Mid-term results after arthroscopic subacromial decompression (ASD) with special focus on the bias due to an application to social insurance for pension

The objective was to evaluate mid-term results after arthroscopic subacromi al decompression (ASD) with special focus on the bias due to an application to social insurance for pension based on sickness disability. The study group consisted of 42 patients (28 male, 14 female). ASD was perf ormed in 1993 or 1994 for impingement stage II. The mean age was 49,5 years . Thirty-nine patients (93%) were evaluated by an independent observer for an average followup of 3,5 years (range 1.5-5). Patients satisfaction with the outcome was assessed by a visual analog scale graded from 0 (extremely dissatisfied) to 10 (extremely satisfied). The functional result was assess ed using the Constant score. At follow-up the mean VAS value was 6,4+/-3,4. The Constant score improved from 49,6+/-18,5 to 84,8+/-14,3. The subgroup of patients having applied to social insurance for pension had significantly worse results compared with the remaining patients: VAS: 4,9+/-3,1 vs. 7,5+/-3,1; Constant-Score: 76,1 +/-12,7 vs. 88,3+/-13,5. The fact that patients try to get benefit from social insurance based on si ckness disability significantly biased the outcome after ASD.