Treatment of Chronic Stern Type III Proximal Interphalangeal (PIP) Joint Contractures with Arterialized Venous Flaps: A Novel Approach

Hypothesis Rarely will treatments for Stern type III proximal inter-phalangeal joint (PIPJ) post traumatic flexion contractures result in full extension(1,2). Although current strategies focus on release of the most restrictive structures, the shortened digital arteries are not addressed and can limit acute intra-operative extension.

We hypothesize that simultaneous soft tissue reconstruction and digital artery lengthening with transplantation of an A-V-A venous flap will allow immediate complete extension and result in superior long-term range of motion.

Methods Six patients with chronic Stern type III PIPJ contractures were treated with release, acute extension pinning, and venous flap transplantation. Average increase in extension, residual extension lag, and percentage of extension gained (post operative extension/intra-operative extension) after this approach was compared to the senior author's in house historical approach utilizing cross-finger flaps without digital artery lengthening. Preoperative and post-operative 2-pt discrimination were compared to assess the impact of acute extension on the digital nerves. Outcome parameters were measured at a minimum of 12 month follow-up (average 14 months). Student's t-test was used to determine statistical difference (p<0.05).

Results In this series, all venous flaps were successful. Five of six cases were acutely pinned at neutral extension. One was pinned 15 degrees short of neutral. Average increased extension was 81 degrees (range 75-90), average residual extension lag was less than 5 degrees (range 0-5 degrees), and percentage of extension gained long term was 100% of that achieved at the time of surgery. In the series treated with cross finger flaps, joints were pinned at an average 15 degree extension lag, average increased extension was 67.8 degrees, average residual extension lag was 15.2 degrees (range 10-25), and percentage of extension gained was 110%. Five cases (50%) had an increase in extension after therapy, however none reached neutral extension. Residual extension lag was significantly smaller for cases treated with venous flap transplantation when the digit could be pinned acutely at neutral extension. There was no change in 2-pt discrimination noted after acute extension.

Summary Points Simultaneous soft tissue augmentation and digital artery lengthening by venous flap transplantation for severe PIPJ flexion contractures is superior to standard techniques in that it • Allows acute complete extension • Does not depend on post fixation gains in extension which were minor and rarely reached neutral • Achieves superior long-term extension

This approach is seemingly ideal for PIPJ flexion contractures where the limiting structures include the digital vessels.