Development of hip displacement in cerebral palsy: a longitudinal register study of 1,045 children

Background and purpose — Hip surveillance in children with cerebral palsy (CP) includes repeated radiographic hip examinations and measurements of the hip migration percentage (MP) to identify hips in need of surgery early, to prevent dislocation with the fewest number of radiographic examinations possible. We analyzed the early development of the MP in hips operated on to prevent hip dislocation and hips stabilized without surgery Patients and methods — From the Swedish Surveillance Programme for CP, 5,899 radiographic measurements from 1,045 children with a Gross Motor Function Classification System level III–V born in 1996–2011 were analyzed. For children operated on to prevent hip dislocation, measurements up to the most recent preoperative radiograph were included. The hip with highest MP was analyzed for each child. A mixed-effects model was used to estimate the development of the MP at each age for each child and the population mean. Results — In the 702 children who did not undergo preventive surgery, the mean MP increased with decreasing velocity up to age 6 years. Here it reached 24% (95% confidence interval [CI] 24–25), with a velocity of 0.3%/year (CI 0.0–0.5), remaining approximately stable up to age 12 years. In the 343 children who underwent preventive surgery (219 adductor–psoas lengthening, 124 varus derotation osteotomy of proximal femur), the mean MP increased with an increasing velocity from a mean of 30% (CI 27–32) 3 years before the operation. Interpretation — An increasing rate of hip displacement in hips with an MP > 24% indicates the need for preventive surgery. Hips stabilized without preventive surgery had a decreasing displacement rate and were usually stabilized with an MP < 30% at age 6 years.

Point Prevalence and Associated Factors of Hip Displacement in Pediatric Patients With Mitochondrial Disease

Objective: Mitochondrial disease is a multisystem disorder resulting from mitochondrial dysfunction. Although musculoskeletal system is vulnerable to mitochondrial dysfunction, little information is available on orthopedic issues such as hip displacement and scoliosis in patients with mitochondrial disease. We aimed to examine the point prevalence of hip displacement and investigate the associated factors in patients with mitochondrial disease.Methods: We retrospectively reviewed the medical records and plain radiographs of patients diagnosed with mitochondrial disease between January 2006 and January 2019 at a single institution. Data, including patient age, sex, follow-up duration, syndromic diagnosis, and gross motor function were collected. Migration percentage was measured on the radiographs. The clinical and radiologic variables were compared between patients classified according to the presence of hip displacement and motor function level.Results: We included 225 patients (135 men, 90 women). The mean age at the latest follow-up was 11.1 years, and the mean follow-up duration was 7.0 years. Hip displacement was noted in 70 (31.1%) patients. The proportion of patients with Leigh disease (p = 0.007) and the ratio of non-ambulators (p &lt; 0.001) were higher among patients with hip displacement. The proportion of patients with Leigh disease was higher in the non-ambulators than the ambulators.Conclusion: One-third of patients with mitochondrial disease developed hip displacement. Hip displacement was more common in non-ambulators or patients with hypertonia. Careful and serial monitoring for hip problems is required for non-ambulatory patients with mitochondrial disease who have increased muscle tone.

Hip surgery and radiology reporting for children with cerebral palsy prior to initiation of a hip surveillance program

PURPOSE: Hip displacement impacts quality of life for many children with cerebral palsy (CP). While early detection can help avoid dislocation and late-stage surgery, formalized surveillance programs are not ubiquitous. This study aimed to examine: 1) surgical practices around pediatric hip displacement for children with CP in a region without formalized hip surveillance; and 2) utility of MP compared to traditional radiology reporting for quantifying displacement. METHODS: A retrospective chart review examined hip displacement surgeries performed on children with CP between 2007–2016. Surgeries were classified as preventative, reconstructive, or salvage. Pre- and post-operative migration percentage (MP) was calculated for available radiographs using a mobile application and compared using Wilcoxon Signed Ranks test. MPs were also compared with descriptions in the corresponding radiology reports using directed and conventional content analyses. RESULTS: Data from 67 children (115 surgical hips) was included. Primary surgery types included preventative (63.5% hips), reconstructive (36.5%), or salvage (0%). For the 92 hips with both radiology reports and radiographs available, reports contained a range of descriptors that inconsistently reflected the retrospectively-calculated MPs. CONCLUSION: Current radiology reporting practices do not appear to effectively describe hip displacement for children with CP. Therefore, standardized reporting of MP is recommended.

Risk factors for hip dislocation in dyskinetic cerebral palsy

Purpose: To investigate the risk factors for hip displacement in patients with dyskinetic cerebral palsy (DCP). Methods: We evaluated 81 patients with DCP, 45 males and 36 females, aged 10–22 years, risk factors for hip displacement were evaluated using multivariate logistic regression analysis with primary brain lesions, Gross Motor Function Classification System (GMFCS) level, gestational age, birth weight, Cobb’s angle, and complication of epilepsy as independent factors. Hip displacement was defined as migration percentage >30%. Primary brain lesions were classified into globus pallidus (GP), thalamus and putamen (TP), and others using brain magnetic resonance imaging (MRI). Perinatal and clinical features were compared between patients with GP lesions and those with TP lesions. Results: Hip displacement was observed in 53 patients (67%). Higher GMFCS levels (p = 0.013, odds ratio [OR] 2.6) and the presence of GP lesions (p = 0.04, OR 16.5) were independent risk factors for hip displacement. Patients with GP lesions showed significantly higher GMFCS levels, more frequent hip displacement, and lower gestational age and birth weight than those with TP lesions. Conclusion: Primary brain lesion location may be an important factor in predicting hip displacement among patients with DCP. Appropriate risk assessment using brain MRI may contribute to the early detection and intervention of hip displacement because brain lesion location can be assessed during infancy before GMFCS level is decided.