The Reliability of Commonly Used Radiographic Parameters in the Evaluation of the Pre-Arthritic Hip: A Systematic Review.

The radiographic parameter with the most metrological evidence in support of its reliability was the lateral center-edge angle (with 22 [100%] of 22 studies reporting acceptable reliability), whereas the Tönnis grade of osteoarthritis consistently demonstrated subpar interrater and intrarater reliability. Side-arm investigations for testing reliability may be needed by individual studies to prove the validity of data-pooling practices as collaborative endeavors continue to become more widespread.