Subacromial Decompression in Patients with Impingement Syndrome Results in Better Clinical Outcome Compared to Physiotherapy in the Long Term. A Prospective Randomised Study

OBJECTIVES: The long-term outcome after treatment of subacromial impingement syndrome (SAIS) with either non-surgical or surgical methods is not thoroughly investigated. The purpose of this study was to evaluate the long-term clinical outcome, the presence of rotator-cuff injuries and osteoarthritis after both surgical and non-surgical treatment. METHODS: Eighty-seven patients with SAIS were randomised to three groups: open acromioplasty (OSG), arthroscopic acromioplasty (ASG) or physiotherapy (PTG). The Constant score and the Watson & Sonnabend score were used as outcome measures. Furthermore, bilateral ultrasound examinations to detect rotator-cuff ruptures and bilateral x-rays to detect osteoarthritis were performed. Sixty-six patients (76%) attended the clinical follow-up, 14 (SD 1.5) years after the initial treatment. RESULTS: The groups were demographically comparable at baseline. The Constant score had improved significantly at follow-up in both the OSG and the ASG (p=0.003 and 0.011 respectively). No improvement was detected in the PTG. The OSG revealed a significant improvement compared to the PTG at follow-up (p=0.011), otherwise no significant differences were found. For the Watson & Sonnabend score the OSG revealed significant improvement in 13/14 questions. The corresponding was found in the ASG and the PTG in 9/14 questions (p=0.14). Using ultra-sound 1/20 patients in the OSG revealed a full-thickness rotator cuff rupture on the index side. The corresponding was found for 1/18 in the ASG and 4/28 in the PTG (p=0.29). On the contralateral side 2/20 patients in the OSG revealed a full-thickness rotator cuff tear. The corresponding was found for 1/18 in the ASG and 4/28 in the PTG (p=0.36). On the x-rays 3/20 patients in the OSG revealed moderate or severe osteoarthritis in the index shoulder. The corresponding was found for 1/18 in the ASG and 0/28 in the PTG (p=0.12). 1/20 patients in the OSG revealed osteoarthritis in the contra-lateral shoulder. The corresponding was found for 1/18 in the ASG and 0/28 in the PTG (p=0.11). CONCLUSION: In the long term surgical treatment of SAIS appears to render better clinical results than physiotherapy. No significant differences were found between the groups in terms of the presence of full thickness rotator cuff ruptures and osteoarthritis.