Presentation
Pain and swelling of the right wrist.
Patient Data
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Fluid intensity signal measuring about 14x16 mm distending the tendon sheath of the extensor carpi radialis brevis(ECRB) distal to the intersection of the extensor pollicis longus(EPL) is suggestive for distal intersection tenosynovitis of the wrist.
Case Discussion
The ECRB, ECRL and EPL tendons intersect distal to the Lister’s tubercle and radiocarpal joint. The tubercle acts as a pulley, changing the EPL tendon angle when it crosses superficially over the ECRL and ECRB tendons. This creates a mechanically disadvantageous arrangement, where motion of the thumb and hand may cause friction between these tendons.