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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., (Copyright © 2019 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Background: The majority of distal biceps tendon injuries can be repaired in a single procedure. In contrast, complete chronic tears with severe tendon substance deficiency and retraction often require tendon graft augmentation. In cases with extensive partial tears of the distal biceps, a human dermal allograft may be used as an alternative to restore tendon thickness and biomechanical integrity., Hypothesis: Dermal graft augmentation will improve load to failure compared with nonaugmented repair in a tendon-deficient model., Study Design: Controlled laboratory study., Methods: Thirty-six matched specimens were organized into 1 of 4 groups: native tendon, native tendon with dermal graft augmentation, tendon with an attritional defect, and tendon with an attritional defect repaired with a graft. To mimic a chronic attritional biceps lesion, a defect was created by a complete tear, leaving 30% of the tendon's width intact. The repair technique in all groups consisted of cortical button and interference screw fixation. All specimens underwent cyclical loading for 3000 cycles and were then tested to failure; gap formation and peak load at failure were documented., Results: The mean (±SD) load to failure (320.9 ± 49.1 N vs 348.8 ± 77.6 N, respectively; P = .38) and gap formation (displacement) (1.8 ± 1.4 mm vs 1.6 ± 1.1 mm, respectively; P = .38) did not differ between the native tendon groups with and without graft augmentation. In the tendon-deficient model, the mean load to failure was significantly improved with graft augmentation compared with no graft augmentation (282.1 ± 83.8 N vs 199.7 ± 45.5 N, respectively; P = .04), while the mean gap formation was significantly reduced (1.2 ± 1.0 mm vs 2.7 ± 1.4 mm, respectively; P = .04). The mean load to failure of the deficient tendon with graft augmentation (282.1 N) compared with the native tendon (348.8 N) was not significantly different ( P = .12). This indicates that the native tendon did not perform differently from the grafted deficient tendon., Conclusion: In a tendon-deficient, complete distal biceps rupture model, acellular dermal allograft augmentation restored the native tendon's biomechanical properties at time zero. The grafted tissue-deficient model demonstrated no significant differences in the load to failure and gap formation compared with the native tendon. As expected, dermal augmentation of attritional tendon repair increased the load to failure and stiffness as well as decreased displacement compared with the ungrafted tissue-deficient model. Tendons with their native width showed no statistical difference or negative biomechanical consequences of dermal augmentation., Clinical Relevance: Dermal augmentation of the distal biceps is a biomechanically feasible option for patients with an attritionally thinned-out tendon.

The success of rotator cuff repair (RCR) surgery can be measured clinically (validated outcome scores, range of motion) as well as structurally (re-tear rates using imaging studies). Regardless of repair type or technique, most studies have shown that patients do well clinically. However, multiple studies have also shown that structurally, the failure rate can be very high. A variety of factors, including poor tendon quality, age over 63 years, smoking, advanced fatty infiltration into the muscle, and the inability of the tendon to heal to bone, have been implicated as the cause of the high re-tear rate in RCRs. The suture-tendon interface is felt to be the weakest link in the RCR construct, and suture pullout through the tendon is believed to be the most common method of failure. This review of the published literature seeks to determine if there is support for augmentation of RCR with acellular dermal matrices to strengthen the suture-tendon interface and reduce the re-tear rate.

Shoulder and elbow tendon injuries are some of the most challenging problems to treat surgically. Tendon repairs in the upper extremity can be complicated by poor tendon quality and, often times, poor healing. Extracellular matrices, such as human dermal allografts, have been used to augment tendon repairs in shoulder and elbow surgery. The indications and surgical techniques regarding the use of human dermal allograft continue to evolve. This article reviews the basic science, rationale for use, and surgical applications of human dermal allograft in shoulder and elbow tendon injuries., (Copyright © 2015 Elsevier Inc. All rights reserved.)