Comparison of an anchor plate with suture anchor and transosseous constructs for rotator cuff repair in a polyurethane foam block: a biomechanical study

Background Rotator cuff repair can be difficult in patients with poor bone quality, as fixation may fail before proper tendon healing occurs. Common repair methods, such as suture anchors and transosseous sutures, are especially vulnerable to anchor pull-out or bone cut-through in osteoporotic bone. To address this limitation, an anchor plate can be employed to dissipate stress more evenly across a larger surface area. Methods Twenty-seven biomechanical tests were performed on spatially distinct regions of a standardized polyurethane foam block. Three fixation techniques were evaluated: anchor plate, suture anchor, and transosseous fixation. Each technique was tested with three suture types: 0.2 mm round suture, 0.5 mm round suture, and 0.5 mm flat suture tape (n = 3 for each combination). All constructs were loaded to failure under the same testing conditions. Ultimate failure load and failure mode were recorded and compared between groups. Results The anchor plate construct showed consistently higher failure loads than both conventional techniques across all suture types. Among the AP suture configurations, the AP construct with the 0.5 mm flat suture showed the highest mean failure load (437 ± 24 N). In comparison, the suture anchor and transosseous constructs reached 162 ± 12 N and 163 ± 16 N, respectively, with the same suture type. The failure pattern also differed between groups. Suture anchor constructs mainly failed by anchor pull-out, transosseous constructs failed by foam cut-through, and anchor plate constructs failed primarily by suture rupture, with only localized indentation of the foam surface. Conclusions In this preliminary biomechanical model, the anchor plate construct showed higher mean ultimate failure loads than both suture anchor and transosseous repair techniques under the tested monotonic loading conditions. These findings suggest that the anchor plate may have potential in this model, but further cadaveric and clinical studies are needed before any clinical recommendation can be made.