आईएसएसएन: 2168-9784
Panagopoulos A, Allom R and Compson J
Introduction: Isolated injuries of the lunotriquetral (LTq) interosseous ligament and associated structures are less common and less well understood than other forms of dissociative carpal instability. For a VISI deformity to occur the LTq interosseous ligament must be disrupted but the progression of lunotriquetral dissociation requires further ligamentous injury, particularly the palmar LTq ligament, and for full dissociation between the lunate and triquetrum, the dorsal radiocarpal ligaments, which finally results in a static volar intercalated segmental instability (VISI) pattern.
Case report: A 52-year old left-handed male patient of black origin was presented with a rare pattern of an acute static volar intercalated instability (VISI). Complete disruption of both the intrinsic lunotriquetral ligaments and the dorsal intercarpal ligaments were identified at surgery. Direct repair and dorsal capsulodesis plus temporary pinning of the lunotriquetral joint were carried out. The patient had a good clinical outcome at 2.5 years of follow up despite the persistent static VISI deformity in the last follow up radiographs.
Conclusion: This case represents a clinical proof of both anatomical and biomechanical studies that in order for a static VISI deformity to occur (Stage III), not only must the lunotriquetral interosseous ligament and the palmar lunotriquetral ligaments be disrupted but there must also be disruption to the dorsal capsule.