A validation of the Swedish version of the WORC index in the assessment of patients treated by surgery for subacromial disease including rotator cuff syndrome.

BACKGROUND: The Western Ontario Rotator Cuff Index (WORC) is a widely used instrument to measure quality of life in patients with subacromial pain or rotator cuff syndrome. The purpose of this study was to evaluate the psychometric properties of the Swedish version of the WORC for assessment of subacromial disease including rotator cuff syndrome treated by surgery. METHODS: A total of 65 patients were included in this study, mean age 60 years (range 36-82), 42% women, all were candidates for surgery for subacromial pain conditions at two orthopedic units during 2004-2006 and 2011-2012. Calculations of the validity of Pearson's correlation coefficient, floor and ceiling effects, reliability and responsiveness have formed the basis of assessment of the WORC index properties. WORC has been tested against Western Ontario Osteoarthritis of the Shoulder (WOOS), Oxford Shoulder Score and EQ-5D. An additional 49 patients, mean age 64 years (range 36-74) 20% of whom were women, were analyzed in a WORC test-retest with ICC and also correlated to Constant-Murley Score. RESULTS: The validity analysis of WORC showed high correlations with both the specific and the generic health measurement instrument. The reliability calculations of the WORC resulted in ICC = 0.97 and Cronbach's alpha = 0.97. Responsiveness was also excellent for WORC with Effect size = 1.35 and Standardized Response mean = 1.01. We found that the WORC showed a strong correlation with the WOOS (0.97) and the Constant-Murley Score (0.85). A good correlation was found with the Oxford Shoulder Score (0.74) and the EQ-5D (0.71). CONCLUSIONS: The Swedish version of WORC can be considered reliable, valid and responsive for use as an assessment of outcome and a health measurement instrument for patients treated by surgery for subacromial disease including rotator cuff syndrome.

Similar results comparing early and late surgery in open repair of traumatic rotator cuff tears.

PURPOSE: The purpose was to investigate whether surgical repair earlier or later than 3 months after injury may result in similar outcomes and patient satisfaction. METHODS: Seventy-three patients (75 shoulders, 58 males, mean age 59) who had undergone surgical intervention for traumatic rotator cuff tears from 1999 to 2011 were assessed by MRI, clinical examination and Western Ontario Rotator Cuff Index (WORC) as a primary outcome measure and Oxford Shoulder score (OSS), Constant-Murley score (CS) and EQ-5D as secondary. The patients treated less than 3 months after injury (n = 39) were compared with patients treated more than 3 months after injury (n = 36). The average follow-up time was 56 months (range 14-149), and the average time from injury to repair for all patients was 16 weeks (range 3-104). A single senior radiologist performed a blinded evaluation of all the MRIs. Rotator cuff integrity, presence of arthritis, fatty degeneration and muscle atrophy were evaluated. RESULTS: No differences were found for any of the assessed outcomes (WORC, OSS, CS and EQ-5D) between the two groups. The mean WORC % was 77 % for both groups. Re-tear frequency was 24 %, nine in both groups. Patients with re-tear reported less satisfaction with their outcome. CONCLUSIONS: The surgical treatment of symptomatic traumatic rotator cuff tears repairable later than 3 months after injury yields a good functional outcome, a high level of subjective patient satisfaction, and at the same level for patients receiving earlier treatment. Based on our findings, surgical repair could be encouraged whenever technically possible. LEVEL OF EVIDENCE: Retrospective Comparative Study, Level III.