Developmental dysplasia of spastic hip (DDSH) in cerebral palsy often causes severe sufferings including pain [1], reduced range of hip motion with associated sitting, standing and walking problems, if not detected early [2]. The incidence of spastic hip displacement in cerebral palsy is reported to vary from 1% to 75% [3,4]. This study was planned to find out DDSH in cerebral palsy, as there is a lack of Indian data on this aspect.

This descriptive study was conducted between May 2014 and January 2015 in children presenting with clinical features suggestive of cerebral palsy at a tertiary care teaching hospital. A total of 118 children with cerebral palsy between 2 to 12 years of age belonging to Gross motor function classification system (GMFCS) grade III-V were enrolled. History and clinical examination using systematically designed forms were taken. Radiograph of pelvis and hip joint with hip abducted in supine position was taken. The degree of hip displacement was measured by Reimer’s Migration Percentage (MP) [1]. Hip migration between 33-80% was labeled subluxation, and over 80% as dislocation. Gross motor function in cerebral palsy was assessed according to GMFCS a five level ordinal scale [5]. This study was approved by the Institutional ethical committee of our institute.

DDSH was found in 15 (12.71%) children (hip subluxation 14, hip dislocation 1). All these children had spastic cerebral palsy. Sublaxation was seen in children (6.2%) with GMFCS grade III, 6 children (16.6%) with GMFCS grade IV and 6 children (12.0%) with GMFCS grade V. One child (2%) with GMFCS grade V had hip dislocation. No hip subluxation or dysplasia was found in dyskinetic cerebral palsy. One child (7.1%) with spastic hemiplegia and 2 children (14.2%) with spastic diplegia had subluxation. Eleven (12.2%) of the 90 children with spastic quadriplegia had subluxation. One child with spastic quadriplegia had hip dislocation.

Hip dysplasia in cerebral palsy is due to asymmetrical activity of the muscles surrounding the hip joint [6]. Previous studies described hip subluxation in 30-60% of children with cerebral palsy which is much higher then in our study [3,7]. The probable reason for less number of DDSH in current study is probably due to the positioning of younger kids on their mothers waist with hips widely abducted.

Soo, et al. [8], demonstrated a linear relationship between the rate of hip displacement and a child’s GMFCS level, with hip displacement seen in 90% of GMFCS V children. They also reported more hip dysplasia in spastic quadriplegia than diplegia [8]. Our study showed similar results.

Limitations of the present study are a descriptive study, and not analyzing serial pelvis X-ray changes. Our hip dysplasia treatment protocol involves abduction brace, Botulinum toxin, abductor tenotomy and/or varus osteotomy based on severity of hip displacement. Early detection and surgical intervention for spastic hip displacement can prevent hip dislocation and need for more invasive surgery.

Acknowledgement: Dr Giriyanna Gowda and Dr Chandana Krishna from the Department of community medicine, Kempegowda Institute of Medical Sciences, Bangalore for valuable inputs regarding data analysis.

Contributors: VR: Revised the manuscript for important intellectual content and guarantor of the paper; VM: Conceptualization of the study, collection, analysis of the data, writing the manuscript; RR: Designed the study, conducted laboratory tests and analyzed the data; PR: Supervision of the work and revision of manuscript.

Funding: None; Competing interests: None stated.

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