Assistant Professor Small Animal Orthopedics North Carolina State University, North Carolina
Biomechanical Analysis of Accessory Tendon Graft Augmentation for Primary Gastrocnemius Tendon Reconstruction in Dogs. Duffy DJ1, Chang Y1, Fisher M1, Moore G2. 1North Carolina State University, Raleigh, NC; 2Purdue University, West Lafayette, IN.
Gastrocnemius tendon (GT) injury is the most common surgical tendinous disease in the dog. Within the human literature, use of surrounding autologous musculotendinous grafts have been reported. The objective of this study was to evaluate the effect of accessory tendon graft (ATG) augmentation as an adjunct to a core locking-loop (LL) and epitendinous suture (ES) repair in a canine GT model. Twenty-two GT musculotendinous specimens were randomly divided into two groups. Following transection, paired GT were repaired with LL+ES alone or with concurrent ATG augmentation. Yield, peak and failure loads, tensile loads required to create 1 mm and 3 mm gapping, and failure modes were evaluated. Yield (P < 0.0001) and peak (P = 0.0001) and failure loads (P = 0.0003) were greater when ATG was used for repair. Greater force was required to cause 1 mm (P = 0.0001) and 3 mm (P = 0.0002) gap formation in the ATG group, however the frequency of gap formation did not differ between groups. All repaired constructs failed exclusively by suture pull-through. Autologous ATG augmentation as an adjunct to primary GT repair increased yield, peak and failure forces by ∼ 1.6 x, 1.9 x, 1.8 x, respectively and required 2.1 x greater force to cause 1 mm and 3 mm formation compared to LL+ES repairs alone. Study limitations include those inherent to its ex vivo design, such as the inability to assess normal processes of tendinous healing. ATG augmentation should be considered as an autologous method to support and strengthen the primary GT repair. These results justify further studies to determine the effect of ATG on clinical function following graft harvest in dogs.