Tendon bone healing can be enhanced by demineralized bone matrix: a functional and histological study.

Rotator cuff repair surgery has high failure rates, with tendon reattachment to bone remaining a challenging clinical problem. Increasing the integrity of the healing tendon-bone interface has been attempted by adopting a number of different augmentation strategies. Because of chondrogenic and osteogenic properties we hypothesise that demineralized bone matrix (DBM) augmentation of a healing tendon-bone interface will result in improved function, and a morphology that more closely resembles that of a normal enthesis, compared with nonaugmented controls in an ovine patellar tendon model. The right patellar tendon was detached from its insertion and reattached to an osteotomized bone bed using suture anchors. Two groups were analyzed, the control group (without augmentation) and the DBM group (DBM interposed between the tendon and bone). Animals were sacrificed at 12 weeks. Force plate, mechanical, and histomorphometric analyses were performed. Tendon repairs failed at a rate of 33 and 0% for the control and DBM groups, respectively. DBM augmentation resulted in significantly improved functional weight bearing and increased amounts of fibrocartilage and mineralized fibrocartilage. This study shows that DBM enhances tendon-bone healing and may reduce the high failure rates associated with rotator cuff repair clinically.