Reattachment of Flexor Digitorum Profundus Avulsion: Biomechanical Performance of 3 Techniques

Purpose To investigate whether inclusion of the volar plate in repair of flexor digitorum profundus avulsions increases the strength of the repair and resists gapping. Methods Cadaveric fingers (n = 18) were divided into 3 equal groups. The first technique involved 2 micro-suture anchors only (A). The second used only volar plate repair (VP). The third group was a hybrid, combining a micro-suture anchor with volar plate augmentation (AVP). Specimens were loaded cyclically to simulate passive motion rehabilitation before being loaded to failure. Clinical failure was defined as 3 mm of gapping, and physical failure as the highest load associated with hardware failure, suture breakage, anchor pullout, or volar plate avulsion. Results Gapping throughout cycling was significantly greater for the A group than VP and AVP with no difference detected between VP and AVP groups. Gapping exceeded 3 mm during cycling of 3 A specimens, but in none of the VP or AVP specimens. Load at clinical and physical failure for A was significantly lower than for VP and AVP, whereas no difference was detected between VP and AVP. Conclusions In this cadaveric model, incorporating the volar plate conferred a significant advantage in strength, increasing the mean load to physical failure by approximately 100 N. Copyright (C) 2014 by the American Society for Surgery of the Hand. All rights reserved.