction of 3-4 kg. Superficial stab incision, blunt preparation through joint capsule, insertion of optic through 3-4 portal and probe through 4-5 portal, and radial and ulnar midcarpal portals, respectively. Either sodium chloride, CO2 or air is used as arthroscopy medium. Diagnostic round with standardized examination of all parts of the joint. Standardized written and high quality photo and/or video documentation to facilitate understandability of the findings.

POSTOPERATIVE MANAGEMENT

Forearm cast for 1 week, limited load for 2 more weeks, then load is increased to normal.

In vivo 3-dimensional analysis of dorsal intercalated segment instability deformity secondary to scapholunate dissociation: a preliminary report

PURPOSE

To investigate in vivo 3-dimensional patterns of dorsal intercalated segment instability deformity resulting from scapholunate dissociation.

METHODS

We studied 6 patients with stage IV scapholunate dissociation in which there were complete tears of the scapholunate interosseous ligament and dorsal intercalated segment instability deformity. Of these, 3 patients had a dorsally displaced distal radius malunion, a condition known to aggravate or produce a dorsal intercalated segment instability deformity. With the wrist in neutral, we created 3-dimensional bone models of the wrists from computed tomography. We calculated centroid locations of each carpal and the rotational angle of the scaphoid and lunate relative to the radius and compared them with those of 6 normal subjects. The joint contact area was visualized to evaluate congruity of the radiocarpal and midcarpal joints.

RESULTS

In the scapholunate dissociated wrists, the scaphoid translated dorsally and radially with rotation in the direction of flexion and pronation. The lunate was extended and supinated. The capitate, trapezoid, and trapezium translated dorsally. Contact area of the radioscaphoid joint shifted dorsoradially owing to dorsoradial subluxation of the scaphoid proximal pole. Congruity was retained in the radiolunate, lunocapitate, and scaphotrapeziotrapezoid joints. In the malunion cases, the scaphoid and distal carpal rows translated more dorsally along dorsal angulation of the distal radius; therefore, incongruity of the radioscaphoid joint became more pronounced.

CONCLUSIONS

Dorsoradial subluxation of the scaphoid proximal pole over the dorsal rim of the radius led to incongruity of the radioscaphoid joint. Dorsal translation of the distal carpal row occurred with maintaining congruency of the radiolunate, lunocapitate, and scaphotrapeziotrapezoid joints. These results suggest that for realignment of the carpal axis of an advanced scapholunate dissociated wrist, we should restore scapholunate rotational malalignment and reduce the dorsally translated distal carpal row back to the anatomical position.

The use of thermal shrinkage for scapholunate instability

Scapholunate interosseous ligament (SLIL) instability is the most common form of carpal instability. There is a lack of consensus among hand surgeons as to the appropriate treatment of various stages. This article reviews the background and results of thermal treatment of predynamic instability of the SLIL. Case examples are discussed as well as a series of patients treated with our protocol for this injury.

[Rotatory subluxation of the scaphoid: pathology and surgical management]

The interosseous scapholunate ligament (IOSLL) is the main stabilizer of the scapholunate (SL) couple but a static instability can appear only in the event of an associated injury of the extrinsic ligaments. Thus, SL dissociation covers a broad spectrum in which only static instability leads with certainty to osteoarthritis. Classically described as a rotatory subluxation of the scaphoid with DISI collapse, static SL instability manifests itself as a complex deformity with dorsolateral subluxation of the unit formed by the scaphoid and the distal carpal row. This deformity explains the dorsolateral radioscaphoid conflict and capitolunar decentering that is the origin of the radioscaphoid and midcarpal osteoarthritis that later appears. It is only within the first 4 to 6 weeks that a repair of the IOSLL, possibly associated with a capsulodesis, makes it possible to expect a good result and can prevent osteoarthritis. Beyond that time, no soft tissue procedure will modify the natural history of the condition. For us, surgery is indicated only for acute injuries and for symptomatic chronic instabilities. Before the occurrence of osteoarthritis, with new-found knowledge of the medium-term results of capsulodesis, it seems reasonable to favour a limited fusion. But in the event of failure, the patient is likely to remain in pain even after a total fusion. It is thus not aberrant to perform a capsulodesis in a sedentary person but it is necessary to inform the patient that osteoarthritis will occur. After occurrence of osteoarthritis, if it is symptomatic, proximal row carpectomy, SLAC procedure, total wrist fusion and denervation, can be considered, depending on the stage, the mobility of the wrist and the wishes of the patient. Denervation of the wrist can give good results with few risks, and does not jeopardize the results of a subsequent procedure.

Comparison of the "contact biomechanics" of the intact and proximal row carpectomy wrist

PURPOSE

The proximal row carpectomy (PRC) is a clinically useful motion-preserving procedure for various arthritides of the wrist. However, there are few studies on the "contact biomechanics" after PRC. The purpose of this study is to evaluate the contact biomechanics in terms of pressure, area, and contact location of the intact and PRC wrist.

METHODS

Six fresh-frozen cadaver forearms were tested in neutral, 45 degrees of flexion, and 45 degrees of extension. In the intact wrist, Fuji UltraSuperLow pressure contact film was placed in the radioulnocarpal joint. The specimen was loaded to a total force of 200 N. We then performed a PRC, and the experiment was repeated using Fuji Low film. The film was scanned and analyzed with a customized MATLAB program. Multivariable analysis of variance with multiple contrast testing and Student's t-test were performed for statistics.

RESULTS

In the intact wrist, scaphoid contact pressure averaged 1.4 megapascals (MPa), and lunate contact pressure averaged 1.3 MPa. In terms of contact location, scaphoid contact in the intact wrist significantly moved dorsal and ulnar in flexion and significantly moved volar and radial in extension. Lunate contact significantly moved dorsal in flexion. PRC wrist contact pressure was 3.8 times that of the intact wrist, and the contact area was approximately 26% that of the intact wrist. Lastly, in terms of the amount of contact translation after PRC, the capitate contact translated (7.5 mm) more than did the scaphoid contact (5.6 mm) and had about equal translation to that of the lunate (7.3 mm).

CONCLUSIONS

Contact pressure increased significantly and contact area decreased significantly after PRC. There is significant contact translation after PRC (more than scaphoid translation but equal to lunate translation), which provides quantitative support of the theory that translational motion of the PRC may explain its good clinical outcomes.

Lunocapitate Fusion Using the OSStaple Compression Staple

Midcarpal arthrodesis is a reliable procedure to treat individuals with symptomatic scapholunate advanced collapse (SLAC) who have failed nonoperative care. The principal keys to a successful midcarpal arthrodesis include achieving union, a proper reduction of the capitolunate interval, and avoiding hardware impingement. A variety of devices are used in an attempt to achieve this. These include Kirchner wires, stainless steel staples, compression screws, and, most recently, circular plates. The performance of these devices has not always been reliable leaving room for improvement. This report describes the use of a new device that facilitates the achievement of the key principals. Staples made of nitinol (OSStaple, BioMedical Enterprises Inc, San Antonio, TX) facilitate provisional reduction, provide continuous compression leading to rapid reliable union, and are low profile.

Osteoarthritis in Other Joints (Hip, Elbow, Foot, Ankle, Toes, Wrist) after Sports Injuries

Osteoarthritis of nonknee joints, although less common than knee osteoarthritis, remains a significant and disabling condition for many present and former athletes. These injuries can be caused by repeated loads or following a specific traumatic event. The resulting pain and loss of motion can limit function and ability. Arthroscopic techniques in many cases enable surgeons to symptomatically treat limitations of range of motion and pain, prolonging active careers. Joint replacement remains the ultimate solution for hip osteoarthritis, and may be a viable option in ankle osteoarthritis.

Changes in radiocarpal loading characteristics after proximal row carpectomy

PURPOSE

To document the changes in wrist loading that occur after proximal row carpectomy in a cadaver model.

METHODS

The normal radioulnar carpal pressure distributions of 7 cadaver wrists were measured using super-low-pressure-sensitive film. Proximal row carpectomies were performed and the loading characteristics re-evaluated.

RESULTS

In the lunate fossa the contact area increased 37%, the average contact pressure increased 57%, and the location of the contact moved radially 5.5 mm. With wrist motion between 40 degrees of extension and 20 degrees of flexion the volar/dorsal excursion of the lunate fossa contact point increased by 108%.

CONCLUSIONS

Significant changes in radiocarpal loading occur after proximal row carpectomy. The increased radiocarpal excursion with wrist motion may explain the low incidence of radiocapitate arthritis in patients who have had proximal row carpectomy.

A survey of the surgical management of acute and chronic scapholunate instability

PURPOSE

Scapholunate instability is a challenging problem and controversy persists among hand surgeons with respect to treatment choice. The purpose of this study was to evaluate the pattern of practice among specialized hand surgeons in the management of both acute and chronic scapholunate instability.

METHODS

A mailed survey study was sent to the 1,628 members of the American and Canadian Societies for Surgery of the Hand. Hand surgeons were asked to complete a comprehensive management questionnaire that examined a surgeon's treatment algorithm in the clinical case of acute and chronic scapholunate instability. The algorithm included the choices of further investigation, timing of surgery, surgical approach, surgical procedure, fixation, and predicted outcome.

RESULTS

Of the 468 hand surgeons who responded to the survey the vast majority elected to perform surgery when confronted with a case of scapholunate instability. Early surgical intervention within 6 weeks of injury using an open dorsal approach was favored in both acute and chronic cases. The preferred surgical procedure in the acute case was scapholunate repair combined with a capsulodesis followed by scapholunate ligament repair alone. Favored management of the chronic case included Blatt capsulodesis alone, capsulodesis combined with a scapholunate ligament repair, or scaphotrapezium-trapezoid arthrodesis. A majority of surgeons used K-wire fixation, especially of the scapholunate and scaphocapitate in both acute and chronic cases.

CONCLUSIONS

This survey confirms a consensus for the early soft tissue surgical management of acute scapholunate instability using a scapholunate ligament repair with or without a capsulodesis. The management of chronic scapholunate instability is highly variable among respondents and the choice of either a soft tissue or bony procedure may depend to a large extent on intraoperative findings.

Long-term results after repair and augmentation ligamentoplasty of rotatory subluxation of the scaphoid

Twenty-two patients had scapholunate ligament repairs combined with a new augmentation ligamentoplasty for chronic scapholunate dissociation. All were evaluated by physical and radiologic examination after a mean postoperative follow-up period of 63 months (range, 12-134 mo). According to Green and O'Brien and Johnson and Carrera scores 5/8 had excellent, 13/12 good, and 4/2 fair results. Thirteen were free of pain; 6 had mild pain and 3 had moderate pain. Nineteen returned to their original occupation. There was an average loss of 10 degrees of flexion, 9 degrees of extension, and 11% of grip force compared with the opposite wrist. Radiologic examination showed an average decrease of 12 degrees of the scapholunate and 10 degrees of the radiolunate angles compared with the levels before surgery. No signs of degenerative osteoarthritis were found in 16 (73%) cases. Five wrists showed a distinct pattern of midcarpal degeneration correlating with notable dorsal intercalated segment instability after surgery, and 2 cases had signs of radioscaphoid degeneration.

Arthroscopic and open management of dynamic scaphoid instability

This article focuses on the pathophysiology and treatment of dynamic scaphoid instability. Cadaver studies suggest that dynamic instability results from isolated injury to the scapholunate interosseous ligament without damage to the dorsal intercarpal and dorsal radial lunotriquetral ligaments. The diagnosis may be made by dynamic fluoroscopic examination, including stress and load views. The role of arthroscopy is twofold: (1) it enables the surgeon to distinguish between a complete, grossly unstable scapholunate interosseous space that requires open treatment and (2) it permits direct visualization of the reduction and percutaneous pinning of the articulation in an effort to stabilize the joint. Operative indications, open and arthroscopic techniques, and results are discussed.

Scapholunate instability in athletes

Sports medicine practitioners must be sensitive to even the smallest injuries that affect athletes. Often, less severe ligament injuries go undetected. Scapholunate dissociation is often overlooked in this manner. The authors provide an overview of presentation, diagnosis, and nonoperative and operative treatments of this condition.

Constraint and material properties of the subregions of the scapholunate interosseous ligament

The material and constraint properties of the dorsal, proximal, and palmar regions of the scapholunate ligament were studied using isolated bone-ligament-bone preparations from 24 adult intact cadaver wrists. Determinations of constraint to differential rotation and translation as well as failure strength were made using a servohydraulic testing machine incorporating an additional rotatory actuator. The dorsal region of the scapholunate ligament offered the greatest constraint to differential translation, while both the dorsal and palmar regions demonstrated statistically significant combined constraints to differential rotation between the scaphoid and lunate. The greatest yield strength was found in the dorsal region (260.3 N +/- 118.1 N), followed by the palmar region (117.9 N +/- 21.3 N) and the proximal region (62.7 N +/- 32.2 N).

Ligamentous injuries of the wrist in the athlete

Wrist instability most commonly results from ligamentous disruption between bones of the proximal carpal row. Scapholunate and lunotriquetral dissociation are forms of this instability pattern. Carpal instability can also occur due to loss of the normal ligamentous restraints between the carpal rows. Ulnar midcarpal instability is an example of this pattern. The treatment of wrist instability depends on the specific type and degree of carpal disruption and the presence or absence of degenerative changes. Options include soft-tissue reconstruction, partial wrist fusion, limited carpal bone excision, or a combination of methods.

Scapholunate advanced collapse wrist: proximal row carpectomy or limited wrist arthrodesis with scaphoid excision?

Proximal row carpectomy (PRC) and limited intercarpal arthrodesis with scaphoid excision (LWF) are useful alternatives to wrist arthrodesis for treatment of degenerative wrist disorders secondary to scapholunate advanced collapse. Because consensus regarding the ideal motion-preserving option is lacking, we sought to better define the indications for and relative merits of PRC versus LWF. Twenty-four wrists treated for symptomatic scapholunate advanced collapse arthritis between 1980 and 1990 with either PRC or LWF were retrospectively reviewed at an average of 5.5 years postoperatively. At follow-up evaluation, satisfactory pain relief, grip strength, and functional performance were observed except in three patients with PRC, one of whom had developed symptomatic radiocarpal arthritis requiring conversion to arthrodesis. Differences in subjective and objective results between the two treatment groups were not statistically significant except for residual range of motion. Incomplete correction of lunate extension when LWF was performed resulted in diminished wrist extension, compared to PRC. Improvements in grip strength and range of motion were noted for at least 1 year after both procedures, and neither declined with time. A stage-dependent surgical approach to the symptomatic scapholunate advanced collapse wrist is advocated in light of comparable outcomes following both PRC and LWF. For wrists without capitolunate arthritis, PRC avoids the technical demands, lengthy postoperative immobilization, and risk of nonunion associated with LWF, but for stage III disease (capitolunate arthritis) pain relief may be unsatisfactory, and LWF is recommended.

Complications of intercarpal arthrodesis

Fifty patients who underwent intercarpal arthrodesis were retrospectively reviewed at an average follow-up period of 34 months. Eighteen patients had a good result, 16 results were fair, and 13 were poor. Thirty-six patients experienced some complication, and 25 patients underwent further surgical therapy: The most common indication for secondary surgery was nonunion (16 patients). Good results were significantly decreased among patients who experienced nonunion, required secondary surgery, or experienced any complication. Patients with static carpal instability treated by scaphoid trapezoid trapezium arthrodesis had a significantly greater proportion of good results.

A comparison of scaphoid-trapezium-trapezoid fusion and four-bone tendon weave for scapholunate dissociation

The contact characteristics of the radiocarpal joint (area, pressure, and ratios of scapholunate area, pressure and force transmitted) were determined with the use of pressure-sensitive film in seven normal wrists after ligament sectioning to create scapholunate instability, with reconstruction involving a scaphoid-trapezium-trapezoid fusion, and with reconstruction involving a four-bone tendon weave procedure. The results demonstrated that the scaphoid-trapezium-trapezoid fusion significantly altered the contact characteristics of the wrist, transferring load, pressure, and area to the radioscaphoid joint, thereby unloading the lunate. In contrast, the tendon weave reconstruction produced characteristics similar to those of the normal joint.

Treatment of scapholunate dissociation by ligamentous repair and capsulodesis

We believe that direct scapholunate ligamentous repair, supported by a dorsal radioscaphoid capsulodesis, should be considered for the treatment of most scapholunate dissociations when there is no osteoarthritis, regardless of the time that has elapsed since injury. We treated 24 patients by this technique between 1972 and 1988. The records of 21 were available for study. Average time from injury to surgical treatment was 17 months (range, 1 to 84 months). Results were evaluated clinically and by means of patient questionnaire and x-ray films. The significant change in range of motion was a loss of palmar flexion, which averaged 11.5 degrees. Grip strength, pain, and x-ray appearance improved in all cases. Only one patient had to change occupations after surgery because of wrist symptoms. Three had minimal x-ray degenerative changes, which did not result in increased pain or in loss of motion and grip strength. There were no complications.

[Lesions of the ligaments associated with distal fractures of the radius. 58 intraoperative arthrographies]

Intracarpal ligamentous tears and fractures of the radius often have a similar mechanism. For instance, no prospective studies have defined the real incidence of such associations, which are not antagonistic. The authors performed a systematic operative wrist arthrogram during distal radius fractures in a group of 58 patients with a mean age less than 50 years. Such a population was at low risk of degenerative ligamentous tears. Triangular fibrocartilage complex was torn in two-thirds of all types fractures. Extra-articular radius fractures were associated with an intracarpal ligamentous tear in 25% and always a luno-triquetral lesion type. In contrast, intra-articular and radius styloid fractures were frequently associated with a scapho-lunate lesion.

[Role of scapho-trapezo-trapezoidal arthrodesis in the treatment of Kienbock disease. 11 cases]

11 patients with Decoulx stage III Kienböck's disease with rotatory subluxation of the scaphoid were treated with scapho-trapezo-trapezoid arthrodesis. The associated procedures were lunate implant resection arthroplasty in 6 cases, lunate resection in 3 cases, shortening of the radius in 1 case. The average follow-up was 40 months (12 to 84 months). There was no complication of the arthrodesis. Relief of pain is satisfactory in 7 of the 11 patients. The average grip strength is 66% of that observed on the affected side. The range of movement was decreased especially for radial deviation. There was a positive correlation between, the exact scaphoid reduction, a wrist without preoperative degenerative arthritis and the good clinical results. No differences were observed in the results between the associated lunate procedures. STT fusion seems to be a useful procedure in the treatment of stage III Kienböck's disease with carpal malalignment as it removes compressive stress from the diseased lunate and treats, the accompanying rotatory subluxation of the scaphoid.

Radiographic analysis of selective ligament sectioning at the carpal scaphoid: a cadaver study

Although scapholunate diastasis with rotatory subluxation of the scaphoid (stage I perilunar instability determined by Mayfield's classification) has been studied by several investigators, the exact contribution of the supporting ligaments is still being defined. We designed and executed an experimental study using six fresh-frozen cadaver specimens to demonstrate the radiographic changes seen on standard and stress wrist radiographs that correlate with the sequential sectioning of the scapholunate stabilizing ligaments. The radioscapho-lunate ligament, the palmar scapholunate interosseous ligament, the dorsal scapholunate interosseous ligament, and the radiocapitate ligament were sectioned sequentially to simulate a progressive wrist injury caused by an extension, intercarpal supination and ulnar deviation force. The results showed significant ligamentous injury must occur before commonly used radiographic limits are exceeded. The lateral scapholunate angle most closely reflected the progressive nature of this injury.

Radiocarpal articular contact characteristics with scaphoid instability

The relative importance of the three major periscaphoid ligament complexes in maintaining the normal radiocarpal articulation was assessed. Pressure-sensitive film recorded the changes in radioscaphoid and radiolunate articular contact that occurred with sequential ligament sectioning in 12 cadaver wrists. Alterations in the radiocarpal articular contact as a result of ligament disruption are evident in the absence of the recognizable static x-ray changes of carpal instability. The scapholunate interosseous ligament is essential in preventing scapholunate diastasis and dorsoradial subluxation of the proximal scaphoid. Rotatory subluxation of the scaphoid occurs when disruption of the scapholunate interosseous ligament is coupled with disruption of either the palmar intracapsular radiocarpal ligaments or the scaphotrapezial ligament complex. These data help explain the development of degenerative arthritis caused by carpal ligamentous instability.

The effects of various load paths and different loads on the load transfer characteristics of the wrist

An experimental model that incorporated a static positioning frame, pressure-sensitive film, and a microcomputer-based videodigitizing system was used to analyze the effects of different loading pathways and various loads on the contact area and pressures within the wrist joint. There was no statistically significant difference in loading the wrist with comparable weights through the second and third metacarpals, through all five metacarpals, or through weights suspended from the wrist flexor and extensor tendons. A nonlinear relation was discovered between increasing loads and greater overall contact areas. The general distribution of the contact between the scaphoid and the lunate contact areas was consistent at all of the loads tested with 60% of the total contact area involving the scaphoid contact area and 40% involving the lunate contact area. Loads greater than 46 pounds were not found to significantly increase the overall contact areas implying that the cartilage of the wrist joint was maximally compressed at loads of this magnitude. At loads higher than 46 pounds it appears that average high pressures increase in a more direct correlation with the increase in weight. The overall contact area even at the highest loads tested were not more than 40% of the available joint surface. The contact areas were not concentric or symmetric as is characteristic of the incongruance of the radio/triangularfibrocartilage (ulna)/carpal joint.