Strength characteristics and failure modes of suture patterns in severed goat tendons

The load-to-gap formation, maximum load, gap present at maximum load, and failure mode were compared among four suture patterns: Bunnell-Mayer, modified Kessler, Mason-Allen, and simple interrupted. Sixty-four goat tendons were sutured with 2-0 monofilament polypropylene in one of the patterns and distracted at 92 cm/min with an electrohydraulic materials testing system. All tests were filmed at 40 frames/sec with an intermittent pin registered camera. The load-to-gap formation was not significantly different among the Bunnell (13.3 +/- 1.5 newtons [N]), Kessler (12.8 +/- 1.3 N), and simple interrupted (11.7 +/- 1.7 N) patterns. The Mason-Allen pattern was significantly different )8.2 +/- 0.5 N). The Bunnell-Mayer had the highest mean maximum load to failure (43.0 +/- 1.6 N) followed by the modified Kessler (34.1 +/- 1.9 N). There was no difference between the Mason-Allen (22.9 +/- 1.4 N) and simple interrupted (21.2 +/- 1.4 N). All of the patterns permitted at least a 1 cm gap to form when the maximum load was applied. The Bunnell pattern caused severe constriction of the tendon and failed by suture material disruption. The modified Kessler caused some focal constriction, but the suture material pulled out before breaking and sliced the tendon in the process. The Mason-Allen and the simple interrupted patterns sliced the tendon as the suture pulled out of the tendon.