Biomechanical analysis of the cruciate four-strand flexor tendon repair

The purpose of this study was to develop and test in vitro a new flexor ten don suture technique that was simple and easy to perform, yet strong enough to withstand the projected forces of an in vivo active motion rehabilitati on protocol. Forty human cadaveric flexor digitorum profundus tendons were divided and repaired using 1 of 4 suture techniques (the modified Kessler, the Strickland, the modified 4-strand Savage, and the Cruciate di-strand re pairs). Each repair was tested using a slow-test machine and displacement c ontrol at 2 mm/s. Force applied, the resultant gap, and ultimate tensile st rength were recorded and statistical comparisons were performed using a two -tailed Student's t-test with level of significance set at p = .05. The Cru ciate suture technique was demonstrated to be nearly twice as strong to 2-m m gap formation (44 N) compared with the Kessler, Strickland, and Savage re pairs. Ultimate tensile strength was also significantly stronger for the Cr uciate technique (56 N) than the Kessler, Strickland, or Savage repairs. Th e technique was significantly faster to perform than the Savage or Strickla nd repairs and was comparable in repair time to the 2-stranded Kessler repa ir. The design of the new suture technique allowed the tendon repair to be completed with the ease and speed of a 2-strand technique, but bestowed on the repair strength that exceeded current 4-strand techniques. Copyright (C ) 1999 by the American Society for Surgery of the Hand.