The effect of barbed suture tendon repair on work of flexion

Purpose To compare the work of flexion, ultimate strength, and gap resistance of a conventional 4-strand tendon repair to a knotless barbed-suture 4-strand tendon repair. Methods Tendon repairs were performed on 16 cadaver flexor digitorum profundus tendons using either a 4-strand double Kessler repair or a similar but knotless 4-strand repair with a unidirectional barbed suture. Work of flexion, gap resistance during cyclical loading, and ultimate strength of both techniques were determined and their means compared. Results There was no difference in mean maximum load and gap formation between the 2 techniques. Work of flexion was higher for the barbed-suture repair group compared with the traditional repair group (39 N·mm vs 31 N·mm). Conclusions The higher work of flexion in the barbed-suture group suggests that barbed suture may negatively affect tendon gliding within the flexor tendon sheath. Clinical relevance Knotless barbed-suture tendon repair leads to increased work of flexion compared with traditional flexor tendon repairs, which may result in an increased rupture incidence.