Open versus arthroscopic subacromial decompression: analysis of one-year results

The results of open subacromial decompression (OSD) were compared with arthroscopic subacromial decompression (ASD) after 1 year in 32 subjects (4 bilateral), and the correlation between the two shoulder rating scales for impingement was documented. Patients were evaluated clinically on the modified University of California at Los Angeles (UCLA) shoulder rating scale, and Constant scale. Scapular position and rotation were evaluated as well as a rotation and abduction shoulder strength test using the Cybex II dynamometer. No parameters revealed significant differences between the groups, except for the UCLA score which indicated an advantage for the ASD group (p = 0.046). The OSD group scored 24.5 (5.45) on the UCLA scale and 73.8 (18.9) on the Constant scale, whereas the ASD group scored 28.3 (5.6) and 80.8 (16.4). To study the correlation between both scales, the Pearson correlation product-moment coefficient was calculated and a high correlation (r = 0.81) obtained. Less mobility was found in the operated arm for all parameters, with the exception of glenohumeral abduction in both groups and passive elevation in the OSD group. Only in the OSD group did the scapula in the operated extremity show more abduction of the inferior angle of the scapula. Weaker abduction strength in the operated side was found in the ASD group, whereas in the OSD group there was significantly less adduction and external rotation strength at 180 degrees/s en 240 degrees/s. We conclude that after one year the open group tends to catch up with the arthroscopic patients and that the main benefits after arthroscopic surgery as described in literature are more evident in the shorter period.