Dorsal intercarpal ligament capsulodesis for scapholunate dissociation: biomechanical analysis in a cadaver model

Scapholunate Ligament Injuries

Injuries to the scapholunate interosseous ligament (SLIL) complex can result in a predictable cascade of incongruous motion in the carpus that leads to radiocarpal degeneration. Both acute traumatic impact and repetitive motion can render the SLIL insufficient. A thorough understanding of SLIL anatomy is required for appropriate diagnosis and treatment. Here, we review scapholunate ligament anatomy, prevention strategies, methods of diagnosis, nonoperative and operative treatments, and outcomes. A myriad of treatment options exist for each stage of the SLIL injury, and management should be an open discussion between the patient and physician.

Biomechanical Comparisons of Different Reconstructive Techniques for Scapholunate Dissociation: A Cadaveric Study

There are many techniques for the treatment of chronic scapholunate dissociation. The three-ligament tenodesis (3LT) is used most widely, but reconstruction of the dorsal ligament alone may not provide sufficient stability. The Mark-Henry technique (MHT) compensates for the insufficient stability of 3LT by additional reconstruction of the volar ligament, but the procedure is complex. The SwiveLock technique (SWT), a recently introduced method, provides stability by using autologous tendons with synthetic tapes, but lacks long-term clinical results. To perform biomechanical comparisons of different reconstructive techniques for scapholunate dissociation using a controlled laboratory cadaveric model. Eleven fresh-frozen upper-extremity cadaveric specimens were prepared. The scapholunate distance, scaphoid rotation, and lunate rotation of the specimens were measured during continuous flexion-extension and ulnar-radial deviation movements. The data were collected using a wrist simulator with a linear guide rail system (tendon load/motion-controlled system) and a motion capture system. Results were compared in five conditions: (1) intact, (2) scapholunate dissociation, (3) SWT, (4) 3LT, and (5) MHT. Paired t-test was employed to compare the biomechanical characteristics of intact wrists to those of scapholunate dissociated wrists, and to those of wrists after each of the three reconstruction methods. SWT and MHT were effective solutions for reducing the widening in scapholunate distance. According to the radioscaphoid angle, all three reconstruction techniques were effective in addressing the flexion deformity of the scaphoid. According to the radiolunate angle, only SWT was effective in addressing the extension deformity of the lunate. In terms of scapholunate angle, only the results after SWT did not differ from those of the intact wrist. The SWT technique most effectively improved distraction intensity and rotational strength for the treatment of scapholunate dissociation. Taking into account the technical complexity of 3LT and MHT, SWT may be a more efficient technique to reduce operating time and minimize complications due to multiple incisions, transosseous tunnels, and complicated shuttling.

Management of Complex Hand and Wrist Ligament Injuries

Ligamentous injuries in the hand and wrist are often underdiagnosed and can present with significant functional limitations if there is untimely recognition of injury. Adequate repair or reconstruction is critical in restoring joint stability and mobility. The purpose of this review is to provide an overview of the metacarpophalangeal joint, scapholunate interosseous ligament (SLIL), and non-SLIL carpal ligament anatomy, diagnosis, imaging, treatment consideration and options, as well as surgical techniques encompassing repair, reconstruction, and fusion.

Current Concepts in Scapholunate Instability Without Arthritic Changes

Scapholunate instability (SLI) is the most common carpal instability described. SLI leads to a degenerative arthritic pattern known as scapholunate advanced collapse (SLAC). Diagnosis of SLI can be challenging in pre-dynamic and dynamic stages. CT arthrogram, MR arthrogram and dynamic fluoroscopy are helpful in diagnosis while arthroscopy remains the gold standard. SLI is a multi-ligament injury, which involves not only the scapholunate interosseous ligament (SLIL) but also the extrinsic carpal ligaments. Hence, it is better described as an injury compromising the 'dorsal scapholunate(dSLL) complex'. A repair can be attempted for acute SLI presenting within 6 weeks of injury. Reconstruction is the mainstay of treatment for chronic SLI without degenerative changes. Multiple repair techniques have been described which include capsulodesis and tenodesis procedures. The clinical outcomes of the techniques have improved over the years. However, a common problem of all these techniques is the lack of long-term data on the outcomes and deteriorating radiological parameters over time. SLI staging is an important factor to be considered in choosing the reconstruction techniques for a better outcome. Currently, there is a trend towards more biological and less invasive techniques. Regardless of the technique, it is important to preserve the nerve supply of the dorsal capsuloligamentous structures of the wrist. Arthroscopic techniques being minimally invasive have the advantage of less collateral damage to the capsuloligamentous structures. Rehabilitation involves a team approach where a protected dart thrower's motion is allowed after a period of immobilization. Strengthening SL-friendly muscles and inhibiting SL-unfriendly muscles is a key principle in rehabilitation.

Wide arthroscopic dorsal capsuloligamentous repair in patients with severe scapholunate instability

A conventional arthroscopic capsuloligamentous repair is a reliable surgical solution in most patients with scapholunate instability. However, this repair does not seem to be sufficient for more advanced injuries. The aim of this study was to evaluate the functional results of a wide arthroscopic dorsal capsuloligamentous repair (WADCLR) in the management of severe scapholunate instability. This was a prospective single-centre study undertaken between March 2019 and May 2021. The primary outcome was the evaluation of the reduction of the radiological deformity and the functional outcomes after WADCLR. A secondary outcome was the evaluation of the effectiveness of this technique in patients with the most severe instability (European Wrist Arthroscopy Society (EWAS) stage 5). The patients were reviewed postoperatively at three, six, and 12 months. The study included 112 patients (70 male and 42 female). Their mean age was 31.6 years (16 to 55). A total of three patients had EWAS stage 3A injuries, 12 had stage 3B injuries, 29 had stage 3C injuries, 56 had stage 4 injuries, and 12 had stage 5 injuries. There was a significant improvement of the radiological signs in all patients with a return to normal values. There was also a significant improvement in all aspects of function except for flexion, in which the mean increase was negligible (0.18° on average). There was also a significant improvement in all criteria for patients with a stage 5 injury, except for some limitation of extension, flexion, and radial and ulnar deviation, although these showed a trend towards improvement (except for flexion). WADCLR is a minimally invasive, easy, and reproducible technique with few complications, offering a clear improvement in function and a reduction in the radiological deformity at one year postoperatively.

Radiocarpal Contact Pressures Are Not Altered after Scapholunate Ligament Tears

Background  The scapholunate interosseous ligament (SLIL) couples the scaphoid and lunate, preventing motion and instability. Prior studies suggest that damage to the SLIL may significantly alter contact pressures of the radiocarpal joint. Questions/Purposes  The purpose of this study was to investigate the contact pressure and contact area in the scaphoid and lunate fossae of the radius prior to and after sectioning the SLIL. Methods  Ten cadaveric forearms were dissected distal to 1-cm proximal to the radiocarpal joint and a Tekscan sensor was placed in the radiocarpal joint. The potted specimen was mounted and an axial load of 200 N was applied over 60 seconds. Results  Sectioning of the SLIL did neither significantly alter mean contact pressure at the lunate fossa ( p  = 0.842) nor scaphoid fossa ( p  = 0.760). Peak pressures were similar between both states at the lunate and scaphoid fossae ( p  = 0.301-0.959). Contact areas were similar at the lunate fossa ( p  = 0.508) but trended toward an increase in the SLIL sectioned state in the scaphoid fossa ( p  = 0.055). No significant differences in the distribution of contact pressure ( p  = 0.799), peak pressure ( p  = 0.445), and contact area ( p  = 0.203) between the scaphoid and lunate fossae after sectioning were observed. Conclusion  Complete sectioning of the SLIL in isolation may not be sufficient to alter the contact pressures of the wrist. Clinical Relevance  Injury to the secondary stabilizers of the SL joint, in addition to complete sectioning of the SLIL, may be needed to induce altered biomechanics and ultimately degenerative changes of the radiocarpal joint.

Outcomes of Acute Versus Subacute Scapholunate Ligament Repair

Purpose

This study investigated the long-term outcomes of direct scapholunate ligament (SLL) repairs with or without dorsal capsulodesis performed within 6 weeks (acute repair) of a SLL tear versus 6 to 12 weeks following injury (subacute repair).

Methods

A review of medical records from April 1996 to April 2012 identified 24 patients who underwent SLL repair (12 acute, 12 subacute). Patients returned to the clinic for radiographic examinations of the injured wrist, standardized physical examinations, and validated questionnaires.

Results

The mean follow-up times for the acute and subacute groups were 7.2 and 6.2 years, respectively. At the final examination, patients with acute surgery regained more wrist extension (acute = 55°, subacute = 47°). The total wrist flexion-extension arcs, grip strengths, pinch strengths, and patient-rated outcome scores were found to be similar between groups. The final scapholunate gap, scapholunate angle, and the prevalence of arthritis were also found to be similar between the acute and subacute groups.

Conclusions

Although SLL repair is more commonly recommended for treatment of acute SLL injuries, there were no significant long-term differences between acute and subacute SLL surgeries (repair ± capsulodesis).

Type of study/level of evidence

Prognostic III.

The Biomechanical Effects of Augmentation With Flat Braided Suture on Dorsal Intercarpal Ligament Capsulodesis for Scapholunate Instability

PURPOSE

Selecting treatment for scapholunate (SL) instability is notoriously difficult. Many methods of reconstruction have been described, but no procedure demonstrates clear superiority. New methods proposed use internal bracing (IB) with suture anchors and flat braided suture (FBS), alone or as an augmentation with tendon autograft for SL ligament injuries. Our goal was to use computed tomography (CT) to analyze alignment of the SL joint after 3 different modes of fixation of SL instability: after reconstruction with IB incorporating either tendon autograft or the dorsal intercarpal ligament (DICL), or DICL capsulodesis without FBS.

METHODS

Ten fresh-frozen, matched-pair, forearm-to-hand specimens were used. Serial sectioning of the SL stabilizing ligaments was performed and the SL interval was measured with CT. We reconstructed the SL ligament with DICL capsulodesis alone (DICL) or with IB augmented with either tendon autograft (IB plus T) or DICL (DICL plus IB). The SL interval was measured with CT. Specimens underwent 500 weighted cycles on a jig and were reimaged. Differences in SL interval after repair and cycling were compared.

RESULTS

Dorsal intercarpal ligament capsulodesis augmented with IB best maintained the SL interval before and after cycling. Dorsal intercarpal ligament capsulodesis alone was inferior to DICL plus IB and IB plus T both before and after cycling.

CONCLUSIONS

Dorsal intercarpal ligament capsulodesis augmented with IB appears to maintain better SL joint reduction than IB with tendon autograft.

CLINICAL RELEVANCE

This work serves as a necessary step for further study of the biomechanical strength and clinical application of FBS technology in the reconstruction of SL instability. Flat braided suture augmentation of DICL capsulodesis may provide another option to consider for reconstruction of SL instability.

Comparison of Three Different Internal Brace Augmentation Techniques for Scapholunate Dissociation: A Cadaveric Biomechanical Study

Internal bracing (IB) is an augmentation method using high-strength nonabsorbable tape. However, there is no detailed information about the direction, location, or number of IBs required for scapholunate interosseous ligament (SLIL) injury repair. Thus, this study compared the biomechanical characteristics of short-transverse IB, long-oblique IB, and the combination of short-transverse and long-oblique (Combo) IB for SLIL injury in a biomechanical cadaveric model. We prepared nine fresh-frozen full upper extremity cadaveric specimens for this study. The scapholunate distance, scapholunate angle, and radioscaphoid angle were measured using the MicroScribe digitizing system with the SLIL intact, after scapholunate dissociation and the three different reconstructions. Three-dimensional digital records were obtained in six wrist positions in each experimental condition. Short-transverse IB had a similar effect compared with long-oblique IB in addressing the widening of the scapholunate distance. However, both were less effective than Combo IB. For scaphoid flexion deformity, short-transverse IB had minimal effect, while long-oblique IB had a similar effect compared to Combo IB. Combo IB was the most effective for improving distraction intensity and rotational strength. This study provides important information about the biomechanical characteristics of three different IB methods for SLIL injury and may be useful to clinicians in treating scapholunate dissociation.

Modified Viegas dorsal capsuloplasty for chronic partial injury of the scapholunate ligament in young athletes: outcomes at 24 months

The treatment of chronic scapholunate ligament tears in patients with high demand, such as young athletes, is difficult as traditional techniques are associated with some loss of wrist motion and grip strength. This retrospective investigation studied young athletes (≤20 years old) with chronic scapholunate ligament lesions and a minimum follow-up of 24 months, treated with a modified Viegas dorsal capsuloplasty. Twenty-six young athletes (mean age 17 years) were included. A partial scapholunate ligament tear (Geissler III) was seen in 25 patients. At the last follow-up, a significantly different improvement was seen in all measured parameters and all patients could return to their original competitive activity, within 6 months (range 4-12) after surgery.Level of evidence: IV.

Surgical Techniques for the Treatment of Acute Carpal Ligament Injuries in the Athlete

The treatment of athletes with carpal ligament injuries provides many challenges. Our initial goals remain to make a timely and accurate diagnosis, provide treatment options, and create an environment for shared decision making. To optimize outcomes and facilitate return to play, early surgical intervention may be warranted. This article reviews common carpal ligament injury patterns in the athlete with a focus on both classic and newer surgical techniques.

The Effects of Capitate Height Alteration on Dorsal Intercalated Segment Instability

Question/Purpose  Carpal kinematics may be influenced by the manipulation of carpal dimensions. This may provide a surgical alternative to unpredictable soft tissue reconstruction for scapholunate dissociation. The purpose of this study was to determine if altering capitate height can correct dorsal intercalated segment instability (DISI). Materials and Methods  Five cadaveric wrists had baseline radiolunate (RL) angles and scapholunate (SL) intervals measured fluoroscopically, confirming no baseline DISI. We simulated open- and clenched-fist testing via a constant load of the wrist extensors and sequential loading of the digital flexors. We confirmed no baseline static/dynamic DISI. The SL ligament and secondary stabilizers (scapho-trapezio-trapezoid [STT] and dorsal intercarpal ligaments) were transected. Repeat loading and fluoroscopic measurements confirmed creation of static DISI. Capitate height was altered in three interventions: 2 mm shortening osteotomy of capitate waist, 7 mm shortening osteotomy of capitate waist, and 2 mm lengthening of original capitate height by insertion of a spacer at capitate waist. The osteotomized capitate was stabilized with a Kirschner wire; RL angles and SL intervals were measured via fluoroscopy during open- and clenched-fist testing. Primary and secondary outcomes were change in RL angle and SL interval, from the DISI stage to each capitate shortening and lengthening stage. Results  SL ligament and secondary stabilizers sectioning created a DISI pattern, with abnormal RL angles (>15°) and widened SL intervals. Neither capitate shortening nor overexpansion corrected RL angles or SL intervals in any DISI-induced wrists. Conclusions  Under the conditions studied, isolated capitate shortening or lengthening did not correct radiographic DISI posturing of the lunate following sectioning of the SL and STT interosseous ligaments. Further study of carpal kinematics with more substantial bone changes and loading of adjacent joints may be beneficial. Clinical relevance  Surgeons performing capitate shortening osteotomy in isolation should not expect to improve DISI.

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.

Current Techniques in Scapholunate Ligament Reconstruction

Scapholunate ligament injuries are common and can lead to a predictable pattern of arthritis (scaphoid lunate advanced collapse wrist) if unrecognized or untreated. This article describes the relevant anatomy, biomechanics, and classification system, and provides an up-to-date literature-based review of treatment options, including acute repair and various reconstruction techniques. It also helps guide surgeons in making decisions regarding a systematic treatment algorithm for these injuries.

Scapholunate kinematics after flexible anchor repair

The scapholunate joint is one of the keystones of the wrist kinematics, and its study is difficult due to the carpal bones size and the richness of surrounding ligaments. We propose a new method of quantitative assessment of scapholunate kinematics through bone motion tracking in order to investigate scapholunate ligament lesion as well as repair techniques. On 6 intact wrists, steel beads were inserted into the bones of interest to track their motions. Experimental set up allowed wrist flexion extension and radio-ulnar deviation motions. Low-dose bi-planar radiographs were performed each 10° of movement for different configurations: 1) intact wrist, 2) scapholunate ligament division, 3) repair by soft anchors at the posterior then 4) anterior part. Beads' 3D coordinates were computed at each position from biplanar X-Rays, allowing accurate registration of each wrist bone. The Monte Carlo sensitivity study showed accuracy between 0.2° and 1.6 ° for the scaphoid and the lunate in motions studied. The maximum flexion-extension range of motion of the scaphoid significantly decreased after anterior repair from 73° in injured wrist to 62.7°. The proposed protocol appears robust, and the tracking allowed to quantify the anchor's influence on the wrist kinematics.

The effect of screw trajectory for the reduction and association of the scaphoid and lunate (RASL) procedure: a biomechanical analysis

The purpose of this study was to determine if screw placement in the reduction and association of the scaphoid and the lunate (RASL) procedure affected the ability of the scapholunate joint to withstand force. After completely disrupting of the scapholunate ligament in 29 fresh-frozen cadaveric wrists, we placed the RASL screw either distal or proximal to the lateral aspect of the dorsal ridge of the scaphoid and into the dorsal or volar aspect of the lunate. Specimens were subjected to repeated cycles of transcarpal axial force, mimicking clenched-fist loading, until failure. Screw placement distal to the lateral aspect of the dorsal scaphoid ridge was significantly associated with failure when examined manually, radiographically (1.8 vs. 0.5 mm) and using real-time motion capture (diastasis: 1.6 vs. 0.4 mm; Euler angle: 4.5 ° vs. 0.8 °). The lateral aspect of the dorsal ridge is a reliable radiographic landmark on the scaphoid and provides surgeons with a convenient starting point to achieve the most biomechanically stable RASL construct, and, therefore, enhances the potential for an optimal clinical outcome.

Radiological evaluation of scapholunate intercarpal ligamentoplasty for chronic scapholunate dissociation in cadavers

We performed a cadaveric study to evaluate radiological performance of a technique for scapholunate intercarpal ligamentoplasty designed for treating reducible scapholunate dissociation. We created scapholunate instability in 12 fresh adult cadaveric forearms by sectioning the dorsal scapholunate interosseous ligament and the dorsal intercarpal ligament. All wrists showed scapholunate diastasis, dorsal intercalated segmental instability and posterior scaphoid subluxation. We performed scapholunate intercarpal ligamentoplasty in six wrists and Garcia-Elias three-ligament tenodesis in another six. Wrists were examined radiographically both after ligament sectioning and after ligamentoplasty to compare static and dynamic scapholunate gaps and scapholunate and capitolunate angles. Improvement was statistically significant in all measurements, reflecting a return to normal values. Posterior scaphoid subluxation was also corrected. There was no significant difference between the two treatment groups. Our findings suggest that ligamentoplasty can restore scapholunate joint stability and normal carpal anatomy.

Impact of scapholunate dissociation on human wrist kinematics

Neither the complex motions of the scapholunate joint, nor the kinematic changes that occur as a result of injury to it, are fully understood. We used electromagnetic tracking within affected bones to evaluate the physiologic motions in the planes of flexion and extension, and of radial and ulnar deviation of human cadaver wrists, before and after complete transection of the scapholunate ligaments. Despite individual variance between each wrist, we were able to establish a pattern in the changes that occurred after scapholunate ligament injury. During the motions examined, the scaphoid showed an increase in translational deviation in almost all motion axes. In contrast, the movement of the lunate seemed to be impaired, especially in radial-ulnar deviation.

Changes in Wrist Motion After Simulated Scapholunate Arthrodesis: A Cadaveric Study

PURPOSE

A high incidence of nonunion and relatively poor outcomes with prior fixation techniques has precluded scapholunate (SL) arthrodesis as a standard treatment for SL instability. Our purpose was to determine the impact on range of motion (ROM) of simulated SL arthrodesis via headless screw fixation.

METHODS

We performed baseline wrist ROM for 10 cadaveric wrists using a standardized mounting-and-weights system. Extension, flexion, radial deviation, ulnar deviation, dart-thrower's extension, and dart-thrower's flexion were assessed. Two 3.0-mm headless compression screws were inserted across the SL joint to simulate SL arthrodesis. Goniometric measurements and fluoroscopic imaging were repeated to assess ROM differences after simulated SL arthrodesis. We assessed SL angle and gap during testing to ensure there was no significant motion between the scaphoid and lunate, thus confirming stable simulated fusion. Differences in ROM were compared between baseline and simulated SL arthrodesis using paired t tests.

RESULTS

Mean SL angle remained constant between pre- and post-arthrodesis imaging (47° ± 6° vs 46° ± 4°) and did not change during post-arthrodesis ROM testing, indicating a stable simulated fusion. Compared with baseline, SL arthrodesis had a statistically significant reduction in maximum flexion of 6° and 9° based on fluoroscopy and goniometry, respectively, in dart-thrower's extension of 5° and 9° based on fluoroscopy and goniometry, respectively, and in dart-thrower's flexion of 6° for both fluoroscopy and goniometry. No other ROMs after simulated SL arthrodesis were significantly different compared with baseline.

CONCLUSIONS

The effects of simulated SL arthrodesis on radiocarpal and midcarpal motion compare favorably with motion after SL soft tissue repair and other reconstructive techniques that have been previously reported. The statistically significant decreases in wrist flexion and dart-thrower's extension-flexion after simulated SL arthrodesis are of questionable clinical importance.

CLINICAL RELEVANCE

These results may support reconsidering SL arthrodesis as a viable treatment option for acute or chronic SL instability with regard to apparent minimal adverse effects on functional wrist ROM.

Injuries of the Scapholunate Interosseous Ligament: An Update

The scapholunate ligament is both a key ligament in the stability of the carpus and one of the most frequently injured. Thorough understanding of the anatomy, biomechanics, and pathophysiology of the wrist is important in treating injuries to the scapholunate ligament. The presentation of scapholunate instability often includes a vague injury history and pain with grip, wrist extension, and sport or labor. Identified injuries are classified based on dynamic and static radiographic findings, chronicity, and the presence or absence of arthrosis. Surgical options for the treatment of low- and high-grade injuries include both open and arthroscopic procedures and can be broadly classified into four categories: limited arthroscopic procedures, primary ligament repair, reconstructive procedures, and salvage procedures. No strong evidence currently supports any one treatment. Decision making is largely based on expert opinion and surgeon experience. Prognosis is often guarded, and patient expectations should be tempered.

Scapholunate Interosseous Ligament Anatomy and Biomechanics

Injury to the scapholunate interosseous ligament is one of the most common causes of carpal instability and can impart considerable compromise to the patient's hand function. However, the management of scapholunate ligament injuries remains a dynamic concept, especially with regard to the multitude of options and techniques that exist for its surgical treatment. We present a thorough review of scapholunate anatomy and morphology, and the role of the scapholunate articulations in the kinetics and pathomechanics of wrist instability. We also review the current literature on the biomechanical properties of the scapholunate ligament and its subcomponents. A sound understanding of the anatomy and biomechanics of the scapholunate ligament can clarify its instability and may better orient current reconstructive procedures or pioneer better future techniques.

Midterm Outcome of Bone-Ligament-Bone Graft and Dorsal Capsulodesis for Chronic Scapholunate Instability

PURPOSE

To assess midterm outcomes of our bone-ligament-bone (BLB) grafts for chronic scapholunate (SL) instability and better define criteria for their use.

METHODS

We conducted a retrospective review of 26 patients treated with BLB grafts and dorsal capsulodesis between 1997 and 2009. Twenty-four patients were reviewed. Mean follow-up was 8.2 years. Two patients had dynamic lesions, 7 had SL dissociation, 14 had a dorsal intercalated segment instability lesion, and 1 had SL advanced collapse stage 1. Mean age at surgery was 46 years. All patients presented with pain and 14 had lack of strength. Results were reviewed clinically and radiologically. Images were assessed by 4 surgeons and 1 radiologist for radial styloid, radioscaphoid, radiolunate, midcarpal, and scaphotrapeziotrapezoid degenerative changes.

RESULTS

Five patients needed subsequent 4-corner arthrodesis. Of the remaining 19 patients at follow-up, both extension and flexion decreased to 73% of the contralateral side. Postoperative grip strength improved from 78% to 90% of the nonsurgical wrist. Quick Disabilities of the Arm, Shoulder, and Hand score was 10 of 100 and the Patient-Rated Wrist Evaluation score was 10 of 100. Radiologically, the SL gap was improved and maintained at follow-up. The SL angle (mean before surgery, 79°) was initially corrected to 69° but returned to preoperative values at follow-up. Eleven of the 19 cases had signs of midcarpal arthritis.

CONCLUSIONS

Bone-ligament-bone grafts with SL dorsal capsulodesis were able to restore and maintain an improved SL interval in all patients. The technique achieved good clinical results and high patient satisfaction, but it did not stop the progression of arthritis, particularly at the midcarpal level. This technique is an option for isolated unrepairable lesion of the dorsal SL ligament with an easily correctable lunate and especially when restoration of grip strength is important.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Radiographic evaluation of a novel horizontal dorsal intercarpal capsulodesis as a treatment of pre-arthritic scapholunate dissociation: a cadaver study

Dorsal capsulodesis is an important part of the treatment of pre-arthritic scapholunate instability. We designed an experimental study using 14 fresh-frozen cadaver wrists to demonstrate the efficacy of a new horizontal dorsal intercarpal capsulodesis. We sectioned the scapholunate ligament to create a scapholunate dislocation. Several radiographic views, static and 'in stress', were recorded and we statistically compared the scapholunate interval before and after the section of the scapholunate ligament, and after the creation of the capsulodesis. The results showed a significant decrease of the scapholunate interval after the creation of the capsulodesis, especially in neutral and maximal ulnar deviation of the wrist. They also proved that our cadaveric model is reliable. This study demonstrated that this novel capsulodesis reduces the scapholunate interval in a cadaveric model.

Radiographic evaluation of the modified Brunelli technique versus a scapholunotriquetral transosseous tenodesis technique for scapholunate dissociation

PURPOSE

To compare reduction of the scapholunate articulation using a transosseous tenodesis through the scaphoid, lunate, and triquetrum (SLT) with the modified Brunelli technique (MBT) in a cadaver model, as measured by scapholunate (SL) angle and diastasis on radiographs.

METHODS

Twelve fresh-frozen cadaveric wrists were radiographically examined in a neutral posture, ulnar deviation, and clenched fist position. The SL angle and diastasis were recorded in each position with the SL ligament intact, after sectioning the ligament and secondary restraints, and after reconstruction by either the MBT (6 wrists) or SLT technique (6 wrists). Wrists were cycled through their maximum flexion and extension arc 100 times to simulate wrist motion after ligament sectioning and reconstruction.

RESULTS

After sectioning and cycling, all wrists demonstrated radiographic evidence of SL diastasis. After ligament reconstruction and cycling, there was no statistically significant difference in diastasis in the MBT reconstructions compared with the SLT reconstructions (3.0 vs 2.4 mm). The SLT group demonstrated better maintenance of the restored SL angle than the MBT reconstructions.

CONCLUSIONS

In this cadaveric model, both MBT and SLT reconstructions restored anatomic parameters in the SL joint, with correction of SL diastasis and SL angle. Future studies to assess the clinical outcomes of SLT tenodesis in patients with chronic SL disruptions are important.

CLINICAL RELEVANCE

The SLT tenodesis, with a central biologic tether along the SL axis and dorsal reinforcement, may prove clinically useful.

Scaphoid overstuffing: the effects of the dimensions of scaphoid reconstruction on scapholunate alignment

PURPOSE

Osteochondral replacement of the proximal scaphoid has been reported using a vascularized flap from the medial femoral trochlea. A concern with this technique is the loss of stability of the scapholunate relationship with resection of the scaphoid proximal pole. Overexpansion of the scaphoid dimensions (overstuffing) during scaphoid reconstruction with the osteochondral flap may play a role in maintaining scapholunate alignment. Our purpose was to determine if overstuffing the scaphoid can correct rotatory carpal instability in a cadaveric model studied radiographically.

METHODS

The radiolunate angle and scapholunate interval were measured for 5 fresh cadaver wrists. We completely incised the scapholunate interosseous ligament and performed an osteotomy to excise the proximal third of the scaphoid to simulate a proximal pole deficiency nonunion and create a dorsal intercalated segmental instability deformity. Radiographic measurements were repeated. The proximal pole of the scaphoid was replaced with its original piece of bone; radiographic measurements were repeated without scapholunate ligament repair. The osteotomy site was overstuffed with a 4-mm sawbone spacer without scapholunate ligament repair, and radiographs were obtained.

RESULTS

Sectioning of scapholunate ligaments and proximal pole excision successfully created carpal instability demonstrated by abnormal radiolunate angles. Without ligament repair, proximal pole replacement did not restore normal radiolunate angles. Expansion of the scaphoid dimensions corrected radiolunate angles on lateral unloaded radiographs and improved scapholunate intervals on clenched fist radiographs. These findings were statistically significant compared with the unexpanded (replaced) scaphoid.

CONCLUSIONS

These findings suggest that scaphoid reconstruction that results in expansion of the scaphoid's normal dimensions will restore carpal alignment without scapholunate ligament reconstruction.

CLINICAL RELEVANCE

Osteochondral reconstruction of difficult proximal pole nonunions may not require any preservation or reconstruction of scapholunate integrity if the reconstruction expands the normal dimensions of the native scaphoid. Scapholunate interval and carpal alignment may be restored by scaphoid over stuffing. The effects on increased contact pressure and range of motion require further investigation.

Dorsal scapholunate stabilization using Viegas' capsulodesis: 25 cases with 26 months-follow-up

Intercarpal instability is often secondary to a scapholunate interosseous (SLIO) ligament lesion. Its reconstruction is thus essential. Classical capsulodesis techniques fix the scaphoid in extension and do not reproduce the physiologic ligamentous isometry of the wrist. The authors use the technique of Viegas, which seems to respect this isometry: the dorsal intercarpal ligament is re-inserted dorsally to reattach the capsule on the dorsal SLIO and to reinforce it. Between 2006 and 2010, 25 wrists were operated on in 12 men and 12 women of mean age 38 years. All patients presented with pain often associated with loss of power, decreased mobility or a debilitating click. The mean follow-up was 26 months. Postoperative and preoperative data were compared. Flexion/extension range increased by 2.6°, radioulnar deviation increased by 21.1°. Grip strength increased by 8.7 kgf. Pain decreased by 3 points on the VAS and the PRWE improved by 59 points. We observed four CRPS, one EPL lesion and one case of superficial track pin infection. We got eleven excellent results, nine good, two moderate and three bad, two of which were re-operated. Viegas' capsulodesis does not present major technical difficulty. The results show no stiffness in flexion/extension. There was evident improvement in radioulnar deviation, grip strength, pain and PRWE scores. This technique provides effective treatment for a difficult or irreparable lesion of the SLIO ligament, without fixed carpal instability corresponding to Geissler arthroscopic stages 2 to 4 and Garcia-Elias stages 3 and 4. The capsulodesis produces an effective stabilization without stiffness. Precautions should be undertaken to avoid CRPS and pin complications.

Arthroscopic dorsal capsulo-ligamentous repair in the treatment of chronic scapho-lunate ligament tears

Introduction Scapholunate ligament injuries usually result due to a fall on the outstretched hand leading to scapholunate instability. The natural history of untreated scapholunate instability remains controversial and usually results in late arthritic changes- the so-called "SLAC" wrist. The advent of wrist arthroscopy helps in early diagnosis and treatment of these serious injuries. In selected cases with reducible scapholunate instability (Garcia-Elias stages 2, 3 and 4) we propose a new "all arthroscopic dorsal capsulo- ligamentous repair" with the added advantage of early rehabilitation and prevention of post-operative stiffness. Material and Methods We report the results of our series of 57 consecutive patients suffering from chronic wrist pain refractory to conservative measures. All patients underwent a thorough clinical examination in addition to a standard set of radiographs and MRI exam; and they were treated by an all-arthroscopic dorsal capsulo-ligamentous repair under loco-regional anesthesia on an ambulatory basis. All patients were available for follow-up at regular intervals during the post-operative period. At follow-up, the wrist ROM in all directions, the grip strength, DASH questionnaire and pain relief based on the VAS were recorded for both- the operated and contra-lateral sides. Results There were 34 males & 23 females with a mean age of 38.72 ± 11.33 years (range 17-63 years). The dominant side was involved in 52 cases. The mean time since injury was 9.42 ± 6.33 months (range 3-24 months) and the mean follow-up was 30.74 ± 7.05 months (range 18-43 months). The mean range of motion improved in all directions. The mean difference between the post- and pre-operative extension was 14.03° (SEM = 1.27°; p < 0.001); while the mean difference between the post-and pre-operative flexion was 11.14° (SEM = 1.3°; p < 0.0001) with flexion and radial deviation reaching 84.3% and 95.72% respectively of the unaffected wrist. The mean difference for the VAS score was -5.46 (SEM = 0.19; p < 0.0001). The mean post-operative grip strength of the affected side was 38.42 ± 10.27 kg (range 20-60 kg) as compared with mean pre-operative grip strength of 24.07 ± 10.51 kg (range 8-40 kg) (p < 0.0001). The mean post-operative grip strength of the operated side was 93.4% of the unaffected side. The DISI was corrected in all cases on post-operative radiographs. The mean difference between the post-and pre-operative SL angles was -8.95° (SEM = 1.28°; p < 0.0001). The mean post-operative DASH score was 8.3 ± 7.82 as compared with mean pre-operative DASH score of 46.04 ± 16.57 (p < 0.0001). There was a negative co-relation between the overall DASH score and the post-operative correction of the DISI deformity with a lower DASH score associated with increasing SL angles. Discussion The dorsal portion of the scapholunate ligament is critical for the stability scapholunate articulation, largely due to its attachment to the dorsal capsule. We have recently conducted a multi-centric anatomical study with international collaboration demonstrating the critical importance of this dorsal scapholunate complex. The all arthroscopic capsulo-ligamentous repair technique provides reliable results in addition to avoiding postoperative stiffness. The overall results at a mean follow-up period of more than 2 years in our series of young, active patients appear to be encouraging.

Current role of open reconstruction of the scapholunate ligament

This paper is a review of the various surgical techniques used in repair or reconstruction of the scapholunate ligament according to the clinical stages and anatomic-pathologic findings. Arthroscopy permits a direct evaluation of the scapholunate injury and the status of the articular surfaces. Specific indications for each type of scapholunate ligament tear are proposed, from the different types of dorsal capsulodesis to bone-ligament-bone techniques and tenodesis procedures. The authors' preferred techniques and literature review of the expected outcomes are presented.

Long-term results of dorsal intercarpal ligament capsulodesis for the treatment of chronic scapholunate instability

The purpose of this study was to assess the clinical and radiological outcomes of dorsal intercarpal ligament capsulodesis for the treatment of static scapholunate instability at a minimum follow-up of four years. A total of 59 patients who underwent capsulodesis for this condition were included in a retrospective analysis after a mean of 8.25 years (4.3 to 12). A total of eight patients underwent a salvage procedure at a mean of 2.33 years (0.67 to 7.6) and were excluded. The mean range of extension/flexion was 88° (15° to 135°) and of ulnar/radial deviation was 38° (0° to 75°) at final follow-up. The mean Disabilities of the Arm Shoulder and Hand (DASH) score and Mayo wrist scores were 28 (0 to 85) and 61 (0 to 90), respectively. After significant improvement immediately post-operatively (p < 0.001 and p = 0.001, respectively), the mean scapholunate and radiolunate angles deteriorated to 70° (40° to 90°) and 8° (-15° to 25°), respectively, at final follow-up, which were not significantly different from their pre-operative values (p = 0.6 and p = 0.4, respectively). The mean carpal height index decreased significantly from 1.53 (1.38 to 1.65) to 1.48 (1.29 to 1.65) indicating progressive carpal collapse (p < 0.001); 40 patients (78%) had radiological evidence of degenerative arthritis.

Capsulodesis did not maintain carpal reduction over time. Although the consequent ongoing scapholunate instability resulted in early arthritic degeneration, most patients had acceptable long-term function of the wrist.

Scapholunate interosseous ligament disruption in professional basketball players: treatment by direct repair and dorsal ligamentoplasty

In the authors' experience scapholunate interosseous ligament (SLIL) disruption with resultant scapholunate dissociation (SLD) is the most frequent disabling carpal injury among professional basketball players. Prompt diagnosis, precision surgical repair, and intensive sport-specific rehabilitation are requisites for optimal recovery. This article reports the techniques and results of a consistent surgical protocol comprising accurate carpal reduction, direct SLIL repair, and dorsal intercarpal ligament augmentation for 25 professional basketball players with disabling SLD. Follow-up assessment supports the contention that early surgery, prior to scar contracture, facilitates treatment and enhances outcome.

Arthroscopic dorsal capsuloligamentous repair in chronic scapholunate ligament tears

This article discusses the preliminary results of treatment of chronic scapholunate lesions by arthroscopic dorsal capsuloligamentous repair, which does not require open exposure of the wrist capsule. Thirty six patients underwent arthroscopically assisted dorsal capsuloplasties. Sixteen had percutaneous pinning. Mean follow-up was at 11.4 months. The average arc of motion was 105°preoperatively and 120°postoperatively. The average grip strength attained 92% of the contralateral side. Most of the results were excellent-to-good. Seven professional athletes returned to preinjury level. Arthroscopic dorsal capsuloligamentous repair is a promising option, but a longer follow-up is necessary to confirm these results.

[Carpal instability]

Carpal instability can be understood as a disturbed anatomical alignment between bones articulating in the carpus. This disturbed balance occurs either only dynamically (with movement) under the effect of physiological force or even statically at rest. The most common cause of carpal instability is wrist trauma with rupture of the stabilizing ligaments and adaptive misalignment following fractures of the radius or carpus. Carpal collapse plays a special role in this mechanism due to non-healed fracture of the scaphoid bone. In addition degenerative inflammatory alterations, such as chondrocalcinosis or gout, more rarely aseptic bone necrosis of the lunate or scaphoid bones or misalignment due to deposition (Madelung deformity) can lead to wrist instability. Under increased pressure the misaligned joint surfaces lead to bone arrosion with secondary arthritis of the wrist. In order to arrest or slow down this irreversible process, diagnosis must occur as early as possible. Many surgical methods have been thought out to regain stability ranging from direct reconstruction of the damaged ligaments, through ligament replacement to partial stiffening of the wrist joint.

Linear and torsional mechanical characteristics of intact and reconstructed scapholunate ligaments

The mechanical behavior of human scapholunate ligaments is not well understood. Presently, intact scapholunate specimens were mechanically tested in linear distraction and torsion. Fresh bovine tendon grafts were used to reconstruct the scapholunate interval and the tests repeated. Tests yielded the following average values for intact specimens: linear stiffness (48.9 Nmm), linear load retained at 100 s (44%), torsional stiffness (19.5 N mmdeg), torque remaining at 100 seconds (66%), torque-to-failure (1253.9 N mm), and angle-to-failure (50.4 deg). Tests showed the following average values for reconstructed specimens: linear stiffness (5.4 Nmm), linear load retained at 100 s (49%), torsional stiffness (12.6 N mmdeg), torque remaining at 100 s (71%), torque-to-failure (936.8 N mm), and angle-to-failure (54.5 deg). There were no statistically significant differences between the intact and reconstructed specimens, with the exception of linear stiffness. Biomechanically, this is the first study in the literature to quantify torsional stress relaxation, failure torque, and failure angle for the intact and repaired human scapholunate ligament. Surgically, reconstruction with bovine tendon may warrant further investigation as a method to potentially retain function and strength after scapholunate injury.

A biomechanical assessment of the coupling of torsion and tension in the human scapholunate ligament

The mechanical behaviour of human scapholunate ligaments is not well described in the literature with regard to torsion. In this study, intact scapholunate specimens were mechanically tested in torsion to determine whether a simultaneous tensile load was generated. Human intact scapholunate specimens ( n = 19) were harvested. The scaphoid and lunate bones were potted in square chambers using epoxy cement, while the interposing ligament remained exposed. Each specimen was mounted rigidly in a specially designed test jig and remained at a fixed axial length during all tests. Specimens were subjected to a torsional load regime that included cyclic preconditioning, ramp-up, stress relaxation, ramp-down, rest, and torsion to failure. Torque and axial tension were monitored simultaneously. The relationship between torsion and tension was determined. Graphs of torque versus tension were generated, from which outcome measures were extracted. Tests demonstrated a clear relationship between applied torsion and the resulting generation of tension for the ligament during ramp-up (torsion-to-tension ratio, 38.86 ± 29.00 mm; linearity coefficient R2 = 0.89 ± 0.15; n = 19), stress relaxation (torsion-to-tension ratio, 23.43 ± 15.84 mm; R2 = 0.90 ± 0.09; n = 16), and failure tests (torsion-to-tension ratio, 38.81 ± 26.39 mm; R2 = 0.77 ± 0.20; n = 16). No statistically significant differences were detected between the torsion-to-tension ratios ( p = 0.13) or between the linearity ( R2) of the best-fit lines ( p > 0.085). A strongly coupled linear relationship between torsion and tension for the scapholunate ligament was exhibited in all test phases. This may suggest interplay between these two parameters in the stabilization of the ligament during normal motion and for injury cascades.

Capsulodesis of the wrist for scapholunate dissociation

We have had favorable results with our early experience using the Mayo modification of the dorsal intercarpal ligament capsulodesis. Our early experience with this technique has shown improvement in carpal alignment and pain relief with the tradeoff of a mild loss of wrist flexion. These results compare with reported results of the various capsulodesis techniques in evolution. Attention must also be paid as to the stage of dissociation at time of surgery. Dynamic dissociation has been treated with capsulodesis alone, whereas a combination of ligament repair in conjunction with dorsal intercarpal ligament capsulodesis is used to treat both dynamic and static variants. Many other investigators report improvements in scapholunate alignment and improvement in pain relief and function with a loss of wrist flexion as a tradeoff. However, despite technical advances in surgical technique and intraoperative improvement of alignment and gapping, these results may diminish by the 2- to 3-year postoperative period. Scapholunate interosseous injuries remain a challenging problem to even experienced hand and upper extremity surgeons. The Mayo modification of the modified dorsal intercarpal ligament capsulodesis is a technique that may be added to the armamentarium of treatment of this pathologic entity.

Dorsal intercarpal augmentation ligamentoplasty for scapholunate dissociation

Carpal instability secondary to scapholunate ligament tears can lead to significant disability of the wrist. Disruption of the ligamentous stabilizers of the scaphoid causes rotatory subluxation of the scaphoid and subsequent abnormal loads across the radioscaphoid joint. Arthritic changes involving the radioscaphoid and midcarpal joint will develop if the wrist is untreated. Treatment of scapholunate ligament tears has varied widely in the literature. Today, most surgeons perform either a soft tissue reconstruction using local tissue or a limited fusion. Motion of the wrist favors soft tissue reconstructions. Also, the relative intercarpal motion with a more flexible carpus may prevent abnormal load patterns that are associated with a rigid radial column and limited fusions. We have reconstructed flexible subacute (>3 weeks) and chronic (>2 months) scapholunate dissociations with a radial-based dorsal intercarpal ligament. Clinical results have demonstrated increased grip strength, decreased pain, and improved intercarpal alignment.

Current status of scapholunate interosseous ligament injuries

Injuries to the scapholunate complex present the surgeon with both diagnostic and treatment dilemmas. The anatomic features, biomechanical properties, radiographic appearance, and surgical treatment algorithms of this small but structurally and kinematically important joint continue to be refined. A thorough history and physical examination, combined with a radiographic evaluation that can include plain radiographs, tomography, motion studies, arthrography, or MRI, usually will define the nature of the ligament injury. Arthroscopy is considered the gold standard for complete evaluation of scapholunate interosseous ligament injury and often is performed as a first step before repair or reconstruction. Procedures such as carpal fusions or capsulodesis can limit excessive scaphoid motion, promote wrist stability, and potentially prevent arthritis, but advances continue to be made in direct scapholunate interosseous ligament reconstruction. Challenges for the future involve improving noninvasive evaluation, defining the degree of extrinsic ligament injury, and improving direct repair and reconstruction.

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.