The primary trapeziometacarpal ligament, also known as the anterior oblique ligament, stabilizes the thumb's trapeziometacarpal joint. The trapeziometacarpal ligament originates on the tuberosity of the trapezium. The trapeziometacarpal ligament is stretched during both the pronation and extension of the thumb. It prevents dislocation but provides the necessary mobility for the thumb. It inserts into the ulnar volar edge of the metacarpal base. The trapeziometacarpal ligament's saddle joint has volar stability. It anchors the volar lip of the first metacarpal to the second metacarpal and the trapezium. During dorsal dislocation, it may remain partially uninjured. A recent study has shown that the trapeziometacarpal ligament must be reconstructed to maintain thumb stability while treating carpometacarpal osteoarthritis. The most common technique to operate on the trapeziometacarpal ligament to manage carpometacarpal osteoarthritis is a trapeziectomy with ligament reconstruction and tendon interposition. However, according to a recent study, ligament reconstruction and tendon interposition produced no difference in key pinch strength or adverse events when compared to regular trapeziectomy.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Trapeziometacarpal ligament