Comparison of scapholunate distance measurements on plain radiography and computed tomography for the diagnosis of scapholunate instability associated with distal radius fracture

Automatic analysis of the scapholunate distance using 4DCT imaging: normal values in the healthy wrist

AIM

Early diagnosis of scapholunate ligament (SLL) injuries is crucial to prevent progression to debilitating osteoarthritis. Four-Dimensional Computed Tomography (4DCT) is a promising dynamic imaging modality for assessing such injuries. Capitalizing on the known correlation between SLL injuries and an increased scapholunate distance (SLD), this study aims to develop a fully automatic approach to evaluate the SLD continuously during wrist motion and to apply it to a dataset of healthy wrists to establish reference values.

MATERIALS AND METHODS

50 healthy wrists were analysed in this study. All subjects performed radioulnar deviation (RUD), flexion-extension (FE), and clenching fist (CF) movements during 4DCT acquisition. A novel, automatic method was developed to continuously compute the SLD at five distinct locations within the scapholunate joint, encompassing a centre, volar, dorsal, proximal, and distal measurement.

RESULTS

The developed algorithm successfully processed datasets from all subjects. Our results showed that the SLD remained below 2 mm and exhibited minimal changes (median ranges between 0.3 mm and 0.65 mm) during RUD and CF at all measured locations. During FE, the volar and dorsal SLD changed significantly, with median ranges of 0.90 and 1.27 mm, respectively.

CONCLUSION

This study establishes a unique database of normal SLD values in healthy wrists during wrist motion. Our results indicate that, aside from RUD and CF, FE may also be important in assessing wrist kinematics. Given the labour-intensive and time-consuming nature of manual analysis of 4DCT images, the introduction of this automated algorithm enhances the clinical utility of 4DCT in diagnosing dynamic wrist injuries.

A Systematic 10-Year Review of the Use of Arthroscopy in the Assessment and Treatment of Intercarpal Ligament Injuries Associated with Acute Distal Radius Fracture

Background: To review the impact that arthroscopy has made on the assessment and treatment of intercarpal (scapholunate [SL] or lunotriquetral [LT]) ligament injuries associated with acute distal radius fractures (DRF). Methods: A systematic review of EMBASE, MEDLINE and COCHRANE databases for articles published between 2011 and 2021 was performed (PROSPERO ID: CRD42021273293) which included studies reported assessment and outcomes of intercarpal ligament injuries associated with acute DRF. Methodological quality was evaluated. The rate of concomitant injury detection, role of arthroscopy and different clinical outcome assessment measurements used were compared between studies. Results: A total of 20 articles were included with data from 1,346 patients (1,358 wrists). A total of 1,024 intra-articular fractures were included and 294 extra-articular fractures (40 not specified). There was a heterogeneous mix of studies; 10 comparative and 10 non-comparative. Some studies investigated initial assessment findings only, while others assessed radiological outcomes, functional outcomes or both domains over 0.3-99 months. The overall rate of SL ligament injury associated with DRF was 35.3%, while LT ligament injury overall was 18.2%. More frequent were concomitant triangular fibrocartilage complex (TFCC) injuries (44.8%), although this review did not aim to review these. The role of arthroscopy was reviewed, which included assistance in anatomic reduction of the articular surface and systematic inspection of the surrounding soft tissues. Included studies investigated either assessment or assessment and management of intercarpal ligament injury. Meaningful meta-analysis in this heterogeneous group of studies was not possible. Outcomes of comparative studies were described in detail. Conclusions: This review suggests that arthroscopy may have a role in improving reduction of intra-articular DRF and diagnosing and managing soft tissue injuries associated with such fractures. Randomised studies are needed to evaluate whether the detection of intercarpal ligament injury in acute distal radial fractures through arthroscopic assessment alters current management and improves clinical outcome. Level of Evidence: Level III (Therapeutic).

Volar Marginal Rim Fractures of the Distal Radius Have a Higher Rate of Associated Carpal Injuries-A Comparative Cohort Study

Background  Volar marginal rim distal radius fractures can be challenging due to volar instability of the carpus. The associated carpal injuries, however, have not previously been reported. Purpose  The aim of this study was to compare volar marginal rim fractures to other distal radius fractures to determine if there is any association with other carpal injuries. If so, do these injuries lead to further instability and fixation failure? Materials and Methods  A retrospective radiological review of 25 volar marginal rim fractures was conducted. This was compared with a comparison cohort of 25 consecutive intra-articular distal radius fractures not involving the volar marginal rim. All radiographs were reviewed for associated carpal injuries, including carpal and ulnar styloid fractures, scapholunate instability, and carpal translocation. Results  Volar marginal rim fractures had a significantly higher incidence of associated carpal injuries per patient (2.52 vs. 1.64), scapholunate diastasis (36 vs. 12%), and carpal dislocation (80 vs. 48%). The fixation chosen was more likely to involve a volar rim-specific plate (44 vs. 0%). Following surgical fixation, the volar marginal rim fractures had a significantly higher incidence of carpal instability (56 vs. 24%), failure of fixation (24 vs. 0%), and revision surgery (12 vs. 0%). Conclusions  Volar marginal rim fractures have significantly more carpal injuries, scapholunate instability, and volar carpal instability, compared with other distal radius fractures. Despite the use of volar rim-specific plating, volar marginal rim fractures have a significantly higher incidence of persistent carpal instability, including scapholunate instability, ulnar translocation, volar subluxation, failure of fixation, and revision surgery. Level of Evidence  This is a level III, retrospective review.

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.

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.

Ultrasonographic Classification of Scapholunate Interosseous Ligament Injury Associated With Distal Radius Fracture

PURPOSE

Although scapholunate interosseous ligament (SLIL) injury is often associated with distal radius fracture, it is frequently missed in x-rays. The purpose of this study was to develop a diagnostic classification based on ultrasonography for SLIL injury and evaluate its diagnostic accuracy.

METHODS

Patients who required surgery for distal radius fracture were included in this study. Ultrasonography and arthroscopy were performed in all patients. The original ultrasonography-based classification of the dorsal part of SLIL was developed as follows: for type A, the SLIL surface was outlined clearly as a continuous flat line; for type B, the SLIL surface was outlined clearly as a continuous bulged line; and for type C, the SLIL surface was not continuous, smooth, or outlined clearly. Arthroscopy was performed at the time of osteosynthesis. We classified its findings according to the arthroscopic classification system of Geissler et al and evaluated interobserver and intraobserver reliabilities for our classification on ultrasonography. We also studied the relationship between the ultrasonographic and arthroscopic classifications.

RESULTS

In total, 40 patients were included in this study. Weighted κ values for interobserver and intraobserver reliabilities for our ultrasonographic classification were 0.83 (95% confidence interval, 0.70-0.96) and 0.88 (95% confidence interval, 0.77-0.99), respectively. There were 17 patients with type A, 14 with type B, and 9 with type C on ultrasonography. Ultrasonography had a sensitivity of 64% and specificity of 93% for the assumption that type C on ultrasonography corresponded to Geissler grades 3 and 4 on arthroscopy. No patient with type A on ultrasonography was classified as Geissler grades 3 and 4 on arthroscopy.

CONCLUSIONS

We concluded that ultrasonography has a high specificity but low sensitivity for the diagnosis of SLIL injury.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic Ⅱ.

Scapholunate Diastasis in Distal Radius Fractures: Fracture Pattern Analysis on CT Scans

Objectives  Our understanding of distal radius fractures with concomitant scapholunate (SL) diastasis primarily comes from plain radiographs and arthroscopy. The clinical implications of SL diastasis are not clear. The aim of this study is to describe fracture characteristics of distal radius fractures on computed tomography (CT) scans in patients with distal radius fractures and static SL diastasis. Methods  We queried our institutional databases to identify patients who were treated for a distal radius fracture, had a CT scan with a wrist-protocol, and static SL diastasis on their CT scan. Our final cohort consisted of 26 patients. We then collected data on their demographics, injury, treatment, evaluated injury patterns, and measured radiographic SL characteristics. Our study cohort consisted of 11 men (42%) and almost half of our cohort ( n  = 12; 46%) had a high-energy mechanism of injury. The majority of the patients ( n  = 20; 77%) had operative treatment for their distal radius fracture and two patients (7.7%) had operative treatment of their SL injury. Results  The mean SL distance was 3.5 ± 1.1 mm. Twenty patients (77%) had an intra-articular fracture. In these patients, we observed three patterns: (1) scaphoid facet impaction; (2) lunate facet impaction; and (3) no relative impaction. We observed other injury elements including rotation of the radial styloid relative to the lunate facet and partial carpal subluxations. Conclusion  Static SL dissociation in the setting of distal radius fractures may be an indication of a complex injury of the distal radius, which may not be directly apparent on plain radiography. If these radiographs do not demonstrate impaction of the lunate or scaphoid facet, a CT scan may be warranted to have a more detailed view of the articular surface. Level of Evidence  This is a Level III, diagnostic study.

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.

Incidence and Functional Outcomes of Scapholunate Diastases Associated Distal Radius Fractures: A 2-year Follow-Up Scapholunate Dissociation

BACKGROUND

The Scapholunate Interosseous Ligament (SLIL) is the first intrinsic carpal ligament to be injured in wrist trauma, present in up to 64% of the distal radius fractures. However, it remains unclear what patients develop symptoms, making primary treatment of these injuries accompanying distal radius fractures remains questionable.

OBJECTIVE

The aim of this study was to evaluate the functional outcomes of patients with scapholunate diastasis associated with distal radius fractures.

METHODS

We evaluated 391 patients with a distal radius fracture. Using Computer Tomography (CT) scans the scapholunate interval was measured. We identified 14 patients with an SLD (>3mm) of the injured wrist, which underwent a CT-scan of the contralateral wrist. To evaluate the functional outcomes at a mean follow up of 136±90 weeks, we used the Quick Disabilities of the Arm, Shoulder and Hand (qDASH) Score.

RESULTS

There were 8 patients with bilateral SLD and 6 patients with unilateral SLD. Five patients had a qDASH score of 0 and one patient showed a qDASH score of 18.2. The patient with a poor score had bilateral preexisting osteoarthritis of the wrist. No patient had additional surgery of the SLIL.

CONCLUSION

In patients with distal radius fractures, more than half of the 14 patients with an SL gap on CT had widening on the contralateral side. It is therefore worthwhile to image the contralateral wrist before diagnosing a SLD. The patients with unilateral SLD should not be surgically treated at initial presentation because they may have good functional outcomes after a follow up of 2 years.

Postoperative Computed Tomography for Articular Fractures: A Systematic Review

OBJECTIVES

To determine the current published patterns of computed tomography (CT) use postoperatively in peri-articular fractures and identify those populations whereby postoperative CT changes management or results in better clinical outcomes.

DATA SOURCES

Systematic review of MEDLINE and Cochrane using a combination of key words, including fracture fixation, fracture healing, and computed tomography. The final update search was performed on May 20, 2015. The search was limited to English language publications of human studies from the past 20 years.

STUDY SELECTION

Eligible studies enrolled internally fixed peri-articular fractures in adults imaged routinely with postoperative CT. Facial and spinal fracture studies were excluded.

DATA EXTRACTION

One thousand five hundred thirty-seven articles were identified using the search strategy. One thousand two hundred ninty-seven articles were excluded by title. One hundred eighty-three studies were excluded by abstract. Fifty-seven full text articles were assessed for eligibility, 31 studies were eligible for study inclusion.

DATA SYNTHESIS

There was no intention to perform combined statistical analysis in the form of a meta-analysis as disparity was anticipated between study populations, interventions, and outcome measures. Routine CT use postoperatively in peri-articular fractures is limited to countries within the developed world, predominantly imaging the lower limb. Only 5 studies detailed postoperative CT leading to a change in patient management; within this pool, only 8 of the 361 individual patients received management changes due to CT scan findings.

CONCLUSIONS

Use of postoperative CT in peri-articular fracture fixation has been demonstrated with minimal evidence, this leads to improved clinical outcomes. Based on available literature, postoperative CT scan use is questionable without convincing evidence of benefit. More research is required to identify selected patients who benefit from postoperative CT imaging.

LEVEL OF EVIDENCE

Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Open Treatment of Acute Scapholunate Instability

Acute treatment of scapholunate instability is important to prevent future complications of dorsal intercalated segment instability and scapholunate advanced collapse. An understanding of the fundamental normal and abnormal mechanics of this problem is vital. Diagnosis in the acute phase is based on clinical and radiographic findings and treatment focuses on primary scapholunate interosseous ligament repair with a reinforcing dorsal capsulodesis. Suture anchor repair with a modified "double-dorsal" capsulodesis is described. Current data show that open repair is a viable option in the acute setting with most patients demonstrating good to excellent functional, clinical, and radiographic results.

Management of Intercarpal Ligament Injuries Associated with Distal Radius Fractures

The prevalence of ligamentous injury associated with fractures of the distal radius is reported to be as high as 69% with injury to the scapholunate interosseous ligament and lunotriquetral interosseous ligament occurring in 16% to 40% and 8.5% to 15%, respectively. There is a lack of consensus on which patients should undergo advanced imaging, arthroscopy, and treatment and whether this changes their natural history. Overall, patients with high-grade intercarpal ligament injuries are shown to have longer-term disability and sequelae compared with those with lower-grade injuries. This article reviews the diagnosis and treatment options for these injuries.