Biomechanical Comparison of Single- Double- and Novel Triple- Row Rotator Cuff Repairs in a Porcine Model Using Generic Anchors

Comparison of a novel triple-row (NTR) rotator cuff repair (RCR) was made to single row (SR) and double row (DR) repairs as measured by gap formation, Ultimate Failure Load (UFL), and mode of failure. Porcine humeri were divided into three groups of forty and the infraspinatus tendons were completely released and then repaired using generic (PEEK) anchors. Biomechanical testing of RCRs consisted of 3500 cycles of a load varied from 10 to 180 Newtons (N). Gap size at all cycle counts was significantly larger for SR and DR than NTR RCRs. 84% of NTR repairs completed the 3500 cycle test versus 66% of DR and 61% of SR repairs. The tendon pulled from the sutures 60%, 49% and 33% of the time for SR, DR and NTR RCRs respectively. UFLs were 464 N for the NTR repairs, 394 N for DR and 414 N for SR repairs. In summary, NTR repairs resulted in smaller gap formation, higher UFLs, and fewer instances of tendons tearing at the sutures than SR or DR repairs. Results of NTR repairs demonstrate that the tendon footprint is securely restored with small gap formation for the range of forces that a shoulder will be subjected to in normal use.