The choice of an optimal graft for the superior capsule reconstruction of the shoulder with a massive rotator cuff tear

Background: The study hypothesis is that the knowledge about the mechanical properties of biological tissues will help surgeons to choose a transplant. Aim: To determine the optimal type of a graft, based on the assessment of the mechanical properties of three types of grafts used for the superior capsule reconstruction of the shoulder joint with a massive rotator cuff tear. Methods: In the experimental work, 3 types of biological tissues were studied: allografts of the fascia lata and of the dura mater, and the DX Reinforcement Matrix (a dermal ECM xenograft). The experiment was divided into two parts. In the first part, the mechanical strength at rupture of the samples was evaluated and compared, in the second part the resistance of a vertical suture was studied. The tests included uniaxial stretching with the force and strain at rupture recorded. Results: The fascia lata allograft showed the highest ultimate tensile strength, while the dura mater allograft had the lowest ultimate tensile strength. All the three materials showed rather high values of the rupture strain. The lowest value of the rupture strain was detected for the dura mater allograft - 15.2±2.6%, the highest value was obtained for the dermal ECM xenograft - 63.3±20.8%. The largest value of the fracture stress was recorded for the DX Reinforcement Matrix - 33.5 N. The minimum value was recorded for the fascia lata allograft - 9.9 N. Conclusion: The fascia lata allograft and DX Reinforcement Matrix have the optimal mechanical characteristics and can be recommended as grafts for the superior capsule reconstruction of the shoulder joint with a massive rotator cuff tear.