Identifying structural hip and knee problems. Patient age, history, and limited examination may be all that's needed.

A likely identification of a given structural disorder of the hip or knee can be suggested by the patient's age. In the hip, developmental dysplasia is usually found in infants, Legg-Calvé-Perthes disease in children of 4 to 10 years, slipped capital femoral epiphysis in somewhat older children, osteonecrosis in young to middle-aged adults, and degenerative joint disease and hip fracture in older adults. In the knee, Blount's disease is usually found in children aged 3 to 8, patellofemoral disease during the teens and early 20s, meniscal tears from the early teens through the mid-50s, ligament injuries from the teens to the 40s, and osteoarthritis throughout adulthood. With relatively little additional information, a useful diagnosis can be made so appropriate therapy can be started or referral made.