Comparison between metal and biodegradable suture anchors in the arthroscopic treatment of traumatic anterior shoulder instability: a prospective randomized study

The purpose of this study was to compare the clinical outcome of arthroscopic treatment of shoulder instability with metal and biodegradable suture anchors. Arthroscopic stabilization was performed in 78 patients with recurrent traumatic anterior shoulder instability. They were divided into 2 groups of 39 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) self-administered questionnaire; Rowe score; Constant score normalized for age and gender, and recurrence of dislocation. On analyzing the results at a 2-year follow-up, we considered the following independent variables: age; gender; arm dominance; duration of symptoms, age at first dislocation, number of dislocations, type of work; type of sport; sports activity level; lesion of the anterior labrum and anterior-inferior gleno-humeral ligament; SLAP lesion, and number of suture anchors. Comparison between groups did not show significant differences for each variable considered. Overall, according to the results, median DASH scores were 4.5 points (range 0-27) in group 1 and 7 points (range 0-25) in group 2 (n.s.); median Rowe scores were 100 points (range 60-100) and 100 points (range 25-100), respectively (n.s.); and median Constant scores were 98 points (range 81-107) and 98 points (range 87-121), respectively (n.s.). Recurrence was observed in 1 patient (2.8%) in group 1 and in 2 patients (5.9%) in group 2. Overall recurrence rate was 4.3%. Univariate and multivariate analysis showed that age, duration of symptoms, number of dislocations, type of work, and type of sports significantly and independently influenced the outcomes. Differences between groups 1 and 2 were not significant. At a short-term follow-up, differences between arthroscopic shoulder stabilization with metal and biodegradable suture anchors were not statistically significant. Clinical relevance of the study is that there is no difference in the use of metal or biodegradable suture anchors for the arthroscopic treatment of shoulder instability.