Evaluation of simple and looped suture and new material for flexor tendon repair.

Flexor tendon repair strength is proportional to the number of suture strands crossing the repair site but it is not clear if each strand needs to result from a separate pass through the tendon. We examined whether one throw of looped suture across a repair site equals two separate throws of suture and whether fewer passes with stronger material such as Fiberwire is equivalent to more passes with a comparatively weaker material such as Supramid. When evaluating the repairs for force required to generate a 2 mm gap and for gap formed at the instant prior to failure, looped suture cannot substitute for two separate passes of suture (Supramid Kessler looped vs. separate passes, 14 N vs. 35 N and 8.8 mm vs. 4.1 mm, respectively; Fiberwire Kessler looped vs. separate passes, 25 N vs. 43 N and 7.6 mm vs. 4.6 mm, respectively; all p<0.05). Two-stranded Fiberwire Kessler repair equalled four-stranded cruciate repair with Supramid for all tested parameters (force at 2 mm gap: 17 N vs. 22 N, respectively; force at failure: 42 N vs. 46 N; and gap formed prior to instant of failure: 6.9 mm vs. 5.6 mm; all p>0.05).