The cerebral palsy hip classification is reliable

Abstract

We have tested the reliability of a recently reported classification system of hip morphology in adolescents with cerebral palsy in whom the triradiate cartilage was closed. The classification is a six-grade ordinal scale, based on the measurement of the migration percentage and an assessment of Shenton's arch, deformity of the femoral head, acetabular deformity and pelvic obliquity. Four paediatric orthopaedic surgeons and four physiotherapists received training in the use of the classification which they applied to the assessment of 42 hip radiographs, read on two separate occasions. The inter- and intra-observer reliability was assessed using the intraclass correlation coefficient and found to be excellent, with it ranging from 0.88 to 0.94. The classification in our study was shown to be valid (based on migration percentage), and reliable. As a result we believe that it can now be used in studies describing the natural history of hip displacement in cerebral palsy, in outcome studies and in communication between clinicians.

Outcome of Femoral Varus Derotational Osteotomy for the Spastic Hip Displacement: Implication for the Indication of Concomitant Pelvic Osteotomy

“…Although MP has been the most commonly used radiologic measurement to describe hip displacement in CP, MCPHCS provides more comprehensive information about the hip morphology in addition to the MP; including integrity of the Shenton line, roundness of the femoral head, development of the acetabulum, and degrees of the pelvic obliquity [30]. The inter-and intra-observer reliability of the system have been demonstrated to be excellent to almost perfect [33,50].…”

An independent assessment of reliability of the Melbourne Cerebral Palsy Hip Classification System

“…However, due to the 2D nature of radiographs, anterior and posterior dislocations do not always show a substantial increase in the migration percentage and is thus a limitation of the use of the MP. 11 The use of CT imaging with 3D reconstruction and MRI has been proposed to circumvent this limitation. 11 , 15 However, this may not be practical, cost-effective or safe due to high levels of exposure during CT imaging as a means of hip surveillance or clinical study in children.…”

“… 11 The use of CT imaging with 3D reconstruction and MRI has been proposed to circumvent this limitation. 11 , 15 However, this may not be practical, cost-effective or safe due to high levels of exposure during CT imaging as a means of hip surveillance or clinical study in children. MRI does not provide as much bony detail and almost always requires sedation.…”

“…The original study of intra- and inter-reliability of this classification system was designed to evaluate radiographs in adolescents with CP with an age range of 14 to 19 years. 11 Murnaghan et al 11 performed the first study of the intra- and inter-reliability of the Melbourne Cerebral Palsy Hip Classification System, as part of the group from Melbourne that developed the system. Our study takes place in a different region (South Western United States) and is the first independent analysis of its reliability.…”

“…Reliability of the Melbourne Cerebral Palsy Hip Classification System has been demonstrated by the authors of the original study in the location of the original study, with inter- and intraobserver reliability of excellent to almost perfect. 11 An independent evaluation of this system’s reliability is important to further validate its use. The purpose of this study is to test the intra- and inter-reliability of this classification system as an independent evaluation.…”