Acellular dermal matrix augmentation significantly increases ultimate load to failure of pectoralis major tendon repair: a biomechanical study

Abstract

Background: Biomechanical studies have demonstrated that standard pectoralis major tendon (PMT) repairs have inferior strength compared with native tendon.

Hypothesis: Augmentation of PMT repair with an acellular dermal matrix (ADM) will increase the ultimate load to failure.

Methods: Eighteen cadaveric specimens were allocated to 3 repair groups: standard repair (SR); augmented repair (AR) with ADM; and intact, native tendon (NT). Specimens were tested for cyclic elongation, linear stiffness, load to 5 mm displacement, maximum load to failure, and method of failure.

Results: Maximum load to failure in AR (1450 ± 295 N) was significantly higher than SR (921 ± 159 N; P = .0042) and equivalent to NT (1289 ± 240 N; P = .49). NT required the highest load to displace 5 mm (709 ± 202 N), which was higher than AR (346 ± 95 N; P < .001) and SR (375 ± 55; P = .0015). NT stiffness (125 ± 42 N/mm) was greater than the AR (69 ± 19 N/mm; P = .0073) or SR (75 ± 11 N/mm; P = .015). The mode of failure for SR was suture pullout from the PMT as opposed to button pullout from the humerus (fracture) for AR.

Conclusion: ADM augmentation of PMT repair significantly increases ultimate load to failure.

Keywords: Pectoralis major tendon; acellular dermal matrix; augmentation; biomechanics; dermal allograft; suture pullout.