Irreparable rotator cuff tears continue to challenge orthopaedic surgeons. Given improved understanding and advances in shoulder arthroscopy, the incidence of such tears may be decreasing, yet many cases are still considered irreparable. In a paper presented at the 2008 AAOS Annual Meeting, Stephen J. Snyder, MD, Jason A. Higgins, MD, James L. Bond, MD, and Joseph P. Burns, MD, presented the results of their study examining arthroscopic implantation of biologic tissue to reconstruct and replace a nonrepairable rotator cuff.
The team conducted a retrospective review of 15 patients with previously documented, massive, contracted, immobile rotator cuff tears that were treated with arthroscopic placement of a GraftJacket® (Wright Medical, Arlington, Tenn.) allograft matrix between March 2003 and March 2004. All patents were treated by a single surgeon and followed up at 3, 6, and 12 months. A minimum 2-year follow-up was also required for inclusion in the study results.
Nine of the patients had previously had rotator cuff repairs that failed, four had pain and dysfunction for more than 1 year, and two had traumatic injuries. The mean age of patients was 54.8 years.
Each patient was examined preoperatively using magnetic resonance imaging. Some patients were treated with a single-stage arthroplasty; those with previously placed suture anchors obstructing the implantation site were treated with a two-stage arthroscopy. The first procedure consisted of débridement, selective subacromial decompression, tension-free partial cuff repair, hemming of the cuff edges, and placement of OBI Tru-Rescue® bone plugs (Smith & Nephew, Andover, Mass.) after anchor removal. The second procedure—arthroscopic placement of the allograft to fill the residual cuff defect—was performed 6 to 8 weeks later.
A dozen successes
At a mean follow-up of 32.6 months (range, 24 to 45 months), the procedure was successful in 12 of the 15 patients and was unsuccessful in 3 patients. The repair failed in two patients during the first 3 months; those patients were eliminated from the study results. A third patient, whose repair failed between the first and second year, was retained in the study.
The reported University of California, Los Angeles (UCLA) shoulder scores were excellent in five patients, good in seven patients, and poor in one patient (Table 1). On the Simple Shoulder Test evaluation, the number of patients able to perform each task increased in all categories but one (ability to sleep on the operated shoulder).
No patients experienced intraoperative or postoperative complications from the procedure, no allografts were rejected, and the allograft material did not need to be removed in the three failed repairs. All patients, including those whose repairs failed, experienced pain relief. Loss of overhead strength was the only common complaint from the study group.
The study’s limitations include the fact that it is a retrospective review of a small cohort with a short-term follow-up. However, it was the first to report significant increases in function after biologic allograft tissue replacement of an otherwise irreparable cuff tear.
The optimal thickness of the graft is still under investigation. The early failed grafts were approximately 1.02 mm thick, and the graft that later failed was approximately 1.6 mm thick. The team reported that their poststudy work in this area has successfully used an allograft approximately 2.0 mm thick. The best technique for securing the graft to the native tissue has not yet been determined.
The appropriate age for patients to undergo a successful procedure is still being debated. The first failed repair occurred in a 74-year-old patient, and since then, the group has not performed the procedure on anyone older than 65.
The group is still investigating the role of growth factors in biologic tissue engineering. They surmised that there may be a growth factor regimen that would allow greater collagen proliferation and a better growth of native tissue into the biologic framework.
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Peter Pollack is a staff writer for AAOS Now. He can be reached at firstname.lastname@example.org