Arthroscopic subacromial decompression: Results and factors affecting outcome

Arthroscopic subacromial decompression was performed on 114 patients with r otator cuff impingement who had not responded to nonoperative measures. Non e of the patients had a full-thickness cuff tear: Patients with associated instability, symptomatic acromioclavicular joint disease, or ruptures of th e long head of biceps were not included. Results were determined by questio ning patients about their satisfaction with the outcome of surgery and by f unctional assessment of the shoulder with the parameters of pain, ability t o perform daily activities, and range of motion according to the Constant s coring system. When reviewed at a mean interval of 19 months after surgery 85 patients (75%) were satisfied with the outcome. Pain scores improved by an average of 8.6 points; "activities of daily living" scores improved by a n average of 5.8 points; range-of-motion scores improved by an average of 3 .6 points. The improvements in all 3 parameters scored were significant (P < .05). The following variables were statistically analyzed to assess their influence on final outcome: age, sex, occupation, duration of symptoms bef ore surgery, dominance of the affected shoulder outcome of the impingement test, state of the cuff, and experience of the surgeon performing the opera tion. The duration of symptoms before surgery was the most significant pred ictor of outcome. Symptoms of prolonged duration were associated with an un satisfactory subjective result (P < .01) and with smaller improvements in t he parameters of the Constant score (P < .001). Recovery after arthroscopic subacromial decompression and eventual outcome were related to the extent of cuff damage. Patients with partial thickness tears or fraying of the cuf f had a delayed return to work (P < .001) and were found to have smaller in creases in the pain and range-of-motion scores (P < .05). A satisfactory su bjective result was most often associated with a positive impingement test (P < .05). Unsatisfactory outcomes were associated with a questionable diag nosis and lack of clear evidence of impingement at arthroscopy, inadequate decompression of the subacromial space, or the presence of calcium deposits in the rotator cuff.