EXTERNAL TIBIAL TORSION
By: Robert H. Sheinberg, D.P.M., D.A.B.P.S., F.A.C.F.A.S.
External tibial torsion is usually a common cause of an out toe gait. The lower leg bone (tibia) rotates excessively to the outside when comparing it to the upper leg bone (femur).
- Not usually due to in utero position as the fetus’ tibia is usually rotated internal.
- Tight ligament and tendon structures (hamstrings, iliotibial band).
- Can be caused by a true twist of the lower portion of the lower leg bone (tibia) relative to the upper portion of the lower leg bone (tibia).
SIGNS AND SYMPTOMS.
- Commonly seen when children begin to walk. Becomes more apparent between the ages of 4 and 7.
- If the hip is normal the knee appears to be straight when watching the child walk but yet the foot and lower leg turn to the outside.
- Usually associated with a flatfoot deformity.
- Poor push off power during running.
- Child may lack coordination during activity.
- Premature fatigue with activity.
- Runs poorly as the child runs through the midfoot and not over the ball of the foot as in a normal gait.
- Usually more commonly seen in one leg more than the other.
- Can be associated with knee pain (patellofemoral instability).
- With the knee flexed at 90 degrees the lower leg bone (tibia) is rotated in and out relative to the upper leg bone (femur).
- The tibia will rotate excessively towards the outside of the body and very little rotation will go towards the inside.
- Must also examine the hips for femoral retroversion (upper leg bone rotates excessively out with limited motion turning in).
- Must rule out flatfoot deformity which would be made worse by the lower leg position (external tibial torsion).
When the knee is pointed directed anterior towards the line of progress, exteral torsion of the tibia causes the foot to be directed outward with mechanical compensation from the foot and/or the knee causing pain.
- If the deformity is significant x-rays may be taken. The lower leg bone (transmalleolar axis) is measured relative to the upper leg bone (bicondylar axis of proximal tibia). In an adult it is approximately 14 degrees external.
- Full lower extremity examination to rule out other coexisting problems.
- If the foot is flat orthotics are necessary for the foot to prevent the creation of or worsening of a flatfoot deformity. It will also help to bring the foot slightly up and in, lessening some of the appearance of the deformity.
- If associated with excessively tight ligaments and tendons around the knee a short course of immobilization in a cast above the knee may be of some benefit. When a cast is applied the lower leg bone (tibia) is gently rotated internally relative to the upper leg bone (femur). This causes a gentle stretch on the ligament and tendon structures around the knee area. Cast may be necessary for up to 8 weeks depending on the degree of problem.
- Following cast removal night splinting of the leg to hold the lower leg (tibia) in internal rotation relative to the upper leg (femur) may be of some benefit.
- If the condition causes problems with gait, pain in the knee or is of significant cosmetic concern, surgery can be performed at the lower leg (above the ankle growth plate) to take some of the rotation out of the lower leg bone (tibia). Surgery should not be performed until the child is 10 or older.