To compare the biomechanical properties and gapping characteristics following loop modification of a 3-loop-pulley (3LP) pattern in an ex vivo canine common calcaneal tendon (CCT) avulsion repair model.
56 skeletally mature hindlimbs from 28 canine cadavers.
The CCTs were randomized to 1 of 4 experimental groups (n = 14/group) then sharply transected at the teno-osseous junction. Groups consisted of a 3LP, 4-loop-pulley (4LP), 5-loop-pulley (5LP), or 6-loop-pulley (6LP) pattern with loops placed 60° apart using size-0 polypropylene. Yield, peak, and failure loads, construct stiffness, loads to produce a 3-mm teno-osseous gap, and failure mode were evaluated and compared between groups.
Yield (P = 0.001), peak (P < 0.001), and failure loads (P < 0.001), construct stiffness (P < 0.001), and loads to 3-mm gap formation (P = 0.005) were all significantly greater for 6LP compared to all other groups. Mode of failure did not differ among groups (P = 0.733) with 75% (42/56) of repairs failing by mechanism of core sutures pulling through the tendinous tissue. Pattern modification by increasing the number of loops increased the repair site strength by 1.4, 1.6, and 1.8 times for 4LP, 5LP, and 6LP compared to 3LP, respectively.
Increasing the number of suture loops compared to a traditional 3LP repair is a relatively simple technique modification that significantly increases teno-osseous repair site strength and loads required to cause 3-mm gap formation. The results of this study justify further focused investigation of increasing the number of suture loops in vivo for teno-osseous CCT repair in dogs.
To evaluate the effect of a double Krackow suture pattern (DK), with and without epitendinous suture augmentation (ES), in a canine gastrocnemius tendon (GT) model.
Paired GTs from 12 adult dog cadavers and 4 control GT.
GTs were assigned to 2 groups (n = 12/group). Transverse tenotomy was performed and repaired with a DK or DK + ES. Yield, peak, and failure force, stiffness, occurrence of 1-and 3-mm gapping, and failure mode were examined.
Yield, peak, and failure loads were greater for DK + ES. Yield force was 48% greater for DK + ES (mean ± SD, 149.56 ± 53.26 N) versus DK (101.27 ± 37.17 N; P = 0.017). Peak force was 45% greater for DK + ES P < 0.001). Failure force was 47% greater for DK + ES (193.752 ± 31.43 N) versus DK (131.54 ± 22.28 N; P < 0.001). Construct stiffness was 36% greater for DK + ES (P = 0.04). All 12 DK and 10 of 12 DK + ES repairs produced a 1-mm gap, with all DK and 4 DK + ES repairs producing a 3-mm gap (P < 0.001). Loads required to create a 3-mm gap were significantly greater for DK + ES (P < 0.013). Suture breakage occurred in all DK repairs, which differed from DK + ES, where suture breakage (7/12) and tissue failure (5/12; P = 0.037) predominated.
Augmentation of a primary DK repair with an ES significantly improved construct strength in canine GT constructs while increasing loads required to cause 1- and 3-mm gap formation, respectively. ES augmentation is a simple technique modification that can be used to significantly increase construct strength, compared with DK alone.