Flexor and Extensor Tenosynovectomy

Flexor and Extensor Tenosynovectomy

Kyle P. Kokko

John T. Capo

Sanjiv Naidu

Jay T. Bridgeman


  • The extensor tendons lie under the dorsal retinaculum in six separate extensor (or dorsal) compartments. They are numbered in succession from one to six, beginning radially and ending ulnarly. The portions of the extensor tendons that lie under the dorsal retinaculum are lined with synovial sheaths (FIG 1A).

  • The extensor tendons that occupy the first dorsal compartment are the abductor pollicis longus (APL) and the extensor pollicis brevis (EPB). They originate as “outcropper” muscles from the distal third of the forearm and cross over the second dorsal compartment tendons—the extensor carpi radialis longus (ECRL) and the extensor carpi radialis brevis (ECRB)—distally at the level of the wrist approximately 4 cm proximal to the radial styloid.

  • The extensor pollicis longus (EPL) in the third extensor compartment makes an acute angle at the Lister tubercle at the level of the wrist and crosses superficial to the second dorsal compartment.

  • The fourth extensor compartment tendons—the extensor digitorum communis (EDC) and the extensor indicis proprius (EIP)—lie under a broad retinaculum. The posterior interosseous nerve (PIN) lies in the floor of the fourth extensor compartment deep to the EDC and EIP tendons on the radial aspect of the compartment.

  • The extensor digitorum quinti (EDQ) in the fifth extensor compartment often is the only tendon to motor the small finger metacarpophalangeal (MCP) joint in the act of extension.

  • The extensor carpi ulnaris (ECU) tendon in the sixth dorsal compartment lies in a fibro-osseous tunnel and is intimately held in the ulnar groove by a subsheath that is critical for distal radioulnar joint stability and is a component of the triangular fibrocartilage complex (TFCC).

  • The wrist flexor tendons—the flexor carpi radialis (FCR), the palmaris longus (PL), and the flexor carpi ulnaris (FCU)—are extrasynovial tendons.

  • The FCR passes through a tight fibro-osseous tunnel in the trapezium before inserting on the base of the second metacarpal (FIG 1B,C). Whereas the FCU, attaches first on the pisiform bone that functions as a sesamoid bone and then has distal attachments to the base of the fifth metacarpal.

    FIG 1A. Extensor compartments of the hand. B. Flexor tendons. (continued)

    FIG 1(continued) C. Carpal tunnel.

  • The digital flexor tendons lie under the transverse carpal ligament in the carpal tunnel. Unlike digital extensor tendons, flexor tendons are almost entirely intrasynovial.

  • The flexor tendons in the digits lie in a fibro-osseous canal formed by the annular and cruciate ligaments.3


  • Rheumatoid arthritis is a disease of synovial tissue that can lead to inflammatory tensosynovitis. However, proliferative extensor tenosynovitis has been described in the absence of rheumatoid arthritis.2

    • Flexor and extensor tenosynovitis is commonly a sequelae of rheumatoid arthritis.

    • Rheumatoid arthritis causes formation of hypertrophic synovium in the joint spaces, thereby destabilizing joints. The hypertrophic synovium invades the tendon sheaths and synovial lining of all tendons.4


  • Inflammatory tenosynovitis usually is painless and can be the first sign of rheumatoid arthritis.

  • The dorsal and volar wrist, as well as the volar digits, are most commonly affected.

  • The synovial tissue proliferates in the tendon sheath and eventually may invade the tendon.

  • The end result can be weakening and rupture of the tendon.4


Jul 22, 2016 | Posted by in ORTHOPEDIC | Comments Off on Flexor and Extensor Tenosynovectomy
Premium Wordpress Themes by UFO Themes