• We present the first published report an unusual anatomic variation of a bifid EDQ with separate tendon sheaths, resulting in tenosynovitis and finger triggering. Anatomic variations of the extensor tendons are common. Duplication or bifid extensor tendons are frequently encountered during surgery. However, these tendons usually run in a common extensor sheath.

• Extensor tenosynovitis is most commonly associated with the first dorsal compartment (DeQuervain’s Syndrome) and occasionally with the sixth dorsal compartment (extensor carpi ulnaris). It is rarely associated with other extensor tendons. Several cases of extensor digiti quinti (fifth compartment) tenosynovitis have been reported in the literature but there are no published reports of tenosynovitis caused by such an unusual anatomic variation.