Tibial bowing is not uncommon. The direction and the apex of
the tibial bow can alert the clinician to the type of the deformity, its
treatment, and its prognosis. Tibial bowing can occur anteriorly, laterally,
anterolaterally, and posteromedially.
Anterior bowing is often associated with fibular hemimelia.
This bowing may be associated with the
loss of the lateral rays of the foot, equinovalgus foot deformity, tarsal
coalition, and significant leg length discrepancy.
Lateral bowing is a common variation, which occurs
bilaterally. This condition is mild and not associated with other problems.
Anterolateral bowing is a serious tibial bowing that may
increase and lead to a fracture as well as pseudoarthrosis of the tibia. This
type of bowing occurs early in infancy. Pseudoarthrosis is usually associated
with neurofibromatosis. 10% of patients with neurofibromatosis will have
anterolateral tibial bowing. Neurofibromatosis is found in 50% of the patients
with ALB. The patient should be carefully examined for café-au-lait spots. In
this type of bowing, bone ends are usually thin and the fibula may also be
involved. Treatment of anterolateral bowing is bracing with total contact
orthosis. In order to treat pseudoarthosis in the tibia, surgery is usually
needed. Multiple options are available for surgery, and none of these options
are perfect. 50% of patients may undergo amputation due to the inability to
achieve healing of pseudoarthrosis.
Posteromedial bowing is a rare calcaneovalgus deformity of
the foot plus leg length discrepancy. This condition usually resolves, but may
have residual leg length discrepancy.