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Flexor Carpi Radialis

- See: Forearm Flexors

- Discussion:
    - origin: medial epicondyle of humerus;
    - anatomy at the wrist:
          - when pt flexes wrist & radially deviates his hand, tendon becomes prominent next to the  palmaris longus;
          - FCR lies radial to the palmaris longus at level of the wrist;
          - tendon enters a fibro-osseous tunnel just proximal to the trapezium;
          - w/ in the tunnel, the tendon is in partial contact w/ the trapezium;
          - after crossing the trapezium, it passes dorsal to the FPL;
    - insertion:
           - small slip to trapezial tuberosity;
           - anterior surface of base of 2nd metacarpal;
           - small slip to base of third metacarpal;
    - innervation: median nerve, C7 > C6;
    - action: flexes and abducts the hand at the wrist;
    - synergist: flexor carpi ulnaris;

- Flexor Carpi Radiolis Tendinitis:
    - FCR tendinitis is less common than tendinitis affecting FCU;
    - it is usually associated with chronic repetitive trauma;
    - diff dx: anomalous connection between FPL and FDP;
    - etiology:
         - tenosynovitis
         - ganglion cyst
         - basal joint arthritis;
         - distal scaphoid fracture;
         - distal radius fracture;
    - patho-anatomy:
         - separate compartment of transverse carpal ligament;
         - overlying scphoid tubercle and trapezial crest;
         - multiple adhesions in the tunnel;
         - fibrous sheath over distal end of this tendon may become constricted secondary to trauma or arthrosis and cause pain at base of palm;
         - close relationship of FCR & median nerve occassionally accounts for irritation of median nerve secondary to tenosynovitis of the FCR;
    - exam:
         - include tenderness & crepitus on palpation over tendon & & pain on wrist flexion and radial deviation against resistance or on passive extension;
         - cause of volar radial wrist pain;
         - pain with flexion and extension
         - point tenderness over FCR at wrist flexion crease;
         - diagnositic injection into the tendon sheath will confirm the diagnosis;
    - surgery:
         - w/ failure of non-op Rx, FCR tunnel should be decompressed;
         - incision radial to FCR to prevent injury to palmar cutaneous branch;
         - reflect thenar muscles off transverse carpal ligament;
         - open the tendon sheath from proximal to distal;
         - release the fibro-osseous tunnel along the ulnar border of the trapezium;
         - optionally consider resection of scaphoid tubercle and trapezial crest;
         - tenolyse and free FCR to insertion;
         - start early motion;

- Rupture of FCR tendon;
    - should be included in diff dx of scaphoid frx; (see diff Dx ):
    - occurs from a fall on the out stretched hand, causing separation of insertion of FCR deep to the thenar muscles;
    - chip of bone may separate w/ tendon, or, in pts > 35 yrs of age, tendon may rupture partially or completely;
    - pain is detected over scaphoid on palmar surface of wrist or is present proximally along the course of the FCR

Spontaneous rupture of the flexor carpi radialis tendon.

Flexor carpi radialis tendinitis. Part II: Results of operative treatment.

Flexor Carpi Radialis Tendinitis. Part I: Operative Anatomy.

Surgical treatment of medial epicondylitis. Results in 35 elbows.