Abstract: Objective To investigate the biomechanical properties of embedded cross-stitch suture and its preliminary application for extensor tendon repair in zone Ⅶ. Methods Thirty-three fresh porcine extensor tendons were randomly divided into 3 groups and repaired with cross-stitch, embedded cross-stitch or Halsted suture method respectively. The tendons were subjected to an Instron tensile testing machine to test 2-mm gap formation force, ultimate strength, stiffness and energy to failure. Embedded cross-stitch was performed for repairing extensor tendons in zone V~ of 56 fingers. Protected passive and active motion protocol was used in each case after operation. Strickland TAM classification was applied to evaluate the function postoperatively. Results Under linear tension mode, embedded cross-stitch was superior to cross-stitch and Halsted method with its 2-mm gap formation force at （49.2±5.6） N, ultimate strength at （68.3±6.3） N, Stiffness at （6.9±0.7） N/mm, and energy to failure at （0.79±0.07） J （P〈0.05）. Patients were followed up for 26 months, no tendon rupture was observed in any of the repaired fingers. Strickland TAM classification showed excellent in 50 fingers, good in 4 fingers, fair in 2 fingers, and the total good rate was 96.4%. Conclusion Embedded cross-stitch suture employs strong biomechanical characters with fewer suture exposure, which can fulfill the requirements for early motion protocol. Therefore, it is suggested for extensor tendon repair.

Key words: Embedded cross-stitch suture, Biomechanics, Tendon repair