Arthroscopic rotator cuff repair with metal and biodegradable suture anchors: a prospective randomized study.

PURPOSE: The purpose of this study was to compare the clinical outcome of arthroscopic rotator cuff repair with metal and biodegradable suture anchors. METHODS: Arthroscopic rotator cuff repair was performed in 110 patients with a full-thickness rotator cuff tear. They were divided into 2 groups of 55 patients each, according to suture anchors used: metal anchors in group 1 and biodegradable anchors in group 2. Results were evaluated by use of the Disabilities of the Arm, Shoulder and Hand (DASH) and Work-DASH self-administered questionnaires, as well as the Constant score normalized for age and sex. On analyzing the results at 2 years' follow-up, we considered the following independent variables: baseline scores; age; sex; arm dominance; location, shape, and retraction of cuff tear; fatty degeneration; treatment of biceps tendon; rotator cuff repair technique (anchors or anchors and side to side); and number of anchors. Univariate and multivariate statistical analyses were performed to determine which variables were independently associated with the outcome. Significance was set at P < .05. RESULTS: Of the patients, 9 (8.2%) were lost to follow-up. Comparison between groups did not show significant differences for each variable considered. Overall, according to the results, the mean DASH scores were 17.6 +/- 17.2 points in group 1 and 22.8 +/- 19.9 points in group 2; the mean Work-DASH scores were 24.9 +/- 28.1 points and 22.5 +/- 24.1 points, respectively; and the mean Constant scores were 104 +/- 20.5 points and 98.6 +/- 14.3 points, respectively. Differences between groups 1 and 2 were not significant. Univariate and multivariate analysis showed that only baseline score, age, tear location, and fatty degeneration significantly and independently influenced the outcome. CONCLUSIONS: At a short-term follow-up, differences between arthroscopic repair of full-thickness rotator cuff tears with metal and biodegradable suture anchors were not significant. LEVEL OF EVIDENCE: Level I, high-quality randomized controlled trial with no statistically significant differences but narrow confidence intervals.