Accuracy of Clinical and Imaging Tests for the Diagnosis of Hip Dysplasia and Instability: A Systematic Review

BACKGROUND: Evidence concerning the accurate clinical or imaging methods to diagnose hip instability or hip dysplasia is currently scarce. OBJECTIVE: To summarize the diagnostic accuracy of clinical and imaging tests for the diagnosis of hip dysplasia and instability. METHODS: A computer-assisted literature search of the MEDLINE, CINAHL, and Embase databases, using key words related to diagnostic accuracy of the hip joint, was conducted on March 6, 2018. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used for the searching and reporting phases of the study. Quality assessment of bias and applicability was conducted using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Diagnostic accuracy, including sensitivity, specificity, likelihood ratio, and 95% confidence interval, was summarized. RESULTS: Out of 3109 citations, 7 articles were included. Two studies reported on 5 clinical tests for hip instability and 5 studies reported on 5 radiographic measures for hip dysplasia. Only 1 study was not of low methodological quality. The prone instability test moderately improved positive posttest probability by 38% to diagnose hip instability. The Shenton line moderately to highly improved posttest probability by 41% to 60% to diagnose hip dysplasia. CONCLUSION: This systematic review summarizes the diagnostic accuracy of various clinical tests and radiographic measures for hip instability and hip dysplasia. Further high-quality studies are necessary to examine the diagnostic accuracy of the clinical examination and radiography to assist in ruling in or ruling out the diagnoses of hip dysplasia and instability. Consensus is required to standardize the definitions of these diagnoses and their reference standards. The study was registered with the International Prospective Register of Systematic Reviews (CRD42018089019).