Swan Neck Deformity: An Unusual Complication Following Trigger Finger Release.

INTRODUCTION: Swan neck deformity (SND) is a common pathologic finding often observed in patients with severe rheumatoid arthritis. However, it has also been seen in injuries such as mallet finger, flexor digitorum superficialis laceration, and intrinsic contracture. Open surgical release of a trigger finger most commonly involves the release of the A1 pulley to relieve a mechanical impingement. Bowstringing is a rare trigger finger release complication caused by excessive pulley resection, usually due to resection of the A2 pulley. As a result of this complication, the flexor tendons move away from their center of rotation, gaining an increased mechanical advantage over the extensors and can ultimately result in a SND.

CASE REPORT: We present a case report of a 61-year-old patient that presented to our clinic with a SND of the 4th digit following a trigger finger release.

CONCLUSION: Our case demonstrated that a previous trigger finger release with disruption of the A2 pulley can cause a cascade of events that can result in SND.