SANE for instability as an alternative to the Rowe score.

BACKGROUND Several functional outcome scores have been proposed for the evaluation of shoulder instability. Most of these are multiple-item questionnaires which can be time consuming and difficult for patients to understand and well as lead to lack of compliance. The Single Assessment Numeric Evaluation (SANE) score is a single question which has recently gained widespread based on its simplicity and correlation with more complex scoring systems. The purpose of this study was to assess the correlation of a new modified version of the SANE score, the SANE-instability score, with the Rowe score post-treatment for shoulder instability. MATERIAL AND METHODS The authors prospectively evaluated a consecutive series of 253 patients (268 shoulders) treated surgically or non-operatively for shoulder instability between November 2017 and November 2019, for whom the Rowe and SANE-instability scores were collected before treatment and/or after treatment. The SANE-instability score was assessed with the following question: "What is the overall percent value of your shoulder if a completely stable shoulder represents 100%?". Correlations were tested using the Pearson's coefficient (r) and interpreted as very high (r=0.90-1.00), high (r=0.70-0.89), moderate (r=0.50-0.69), low (r=0.30-0.49) or negligible (r=0.00-0.29). Sub-group analyses were also performed to observe correlation variations according to follow-up length (before treatment and at 6, 12, 26, 52, and 104 weeks after treatment), patient age (<20, 20-29, 30-39 and ≥ 40 years) and type of treatment (non-operative, surgical). RESULTS The overall correlation between the SANE-instability and Rowe scores was high (r=0.85; p<0.001). Subgroup analyses revealed that the correlation between both scores was high before treatment (r=0.74), moderate at 6 and 12 weeks after treatment (r=0.66 and 0.57) and then high at 26, 52 and 104 weeks (r=0.75, 0.75 and 0.78) (p<0.001). The correlation was high across all types of treatment (r=0.76 to 0.85), high for patients older than 20 years (r=0.80 to 0.86) and very high for patients younger than 20 years (r=0.93) (p<0.001). CONCLUSION This study demonstrated a significant correlation between the SANE-instability and Rowe scores before and after treatment, as well as across all patient age groups and treatments. Owing to its high simplicity, the SANE-instability could be used as an alternative to the Rowe score for patient follow-up at various time points.