Combining orthopaedic special tests to improve diagnosis of shoulder pathology.

The use of orthopedic special tests (OSTs) to diagnose shoulder pathology via the clinical examination is standard in clinical practice. There is a great deal of research on special tests but much of the research is of a lower quality implying that the metrics from that research, sensitivity, specificity, and likelihood ratios, is likely to vary greatly in the hands of different clinicians and in varying practice environments. A way to improve the clinical diagnostic process is to cluster OSTs and to use these clusters to either rule in or out different pathologies. The aim of the article is to review the best OST clusters, examine the methodology by which they were derived, and illustrate, with a case study, the use of these OST clusters to arrive at a pathology-based diagnosis.