Injuries of the Scapholunate Interosseous Ligament: An Update

Mapping wrist motion: 3D CT analysis after scapholunate ligament transection

The injury of the scapholunate (SL) ligament is common in wrist traumas leading to pain and reduced wrist function. The wrist's unique joint design and possible underlying theories as the carpal row theory were subject to earlier investigations studying wrist kinematics. Nevertheless, a comprehensive understanding of how SL ligament injuries affect wrist biomechanics is still lacking. Through a quantitative analysis of carpal bone motion patterns, we evaluated the impact on wrist kinematics occurring after SL ligament injury. We conducted a study using computer tomography imaging to analyse wrist kinematics after SL ligament transection in 21 fresh-frozen anatomical specimens. The collected data were then transformed into 3D models, employing both standardized global and object coordinate systems. The study encompassed the evaluation of rotation and translation for each individual carpal bone, as well as the ulna, and all metacarpal bones in reference to the radius. The study showed a significant increase in rotation towards palmar (p < 0.01), particularly notable for the scaphoid, following transection of the SL ligament during palmar flexion. Ulnar deviation did not significantly affect rotation or translation, and radial deviation also showed no significant changes in rotation or translation. The study highlights the significance of the SL ligament in wrist kinematics, revealing that SL ligament tears lead to changes in wrist motion. While we observed significant rotational changes for the scaphoid, other carpal bones showed less pronounced alterations, emphasizing the complexity of wrist biomechanics.

Comparing Patient-Reported Outcomes on Three-Ligament Tenodesis Between Partial and Complete Scapholunate Ligament Injuries: A Cohort Study

PURPOSE

Multiple studies report outcomes after 3-ligament tenodesis (3-LT) in treating traumatic scapholunate interosseous ligament injury (SLIL). However, investigators do not differentiate between patients with partial or complete SLIL injury. The relation between the extent of SLIL disruption and surgical outcomes and if this should be considered when treating a patient with SLIL injury remains unknown. We aimed to evaluate differences in patient-rated wrist evaluation (PRWE) scores, satisfaction and return to work between patients with partial or complete chronic traumatic SLIL injury treated with 3 ligament tenodesis at 12 months after surgery.

METHODS

All patients with chronic SLIL injury (partial and complete) who were treated with 3-LT at our clinic and received the same postoperative management between December 2011 and December 2019 were studied. Only patients who had completed the PRWE and return to work questionnaires preoperatively and 12 months after surgery were included. Patients were allocated to the partial (classified as Geissler 2 or 3) or complete SLIL injury group (classified as Geissler 4) by retrospectively assessing wrist arthroscopy reports.

RESULTS

Thirty-nine patients with partial and 90 with complete SLIL injuries were included. At 1-year follow-up, PRWE scores had significantly improved in both groups. When adjusting for clinical baseline characteristics, there was no statistically significant difference between patients with partial or complete SLIL injury. Patients with complete SLIL injury had a 70% higher return to work within the first 12 months after 3-LT; however, satisfaction with the treatment result was similar for both study groups 1 year after surgery.

CONCLUSIONS

Patients with complete and partial traumatic SLIL injury report better PRWE total scores at 12 months after 3-LT, but there was no statistically significant difference between the groups in PRWE scores or satisfaction with the treatment result.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Arthroscopic management of scapholunate complex injuries associated with distal radius fractures

Scapholunate complex injuries are the most frequent lesions associated with distal radius fractures and the treatment algorithm according to the stage of the instability remains controversial. However, there is an admitted consensus around the necessary treatment of the associated high-grade instabilities. They occur frequently in young patients after high energy trauma, and not treated, they can lead to chronic wrist pain and eventually to scapholunate advanced collapse. The routine use of the arthroscopy provides an accurate intraoperative staging of the lesions and allows a tailored treatment depending on the severity of the scapholunate instability.

Three‑dimensional finite element analysis: Anatomical splint fixation for Colles fractures

With the rapid development of digital research in clinical orthopedics, the efficacy and safety of splint fixation can be better evaluated through biomechanical analysis based on a three-dimensional (3D) finite element model. It is essential to address the current gap in understanding the biomechanical implications of anatomical splint fixation for Colles fractures. By employing advanced 3D finite element analysis, the present study aimed to provide a comprehensive evaluation, offering valuable insights that can contribute to enhancing the effectiveness of anatomical splint fixation in the clinical management of Colles fractures. The 3D finite element models of the forearm and hand were constructed using Mimics 15.0 according to data from computed tomography of a patient with a Colles fracture. After the validity of the model was verified, the corresponding material properties of the models were adjusted to simulate a Colles fracture. Subsequently, the reduction functions, such as radial inclination and ulnar deviation, of the simulated fracture were completed and the mechanical changes of the tissues surrounding the fracture were calculated. Anatomical splints were then placed on the surfaces of the 3D finite element models of Colles fractures at various positions to analyze the changes in the stress cloud diagram, such as for the soft tissue and anatomical splints. In the present study, the constructed 3D finite element models were accurate and valid. The maximum stress of the anatomical splints and soft tissues was 2.346 and 0.106 MPa in pronation, 1.780 and 0.069 MPa in median rotation and 3.045 and 0.057 MPa in supination, respectively. Splint stress reached the highest level in supination and soft tissue stress achieved the highest level in pronation. The peak of splint stress occurred during supination, which contrasts to the peak of soft tissue stress observed in pronation, suggesting splint fixation median rotation can effectively avoid compression of the local soft tissue.

Arthroscopic scapholunate ligament repair and dorsal capsulodesis with suture anchor in acute and subacute scapholunate dissociation

PURPOSE

The objective of this study was to investigate the potential of arthroscopic scapholunate ligament repair and dorsal capsulodesis with suture anchor as a treatment option for patients experiencing symptomatic acute and subacute (< 3 months) scapholunate instability.

METHODS

From Jan. 2017 to Jan 2020, 19 wrists with acute or subacute tears of the SL ligament with symptomatic instability were treated with arthroscopic SL repair and dorsal capsulodesis with a suture anchor. The average time from injury to operation was 8.8 weeks (range, 4-11 weeks) and the regular follow-up mean duration at our clinic was 26.5 months (range, 24-32 months). The pain score according to the visual analog scale, wrist range of motion, grip strength, radiographic outcomes and functional outcomes according to the Modified Mayo Wrist Score (MMWS) were evaluated preoperatively and postoperatively during the follow-up period.

RESULTS

All 19 patients had rupture and dissociation of the SL ligament in the radiocarpal joint. The total arc of wrist motion in the flexion-extension plane loss averaged 5.1° (P > .01).The Wilcoxon signed-rank test was used to compare the results: grip force improved significantly with 14.7% improvement of that on the normal side (P < .01); the postoperative MMWS was significantly better than the preoperative scores (P < .01). Of 19 patients of the series, 18 patients (94.7%) achieved good or excellent results according to the MMWS and 16 patients (84.2%) resumed their previous activities. Only one patient (5.3%) had residual laxity of the scapholunate ligament joint at 15 months of follow-up.

CONCLUSIONS

At a minimum of two years of follow-up, patients with acute or subacute symptomatic dissociation of scapholunate ligament instability who underwent arthroscopic scapholunate ligament repair and dorsal capsulodesis with suture anchor treatment had satisfactory results.

LEVEL OF EVIDENCE

Level IV, case series.

Assessment of Scapholunate Instability on 4D CT Scans in Patients with Inconclusive Conventional Images

Background Initial imaging work-up using radiography and CT arthrography sometimes can be insufficient to identify a scapholunate (SL) instability (SLI) in patients suspected of having SL ligament tears. Purpose To determine the diagnostic performance of four-dimensional (4D) CT in the identification of SLI and apply the findings to patients suspected of having SLI and with inconclusive findings on radiographs and CT arthrograms. Materials and Methods This prospective single-center study enrolled participants suspected of having SLI (recent trauma, dorsal pain, positive Watson test results, decreased grip strength) between March 2015 and March 2020. Participants with wrist fractures, substantial joint stiffness, or history of wrist surgery were excluded. Each participant underwent radiography, CT arthrography, and 4D CT on the same day. Participants were divided into three groups: those with no SLI, those with SLI, and those with inconclusive results. SL gap and radioscaphoid and lunocapitate angle were measured using semiautomatic quantitative analysis of 4D CT images by two independent readers. Receiver operating characteristic curves were used to evaluate the diagnostic performance of 4D CT. Thresholds were determined with the Youden index and were applied to the inconclusive group. Results Of the 150 included participants (mean age, 41 years ± 14 [SD]; 102 male, 48 female), there were 63 with no SLI, 48 with SLI, and 39 with inconclusive results. The maximum value and range of SL gap measurements on 4D CT scans showed high sensitivity (83% [40 of 48] and 90% [43 of 48], respectively) and high specificity (95% [59 of 62] and 81% [50 of 62], respectively) in the identification of SLI. At least one of these parameters was abnormal on 4D CT scans in 17 of 39 (44%) participants in the inconclusive group, and 10 of 17 (59%) participants had confirmed SLI. In the 22 participants in the inconclusive group with no indication of SLI at 4D CT, follow-up showed no evidence of SLI in 10 (45%) and enabled confirmation of SLI via arthroscopy in three (14%). Conclusion Scapholunate gap measurements on kinematic 4D CT scans enabled correct identification of SLI in 59% of participants with inconclusive results on conventional images. ClinicalTrials.gov registration no. NCT02401568 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Demehri and Ibad in this issue.

Return to sport or work following surgical management of scapholunate ligament injury: a systematic review

INTRODUCTION

This systematic review aims to compare the rate and time to return to sport or work following surgical interventions for isolated scapholunate ligament (SLL) injury.

SOURCES OF DATA

A PRISMA-compliant systematic search of Medline, EMBASE, Cochrane, AMED, CINAHL Plus and SPORTDiscus was performed using keywords 'scapholunate', 'scapholunate ligament', 'scaphoid lunate', 'sport', 'sport injury', 'athlete', 'athletic performance', 'elite', 'return to sport', 'training', 'work', 'activity', 'return to activity'. Adult patients with isolated SLL injury, without osteoarthritis, were included.

AREAS OF AGREEMENT

Fourteen papers, including six different surgical interventions, met the criteria for the final analysis. All surgical techniques demonstrated acceptable rates of return to work or sport (>80%).

AREAS OF CONTROVERSY

The optimal surgical intervention for isolated SLL injury remains undetermined due to heterogeneity and limited sample sizes of published studies.

GROWING POINTS

This systematic review has provided clarification on the available literature on treatment modalities for isolated SLL injuries in the absence of osteoarthritis.

AREAS TIMELY FOR DEVELOPING RESEARCH

Prospective, randomized, primary studies are needed to establish optimal treatment for acute isolated SLL injuries.

Kinematic 4D CT case-control study of wrist in dart throwing motion "in vivo": comparison with other maneuvers

OBJECTIVES

To compare the diagnostic performance of scapholunate gap (SLG) measurements acquired with dart throwing (DT), radio-ulnar deviation (RUD), and clenching fist (CF) maneuvers on 4D CT for the identification of scapholunate instability.

METHODS

In this prospective study, 47 patients with suspected scapholunate interosseous ligament (SLIL) tears were evaluated from March 2015 to March 2020 with semiautomatic quantitative analysis on 4D CT. Five parameters (median, maximal value, range, and coefficient of variation) for SLG, lunocapitate angle (LCA), and radioscaphoid angle (RSA) obtained during DT maneuver were evaluated in patients with and without SLIL tears. CT arthrography was used as the gold standard for the SLIL status. The SLG values obtained were also compared with those obtained during CF and RUD maneuvers.

RESULTS

Significant differences in all SLG- and LCA-derived parameters are found between patients with and without SLIL tears with DT (p < 0.003). The best diagnostic performance for the diagnosis of SLIL tears was obtained with median and maximal SLG values (sensitivity and specificity of 86-89% and 95%) and with maximal and range LCA values (sensitivity and specificity of 86% and 74%). No significant differences were observed for RSA values (p > 0.275). The SLG range obtained with DT maneuver was the only dynamic parameter statistically different between patients with partial and complete torn SLIL (p = 0.037).

CONCLUSION

4D CT of the wrist during DT showed a similar performance than RUD and a better performance than CF for the differentiation between patients with and without SLIL tears.

KEY POINTS

• Four-dimensional computed tomography can dynamically assess scapholunate instability. • The best results for differentiating between patients with and without SLIL tears were obtained with SLG median and maximal values. • The dart throwing and radio-ulnar deviation maneuvers yielded the best results for the dynamic evaluation of scapholunate instability.

Radiographic Incidence and Functional Outcomes of Distal Radius Fractures Undergoing Volar Plate Fixation With Concomitant Scapholunate Widening: A Prospective Analysis

Background: Scapholunate (SL) ligament injuries can occur concomitantly with distal radius fractures (DRFs), and the management of acute SL injury in the setting of DRFs remains controversial. The purpose of the study is to identify the radiographic incidence of SL widening in DRF treated with volar plate fixation and to determine the functional outcomes of DRF with concomitant radiographic SL-widening. Methods: One hundred and seventeen patients with DRFs, with and without radiographic SL-widening, and treated with volar locked plating, were prospectively enrolled. No SL ligament repairs or reconstructions were performed in any cases. Patients with DRFs with radiographic criteria for SL widening were compared to those without. Patients were evaluated at 3 months and 1 year postoperatively with Quick Disabilities of the Arm, Shoulder, and Hand and Patient-Rated Wrist Evaluation (PRWE) questionnaires. Results: Thirty-one patients (26.5%) were found to have radiographic evidence of SL widening. Patients with concomitant SL widening had less wrist extension at 3 months (52.4 degrees vs 60.8, P = .034) and at 1 year (64.5 degrees vs 71.8, P = .023). The group with SL widening had greater articular step off at 3 months (0.33 vs 0.06, P = .042), but no difference at 1 year (0.11 vs 0.05, P = .348). There were no differences in wrist flexion, supination, pronation, volar tilt, radial inclination, radial height, ulnar variance, PRWE scores, and Quick Dash scores at 3 months and 1 year. Conclusions: Radiographic SL-widening is a common finding associated with DRFs undergoing surgical repair. There are similar clinical outcomes between those with untreated SL widening compared to those without an SL widening at 1-year postoperatively.

Outcomes after Bone-Ligament-Bone Intercarpal Ligament Reconstruction

BACKGROUND

Numerous surgical reconstructive techniques have been described for chronic scapholunate and lunotriquetral interosseous ligament instability.

METHODS

The authors retrospectively reviewed 16 consecutive patients who underwent bone-ligament-bone reconstruction for scapholunate or lunotriquetral intraosseous ligament predynamic and dynamic instability at a single tertiary care institution from 2013 to 2019. Clinical and radiographic outcomes, and complications, were recorded.

RESULTS

Eleven patients had bone-ligament-bone reconstruction for scapholunate ligament injury and five for lunotriquetral instability. Fourteen patients (87.5 percent) underwent diagnostic arthroscopy before bone-ligament-bone reconstruction, with nine of 14 having grade 3 and four of 14 having grade 4 injury. Capitohamate bone-ligament-bone grafts were used in nine patients (56 percent) and the graft was taken from Lister tubercle in seven (44 percent). The average age at surgery was 37 years. The average follow-up was 60.6 weeks. There were no significant differences between preoperative and postoperative radiographic parameters. Median postoperative wrist flexion was 45 degrees, and mean postoperative wrist extension was 53 degrees, which were significantly less than contralateral flexion (85 degrees; p < 0.0001) and extension (78 degrees; p < 0.0001). Thirty-eight percent of patients complained of persistent pain at final follow-up, and two patients (13 percent) underwent salvage procedures, both at approximately 6.5 months after the index reconstruction.

CONCLUSION

Short-term outcomes of bone-ligament-bone reconstruction for early-stage scapholunate and lunotriquetral ligament injuries reveal many patients with residual postoperative wrist pain and disability, and almost uniform limitations in flexion-extension motion.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Preoperative and Postoperative Imaging of Scapholunate Ligament Primary Repair and Modified Brunelli Reconstruction

Injury of the scapholunate ligament (SLL) complex can lead to scapholunate dissociation, characterized by scapholunate interval widening and volar rotary subluxation of the scaphoid. Loss of the mechanical linkage between the scaphoid and lunate results in carpal instability and eventual scapholunate advanced collapse (SLAC) arthropathy. SLL complex injuries vary from acute and traumatic to chronic and degenerative. A staging system can be used to guide treatment options for these injuries on the basis of the reparability of the SLL dorsal band, carpal alignment and malalignment reducibility, and cartilage damage. Preoperative imaging with radiography and MRI is a component of injury staging and aids in planning surgical procedures. If the SLL dorsal band is reparable, then direct primary ligament repair with dorsal capsulodesis or dorsal intercarpal (DIC) ligament transfer can be performed. If the SLL dorsal band is irreparable with normal alignment or reducible malalignment, then reconstruction can be performed. In the setting of irreducible malalignment or SLAC arthropathy, a salvage procedure can be performed. Knowledge of SLL primary repair and various reconstruction techniques is important not only when evaluating postoperative images but also for accurate description of SLL injuries and aiding the surgeon in treatment planning. The authors present the normal anatomy of the SLL complex, a staging classification of SLL injury with radiographic and MRI findings, and common surgical procedures. Special attention is given to the operative techniques and postoperative imaging appearances of primary SLL repair with DIC ligament transfer and modified Brunelli reconstruction. ^©RSNA, 2021.

Histomorphology of the Subregions of the Scapholunate Interosseous Ligament and Its Enthesis

Background  The scapholunate interosseous ligament (SLIL) has three subregions: dorsal, proximal, and volar. The SLIL enthesis has not previously been studied despite its important mechanical function in wrist joint biomechanics. Questions/Purposes  This study aims to compare the histomorphological differences between the SLIL subregions, including at their entheses. Three questions are explored: Do the gross dimensions differ between SLIL subregions? Does the enthesis qualitatively, and its calcified fibrocartilage (CF) quantitatively, differ between (a) SLIL subregions and (b) scaphoid and lunate attachments? Methods  Twelve fresh-frozen human cadaveric wrists were dissected and the gross dimensions of the SLIL subregions measured. Subregions were histologically processed for morphological and compositional analyses, including quantification of enthesis CF area. Results  The dorsal subregion was the thickest. The dorsal and volar subregions had fibrocartilaginous entheses, while the proximal subregion was attached to articular cartilage. The dorsal subregion had significantly more CF than the volar subregion. There was no significant difference in the enthesis CF between scaphoid and lunate attachments in the three subregions. Conclusions  There are significant morphological differences between the SLIL subregions. The dorsal subregion has the largest amount of CF, which is consistent with the greater biomechanical force subjected to this subregion. The similar histomorphology of the ligament at the scaphoid and lunate entheses suggests that similar biomechanical forces are applied to both attachments. Clinical Relevance  The histomorphological results confirm that the dorsal subregion is the strongest of the three subregions. The results from the entheseal region may have important implications in the study of graft incorporation during SLIL reconstruction.

Early Outcomes of Scapholunate Injuries With Concomitant Distal Radius Fractures

Background: There is limited literature regarding the treatment of concomitant scapholunate ligament (SL) injuries in acute distal radius fractures (DRFs). We hypothesized that surgical treatment of SL injuries in adult patients with DRFs leads to improved functional outcomes. Methods: A retrospective review was made of 42 adult patients who underwent surgical treatment of a DRF with a SL injury between 2005 and 2013. In all, 39 of the 42 patients sustained an intra-articular DRF (AO B or C). SL injury was diagnosed by SL diastasis > 3 mm on posteroanterior (PA) radiographs, magnetic resonance imaging, or with wrist arthroscopy. Patients were divided into 3 groups: 23 had a SL repair and were treated within 21 days of injury (acute), 8 underwent SL repair greater than 21 days from injury (subacute/chronic), and 11 did not undergo repair (non-operative). Median overall time to clinical follow-up was 5.1 years. Mayo Wrist Scores (MWS) and Disabilities of the Arm, Shoulder and Hand (DASH) scores were used to evaluate functional outcome. Results: Clinical outcomes measured by the MWS at final follow-up (6 months-12 years) showed no significant differences between the 3 groups. Of patients treated acutely, 17.3% had good to excellent MWS. MWS at 1-year follow-up was 68.4, 70, and 64 in the acute, subacute/chronic, and non-operative groups, respectively. DASH scores were 16.7, 14.3, and 11.8 in the acute, subacute/chronic, and nonoperative groups, respectively, at a mean of 7.8 years. Conclusions: At mid-term follow-up, all 3 treatment groups had similar DASH scores to the general population. There were no statistical functional differences between any of the groups based upon MWS or DASH scores.

Motion and Strength Analysis of 2-Tine Staple and K-Wire Fixation in Scapholunate Ligament Stabilization in a Cadaver Model

Purpose

Previous studies have demonstrated the benefits of 2- and 4-tine staple fixation in scapholunate interosseous ligament (SLIL) reconstruction, including improved rotational control and avoidance of the articular surface. This study compared scaphoid and lunate kinematics after SLIL fixation with traditional Kirschner wire (K-wire) fixation or 2-tine staple fixation.

Methods

Eight fresh frozen cadaver arms with normal scapholunate (SL) intervals were included. Infrared motion capture was used to assess kinematics between the scaphoid and lunate as the wrists were moved through a simulated dart-throw motion. Kinematic data were recorded for each wrist in 4 states: SLIL intact, SLIL sectioned, K-wire fixation across SL interval and scaphocapitate joint, and 2-tine Nitinol staple fixation across SL interval. Strength of the SL staple fixation was evaluated using an axial load machine to assess load to failure of the staple construct.

Results

Range of motion of the scaphoid and lunate with SLIL intact and SLIL sectioned were similar. K-wire fixation across the SL interval significantly decreased the overall wrist range of motion as well as scaphoid and lunate motion in all planes except for scaphoid flexion. Conversely, scaphoid and lunate motion after staple fixation was similar to that in normal wrists, except for a significant decrease in scaphoid extension. Under axial load simulating a ground-level fall, 3 of 8 arms demonstrated no failure, and none of the failures was due to direct failure of the 2-tine staple.

Conclusions

This study demonstrates 2-tine staple fixation across the SL interval is effective in providing initial stability and maintaining physiologic motion of the scaphoid and lunate compared with K-wire fixation after SLIL injury.

Clinical relevance

This study demonstrates an alternate technique for the stabilization of the SL interval in repair of acute SLIL injuries using 2-tine staple fixation, which maintains near physiologic motion of the scaphoid and lunate after SLIL injury.

Suture Tape Augmentation for Scapholunate Ligament Repair: A Biomechanical Study

PURPOSE

Scapholunate (SL) ligament tears in the acute setting can be treated by primary repair through various techniques. The purpose of this study was to compare repair of the SL ligament with suture anchors alone versus repair of the SL ligament augmented with suture tape.

METHODS

Twelve fresh-frozen cadavers (6 matched pairs) underwent a dorsal approach to the wrist and the SL ligament was sharply dissected off of its scaphoid attachment. Six cadavers underwent direct repair of the SL ligament using 2 suture anchors. The other 6 underwent repair of the SL ligament, which was then augmented with suture tape. All specimens then underwent load to failure testing using tensile distraction forces applied by a universal testing system. Maximum load to failure and mode of failure were recorded.

RESULTS

Maximum load to failure (135 N; SD, 44.94 N) for specimens that were repaired and augmented with the internal brace was higher than that for specimens in the repair-only group (68 N; SD, 14.69 N).

CONCLUSIONS

Biomechanical testing demonstrated a higher maximum load to failure in SL ligament repairs augmented with suture tape compared with a repair-only technique in this cadaveric model.

CLINICAL RELEVANCE

Acute SL ligament injuries may benefit from suture tape augmentation by increasing the stability of the primary repair. This may prove to be beneficial in higher-demand patients.

Nuanced Trans-scaphoid, Perilunate Fracture Dislocations With Complete Scapholunate Dissociation: Two Cases With Proximal Row Preservation

We offer two reports of trans-scaphoid perilunate fracture dislocations, both involving complete dissociations and loss of vascular supply to the proximal scaphoid poles. Case 1 involves a 25-year-old man who fell on an outstretched hand and suffered a trans-styloid, trans-scaphoid, perilunate fracture dislocation. The patient underwent open reduction and screw fixation of the scaphoid using a dorsal approach. Kirchner wire fixation and suture anchor ligamentous repairs were used to reduce the scapholunate, lunar-triquetral, and radioscaphocapitate intervals. At 6 months, the patient was released to work without restrictions. Case 2 is a 66-year-old man who suffered a trans-scaphoid, perilunate fracture dislocation after a fall from a horse. A portion of the completely torn scapholunate ligament remained intact to the proximal pole, but no soft-tissue attachment to the rest of the carpus remained. The patient underwent open reduction of the scaphoid with compression screw and Kirschner wire fixation to repair the scapholunate and lunar-triquetral ligaments. At 1-year, the patient was released to full activity. Intraoperatively, the proximal scaphoid poles were completely devoid of any uninterrupted soft-tissue attachments, elevating concern for osteonecrosis. Although both patients showed radiographic signs of transient ischemia, neither patient displayed osteonecrosis or proximal pole collapse at their terminal visits.

Arthroscopic Reinsertion of Acute Injuries of the Scapholunate Ligament Technique and Results

Objective  To describe a technique for treating acute injuries of the scapholunate ligament (SLL) by performing an arthroscopic reinsertion of the SLL and dorsal capsulodesis and to present the results obtained. Methods  The study deals with an analytical, prospective clinical study that included 19 consecutive patients with acute injury of the SLL. The range of joint motion, grip strength, pain according to the visual analog scale, functional outcomes according to the Mayo Wrist Score (MWS), and the QuickDASH Score were studied preoperatively and 6 and 12 months postoperatively. The complications and necessary reinterventions were recorded. Results  Nineteen patients with acute injury of the SLL were studied; mean age was 44 ± 2 years, 74% males, 58% complete rupture, and 42% partial rupture, treated with the above-mentioned technique. Thirty-seven percent also had a distal radius fracture and there was one case of perilunate dislocation. Improvement in pain, grip strength, joint balance, and functionality was observed 6 and 12 months postoperatively, with 79% of the cases with good or excellent results Conclusion  The arthroscopic reinsertion and dorsal capsular reinforcement of the SLL, allow a reliable and stable primary repair of the dorsal aspect of the ligament in acute or subacute SL injuries where there is tissue that can potentially be repaired, thus achieving an anatomical repair similar to that obtained with open surgery, but without the complications and stiffness secondary to aggressive interventions on the soft tissues that are inherent to the open dorsal approach.

Intercarpal Ligament Injuries Associated With Distal Radius Fractures

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

Radiographs Detect Dorsal Scaphoid Translation in Scapholunate Dissociation

Background  Dorsal translation of the proximal scaphoid pole onto the rim of the distal radius is a late finding associated with chronic scapholunate instability. Dorsal scaphoid translation (DST) has been identified by magnetic resonance imaging in patients with scapholunate dissociation (SLD). Purpose  The authors proposed to determine whether DST can be reliably detected on radiographs using two different measurement techniques. Patients and Methods  Lateral radiographs of 20 patients with operatively confirmed SLD were compared with 20 uninjured patients in blinded assessment. DST was assessed using the concentric circle and dorsal tangential line methods. Reliability was calculated using intraclass correlation (ICC) values. Results  Using both techniques, the scaphoid demonstrated increased dorsal translation in patients with SLD. Inter-rater reliabilities for the concentric circles and dorsal tangential line method on radiographs had ICCs > 0.80. Similarly, intra-rater reliabilities had ICCs > 0.90. Conclusions  Both the concentric circles and dorsal tangential line techniques had excellent reliabilities, but the dorsal tangential line method is clinically more practical. Type of Study/Level of Evidence  This is a Level III, diagnostic study.

Surgical outcomes of chronic isolated scapholunate interosseous ligament injuries: a systematic review of 805 wrists

Background

Management of chronic isolated scapholunate interosseous ligament (SLIL) injuries has generated a substantial volume of low-quality literature with descriptions of multiple new surgical techniques, and the impact of instability pattern and the optimal surgical technique remain unclear. The primary goal of this review was to compare clinical, radiographic and patient-rated outcomes between current surgical techniques.

Methods

We performed a systematic literature search using multiple databases. We analyzed clinical, radiographic and patient-reported outcomes. We used a fixed-effects model weighted by sample size with combined outcomes estimated via least squares means with 95% confidence intervals. We also performed a subgroup analysis of static versus dynamic instability.

Results

We assessed 805 procedures from 37 study groups, with 429 procedures used in subgroup analysis. There were no statistically significant differences in outcomes between surgical techniques or in subgroup analysis. Overall, postoperative wrist flexion and pain scores decreased, and grip strength and patient-rated outcomes improved.

Conclusion

Compared to overall preoperative values, modest improvements in pain score, grip strength and functional outcome scores were obtained from a range of reconstructive procedures performed for chronic isolated SLIL injuries. No significant differences could be ascertained between surgical techniques, potentially owing to the low quality of evidence and procedure heterogeneity. This study provides accurate preoperative reference values for future studies, highlights the controversial clinical impact of instability classification, and the need for higher-quality multicentre or collaborative trials to improve our understanding and management of this common injury.

Dynamic CT Scan of the Normal Scapholunate Joint in a Clenched Fist and Radial and Ulnar Deviation

BACKGROUND

Injuries to the scapholunate can have severe long-term effects on the wrist. Early detection of these injuries can help identify pathology. The purpose of this study was to evaluate the motions of the scapholunate joint in normal wrists in a clenched fist and through radial and ulnar deviation using novel dynamic computed tomography (CT) imaging.

METHODS

Fifteen participants below 40 years of age consented to have their wrist scanned. Eight participants were randomized to have the right wrist scanned and 7 the left wrist. Volunteers were positioned at the back of the gantry with the wrist placed on the table, palmar side down. Participants began with the hand in a relaxed fist position and then proceeded through an established range of motion protocol. Dynamic CT imaging was captured throughout the range of motion.

RESULTS

The movement in the healthy scapholunate joint through a clenched fist and radial and ulnar deviation is minimal. The averages were 1.19, 1.01, and 0.95 mm, representing the middle, dorsal, and volar measurements, respectively.

CONCLUSIONS

This novel dynamic CT scan of the wrist is a user-friendly way of measuring of the scapholunate distance, which is minimal in the normal wrist below 40 years of age.

Pregnancy-Related Ligamentous Laxity Mimicking Dynamic Scapholunate Instability: A Case Report

CASE

A 29-year-old woman presented with spontaneous, isolated, total palmar scaphoid subluxation in the left hand approximately 6 weeks postpartum. She had a positive Watson scaphoid shift test, with an easily subluxable and reducible scaphoid unilaterally. She was diagnosed with scapholunate ligamentous laxity with dynamic instability. Approximately 4 months after stopping lactation, she had complete resolution of the scapholunate subluxation; there was no recurrence of symptoms over the next 5 years of follow-up.

CONCLUSION

Women can have manifestations of pregnancy and lactation-related ligamentous laxity, including scapholunate instability, which may spontaneously resolve upon cessation of lactation.

The biomechanical analysis of three-dimensional distal radius fracture model with different fixed splints

BACKGROUND

The distal radius fracture is one of the common clinical fractures. At present, there are no reports regarding application of the finite element method in studying the mechanism of Colles fracture and the biomechanical behavior when using splint fixation.

OBJECTIVE

To explore the mechanism of Colles fracture and the biomechanical behavior when using different fixed splints.

METHODS

Based on the CT scanning images of forearm for a young female volunteer, by using model construction technology combined with RPOE and ANSYS software, a 3-D distal radius fracture forearm finite element model with a real shape and bioactive materials is built. The material tests are performed to obtain the mechanical properties of the paper-based splint, the willow splint and the anatomical splint. The numerical results are compared with the experimental results to verify the correctness of the presented model. Based on the verified model, the stress distribution of different tissues are analyzed. Finally, the clinical tests are performed to observe and verify that the anatomical splint is the best fit for human body.

RESULTS

Using the three kinds of splints, the transferred bone stress focus on the distal radius and ulna, which is helpful to maintain the stability of fracture. Also the stress is accumulated in the distal radius which may be attributed to flexion position. Such stress distribution may be helpful to maintain the ulnar declination. By comparing the simulation results with the experimental observations, the anatomical splint has the best fitting to the limb, which can effectively avoid the local compression.

CONCLUSION

The anatomical splint is the most effective for fixing and curing the fracture. The presented model can provide theoretical basis and technical guide for further investigating mechanism of distal radius fracture and clinical application of anatomical splint.

Update on operative treatment of scapholunate (SL) instability for radiologists: part 1-SL ligament repair, dorsal capsulodesis and SL ligament reconstruction

Scapholunate instability is the most common form of carpal instability. Imaging (especially radiography) plays an important role in the staging, management and post-operative follow-up of scapholunate (SL) instability. The goals of this article are to review the pre-operative staging of SL instability, the surgical options for repair and reconstruction of the SL ligament, along with the normal postoperative imaging findings as well as complications associated with these surgical options.

Arthroscopic Scapholunate Capsuloligamentous Repair: Suture With Dorsal Capsular Reinforcement for Scapholunate Ligament Lesion

Scapholunate ligament (SLL) injury is the most frequent injury of the intrinsic carpal ligaments. The dorsal part of the SLL is the most important part for the stability of the scapholunate joint, and tears of this part and at least one of its secondary capsular attachments cause scapholunate dissociation. The arthroscopic technique most frequently used for acute injuries is reduction and fixation with Kirschner wires, and techniques that involve a primary repair of the injured ligament are performed by open surgery with efficient results. However, they lead to significant stiffness of the wrist due to injury to the soft tissue caused by damage to the secondary dorsal stabilizers; the dorsal blood supply; and in many cases, the proprioceptive innervation of the posterior interosseous nerve. We present an all-arthroscopic technique for the direct repair of acute injuries of the dorsal part of the SLL using bone anchors, complemented by a dorsal arthroscopic plication that reconstructs the dorsal capsulo-scapholunate septum of the scapholunate complex.

Carpal Kinematics and Kinetics

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