Developmental issues occur when growth ceases or progresses incorrectly.
These issues include:
- Blount’s disease
- Gait abnormalities
- Leg length inequalities
- Rotational deformities of the limbs
Blount’s disease: Blount’s disease is a growth disorder of the shin bone (tibia) in which the lower leg turns inward, resembling a bowleg. Blount’s disease occurs in young children and adolescents. The cause is unknown but is thought to be due to the effects of weight on the growth plate. The inner part of the shin bone, just below the knee, fails to develop normally. Unlike bowlegs, which tend to straighten as the child develops, Blount’s disease slowly gets worse. It can cause severe bowing of one or both legs. Braces are used to treat children who develop severe bowing before the age of 3. If braces do not work, or if the problem is not diagnosed until the child is older, surgery is usually required. Surgery may involve cutting the shin bone to place it in the proper position and sometimes lengthen it. Other times, the growth of the outer half of the shin bone can be restricted. This is done with surgery and allows the child’s natural growth to reverse the bowing process. This second, much smaller surgery is most effective in children with less severe symptoms who still have quite a bit of growing to do.
Gait abnormalities: The pattern of how a person walks is called the gait. Many different types of walking problems occur without a person’s control. Most, but not all, are due to some physical condition. Some walking abnormalities have been given names:
- Propulsive gait: a stooped, stiff posture with the head and neck bent forward
- Scissors gait: legs flexed slightly at the hips and knees like crouching, with the knees and thighs hitting or crossing in a scissors-like movement
- Spastic gait: a stiff, foot-dragging walk caused by a long muscle contraction on one side
- Steppage gait: foot drop where the foot hangs with the toes pointing down, causing the toes to scrape the ground while walking, requiring someone to lift the leg higher than normal when walking
- Waddling gait: a duck-like walk that may appear in childhood or later in life
Leg length inequalities: Leg length inequality (or Leg Length Discrepancy) is a condition of unequal lengths of the lower limbs. The discrepancy may be in the femur, tibia or both. Some children are born with absence or underdeveloped bones in the lower limbs, e.g., congenital hemimelia. Others have a condition called hemihypertrophy that causes one side of the body to grow faster than the other. In other cases, injury or infection involving the epiphyseal plate (growth plate) of the femur or tibia inhibits or stops the growth of the bone altogether. Fractures healing in an overlapped position can also cause limb length discrepancy. The key to treating LLD in a child is to predict what the discrepancy will be at maturity. If it is predicted to be less than 2 cm, no treatment is needed. Limb length discrepancies of up to 2 or 2.5 cm can be compensated very well with a lift in the shoe. Beyond 2.5 cm, it becomes increasingly difficult to compensate with a lift in the insole. Building up the shoe becomes un-cosmetic and cumbersome, and some other way of compensating for the discrepancy becomes necessary. Surgical operations to equalize leg lengths include the following:
- Shortening the longer leg. This is usually done if growth is already complete, and the patient is tall enough that losing an inch is not a problem.
- Slowing or stopping the growth of the longer leg.
- Lengthening the short leg.
Rotational deformities of the limbs: Rotational deformities in the limbs of children can occur in the upper or lower extremities and may result from congenital defects in fetal development or is acquired during growth. Deformities may arise from trauma, infection, benign and malignant tumors, or medical conditions. These deformities include bowlegged deformity, knock knees and growth plate injuries.