Compression of an Autograft Biceps into an Augmentation Patch does not Cause Mechanical Damage to the Tenocyte

Abstract

A compression plate has recently been reported as a point of care processor for adapting the long head of the biceps into an autograft patch for rotator cuff augmentation. The purpose of this study was to evaluate the effects of this graft preparation technique on histological evidence of tenocyte mechanical damage. A consecutive series of patients undergoing biceps tenodesis for shoulder pathology were evaluated. After supra-pectoral tenodesis, 27 mm of the long head of the biceps was secured for compression into the patch. The remaining length of residual tendon was longitudinally split, resulting in two equal lengths of remnant tendon from the same zone. One sample was sent to pathology with no preparation, and the other was prepared as a compressed biceps autograft patch according to the manufacturer's recommendations. Both grafts were sent to pathology for evaluation of tenocyte morphology. Records were reviewed to determine if compression resulted in mechanical damage to the tenocytes at the time of biceps augmentation. 55 shoulder procedures and 110 samples were sent for pathology analysis. 42 of the 55 (76%) specimens demonstrated morphologically normal tenocytes in both the compressed and non-compressed groups, and 7 (13%) cases showed evidence of tenocyte necrosis or mechanical damage in both groups. The difference abnormal tenocyte morphology between the compressed group and the native group was not statistically significant (p=0.625). Autograft biceps compression into a point of care patch did not result in mechanical damage to tenocyte morphology at the time of insertion for augmentation of rotator cuff pathology. Free proximal biceps tendon compression can result in a patch that does not mechanically damage the tenocyte. The patch can be used as a biologic autograft to enhance shoulder rotator cuff repair, as well as subscapularis repair in the setting of shoulder arthroplasty.