Association between functional outcome scores and MRI-based structural integrity after rotator cuff repair: a prospective cohort study

Purpose Natural history of rotator cuff tears is poorly understood. Repair of rotator cuff tears has shown to improve functional outcomes in full-thickness tears. However, high re-tear rates have been reported in literature, which does not correlate with poorer outcomes. Primary aim of this study was to explore association between functional outcome scores and structural integrity of rotator cuff, using magnetic resonance imaging (MRI)-based grading. Methods Patients with MRI-proven full-thickness rotator cuff tears, undergoing mini-open rotator cuff repair, were assessed for shoulder abduction strength and functional outcome scores before the surgery and 2 years after the procedure. Association between functional outcome scores and MRI grading for rotator cuff healing (Sugaya grading) was analyzed. Results A total of 38 patients (18 females and 20 males), with a mean age of 50.6 years (SD: 10.9), were included in the study. Mean duration of symptoms was 6.05 months (SD: 4.2). On postoperative MRI, healing of the cuff was categorized as Sugaya grade 1 in 12 patients, grade 2 in 20 patients and grade 3 in 6 patients. Higher Sugaya grades (T: 13.48, p: 0.001) and grades of fatty degeneration (T: 14.05, p: 0.001) were found to be associated with longer duration of symptoms. Improvement in shoulder abduction strength correlated negatively with the duration of symptoms (r: -0.39, p: 0.01). There was a significant improvement in functional outcome scores after the surgery. There was no association between postoperative structural integrity of the repaired tendon (Sugaya grading) and functional outcome scores. Conclusion Early repair of rotator cuff results in better functional outcomes and shoulder strength. The findings from this study suggest there is a dissociation between MRI-based grades of healing of repaired rotator cuff and function of the shoulder. Study design Level II, Prospective cohort study