The Belfast hip screener: from infancy to maturity.

Hip dislocation remains the most significant childhood orthopaedic abnormality despite the efforts of neonatal screening, first described in 1910. A new method of enhancing the performance of screening, the Belfast hip screener, is a non-invasive device developed to detect and interpret the vibrations ("clicks" and "clunks") which are emitted as the hips are physically tested. A progress report is presented covering ten years' work from early records made with tape recorders to modern methods of digital signal processing.