Individuals with spina bifida commonly have hip instability or dislocation as the muscles on one side of the joint may pull strongly while the other side pulls weakly or not at all. This is due to the fact that hip flexors and adductors are controlled primarily by L1 and L2 level nerves, whereas hip extensors and abductors are controlled primarily by nerves at levels L5 to S1.
The main concern about the dislocated hip is not the effects on walking, but rather the development of asymmetric (uneven) hips which causes the pelvis to lie at an angle. The development of pelvic tilt can make seating difficult, predispose an individual to pressure sores, and lead to Scoliosis.
It is beneficial to intervene early with physical therapy in order to prevent hip contractures. This occurs when the strong muscles cannot be stretched back to their normal position, and the joint cannot be straightened. A Pavlik harness, worn during sleep, may also be helpful for children up to 2 years of age to encourage the joint to develop a normal shape.
Some children with spina bifida are born with clubbed feet, which cause the child's feet to point down and inwards. It is important to make sure that the feet are well aligned when a child is ready to stand and walk (with or without braces). An orthopedic surgeon or physiotherapist may put casts on a baby's feet to correct or partially correct their position. Sometimes surgery is required.
Any muscle imbalance around the spine affects the position of the vertebrae and can produce an abnormal spinal curve. Such a curve may make it difficult to sit or stand comfortably. There are 3 types of abnormal spinal curves:
- Lordosis - a hollow in the low back,
- Kyphosis - excessive rounding of the upper back,
- Scoliosis - a bend to the side.
Congenital scoliosis (present at birth) occurs in around 15-25 percent of newborns with spina bifida, most commonly those with thoracic level lesions and associated vertebral abnormalities. Paralytic scoliosis (that which develops after birth) usually has a gradual onset between the ages of five and nine years, although it may arise for the first time in the second decade of life. The degree of scoliosis may be stable or progress slowly initially but has the potential to increase rapidly, especially during puberty.
Although mild scoliosis can be quite insignificant to the overall function and health of the child, more severe scoliosis can have dire consequences:
- increase in pressure on the ischium (the sit bone), can cause severe pressure sores to develop
- interference with mobility by making walking more inefficient or even impossible
- can cause back pain
- respiratory compromise - chest wall can become so misshapen that it dangerously restricts the capacity of the lungs
The management of scoliosis aims to preserve symmetry and prevent progression. For rapidly progressing scoliosis or curves in excess of 45 degrees, surgery may be considered. For slowly progressive curves under 45 degrees, it is generally possible to manage the problem with bracing. In many cases, this will be sufficient to prevent progression or to allow the child to reach the age of 9-12 years before surgery is necessary.
For more information, see our Scoliosis links