Prevalence of specific gait abnormalities in children with cerebral palsy revisited: influence of age, prior surgery, and Gross Motor Function Classification System level.

Aim: To examine the impact of age, surgery, and Gross Motor Function Classification System (GMFCS) level on the prevalence of gait problems in children with cerebral palsy (CP).

Method: Gait analysis records were retrospectively reviewed for ambulatory patients with CP. Gait abnormalities were identified using physical exam and kinematic data. Relationships among age, sex, previous surgery, GMFCS level, and prevalence of gait abnormalities associated with crouch and out-toeing, and equinus and in-toeing were assessed using univariable and multivariable logistic regression.

Results: One-thousand and five records were reviewed. The most common gait problems were in-toeing, excessive knee flexion, stiff knee, hip flexion, internal rotation, adduction, and equinus (all >50%). Odds ratios (OR) for various gait problems associated with crouch and out-toeing increased (OR 1.07-1.32), and those associated with equinus and in-toeing decreased (OR 0.80-0.94) significantly with increasing age for patients in GMFCS levels I to III. The same trends were seen with prior surgery (OR for crouch and out-toeing: 1.86-7.14; OR for equinus and in-toeing: 0.16-0.59).

Interpretation: The prevalence of gait abnormalities varies by GMFCS level, but similarities exist among levels. The study results suggest that in younger children, particularly those in GMFCS levels III and IV, treatments for equinus and in-toeing should be undertaken with caution because these problems tend to decrease with age even without orthopedic intervention. Such children may end up with the 'opposite' deformities of calcaneal crouch and out-toeing, which tend to increase in prevalence with age.