Cross-cultural adaptation and validation of the Musculoskeletal Tumor Society (MSTS) scoring system and Toronto Extremity Salvage Score (TESS) for musculoskeletal sarcoma patients in Greece

PurposeTo perform translation, cross-cultural adaptation, and validation of the Toronto Extremity Salvage Score (TESS) and Musculoskeletal Tumor Society (MSTS) scoring system in Greek patients with lower extremity sarcoma.MethodsThe Greek version of the MSTS for the lower extremity and TESS questionnaires was developed using previously reported methods. Included were 100 patients with musculoskeletal sarcoma who underwent limb salvage surgery. The test-retest reliability [interclass correlation coefficient (ICC) between 2 different time points], internal consistency (Cronbach's alpha), construct validity (Kaiser's criteria, Eigenvalue>1 rule), and external validity (Short form-36, Spearman's Rho) were assessed.ResultsThe test-retest reliability (ICC was 0.99 for MSTS-LE and 1 for TESS) and internal consistency were high (Cronbach's alpha was 0.763 for MSTS-LE and 0.924 for TESS) for both questionnaires. Based on the Scree plot, the number of factors retained was 1 for MSTS-LE and 2 for TESS. The TESS showed a strong correlation with SF-36 (Spearman's rho=0.714, p<0.001), but the correlation between MSTS for lower extremity and SF-36 was weak (Spearman's Rho=0.313, p=0.002).ConclusionsThe Greek version of both the MSTS for lower extremity and TESS questionnaire showed sufficient reliability, internal consistency and good performance using the loading factor analysis when used postoperatively in Greek patients who underwent surgical resection of lower extremity sarcoma. However, only the TESS showed strong correlation with the SF-36, indicating that MSTS for lower extremity was not as powerful for the evaluation of the global health status of these patients.