Movement Patterns of the Shoulder Post Synthetic Interpositional PTFE Patch Repair for Large Rotator Cuff Tears

The use of a synthetic polytetrafluoroethylene patch to repair large rotator cuff tears has resulted in good postoperative outcomes with respect to strength and range of motion. However, there is little information evaluating the movement patterns of the shoulder after patch repair. Following a reliability study of radiography to assess shoulder joint angles, radiographic assessment of shoulder kinematics was performed at 68±52 weeks (mean±SEM) postoperatively. This study compared the outcomes of polytetrafluoroethylene patch repair (n=15), suture-anchor repair (n=8), reverse total shoulder arthroplasty (n=7), and normal shoulders (n=5). The inter-rater and intrarater reliability of radiography was excellent (r=0.98, 0.96). Glenohumeral joint movement at maximal active abduction following patch repair (59±5 degrees), suture-anchor repair (57±8 degrees) and reverse total shoulder arthroplasty (52±7 degrees) was less than asymptomatic shoulders (95±3 degrees; P<0.01). Scapulothoracic motion remained similar between all cohorts. The present study demonstrated that the abnormal relationship between glenohumeral and scapulothoracic motion post rotator cuff repair is due to a decrease in glenohumeral joint movement, rather than a compensatory increase in scapulothoracic motion.