Scoliosis is defined as a three-dimensional deformity of the spine characterized by lateral tilt and axial rotation of the vertebrae. Its magnitude in the frontal plane is identified by a Cobb angle greater than 10o.

The aim of the study was to systematically examine the clinimetric properties of the Spinal Appearance Questionnaire (SAQ) in its cross-cultural adaptations in different languages.

The research protocol has been registered in the International Prospective Registry of Systematic Reviews (PROSPERO) CRD42021250114. The databases Medline (PubMed), CINAHL, EMBASE, Science Direct, PsycINFO and WorldWideScience.org. Used for screening studies until July 16, 2022. Records on the development, evaluation and translations of the SAQ instrument with adolescents in idiopathic scoliosis were included in this review. In addition, two reviewers defined whether the studies were eligible, as well as analyzed their psychometric properties of Internal Consistency, Reliability, Content Validity, Cross-cultural Validity, Construct Validity and Structural Validity, according to Consensus-based Standards for the Selection of health Measurement Instruments (COSMIN). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE), recommendation of modified quality classification was applied for evidence synthesis.

95 articles were selected by title and abstract. After the removal of duplicates, complete reading and search in the references, there were 13 studies in this review. The original version of the SAQ was described in English and its analysis was made in 2 articles and the instrument was translated into Polish, Canadian French, Simple Chinese, Spanish (Europe), Danish, Traditional Chinese, Portuguese (Brazil), Korean, German, Turkish and Persian. The evidence was moderate for construct validity, low for internal consistency, very low for reliability and cross-cultural validity; the properties of content and structural validity did not present minimum data for classification.

The quality of the clinimetric properties of the SAQ instrument for patients with Adolescent Idiopathic Scoliosis was low, due to lack of clinical analysis properties or questionable methodological quality. However, we recommend the instrument for evaluating the self-perception of the spine in adolescents due to its own organizational characteristics, its most current translation in the language. The Persian version stood out from the others for its sample and organization of clearly demonstrated statistical tests, compatible with the general purpose of the research and strengthening the exposures of the measurement properties experienced.

We are cautious about using the questionnaire to measure self-image in adolescents with idiopathic scoliosis in clinical practice. Based on the analysis of the quality of the properties suggested by COSMIN, the Spinal Appearance Questionnaire presents dubious quality in general. The Persian version, perhaps because it is more current, complies with the proposed guidelines. We suggest that further translation and validation studies of the SAQ be based on current recommended guidelines.