There are three major types of childhood hip problems that can lead to arthritis in adult years:
- Developmental dysplasia of the hip (DDH)
- Perthes disease
- Slipped capital femoral epiphysis (SCFE)
Each of these diseases develops early on in life. DDH is present at birth and is usually diagnosed at that time or within the first year of life. Perthes disease presents as hip pain or a limp between ages 3 and 8 years. Slipped capital femoral epiphysis occurs in young adolescents between ages 11 and 14 years. All of these diseases may be treated successfully during childhood years but may then cause symptomatic arthritis later on. After treatment, patients may have normal function with little or no pain until early adult years or middle age. Some may have a limp or a residual rotation of the leg. Most patients, however, are active and participate in sports and athletic activities well into their adult years.
As with other forms of arthritis, the time to consider surgery is when you can no longer tolerate the pain. Disease may be unilateral or bilateral if both hips were affected by the disease. Surgery in these situations may be more complicated because of the residual anatomic deformity. In DDH, the hip joint socket may be relatively high and shallow. The hip may be dislocated and form a false socket above the normal anatomic level. The femoral canal may be small and narrow.
The angle of the femoral neck (anteversion) may be abnormally high. Custom components may be needed in these sit-uations. Additional reconstruction, such as shortening of the femur to bring the hip back to its natural socket, may be necessary. In Perthes disease, the femoral head may be wide and flat, and the neck of the femur may be unusually large. The acetabulum may be deformed to accommodate the abnormal shape of the femoral head. All of these changes need to be considered when the surgeon plans his procedure. In SCFE the femoral neck may be deformed and sometimes rotated backward (retroverted).
Patients with this disease may turn their leg outward or have an external rotation gait. They have frequently undergone a surgical procedure such as pinning or osteotomy as part of treatment for the disease. Both the deformity and the hardware are factors when surgery is planned. While the symptoms of these diseases are similar to those of osteoarthritis, hip replacement can be more challenging due to the variable anatomy.