Biomechanical and morphological comparison of two interposition graft rotator cuff repair techniques

Interposition graft rotator cuff repair is one option for the treatment of massive, otherwise irreparable rotator cuff tears. It is undetermined how different suturing techniques influence morphology at the patch-tendon interface in interposition rotator cuff repairs, particularly with respect to increased cross-sectional area at the repair site post-exposure to cyclic loading, which may influence healing. We aimed to analyze how the morphology of the grafts used in polytetrafluoroethylene (PTFE) interposition rotator cuff repairs differed according to whether the graft was secured using the multiple mattress technique or the weave technique respectively.

Twelve PTFE interposition rotator cuff repairs (two groups, n = 6) were cyclically loaded. The thickness, width, cross-sectional area at the individual patches and at the repair site, and patch elongation were compared between repairs using the 'multiple mattress' technique and repairs that used the 'weave' technique.

At all loads, repair site cross-sectional area and thickness was greater in the weave group than in the multiple mattress group (P<0.05), despite repair site width being greater in the multiple mattress group (P<0.05). No significant differences in elongation were found between the multiple mattress and weave groups.

Greater repair site cross-sectional area under cyclic loading was observed in polytetrafluoroethylene interposition rotator repairs that used the weave technique than in those that used the multiple mattress technique. Increased repair site cross-sectional area in the weave group occurred due to increased thickness and decreased width relative to the multiple mattress group. No differences in cross-sectional area were found between groups at the individual patches.