Efficacy of a Hip Brace for Hip Displacement in Children With Cerebral Palsy: A Randomized Clinical Trial

Abstract

Importance: There is no consensus on interventions to slow the progress of hip displacement in patients with cerebral palsy.

Objective: To investigate the efficacy of a novel hip brace in preventing progressive hip displacement in patients with cerebral palsy.

Design, setting, and participants: This 2-group randomized clinical trial was conducted at 4 tertiary hospitals in South Korea from July 2019 to November 2021. Participants included children aged 1 to 10 years with nonambulatory cerebral palsy (Gross Motor Function Classification System level IV or V). Block randomization was used to assign an equal number of patients to the study and control groups via computerized random allocation sequences. Data were analyzed from November to December 2021.

Interventions: The intervention group wore the hip brace for at least 12 hours a day for the study duration (ie, 12 months). Follow-up evaluations were performed after 6 and 12 months of wearing the brace. Both groups proceeded with conventional rehabilitation therapy during the trial.

Main outcomes and measures: The primary outcome was the Reimers migration index (MI) on radiography, as assessed by 3 blinded investigators. Primary outcome variables were analyzed using linear mixed models. Secondary outcomes include change in the Caregiver Priorities & Child Health Index of Life with Disabilities, on which lower scores indicate better quality of life.

Results: A total of 66 patients were included, with 33 patients (mean [SD] age, 68.7 [31.6] months; 25 [75.8%] boys) randomized to the intervention group and 33 patients (mean [SD] age, 60.7 [24.9] months; 20 [60.6%] boys) randomized to the control group. The baseline mean (SD) MI was 37.4% (19.3%) in the intervention group and 30.6% (16.3%) in the control group. The mean difference of the MI between the intervention group and control group was -8.7 (95% CI, -10.2 to -7.1) percentage points at 6 months and -12.7 (95% CI, -14.7 to -10.7) percentage points at 12 months. The changes in the Caregiver Priorities & Child Health Index of Life with Disabilities were favorable in the study group and reached statistical significance at the 6-month follow-up compared with the control group (difference, -14.2; 95% CI, -25.2 to -3.3).

Conclusions and relevance: In this randomized clinical trial, the novel hip brace was significantly effective in preventing the progression of hip displacement, compared with the control group. It effectively improved quality of life in patients with nonambulatory cerebral palsy. Therefore, hip brace use could be a promising treatment method to delay hip surgery and improve the quality of life of patients with nonambulatory cerebral palsy.

Trial registration: ClinicalTrials.gov Identifier: NCT04033289.

Figure 1.. Flowchart of the Patients Through the Trial

Figure 2.. Hip Brace and Example Radiographs of a Patient Before and After Wearing the Hip Brace

^aUpper straps were designed to protect hip joints from displacement. ^bLower straps were designed to prevent coxa valga. ^cThigh straps were designed to prevent hip adduction. ^dTo maximize the preventive effect on hip joint displacement, the greater trochanter (d) should be located between the upper and lower straps. ^eThe round design was applied at the buttock area of the fabric to allow comfort when lying or sitting and to prevent movement of the orthosis. ^fThe hip brace compresses the capsule and ligaments around the hip joints where displacement occurs, thereby helping with normal alignment.

Figure 3.. Mean Reimer Migration Index Scores at Baseline and 6 and 12 Months

After 12 months, the migration index for both sides was significantly decreased from 37.4% to 34.6% in the intervention group and significantly increased from 30.6% to 40.1% in the control group (P < .001). Whiskers indicate range; top and bottom of the boxes, IQR values; dark line, median; diamond, mean.