Tensile properties of suture methods for repair of partially lacerated human flexor tendon in vitro

The decision to treat zone II partially lacerated flexor tendons is challenging, because there can be justification for either repair or no repair, depending on the surgeon’s assessment of the strength of the residual intact portion of the tendon. In this study tensile properties of various repair techniques were compared. Cadaveric human flexor tendons (n = 118) were lacerated to 75% of their cross-section and repaired with either a core suture method (Kessler, modified Kessler, Savage, Lee, augmented Becker, or Tsuge all finished with a circumferential running suture), an epitendinous suture alone (circumferential or partial), or the tendons were left unrepaired. Among the core suture methods there was no significant difference (p >. 05) in maximum failure force (overall mean, 211.2 N; SD, 53.2) or force to produce a 1.5-mm gap (74.1 N; SD, 49.7). Likewise there was no significant difference (p >. 05) in tendon stiffness (41.0 N/mm; SD, 14.0) or resistance to gap formation (52.3 N/mm; SD, 23.1). In comparison, repairs without the core suture, including unrepaired tendons, were significantly weaker (144.7 N, p <. 001) and had a marginally lower stiffness (p =. 04) but had a similar resistance to gap formation (43.5 N/mm).