Long-term Rotator Cuff Strength And Shoulder Function In Nonoperative Vs. Operative Treatment Of Midshaft Clavicle Fractures

PURPOSE: To compare long-term rotator cuff (RC) strength and shoulder function following nonoperative versus operative treatment of midshaft clavicle fractures. Also, to investigate the effect of clavicular shortening (CS) on RC strength and shoulder function. METHODS: Thirty-one patients with midshaft clavicle fractures treated either nonoperatively (n = 15; age: 31.4 ± 7.7) or operatively (n = 16; age: 32.8 ± 10.5) were included in the study. Mean follow-up was 52.7 ± 29.2 months (range: 15-108 months). CS was measured using the initial anterior-posterior radiograph. Bilateral shoulder internal (IR) and external rotator (ER) strength were measured at 60°/s and 180°/s in the scapular plane using an isokinetic device. The American Shoulder and Elbow Surgeons Score was used for the evaluation of shoulder function.Independent samples t-test compared outcomes between nonoperative and operative groups, while paired samples t-test compared the differences between involved and uninvolved sides. The Pearson correlation analysis was used to examine the relationship between CS and RC strength and shoulder function. RESULTS: IR strength was significantly higher in the nonoperative group compared to the operative group at 60°/s (p = .002) and 180°/s (p = .005). There were no significant differences in ER strength at 60°/s (p = .10) and 180°/s (p = .10), or in shoulder function (p = .08) between groups. In the operative group, only the IR strength at 60°/s was significantly lower on the involved side (p = .03), while no differences were found between the extremities at other angular velocities (p > .05). There were no significant differences in the nonoperative group in terms of RC strength in the between extremities (p > .05). The average CS was 0.86 ± 0.9 cm in the nonoperative group and 1.63 ± 1.3 cm in the operative group. No significant association was found between CS and RC strength at each angular velocity (p > .05) and shoulder function (p = .48) in the long term. CONCLUSIONS: Nonoperative treatment resulted in greater shoulder IR strength compared to operative treatment. Also, the lower IR strength at 60°/s in the involved extremity in the operative group suggests potential long-term IR weakness after clavicle fractures. Additionally, initial CS may not be a determining factor in long-term RC strength and shoulder function.