Objective

The Western Ontario Shoulder Instability Index (WOSI) is a specific self-questionnaire which measures the functional impact during patients’ everyday life activities in order to evaluate the therapeutic care face to a chronic scapula-humeral instability. In his original version in English, it is valid, reliable and sensible to change. The goal of this study is to translate and culturally adapt the original algo-functional score WOSI in French and to evaluate metrological quality of this version with patients suffering of chronic instability after scapula-humeral luxation.

Material/patients and methods

The WOSI has been translated and culturally adapted in French according to recommendations. Several groups were constituted (Non-operated group [NOG], Operated group [OG], TotG = NOG + OG, PPOG: chronic shoulder instability during pre- and postoperation, and TémG: control group) in order to analyze built version’s validity by comparing WOSI French version to Rowe, WalchDuplay, QuickDASH scores, and Visual Analogical Scale (VAS) pain; and reliability by the reproducibility and the internal consistency.

Results

WOSI French version was done and accepted by an expert group ( n = 7). There was a significant correlation between the WOSI and the different algo-functional scores for GTot, for GO and for GNO (except for VAS pain and QuickDASH for the last group); correlation between the WOSI and the VAS pain was also significant ( r = 0.48 P < 0.01). The reproducibility ( n = 27) was good: the Intra-Class Correlation (ICC) for the total score was 0.88 (IC 95%: 0.47–0.98), variating from 0.80 to 0.94 including the 4 domains and from 0.70 to 0.94 for the different items separately. The Cronbach alpha was 0.953. As for TotG, the Standard Error Measure (SEM) and the Minimal Detectable Change (MDC) was respectively 12.2 (5.7%) and 333 (15.9%).

Discussion–Conclusion

WOSI French version is disponible, culturally adapted and translate, validate and reliable. We suggest to use it for the follow up of patient with chronic scapula-humeral instability.