The effect of botulinum toxin type A and a variable hip abduction orthosis on gross motor function: a randomized controlled trial

Hip displacement is the second most common deformity after equinus in children with cerebral palsy (CP), and may result in dislocation, pain, fixed deformity and loss of function. We studied the combined effects of intramuscular injections of botulinum toxin type A (BTX-A) to the adductors and hamstrings and a variable hip abduction orthosis (SWASH). on gross motor function, hip displacement and progression to surgery, in a randomized clinical trial. Thirty-nine children, with bilateral spastic cerebral palsy, and mean age 3 years + 2 months (range 1 year + 7 months -4 years + 10 months) entered the trial. Gross Motor Function Classification System (GMFCS) levels were as follows: one child was level II, 11 were level III, 13 were level IV and 14 were level V. After concealed randomization. 20 were allocated to the control group and 19 to the intervention group. Thirty-five children completed the follow up at 1 year. The novel intervention group received up to 4.0 U BOTOX(R)/kg/ muscle, 16 U/kg/body weight every 6 months plus the use of a SWASH brace. The control group received clinical best practice comprising physiotherapy but no hip abduction bracing. Both groups showed improvements in total Gross Motor Function Measure (GMFM) score [mean 6.0% BTX-A group; 6.1% Control 95% CI - 6.7, 6.5 (NS)], however, there was no additional treatment effect for the study group. There were similar improvements on GMFM goal scores and GMFM-66 scores, but again no additional treatment effect was observed. Multiple regression of change in total GMFM by GMFCS classification for each group showed greater improvement in the total scores from baseline in the BTX-A/SWASH treated group than the control group. In the first year. nine children (two in the intervention group and seven in the control group) required soft tissue surgery because of progressive hip migration in excess of 40%. A longer-term follow up of a larger cohort may be required to determine the effect of the combined treatment on hip displacement.