Clinical and radiographic analysis of Perthes deformity in the adolescent and young adult.

The residual deformity of Perthes disease can present with a wide variety of proximal femoral pathomorphology with associated intra- and extra-articular sources of pain. A systematic clinical and radiographic analysis is critical to understanding the deformity and identifying the source of pain. Groin pain and lateral hip pain are the most common complaints but patients can present with buttock, thigh, knee or even low back pain. Each location can suggest a different source of pain. Understanding the potential associated deformities can also help one identify the source of the clinical complaints as intra- or extra-articular. A thorough physical examination of the hip and lower extremities is critical and should include evaluation of the patient standing, supine, prone and in the lateral position. Each examination element can help link the clinical complaint to the underlying proximal femoral deformity. Radiographic evaluation should utilize a standard technique and the initial imaging should include an anteroposterior pelvis, lateral of the proximal femur and false-profile of the hip. Advanced imaging, including computed tomographic scans and gadolinium enhanced arthro-magnetic resonance imaging, can be helpful in delineating the three dimensional deformity and labral and articular cartilage injury. A thorough understanding of all three elements (clinical complaints, physical examination, radiographs) is critical to tailoring a treatment plan for the symptomatic patient with residual Perthes disease.