Comparison of Radiographic Stress Views in Detecting Scapholunate Ligament Injuries: A Cadaveric Model Study

Background/Objectives: Scapholunate ligament injuries represent one of the most challenging diagnostic problems in wrist surgery, with conventional radiographs often appearing normal despite significant ligamentous disruption. The optimal stress radiographic views for detecting these injuries remain incompletely defined. To systematically evaluate and compare the diagnostic utility of eight different stress radiographic views in detecting isolated scapholunate ligament disruption using a cadaveric model. Methods: Nine fresh-frozen cadaveric wrists underwent complete scapholunate ligament transection while preserving secondary stabilizers. Eight radiographic positions were evaluated: posteroanterior (PA) neutral, PA wrist extension, PA wrist flexion, PA radial deviation, PA ulnar deviation, anteroposterior (AP) clenched fist, AP neutral, and lateral neutral. Scapholunate gap measurements were obtained using calibrated digital software with 20 mm reference markers. Statistical analysis employed repeated-measures ANOVA with post hoc comparisons. Results: PA wrist extension demonstrated the greatest scapholunate gap widening (2.68 ± 0.84 mm, p = 0.006), followed by AP clenched fist views (2.32 ± 1.07 mm, p = 0.036). PA wrist flexion showed significant gap reduction (0.47 ± 0.44 mm, p < 0.001). Twenty-two percent of specimens demonstrated scapholunate angles exceeding 70° on lateral radiographs. Inter-specimen variability was observed, with gap measurements ranging from 1.2 to 4.8 mm across different positions. Conclusions: PA wrist extension and AP clenched fist views demonstrate superior diagnostic utility for detecting scapholunate ligament injuries compared to neutral radiographs. These stress radiographic techniques offer accessible, cost-effective alternatives to advanced imaging modalities for early detection of scapholunate ligament pathology in clinical practice.