Biomechanical Comparison of Volar Plate Repair Versus Volar Plate Repair With Suture Tape Augmentation at the Finger Proximal Interphalangeal Joint.

Abstract

The purpose of this study was to perform a biomechanical comparison of volar plate repair alone versus volar plate repair with suture tape augmentation in a hyperextension laxity injury model at the proximal interphalangeal (PIP) joint. Ten matched cadaveric fingers were obtained from five cadavers (average age, 59 ± 7 years). The specimens underwent 5 and 10 N·cm of extension load at the PIP joint to measure the laxity of the intact joint. Next, an injury model was created by incising the proximal volar plate and loading the specimen on a testing machine to 30° of hyperextension; laxity testing was repeated. Within each matched pair, one side was used for volar plate repair, and the contralateral side was used for volar plate repair with suture tape augmentation. Laxity measurements were repeated. The specimens were then loaded from 2 to 5 N·cm for 30 cycles, and then loaded to failure. In both groups, extension angle significantly increased following PIP joint injury. Both repair groups significantly decreased extension angle compared with injury. Specimens that underwent volar plate repair with suture tape augmentation demonstrated significantly increased stiffness at 10, 20, and 30 cycles compared with volar plate repair alone (3.4, 3.5, and 3.6 N·cm/° vs 2.5, 2.5, and 2.6 N·cm/°, respectively), a higher yield load (16.7 vs 12.4 N·cm), and ultimate load (25.9 vs 19.1 N·cm) and absorbed more energy at ultimate load (4.1 vs 2.6 N·cm). Suture tape augmentation increased construct stiffness, yield load, load to failure, and ultimate load in this biomechanical study and may offer additional support in volar plate repair for chronic PIP joint hyperextension laxity. This finding lends support to using suture tape as an augment to produce a stronger PIP joint repair, potentially leading to an expedited recovery and earlier return to activities.