Journal of Hand Surgery European - 2026-07-22 - Journal Article
Primary and secondary stabilizers of the scapholunate joint: a systematic review of cadaveric ligament sectioning studies.
Andrews J, Bellringer S, Amarasooriya M, Bain G
Topics
Key Takeaway
SLIL sectioning alone increases scapholunate gap by mean 1.7 mm and SL angle by 8°, but DISI deformity requires combined SLIL plus DIC (or STT complex) disruption.
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Summary
This systematic review of cadaveric ligament-sectioning studies evaluated the relative contributions of intrinsic and extrinsic wrist ligaments to scapholunate stability by synthesizing kinematic data (SLG, SLA, RLA, DISI) across 33 studies and 406 wrists. Isolated extrinsic ligament sectioning with an intact SLIL produced minimal kinematic change, while SLIL sectioning increased SLG by 1.7 mm and SLA by 8°. Full DISI deformity occurred only with combined SLIL plus DIC or STT complex sectioning, identifying the DIC as the dominant secondary stabilizer.
Key Limitation
All data derive from cadaveric models under controlled loading conditions, which cannot replicate the dynamic muscular and neuromuscular stabilization present in vivo, limiting direct translation of kinematic thresholds to clinical decision-making.
Original Abstract
INTRODUCTION
Scapholunate instability is the most common pattern of carpal instability, yet the relative contributions of the intrinsic and extrinsic ligaments remain debated. This systematic review evaluated cadaveric studies of wrist biomechanics assessing kinematic changes following carpal ligament sectioning to clarify the stabilizing roles of individual ligaments.
METHODS
The EMBASE, MEDLINE, Cochrane and Scopus databases were searched from inception to June 2025. Cadaveric studies reporting scapholunate gap (SLG), scapholunate angle (SLA), radiolunate angle (RLA) or dorsal intercalated segment instability (DISI) after ligament sectioning were included. Data were extracted for cumulative and sequential sectioning patterns and synthesized qualitatively.
RESULTS
Thirty-three studies involving 406 wrists were included. With an intact scapholunate interosseous ligament (SLIL), sectioning single or multiple extrinsic carpal ligaments produced minimal changes in SLG, SLA, or RLA. Scapholunate interosseous ligament sectioning increased SLG (mean +1.7 mm), SLA (+8°) and RLA (+3°), with clenched-fist loading further elevating SLG (+0.7 mm) and SLA (+4°). The dorsal intercarpal ligament (DIC) was the dominant secondary stabilizer. Combined SLIL-DIC injury produced the greatest increases across all measures, and DISI occurred only when the SLIL and either the DIC or the scaphotrapeziotrapezoid complex was sectioned.
CONCLUSION
Cadaveric evidence confirms the SLIL as the primary stabilizer of the scapholunate joint and identifies the DIC as the key secondary stabilizer. These biomechanical findings support early diagnosis, targeted reconstruction and the need to restore both primary and secondary stabilizers to prevent progressive scapholunate instability.