A biomechanical in vitro comparison of open versus percutaneous repair of tendon Achilles

A study was undertaken to compare the in vitro strengths of percutaneous Achilles tendon repair to open Achilles tendon repair. Ten fresh frozen cadaver below-the-knee specimens underwent Achilles tenotomy. The specimens were divided into two groups of five specimens each. Group I specimens underwent open Achilles repair using a Bunnell suture technique. Group II specimens underwent percutaneous repair. Each specimen was placed on an apparatus which produced progressive ankle dorsiflexion. Measurements of anastomotic gap were correlated with angle of dorsiflexion. Group I anastomoses were able to resist almost twice the amount of ankle dorsiflexion compared to Group II anastomoses (P less than .05). Entrapment of the sural nerve occurred in three out of five specimens in Group II. Percutaneous anastomoses were malaligned in four out of five specimens. Based on this study, percutaneous repair of Achilles tendon ruptures provides approximately 50% of the initial strength afforded by open repair. Percutaneous repair places the sural nerve at risk for injury.