Assessment of the distal extent of the A1 pulley release: a new technique.

OBJECTIVE: Sharp division of the A1 pulley is a time-honored technique for the treatment of flexor tendon entrapment; however, this procedure is not without complications. The anatomy of the A1 pulley system has been carefully investigated. Knowledge of superficial anatomic landmarks can assist with demarcating the distal edge of the A1 pulley and prevent damage to the critical A2 pulley.

METHODS: Nine fresh cadaveric hands were dissected with the aid of loupe magnification. On the basis of known anatomic landmarks of the proximal portion of the cruciate (C0) pulley, percutaneous placement of a 25-gauge needle 5 mm proximal to the palmar digital crease marked the distal extent of the trigger finger release. Sharp division of the A1 pulley was performed with a scalpel until the needle was encountered, thus completing the release.

RESULTS: A complete release of the pulley was achieved in all specimens with preservation of the A2 pulley. No digital nerve or artery injuries were noted with open inspection of the flexor sheath.

CONCLUSION: Percutaneous marking of the distal extent of the A1 pulley is a safe and reliable method that not only ensures complete release of the A1 pulley but also preserves the A2 pulley. The placement of a small gauge needle adds no morbidity to this minimally invasive technique.