Transosseous Sutures in Tendon-to-Bone Repairs: the Role of the Epitendinous Suture.

BACKGROUND: Numerous transosseous fixation techniques for flexor tendon injuries in Zone 1 of the hand have been described in the literature. While relatively high maximal loads to failure are documented in different biomechanical experiments, several tests revealed a low 2 mm gapping resistance of the tendon-to-bone repairs. We therefore aimed to investigate the effect on gap formation adding a peripheral suture to an established transosseous fixation technique. In addition, we analyzed the influence of different suture materials (braided vs. non-braided) on the stability of the core suture.

METHOD: A total of 30 porcine flexor digitorum profundus tendons were divided into 3 groups (n = 10 each) and repaired using the transverse intraosseous loop technique (TILT). In group 1 and group 2 the repairs were performed using PDS 3-0 or Ethibond 3-0, respectively. In group 3, a peripheral suture was added to the core suture (PDS 3-0) consisting of two figure-of-eight stitches with PDS 5-0. The biomechanical performance of the repaired tendons was analyzed using a standardized protocol.

RESULTS: The suture material and peripheral suture showed no effect on the ultimate failure load in our testing. However, the addition of a peripheral suture led to a statistically significantly higher 2 mm gap force when compared with the repair with a core suture only.

CONCLUSION: In conclusion, addition of a palmar epitendinous suture to the transosseous core suture significantly increases the load to 2 mm gap formation in Zone 1 flexor tendon repairs and thus allows an immediate controlled mobilization.