midcarpal instability
Abnormal motion between proximal and distal carpal rows causing painful clicking and weakness with wrist movement.
Full Definition
Midcarpal instability is a complex wrist condition characterized by abnormal motion patterns between the proximal and distal carpal rows. Patients typically present with a painful audible and palpable clunk during wrist motion, particularly with ulnar deviation and flexion. The instability can be classified as intrinsic (due to ligamentous laxity) or extrinsic (secondary to other pathology). The condition often affects young patients with generalized joint laxity and can be bilateral. Diagnosis is challenging and may require dynamic imaging or wrist arthroscopy. Treatment options include activity modification, strengthening exercises, splinting, and in severe cases, surgical stabilization procedures such as four-corner fusion or capsulodesis.
Usage
Usage note: Distinguish from other carpal instability patterns; often requires specialized testing for accurate diagnosis.
In Context
- "The patient demonstrated a positive midcarpal shift test with reproduction of the characteristic painful clunk." — Physical examination note
- "Video fluoroscopy confirmed midcarpal instability with abnormal stepoff during ulnar deviation." — Diagnostic imaging report