Extensor Tunnel I 



- Anatomy:
    - transports APL & EPB tendons;
    - these tendons represent the radial border of the anatomic snuff box;
    - when pts thumb is extended, you can distinguish between the tendons as they exit the tunnel;
    - near insertions of tendons, distal to the tunnel, the EPB lies on ulnar side of the APL;
    - in general, the surgeon should expect to find anatomic variants in this area,
           - often there are multiple slips of the APL and complete compartmentalization of the EPB;

- Clinical Significance:
    - it is the site for stenosing tenosynovitis (DeQuervain's disease) in which inflammation of synovial lining of tunnel narrows tunnel opening & results in pain when tendons move;
    - cross over syndrome:
           - the tendons of the first compartment may cross over the tendons of the second compartment (ECRL/B), just proximal to the extensor retinaculum;
           - the resultant tenosynovitis occurs mainly in the second compartment, and steroid injections into this compartment relieve most symptoms



Treatment of de Quervain tenosynovitis. A prospective study of the results of injection of steroids and immobilization in a splint.

Common variations of the radial wrist extensors.



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Friday, December 21, 2012 11:47 am