Degradation of Cylindrical Poly-Lactic Co-Glycolide/Beta-Tricalcium Phosphate Biocomposite Anchors After Arthroscopic Bankart Repair: A Prospective Study

Abstract

The purpose of this study was to examine widening and ossification of anchor holes after arthroscopic Bankart repair with the use of cylindrical biocomposite anchors made of 70% poly-L-lactide-co-glycolide acid (PLGA) and 30% beta-tricalcium phosphate (ß-TCP). Twenty-two patients were enrolled in a clinical trial to acquire marketing approval of a PLGA/ß-TCP biocomposite suture anchor in Japan and underwent arthroscopic Bankart repairs with the anchors. Eleven of 22 patients had computed tomography scans after 2-year follow-up. Three surgeons independently evaluated width and ossification of anchor holes in 4 grades using computed tomography scans. When the evaluations disagreed, the final grade was determined based on the 3 surgeons' consensus. Seven men and 4 women were evaluated at a mean of 30 months (range, 28-32 months) after surgery, and a total of 47 anchors were implanted. Anchor holes were narrowed in 39 (83%) of 47 anchor sites and were almost or completely filled in (type 3 or 4) in 21 (45%) of 47 anchor sites. Ossification was seen in 46 (98%) of 47 anchor sites and was nearly complete or complete (type 3 or 4) in 16 (34%) of 47 anchor sites. There were no significant differences in both anchor hole width and ossification score on comparison of the anteroinferior (4- to 6-o'clock positions in the right shoulder) with other anchor sites. Cylindrical biocomposite anchors made of 70% PLGA/30% ß-TCP showed a low incidence of anchor hole widening and excellent ossification regardless of anchor site. [Orthopedics. 2018; 41(3):e348-e353.].