Causes of out-toeing gait in children with cerebral palsy.

Background: Out-toeing is common in children with cerebral palsy (CP), contributing to lever arm dysfunction and functional limitations. It is important to determine the cause(s) of out-toeing prior to treatment, whether surgical or non-surgical.

Research Questions: What are the contributors to out-toeing in children with CP and do they differ between children with bilateral and unilateral involvement?

Methods: The causes of out-toeing gait were determined retrospectively, with the use of computerized gait analysis, in 261 children with cerebral palsy (344 sides). The prevalence of various causes was calculated separately for children with bilateral and unilateral involvement, and compared statistically between groups using Fisher's Exact analysis.

Results: The most common cause of out-toeing was pes valgus in bilaterally involved subjects (71%) and pelvic external rotation (64%) in unilaterally involved subjects. Over half of the cases of out-toeing were due to multiple causes: 62% of the unilateral group and 53% of the bilateral group. In limbs with multiple causes of out-toeing in the bilateral group, pes valgus was one of the causes in 91% of limbs (146/161), and was most commonly combined with hip external rotation (27%), pelvic external rotation (22%), or external tibial torsion (20%). For the unilateral group with multiple causes of out-toeing, pelvic external rotation was one of the causes in 83% of limbs (20/24) and hip external rotation in 63% (15/24). Both were present (with or without additional causes) in 46% (11/24) of such limbs.

Significance: The causes of out-toeing are multifactorial in over half of affected limbs of children with cerebral palsy. They also differ for children with bilateral and unilateral involvement. These findings should be carefully considered prior to non-surgical or surgical treatment of out-toeing gait in these patients, to allow all sites of pathology to be addressed, and to optimize outcomes.