Epitendinous Suture Techniques in Extensor Tendon Repairs—An Experimental Evaluation

Purpose The tension-band principle might be relevant to extensor tendon repairs, and a dorsal-only Silfverskiöld epitendinous repair is stronger and stiffer than more conventional techniques in vitro . We aimed to evaluate the strength and stiffness of the strongest epitendinous sutures described, using an in vitro model that subjects the repair to angular force over a pulley, thereby creating a tension-band model. Methods Silfverskiöld dorsal-only epitendinous extensor tendon repairs in porcine foot tendons (n = 8) were compared to reverse (buried) Silfverskiöld (n = 8), Halsted (n = 8), and interrupted horizontal mattress (IHM) repairs (n = 6) in vitro with a tensiometer around a 45° pulley. Thirty tendons total were tested to assess the force required for 2-mm gapping and ultimate tensile strength. Results The IHM repair had a significantly higher ultimate tensile strength (43 N; SD, 10 N) than the other repairs, which had strengths between 27 N (SD, 4 N) and 31 N (SD, 7 N). The IHM was also significantly more resistant to gapping than the Silfverskiöld and Halsted repairs. Conclusions Interlocking horizontal mattress, dorsal-only extensor tendon repairs were significantly stronger and more resistant to gapping than Silfverskiöld and Halsted repairs. Other repairs were still strong and resistant to gapping in comparison to previously published data for conventional repairs. Clinical relevance The IHM is a relatively difficult technique to perform, and it remains to be seen whether the additional strength translates to clinical benefits over the easier Silfverskiöld technique.