IN-VITRO BIOMECHANICAL ANALYSIS OF SUTURE METHODS FOR FLEXOR TENDON REPAIR

This study was designed to compare five different suture methods that are used clinically for tendon repair. The flexor digitorum profundus tendons from the digits of adult mongrel dogs and adult human cadavers were used as models. The tendons in zone II of the hand, defined as t he region from the distal palmar crease to the insertion of the flexor digitorum superficialis tendon at the middle phalanx, were transected and then were repaired by one of the suture methods developed by Kess ler, Tsuge, Tajima, Savage, or Lee. The gliding function and tensile p roperties of the repaired tendons were evaluated biomechanically at ti me zero. The Tajima and Savage methods produced better gliding functio n than the other techniques. In the canine specimens that had been rep aired by one of these two methods, the rotation of the distal interpha langeal joint was more than 60% of the rotation of the canine control specimens; only the Savage technique produced a rotation 124% that of the human control specimens. After the Tajima repair, the rotation of the proximal interphalangeal joint was 113% that of the canine control specimens and 157% that of the human controls. In the canine specimen s that had had the Tajima or Savage repair, excursion of the tendon wa s greater than 55% that of the controls. The tendons repaired by the S avage method tolerated a significantly higher ultimate load to failure (14 and 25% that of the canine and human control specimens, respectiv ely) than the other methods. Of the suture methods that were tested, t he Savage technique provides sufficiently satisfactory gliding functio n and has enough initial stiffness and strength that it may be able to withstand early active mobilization following primary repair of flexo r tendons.