1.3 Hip disorders

Developmental hip dislocation, commonly called congenital hip dislocation, refers to a partially or completely displaced femoral head in relation to the acetabulum. It is estimated that it occurs six times more often in females than in males, it may be bilateral or unilateral, incurring most often in the left hip.

Generally, the acetabulum is shallower on the af­fected side than on the nonaffected side, and the fem­oral head is displaced upward and backward in rela­tion to the ilium. Ligaments and muscles become deranged, resulting in a shortening of the rectus femoris, hamstring, and adductor thigh muscles and af­fecting the small intrinsic muscles of the hip. Pro­longed malpositioning of the femoral head produces a chronic weakness of the gluteus medius and mini­mus muscles. A primary factor in stabilizing one hip in the upright posture is the iliopsoas muscle. In de­velopmental hip dislocation, the iliopsoas muscle serves to displace the femoral head upward- this will eventually cause the lumbar vertebrae to become lordotic and scoliotic.

Detection of the hip dislocation may not occur until the child begins to bear weight or walk. The child walks with a decided limp in unilateral cases and with a waddle in bilateral cases. No discomfort or pain is normally experienced by the child, but fatigue tolerance to physical activity is very low. Pain and discomfort become more appar­ent as the individual becomes older and as postural deformities become more structural.

Medical Treatment. Medical treatment of the developmental hip disloca­tion depends on the age of the child and the extent of displacement. Young babies with a mild involve­ment may have the condition remedied through gradual adduction of the femur by a pillow splint, whereas more complicated cases may require trac­tion, casting, or operation to restore proper hip con­tinuity. The thigh is slowly returned to a normal po­sition.

Therapeutic Treatment. Active exercise is suggested along with passive stretching to contracted tissue. Primary concern is paid to reconditioning the movement of hip exten­sion and abduction. When adequate muscle strength has been gained in the hip region, a program of ambulation is conducted, with particular attention paid to walking without a lateral pelvic tilt.

A child in the adapted physical education or ther­apeutic recreation program with a history of devel­opmental hip dislocation will, in most instances, re­quire specific postural training, conditioning of the hip region, continual gait training, and general body mechanics training. Swimming is an excellent activity for general conditioning of the hip, and it is highly recommended

Activities should not be engaged in to the point of discomfort or fatigue.

1.4 Coxa plana (legg-perthes disease)

Coxa plana is the result of osteochrondritis dissecans, or abnormal softening, of the femoral head. Its gross signs reflect a flattening of the head of the femur, and it is found predominantly in boys between the ages of 3 and 12 years. The exact cause of coxa plana is not known; trauma, infection, and endocrine imbalance have been suggested as possible causes.

Coxa plana is characterized by degeneration of the capital epiphysis of the femoral head. Osteoporosis, or bone rarefaction, results in a flattened and de­formed femoral head. Later developments may also include widening of the femoral head and thickening of the femoral neck. The last stage of coxa plana may be reflected by a self-limiting course in which there is a regeneration and an almost complete return of the normal epiphysis within 3 to 5 years. However, recovery is not always complete, and there is often some residual deformity present. The younger child with coxa plana has the best prognosis for complete recovery.

The first outward sign of this condition is often a limp favoring the affected leg, with pain referred to the knee region. Further investigation by the physi­cian may show pain upon passive movement and re­stricted motion upon internal rotation and abduction. X-ray examination will provide the definitive signs of degeneration. The physical educator or therapist may be the first person to observe the gross signs of coxa plana and bring it to the attention of parents or phy­sician.

Medical Treatment. Treatment of coxa plana primarily entails the removal of stress placed on the femoral head by weight bear­ing. Bed rest is often employed in the acute stages, with ambulation and non-weight-bearing devices used for the remaining period of incapacitation. The sling and crutch method for non-weight bearing is widely used for this condition.

Weight-bearing exercise is contraindicated until the physician discounts the possibility of a pathological joint condition.

Therapeutic Treatment. The individual with an epiphyseal affection of the hip presents a problem of muscular and skeletal stability and joint range of movement. Stability of the hip re­gion requires skeletal continuity and a balance of muscle strength, primarily in the muscles of hip ex­tension and abduction. Prolonged limited motion and non-weight bearing may result in contractures of tissues surrounding the hip joint and an inability to walk or run with ease. Abnormal weakness of the hip extensors and abductors causes the individual to display the Trendelenburg sign.

A program of exercise must be carried out to pre­vent muscle atrophy and general deconditioning. When movement is prohibited, muscle-tensing exer­cises for muscles of the hip region are conducted, together with isotonic exercises for the upper ex­tremities, trunk, ankles, and feet.

When the hip becomes free of symptoms, a pro­gressive isotonic, non-weight-bearing program is first initiated for the hip region. Active movement emphasizing hip extension and abduction is recom­mended. Swimming is an excellent adjunct to the regular exercise program.

The program of exercise should never exceed the point of pain or fatigue until full recovery is accom­plished. A general physical fitness program emphasiz­ing weight control and body mechanics will aid the student in preparing for a return to a full program of physical education and recreation activities.

Principles described in the opening section of this chapter may be applied to persons with coxa plana to include them in games and sports. To the greatest extent possible, children with coxa plana should be taught activities that parallel those of nonhandicapped children.