When seeing a patient with unexplained knee pain, it is imperative to examine and study the hip. Careful examination and maintaining notes on the patient's ability to walk and to perform daily functions will help determine when and if surgical treatment should be advised. Early consultation with an orthopedic surgeon will frequently be useful in determining whether an intertrochanteric osteotomy of the femur, a resurfacing operation of the hip, or a total hip replacement is indicated. From the orthopedist's point of view, it would be preferable to see the patient when at least 70 degrees of flexion is present. Although intertrochanteric osteotomy is rarely performed in the United States, it is the most common operation for uncomplicated coxarthrosis performed in Europe, and, when done at the right time, can provide the patient with an additional 10 to 15 years of use of his own hip. Resurfacing operations for the femoral head and acetabulum are valuable, if temporary, measures for treating arthritis in the younger patient; for the older patient, total hip replacement is preferred.