This prospective randomized controlled study from Australia evaluated the efficacy of the use of the Restore xenograft (DuPuy Orthopaedics, Warsaw, Indiana) fabricated from small intestine mucosa of pigs for the use of augmentation of massive rotator cuff repairs. Nineteen patients received a xenograft during the course of rotator cuff repair in patients identified as having poor quality tendon or large to massive full thickness tears of the rotator cuff over a nine month period and were compared to an age and cuff tear size matched group. However, the randomized control trial was abandoned after four of the nine patients developed a severe local inflammatory reaction necessitating reoperation for irrigation and debridement as well as removal of the xenograft. The average age of the patients was 60 years with a mean tear size of 9 cm.2 At a two year follow-up visit, pain questionnaires at rest were similar in both groups, however, pain during activity took a mean of three months longer to resolve in the xenograft group than in the control group. At two years, the reported participation in sports activities in the xenograft group was significantly less than in the control group and the xenograft group reported significantly more difficulty with behind the back activities. Except for external rotation, there was a global loss of strength in the xenograft group compared to the control group with significantly higher impingement scores in the xenograft group. At two year follow up, recurrent tear rates as defined by MRI were comparable between the two groups with 6 of 10 in the xenograft group and 7 of 12 in the control group indicating recurrent tear. Mean tendon thickness was not significantly different between the two groups.
This study indicates that in four of nineteen patients, a significant inflammatory response was noted necessitating additional operative intervention and removal of the xenograft. In addition, there did not appear to be a benefit at two year follow- up in the use of the Restore xenograft patch for augmenting massive rotator cuff repairs. That is, the xenograft group had increased weakness, diminished range of motion, and a similar recurrent tear rate as well as diminished return to sports activities and increased impingement scores. Therefore, there does not appear to be a recognizable benefit for human use of the xenograft patch for the management of massive rotator cuff repairs.
Shoulder, Rotator, Cuff, Tear, Xenograft, Augmentation