Does surgical intervention alter the natural history of degenerative rotator cuff tears? Comparative analysis from a prospective longitudinal study.

ABSTRACT

BACKGROUND: The natural history of rotator cuff tears often involves progressive pain development, tear enlargement, and advancing muscle fatty degeneration. Both surgery and conservative management have proven to be effective treatments. Our study purpose was to compare the short- to mid-term effects of rotator cuff repair on shoulder function, progression of tear size, and muscle degeneration compared to controls with asymptomatic tears that developed pain and were managed nonoperatively. METHODS: This comparative study consists of 2 separate longitudinal study arms. The control group consisted of asymptomatic degenerative cuff tears followed until pain development and then managed nonoperatively with continued surveillance. The surgical group consisted of subjects with degenerative tears that failed nonoperative treatment and underwent surgical intervention with a minimum of 2 years follow-up. Outcomes included visual analog scale pain, American Shoulder and Elbow Surgeons, active range of motion, strength, and ultrasonography. RESULTS: There were 83 controls and 65 surgical shoulders. The surgical group was younger at enrollment (58.9 ± 5.3 yr vs. 61.2 ± 7.8 yr, P = .04). The median follow-up for control subjects after pain development was 5.1 years (interquartile range [IQR] 3.6) and the median postoperative follow-up for the surgical group was 3.0 years (IQR 0.2). Baseline tear widths (median 14 mm, IQR 9 vs. 13 mm, IQR 8; P = .45) and tear lengths (median 14 mm, IQR 13 vs. median 11 mm, IQR 8; P = .06) were similar between the surgical group and controls. There were no differences in the baseline prevalence of fatty degeneration of the supraspinatus or infraspinatus muscles between groups (P = .43 and P = .58, respectively). At final follow-up, the surgical group demonstrated significantly lower visual analog scale pain (0 [IQR 2] vs. 3.5 [IQR 4], P = .0002), higher composite American Shoulder and Elbow Surgeons (95 [IQR 13] vs. 65.8 [IQR 32], P = .0002), and activities of daily living scores (29 [IQR 4] vs. 22 [IQR 8], P = .0002), greater abduction strength (69.6 N [standard deviation {SD} 29] vs. 35.9 N [SD 29], P = .0002), greater active forward elevation (155° [SD 8] vs. 142° [SD 28], P = .002), greater active external rotation in abduction (mean 98.5°, SD 12 vs. mean 78.2°, SD 20; P = .0002) compared to controls. Additionally, the prevalence of fatty muscle degeneration was lower in the surgical group for the supraspinatus and infraspinatus (25% vs. 41%, P = .05; 17% vs. 34%, P = .03; respectively). CONCLUSION: This prospective longitudinal study comparing a surgical cohort undergoing rotator cuff repair with a control group treated nonoperatively supports the notion that surgical intervention has the potential to alter the early natural history of degenerative rotator cuff disease. Patients in the surgical group demonstrated clinically relevant differences in pain and functional outcomes. Surgical intervention was protective against progressive muscle degeneration compared to nonoperative treatment.