Incidence and Risk Factors for Hip Displacement in Thai Children with Cerebral Palsy under a 10-Year Surveillance Program: A retrospective analytical study at Queen Sirikit National  Institute of Child Health

Pattarapa Yamdee

Authors

Pattarapa Yamdee Department of Rehabilitation Medicine, Queen Sirikit National Institute of Child Health, Bangkok

Keywords:

cerebral palsy, hip displacement, hip surveillance, incidence, risk factors, Gross Motor Function Classification System

Abstract

Objectives: To evaluate the cumulative incidence of significant hip displacement, defined as a migration percentage (MP) > 40% or the requirement for hip reconstructive surgery among children with cerebral palsy (CP) enrolled in a 10-year institutional hip surveillance program, and to identify independent clinical predictors of displacement.

Study design: Retrospective cohort study

Setting: Queen Sirikit National Institute of Child Health

Participants: Children with cerebral palsy (CP) undergoing their first surveillance radiograph with baseline MP ≤ 40.0%.

Methods: This retrospective cohort study at Queen Sirikit National Institute of Child Health, a national tertiary referral center in Thailand (2016 to 2025), analyzed children with CP having baseline MP ≤ 40.0%. The primary outcome was the cumulative incidence of hip displacement (MP > 40% or surgery), estimated using Kaplan-Meier analysis. Multivariable Cox regression was used to identify risk factors, adjusting for Gross Motor Function Classification System (GMFCS) level, CP subtype, and epilepsy.

Results: A total of 265 patients were included. The cumulative incidence of significant hip displacement of the patients progressively increased over time: 17.8% at 2 years of follow-up, 30.5% at 4 years of follow-up, reaching 41.0% at 6 years of follow-up. Among the children who developed significant hip displacement during the surveillance period, the mean age at the time of initial documentation of displacement was 5.0 (SD = 2.2) years. Multivariable analysis identified GMFCS levels IV-V as the strongest independent predictor (adjusted Hazard Ratio [aHR] 3.09; 95% CI: 1.24, 7.70; p = 0.015) compared to levels I-III. Non-spastic CP subtypes were associated with a significantly lower risk (aHR 0.22; p = 0.017) compared to spastic diplegia. Epilepsy was not found to be an independent risk factor after adjusting for motor severity (aHR = 0.76; p = 0.407).

Conclusions: The cumulative risk of hip displacement in this surveillance cohort is high, particularly among children with severe motor impairment (GMFCS IV-V), reaching 41.0% at 6 years of follow-up. These findings underscore the necessity for rigorous, long-term surveillance stratified by GMFCS level and provide crucial data for prognostic counseling to facilitate timely interventions.

References

Li J, Ganjwala D, Johari A, Miller S, Schaeffer EK, Mulpuri K, et al. Hip surveillance for children with cerebral palsy: a survey of orthopaedic surgeons in India. Indian J Orthop [Internet]. 2022 Jan [cited 2026 Jan 14];56(1):58-65. Available from: https://pubmed.ncbi.nlm.nih.gov/35070143/ doi:10.1007/s43465-021-00432-3

Shore B, Spence D, Graham HK. The role for hip surveillance in children with cerebral palsy. Curr Rev Musculoskelet Med [Internet]. 2012 Jun [cited 2026 Jan 15];5(2):126-34. Available from: https://pubmed.ncbi.nlm.nih.gov/22430862/ doi:10.1007/s12178-012-9120-4

Aroojis A, Mantri N, Johari AN. Hip displacement in cerebral palsy: the role of surveillance. Indian J Orthop [Internet]. 2021 Jan [cited 2026 Jan 12];55(1):5-19. Available from: https://pubmed.ncbi.nlm.nih.gov/33569095/ doi:10.1007/s43465-020-00162-y

Bugler KE, Gaston MS, Robb JE. Hip displacement in children with cerebral palsy in Scotland: a total population study. J Child Orthop [Internet]. 2018 Dec [cited 2026 Jan 17];12(6):635-9. Available from: https://pubmed.ncbi.nlm.nih.gov/30607212/ doi:10.1302/1863-2548.12.180106

Lomaneenoparat R. Results of hip subluxation prevention program in cerebral palsy children at Queen Sirikit National Institute of Child Health. J Dept Med Serv [Internet]. 2023 Jan-Mar [cited 2026 Jan 17];48(1):12-9. Available from: https://he02.tci-thaijo.org/index.php/JDMS/article/view/257269

Huser A, Mo M, Hosseinzadeh P. Hip surveillance in children with cerebral palsy. Orthop Clin North Am [Internet]. 2018 Apr [cited 2026 Jan 17];49(2):181-90. Available from:https://pubmed.ncbi.nlm.nih.gov/29499819/ doi:10.1016/j.ocl.2017.11.006

Kentish M, Wynter M, Snape N, Boyd R. Five-year outcome of state-wide hip surveillance of children and adolescents with cerebral palsy. J Pediatr Rehabil Med [Internet]. 2011 [cited 2026 Jan 17];4(3):205-17. Available from:https://pubmed.ncbi.nlm.nih.gov/22207097/ doi:10.3233/PRM-2011-0176

Wordie SJ, Robb JE, Hägglund G, Bugler KE, Gaston MS. Hip displacement and dislocation in a total population of children with cerebral palsy in Scotland: status after five years’ hip surveillance. Bone Joint J [Internet]. 2020 Mar [cited 2026 Jan 17];102-B(3):383-7. Available from:https://pubmed.ncbi.nlm.nih.gov/32114804/ doi:10.1302/0301-620X.102B3.BJJ-2019-1203.R1

Gordon GS, Simkiss DE. A systematic review of the evidence for hip surveillance in children with cerebral palsy. J Bone Joint Surg Br [Internet]. 2006 Nov [cited 2026 Jan 17];88-B(11):1492-6. Available from:https://pubmed.ncbi.nlm.nih.gov/17075096/ doi:10.1302/0301-620X.88B11.18114

Hagglund G, Lauge-Pedersen H, Wagner P. Characteristics of children with hip displacement in cerebral palsy. BMC Musculoskelet Disord [Internet]. 2007 Oct [cited 2026 Jan 17];8:101. Available from:https://pubmed.ncbi.nlm.nih.gov/17963501/ doi:10.1186/1471-2474-8-101

Lindgren AM, Asma A, Rogers KJ, Miller F, Shrader MW, Howard JJ. Hip displacement after triradiate closure in ambulatory cerebral palsy: who needs continued surveillance? J Pediatr Orthop [Internet]. 2024 Nov [cited 2026 May 17];44(10):601-7. Available from: https://pubmed.ncbi.nlm.nih.gov/39099047/ doi:10.1097/BPO.0000000000002783

Thamphunanon V, editor. Clinical Practice Guideline for Hip Dysplasia in Cerebral Palsy: Management Program in QSNICH. 1st ed. Bangkok: Queen Sirikit National Institute of Child Health, Department of Medical Services, Ministry of Public Health; 2016.

Reimers J. The stability of the hip in children: a radiological study of the results of muscle surgery in cerebral palsy. Acta Orthop Scand Suppl [Internet]. 1980 [cited 2026 Feb 16];184:1-100. Available from:https://pubmed.ncbi.nlm.nih.gov/6930145/ doi:10.3109/ort.1980.51.suppl-184.01

Hägglund G, Alriksson-Schmidt A, Lauge-Pedersen H, Rodby-Bousquet E, Wagner P, Westbom L. Prevention of dislocation of the hip in children with cerebral palsy. Bone Joint J [Internet]. 2014 Nov [cited 2026 Jan 18];96-B(11):1546-52. Available from:https://pubmed.ncbi.nlm.nih.gov/25371472/ doi:10.1302/0301-620X.96B11.34385

Wynter M, Gibson N, Willoughby KL, Love S, Kentish M, Thomason P, et al. Australian hip surveillance guidelines for children with cerebral palsy: 5-year review. Dev Med Child Neurol [Internet]. 2015 Sep [cited 2026 Feb 18];57(9):808-20. Available from:https://pubmed.ncbi.nlm.nih.gov/25846730/ doi:10.1111/dmcn.12754

Larnert P, Risto O, Hagglund G, Wagner P. Hip displacement in relation to age and gross motor function in children with cerebral palsy. J Child Orthop [Internet]. 2014 Apr [cited 2026 May 12];8(2):129-34. Available from:https://pmc.ncbi.nlm.nih.gov/articles/PMC3965763/ doi:10.1007/s11832-014-0570-7

Soo B, Howard JJ, Boyd RN, Reid SM, Lanigan A, Wolfe R, et al. Hip displacement in cerebral palsy. J Bone Joint Surg Am [Internet]. 2006 Jan [cited 2026 Feb 18];88(1):121-9. Available from:https://pubmed.ncbi.nlm.nih.gov/16391257/ doi:10.2106/JBJS.E.00071

Scrutton D, Baird G. Surveillance measures of the hips of children with bilateral cerebral palsy. Arch Dis Child [Internet]. 1997 Apr [cited 2026 Feb 5];76(4):381-4. Available from:https://pubmed.ncbi.nlm.nih.gov/9166039/ doi:10.1136/adc.76.4.381

Rutz E. Are hips stable in children with cerebral palsy? Dev Med Child Neurol [Internet]. 2012 Oct [cited 2026 Feb 18];54(10):878. Available from:https://pubmed.ncbi.nlm.nih.gov/22881187/ doi:10.1111/j.1469-8749.2012.04380.x

Dobson F, Boyd RN, Parrott J, Nattrass GR, Graham HK. Hip surveillance in children with cerebral palsy: impact on the surgical management of spastic hip disease. J Bone Joint Surg Br [Internet]. 2002 Jul [cited 2026 Feb 18];84-B(5):720-6. Available from:https://pubmed.ncbi.nlm.nih.gov/12188492/ doi:10.1302/0301-620x.84b5.12398

Australian National Hip Surveillance Working Group. Australian hip surveillance guidelines for children with cerebral palsy 2020 [Internet]. Melbourne: Australasian Academy of Cerebral Palsy and Developmental Medicine (AusACPDM); 2020 Nov [cited 2026 Feb 10]. Available from:https://www.oceaniaacademy.org/wp-content/uploads/2020/12/200240-Hip-survey-A5-booklet-WEB.pdf

Pruszczynski B, Sees J, Miller F. Risk factors for hip displacement in children with cerebral palsy: systematic review. J Pediatr Orthop [Internet]. 2016 Sep [cited 2026 Jan 18];36(6):629-33. Available from:https://pubmed.ncbi.nlm.nih.gov/26090973/ doi:10.1097/BPO.0000000000000577

Elkamil AI, Andersen GL, Hägglund G, Lamvik T, Skranes J, Vik T. Prevalence of hip dislocation among children with cerebral palsy in regions with and without a surveillance programme: a cross sectional study in Sweden and Norway. BMC Musculoskelet Disord [Internet]. 2011 Dec [cited 2026 Feb 18];12:284. Available from:https://pubmed.ncbi.nlm.nih.gov/22177473/ doi:10.1186/1471-2474-12-284

Terjesen T, Vinje S, Kibsgard T. The relationship between hip displacement, scoliosis, and pelvic obliquity in 106 nonambulatory children with cerebral palsy: a longitudinal retrospective population-based study. Acta Orthop [Internet]. 2024 Feb [cited 2026 Feb 15];95:55-60. Available from:https://pubmed.ncbi.nlm.nih.gov/38288626/ doi:10.2340/17453674.2024.39915

Pountney TE, Mandy A, Green E, Gard PR. Hip subluxation and dislocation in cerebral palsy: a prospective study on the effectiveness of postural management programmes. Physiother Res Int [Internet]. 2009 Jun [cited 2026 Feb18];14(2):116-27. Available from:https://pubmed.ncbi.nlm.nih.gov/19194957/ doi:10.1002/pri.434