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Developmental
dysplasia of the hip (formerly congenital dislocation of the hip):
Dysplasia is abnormal development of the hip joint, leading to subluxation or dislocation. It is more common among infants with breech presentation, especially females. It seems to result from laxity of the ligaments around the joint or from in utero positioning. Dysplasia can be unilateral or bilateral. Asymmetric skin creases in the thigh and groin are common, but such creases also occur in infants without hip dysplasia. If dysplasia remains undetected and untreated, the affected leg eventually becomes shorter, and the hip may become painful. Abduction of the hip is often impaired, due to adductor spasm.
Two screening procedures commonly are used. In the Ortolani maneuver, the thigh of the hip being tested is abducted and gently pulled anteriorly. Instability is indicated by the palpable, sometimes audible, clunk of the femoral head moving over the posterior rim of the acetabulum and relocating in the cavity. Next, in the Barlow maneuver, the hip is adducted while the thigh is pushed posteriorly. A clunk indicates that the head of the femur is moving out of the acetabulum. Also, a difference in knee height when the child is prone with hips flexed, knees bent, and feet on the examining table (Galeazzi sign) suggests dysplasia, especially unilateral. Somewhat later, subluxation or dislocation is indicated by inability to completely abduct the thigh when the hip and knee are flexed; abduction is impeded by adductor spasm, which is often present even if the hip is not actually dislocated at the time of examination. Minor benign clicks are commonly detected. Although clicks usually disappear within 1 or 2 mo, they should be checked regularly. Because bilateral dysplasia may be difficult to detect at birth, periodic testing for limited hip abduction during the 1st year of life is advised.
All female neonates who were in breech position require ultrasonography of the hips to rule out dysplasia. For all other infants, imaging is required when any abnormality is suspected during examination. Hip ultrasonography can accurately establish the diagnosis early. Hip x-rays are helpful after the bones have started to ossify, typically after age 3 or 4 mo.
Early treatment is critical. With any delay, the potential for correction without surgery decreases steadily. The hip usually can be reduced immediately after birth, and with growth, the acetabulum can form a nearly normal joint. Treatment is with devices, most commonly the Pavlik harness, which holds the affected hips abducted and externally rotated. The Frejka pillow and other splints may help. Padded diapers are not effective.
Femoral
torsion (twisting):
The femoral head may be twisted. Torsion may be either internal (femoral anteversion; knees pointing toward each other with toes in) or external (femoral retroversion; knees pointing in opposite directions) and is common among neonates. At birth, internal torsion can be as much as 40° and still be normal. External torsion can also be prominent at birth and still be normal.
Children with internal torsion may regularly sit in the W position or sleep in a prone position with legs extended or flexed and internally rotated. These children probably assume this position because it is more comfortable. The W sitting position was thought to worsen the torsion, but there is little evidence that the position should be discouraged or avoided. By adolescence, internal torsion tends to gradually decrease to about 15° without intervention.
External torsion may occur if in utero forces result in an abduction or external rotation soft-tissue positioning. If external torsion is prominent at birth, a thorough check (including x-rays or ultrasonography) for hip dislocation is indicated. External torsion typically corrects spontaneously, especially after children begin to stand and walk, but orthopedic referral is needed when excessive torsion persists after 8 yr.
Genu varum
and valgum:
The 2 major types of knee or femoral-tibial angular deformities are genu varum (bowlegs) and genu valgum (knock-knees). Untreated, both can cause osteoarthritis of the knee in adulthood.
Genu varum is common among toddlers and usually resolves spontaneously by age 18 mo. If it persists or becomes more severe, Blount disease (progressive tibial osteochondrosis) should be suspected. Early diagnosis of Blount disease is difficult, because x-rays may be normal. Rickets also should be ruled out. Early use of a Danish night splint can be effective, but osteotomy is often needed.
Genu valgum is less common and, even if severe, usually resolves spontaneously by age 9 yr. Skeletal dysplasia or hypophosphatasia should be excluded. If marked deformity persists after age 10 yr, surgical stapling of the medial distal femoral epiphysis is indicated.
Knee
dislocation:
Anterior knee dislocation with hyperextension is rare at birth but requires emergency treatment. It may occur with Larsen's syndrome, which consists of multiple congenital dislocations (eg, elbows, hips, knees), clubfoot, and characteristic face (eg, prominent forehead, depressed nasal bridge, wide-spaced eyes) or with arthrogryposis (see Congenital Craniofacial and Musculoskeletal Abnormalities: Arthrogryposis Multiplex Congenita). The dislocation may be related to muscle imbalance (if myelodysplasia or arthrogryposis is present) or intrauterine positioning. Ipsilateral hip dislocation often coexists.
If the infant is otherwise normal, immediate treatment with daily passive flexion movements and splinting in flexion usually results in a functional knee.
Tibial
torsion:
Tibial torsion can be external (lateral) or internal (medial) twisting. External torsion occurs normally with growth: from 0° at birth to 20° by adulthood. External torsion is rarely a problem. However, tibial bowing with a narrow sclerotic intramedullary canal (Blount disease), seen on x-ray, has a high risk of fracture and pseudarthrosis and requires a protective orthosis. Tibial bowing also may be due to rickets.
Internal torsion is common at birth, but it typically resolves with growth. However, an excessive degree of torsion may indicate a neuromuscular problem. Persistent, excessive torsion can lead to toeing-in and bowlegs.
Talipes
equinovarus:
Sometimes called clubfoot, talipes equinovarus is characterized by plantar flexion, inward tilting of the heel (from the midline of the leg), and adduction of the forefoot (medial deviation away from the leg's vertical axis). It results from an abnormality of the talus. It occurs in about 2 of every 1000 births, is bilateral in up to 50% of affected children, and may occur alone or as part of a syndrome. Deformities that result from in utero positioning can be distinguished from talipes equinovarus clubfoot because they can be easily corrected passively.
Treatment requires orthopedic care, which consists initially of repeated cast applications, taping, or use of malleable splints to normalize the foot's position. If casting is not successful and the abnormality is severe, surgery may be required. Optimally, surgery is done before 12 mo, while the tarsal bones are still cartilaginous.
Talipes
calcaneovalgus:
The foot is flat or convex and dorsiflexed, with the heel turned outward. The foot can easily be approximated against the lower tibia. Early treatment with a cast (to place the foot in the equinovarus position) or with corrective braces is usually successful.
Metatarsus
adductus:
The forefoot turns toward the midline. The foot may be supinated at rest. Usually, the foot can be passively abducted and everted beyond the neutral position when the sole is stimulated. Occasionally, an affected foot is rigid, not correcting to neutral. The deformity usually resolves without treatment during the 1st year of life. If it does not, casting or surgery (abductory midfoot osteotomy) is required.
Metatarsus
varus:
The plantar surface of the foot is turned inward, so that the arch is raised. This deformity usually results from in utero positioning. It typically does not resolve after birth and may require corrective casting.
Last full review/revision November 2005
Content last modified November 2005
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