[Unusual secondary coxarthrosis and posterior coxarthrosis]

Certain atypical forms of osteoarthritis of the hip are misleading: forms with very severe pain, forms with pain predominantly in the sitting position, forms with disproportionate pain. These atypical features can sometimes be explained by certain anatomical arrangements: superomedial narrowing over an aggressive double line, posterior osteoarthritis of the hip which can only be demonstrated on a false lateral view in the form of posteroinferior narrowing with its corollaries: anterosuperior diastasis and marked osteophytes of the posterior horn appearing to advanced underneath the femoral head on the lateral view. These atypical forms frequently only last several months or years. Posterior osteoarthritis of the hip has a less severe and slower course than the usual forms with superior narrowing.