Journal of Hand Surgery European - 2026-03-21 - Journal Article
The role of the dorsal scaphotriquetral ligament: a biomechanical study.
Rodriguez GLG, Muratore A, Arnaout A, Delgado PJ, Bain G, Kakar S
Topics
Key Takeaway
Sequential cadaveric sectioning demonstrates that DSTL sectioning—after prior dorsal SLIOL disruption—produces the largest biomechanical changes, converting dynamic SL instability to static DISI with marked SL diastasis and increased carpal angles.
Summary Depth
Choose how much analysis to show on this article page.
Summary
This cadaveric study used sequential ligament sectioning across four phases to isolate each structure's contribution to SL stability under axial loading (60 N static; 60-200 N cyclic) and wrist motion. Dorsal SLIOL sectioning (phase 2) produced dynamic instability with load-dependent SL gap widening and dorsal scaphoid translation but no resting DISI; superficial DICL sectioning (phase 3) added no measurable instability. DSTL sectioning (phase 4) produced the largest changes across all metrics—SL diastasis, carpal angle increases, elevated DISA—and converted the pattern to static DISI at rest and under load.
Key Limitation
The sequential sectioning model forces a fixed order of ligament disruption that does not reflect the variable injury patterns seen clinically, limiting direct translation of the instability thresholds to acute traumatic presentations.
Original Abstract
INTRODUCTION
The biomechanical role of the dorsal scaphotriquetral ligament (DSTL) ligament in scapholunate (SL) stability remains debated. We assessed DSTL contribution using a cadaveric sectioning model.
METHODS
Twenty-four wrists underwent sequential sectioning: none (phase 0), palmar/proximal scapholunate interosseous ligament (SLIOL) (phase 1), dorsal SLIOL (phase 2), superficial dorsal intercarpal ligament (DICL) (phase 3) and DSTL (phase 4). Under axial loading (60 N; cyclic 60-200 N) and wrist motion, the SL gap and carpal angles, and a CT-derived dorsal instability scaphoid angle (DISA) were measured.
RESULTS
Phase 1 produced no significant instability. Dorsal SLIOL sectioning (phase 2) initiated dynamic instability, with increased SL gap and angles under load and dorsal scaphoid translation, but no resting dorsal intercalated segment instability (DISI). Sectioning the superficial DICL fascicle (phase 3) did not add instability. DSTL sectioning (phase 4) produced the largest changes, with marked SL diastasis, increased angles and DISA, and DISI at rest and under load.
CONCLUSION
Dorsal SLIOL sectioning produced load-dependent (dynamic) SL instability, whereas subsequent DSTL sectioning was associated with progression to static instability, supporting the DSTL as an important dorsal restraint. The DISA may provide an additional CT-based measure of dorsal scaphoid subluxation; however, clinical validation is required.