Knee arthrotomy closure with barbed suture in flexion versus extension: a porcine study

The purpose of this biomechanical study was to evaluate knee arthrotomy closure with a barbed suture in flexion versus extension. 48 porcine knees were randomized into three groups: full extension, 30° flexion, and 60° flexion. Each knee was then flexed to 90° and then 120°, with failures recorded. Arthrotomy closure in extension had significantly higher failure rates (6/16) upon flexion to 90° compared to arthrotomy closure in either 30° or 60° flexion (0/32) (P = 0.032). Upon ranging from 0° to 120°, arthrotomy failure occurred in 50% (8/16) of arthrotomies in the extension group, 6.25% (1/16) in the 30° flexion group and 18.75% (3/16) in the 60° flexion group (P = 0.022). Knee arthrotomy closure in extension compared to flexion had significantly higher rates of failure.