Flexor retinaculum

Description[edit|edit source]

Flexor retinaculum is a strong fibrous band which bridges the anterior concavity of the carpal bones thus converts it into a tunnel, the carpal tunnel^[1].

Attachments[edit|edit source]

一般地,

• To thepisiformbone
• To thehook of the hamate

Laterally,

• To the tubercle of thescaphoid
• To the crest of thetrapezium^[1]

These four bony points are all palpable in the living hand and it should be noted that pisiform is the only carpal bone that gives attachments to both flexor and extensor retinacula.

On either side the retinaculum has a slip.

• Lateral deep slip- It is attached to the medial lip of the groove on the trapezium thus converts it into a fibro-osseous tunnel that transmits the tendon of the flexor carpi radialis and its synovial sheath.
• Medial superficial slip- It is attached to the pisiform bone and it forms a small canal (of Guyon). The ulnar vessels and nerves pass deep to this slip. Occasionally Compression of the尺骨神经may occur within this canal.^[1]［2］

^[3]

Function[edit|edit source]

Principal function of the flexor retinaculum is to serve as a pulley for the carpal flexor muscles and to stabilize the carpal system^[4].

In addition,

• The volar surface gives rise to muscles of thethenar and hypothenareminences
• It is Related to the tendon of thepalmaris longus
• Its Upper margin continues in the palmar carpal ligament and lower margin merges with the palmar aponeurosis

Clinical relevance[edit|edit source]

Carpal tunnel syndromeresults when the retinaculum compresses the underlyingmedian nerve^[4]

References[edit|edit source]