Legg-Calvé-Perthes disease (LCPD) is a pediatric hip disorder where the blood supply to the femoral head is temporarily interrupted. This interruption causes avascular necrosis (bone tissue death), leading to a period of bone breakdown and subsequent re-growth and healing. Although the disease resolves in childhood, the temporary loss of blood flow permanently alters the shape of the femoral head. These structural changes are the primary drivers of long-term orthopedic consequences that emerge in adulthood, defining the adult experience and affecting mobility decades later.
Residual Deformity in the Adult Hip
The orthopedic issues faced by adults who had LCPD are rooted in structural changes from the childhood healing phase. The femoral head often loses its spherical shape, becoming flattened, a condition known as coxa plana. Simultaneously, the head of the femur may widen or enlarge (coxa magna), affecting how the ball fits into the hip socket.
These changes result in joint incongruity, meaning the ball and socket no longer fit together smoothly. This mismatch causes abnormal contact forces and friction during hip movement. The neck of the femur can also become relatively shortened (coxa breva), and the greater trochanter may overgrow, altering muscle mechanics. These accumulated deformities create a hip joint vulnerable to premature wear and tear.
Lifetime Risk of Osteoarthritis and Joint Replacement
The residual deformities established in childhood make the affected hip highly susceptible to developing secondary osteoarthritis (OA) in adulthood. This degenerative process is accelerated because the incongruent joint surfaces grind against each other, causing the articular cartilage to wear away much faster than normal. The severity of the initial Perthes disease and the final shape of the femoral head are the strongest predictors of the long-term risk of developing OA.
The onset of symptomatic arthritis is often premature, frequently beginning in a person’s 30s, 40s, or 50s, which is decades earlier than typical primary OA. In one study, the average age for patients requiring a total hip arthroplasty (THA) was found to be as young as 37.8 years. This surgical intervention becomes necessary when pain and functional decline from OA become severe and non-responsive to conservative management.
Total hip arthroplasty (THA) in this patient group is technically challenging due to the unique, non-standard anatomy of the healed hip. Surgeons must navigate the enlarged and misshapen femoral head, a potentially shortened femoral neck, and bone changes resulting from previous childhood surgeries. Despite these complexities, THA offers a highly effective solution for pain relief and functional improvement. However, requiring THA at a younger age means the patient may require a revision surgery later in their lifetime.
Managing Functional Limitations and Chronic Pain
The anatomical changes in the hip translate directly into significant limitations in daily life function and chronic pain for adults. Common issues include a reduced range of motion, particularly in hip rotation and flexion, which can make simple tasks like putting on socks or tying shoes difficult. Many adults experience a persistent limp, often referred to as an antalgic or Trendelenburg gait, and struggle with activities that require sustained weight-bearing, such as standing or walking for long periods.
Management of chronic hip pain often involves a multi-faceted approach distinct from surgical treatment.
- Non-steroidal anti-inflammatory drugs (NSAIDs) can manage pain and inflammation during flare-ups.
- Physical therapy focuses on strengthening surrounding muscles to improve stability and preserve flexibility.
- Maintaining a healthy body weight is recommended to minimize stress on the compromised joint.
- Low-impact exercises, such as swimming or cycling, help keep the joint mobile without excessive impact.
Secondary Conditions Related to Gait Alterations
The altered biomechanics of the hip joint often lead to compensatory issues in the musculoskeletal system. The persistent limp or altered gait pattern (such as a Trendelenburg gait) causes an uneven distribution of forces throughout the body. This uneven loading can lead to premature wear and strain on the contralateral joints.
The knee and ankle on the affected side, as well as the opposite hip and knee, may experience increased stress as the body attempts to stabilize movement. A common finding is a limb length discrepancy, where the affected leg is shorter. This difference forces the pelvis to tilt, contributing to muscle imbalances and chronic strain, potentially causing discomfort in the lower back and sacroiliac joints. Addressing these secondary conditions, often through physical therapy and orthotic shoe lifts, is necessary.