The transverse carpal ligament (flexor retinaculum) bridges the concave arch of the carpal bones to form the rigid carpal tunnel through which the median nerve and nine flexor tendons travel from the forearm to the hand. Its division (carpal tunnel release) is the most commonly performed surgical procedure in orthopaedics. The retinaculum also provides attachment for the thenar and hypothenar muscles at its lateral and medial borders respectively.
| Origin | Scaphoid tubercle and trapezium laterally |
|---|---|
| Insertion | Pisiform and hook of hamate medially |
| Actions | Forms the roof of the carpal tunnel — constrains the median nerve and nine flexor tendons within the tunnel |
|---|
Carpal tunnel release by dividing the transverse carpal ligament decompresses the median nerve within the tunnel, resolving the nocturnal hand tingling, thenar weakness, and hand numbness of carpal tunnel syndrome. Open and endoscopic techniques produce equivalent outcomes. Complications include incomplete release (persistent symptoms from residual ligament), bowstringing of the flexor tendons if the retinaculum heals too widely, and injury to the palmar cutaneous branch of the median nerve (superficial to the retinaculum) causing scar tenderness.
The transverse carpal ligament forms the unyielding roof of the carpal tunnel whose division releases the compressed median nerve in carpal tunnel syndrome.
