The triquetrohamate ligament is an intrinsic interosseous intercarpal ligament connecting the medial surface of the triquetrum to the proximal surface of the hamate. It forms the medial boundary of the midcarpal joint and contributes to the helical motion of the proximal carpal row. A superficial palmar and dorsal portion are described in addition to a thin central interosseous portion.
Stabilises the triquetrohamate articulation and governs the rotation of the proximal carpal row during radial and ulnar deviation, contributing to the coupled flexion-extension that characterises normal carpal kinematics.
The triquetrohamate ligament is the central element of the triquetrohamate instability pattern, a form of midcarpal instability (CIND) where abnormal carpal motion produces a painful, audible, high-velocity clunk at the midcarpal joint during ulnar deviation. This is the most common midcarpal instability pattern. Diagnosis requires fluoroscopic wrist assessment under load. Treatment options include physiotherapy, soft tissue imbrication, or limited arthrodesis of the triquetrohamate joint.
Laxity of the triquetrohamate ligament produces a catch-up clunk at the midcarpal joint during active ulnar deviation under load, a pathological variant of the normal helical carpal motion, managed with physiotherapy or triquetrohamate arthrodesis in refractory cases.
