Legg-Calvé-Perthes syndrome
Overview
Legg–Calvé–Perthes syndrome is a degenerative disease of the hip joint, where a add/loss of bone mass leads to some degree of collapse of the hip joint, that is, to deformity of the ball of the femur and the surface of the hip socket. The disease is typically found in young children and small dogs, and it can lead to osteoarthritis in adults. The effects of Perthes can also sometimes continue into adulthood.
Symptoms
Symptoms are hip, knee, or groin pain, exacerbated by hip/leg movement. The pain feels like a tooth ache, possibly severe. There is a reduced range of motion at the hip joint and a painful or antalgic gait. There may be atrophy of thigh muscles from disuse and an inequality of leg length. In some cases, some activity can cause severe irritation or inflammation of the damaged area including standing, walking, running, kneeling, or stooping repeatedly for an extended period of time. The first signs are complaints of soreness from the child, which are often dismissed as growing pains, and limping or other guarding of the joint, particularly when tired. The pain is usually in the hip, though can also be felt in the knee (so-called 'referred pain'). In some cases, pain is felt in the unaffected hip and leg.[citation needed] This is due to the child favoring the injured side and placing the majority of the weight on the "good" leg. It is predominantly a disease of boys (4:1 ratio). Whereas Perthes is generally diagnosed between 5 and 12 years of age, it has been diagnosed in children as young as infants. Typically the disease is only seen in one hip, bilateral perthes is seen in about 8-10% of children diagnosed.
Causes
The direct cause is a reduction in blood flow to the joint. It is thought that the artery of the ligamentum teres femoris closes too early, not allowing time for the medial circumflex femoral artery to take over.[citation needed]Genetics does not appear to be a determining factor, though it may be involved. Some evidence suggests that parental smoking may be a factor, though this is not yet proven, or more recently that a deficiency of some blood factors used to disperse blood clots may lead to blockages in the vessels supplying the joint, but that, too, has not been proven.
Diagnosis
X-Rays of the hip joint are absolutely necessary. X-rays will show a small, flattened and fragmented head of femur. A bone scan may be useful in helping determine the extent of the avascular changes. A hip aspiration may be performed if there is suspicion of a septic arthritis. Diagnosis is made predominantly by X-ray study, together with physical examination (MRIs have also been found useful for judging the extent of the deformity). Sufferers typically have limited range of motion in their hip, particularly when rotating the joint.
Prognosis
Children younger than 6 or 7 have the best prognosis since they have time for the dead bone to revascularize and remodel. Children that have been diagnosed with Perthes' Disease after the age of 10 are at a very high risk of developing osteoarthritis and Coxa Magna.
Treatment
The goal of treatment is to avoid severe degenerative arthritis. Orthopedic assessment is crucial. Younger children have a better prognosis than older children. Treatment has traditionally centered on removing pressure from the joint until the disease has run its course. Options have included bed rest and traction (to separate the femur from the pelvis and reduce wear), often for several months or even years, this practice has long since been abandoned since there was no evidence to show that it made any difference to the long term prognosis. Plaster casts were also popular, again to isolate the joint. Recent evidence suggests that these methods are not effective, and treatment seems to be moving towards a mixture of careful monitoring, physiotherapy, and surgical intervention when necessary.To maintain activities of daily living, a custom orthoses may be used. These devices internally rotate the femoral head and abduct the leg(s) at 45 degrees. Orthoses can start as proximal as the lumbar spine (LSO),and extend the length of the limbs to the floor. Most functional bracing is achieved using a waist belt and thigh cuffs derived from the Scottish-Rite Orthosis [2]. These devices are typically prescribed by a physician and implemented by a certified orthotist. For older children, the distraction method has been found to be a successful treatment by using an external fixator which relieves the hip from carrying the body's weight. This allows room for the top of the femur to regrow and shape better. Many children need no intervention at all and are simply asked to refrain from contact sports or games which impact the hip, The Perthes Association have a "library" of equipment which can be borrowed to assist in keeping life as normal as possible, newsletters and a helpline and events for the families help children and parents to feel less isolated. Modern treatment focuses on removing pressure from the joint in concert with physiotherapy. Pressure is minimized on the hip through use of crutches or a cane, and the avoidance of running-based sports. Swimming is highly recommended - it allows exercise of the hip muscles with the full range of motion, while reducing the stress to a minimum. Physiotherapy treatment generally involves a daily series of exercises, with weekly meetings with a physiotherapist to monitor progress. These exercises focus on improving and maintaining a full range of motion of the femur within the hip socket. Performing these exercises during the healing process is essential to ensure that the femur and hip socket have a perfectly smooth interface. This will minimize the long term effects of the disease. Perthes is a long-term problem - treatment is aimed at minimizing damage while the disease runs its course, not at 'curing' the disease. As sufferers age, problems in the knee and back can arise secondary to abnormal posture and stride adopted to protect the affected joint. The condition is also linked to arthritis of the hip and other joints, though this appears not to be an inevitable consequence. Hip replacements are relatively common as the already damaged hip suffers routine wear; this varies by individual, but generally is required any time after age 50.