How is a stenosing synovitis of extensor carpi ulnaris (ECU) etiology of ulnar-sided wrist pain diagnosed and treated?

Updated: Apr 26, 2021
  • Author: David M Lichtman, MD; Chief Editor: Harris Gellman, MD  more...
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The sixth dorsal compartment is the second most common location of stenosing tenosynovitis in the upper extremity. Although relatively uncommon, stenosing tenosynovitis must be included in the differential diagnosis for ulnar wrist pain. [11]

Patients present with generalized pain of the wrist, with dorsal swelling over the ulna. Many patients are athletes whose sport requires repetitive wrist motion. Clinically, the patient's symptoms may be exacerbated with resistance to dorsiflexion and ulnar deviation. Crepitus is occasionally palpable over the ECU sheath. An injection of lidocaine and cortisone into the sheath can be both diagnostic and therapeutic. As with subluxation, MRI can be used to confirm the diagnosis.

Conservative treatment includes activity modification, ice, splinting, steroid injections, and nonsteroidal anti-inflammatory drugs (NSAIDs). Surgical release is often necessary with progressive fibrosis of the sixth compartment.

With partial rupture or calcific tendinitis, the ECU may be tender, red, and tense. A radiograph is diagnostic for calcific tendinitis.

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