Pelvic obliquity and measurement of hip displacement in children with cerebral palsy

Gunnar Hägglund, Mikael Goldring, Maria Hermanson, Elisabet Rodby-Bousquet, Gunnar Hägglund, Mikael Goldring, Maria Hermanson, Elisabet Rodby-Bousquet

Abstract

Background and purpose - Pelvic obliquity, common in individuals with cerebral palsy (CP), changes the muscle force vector on the hip joint and probably affects the risk of hip dislocation. We evaluated a new method for measurement of hip displacement in CP that takes the pelvic obliquity into account: the pelvic adjusted migration percentage (PAMP). Children and methods - From the Swedish surveillance program for cerebral palsy (CPUP), the first pelvic radiograph of 268 children <18 years in southern Sweden during a 3-year period were evaluated. Pelvic obliquity, PAMP, and the migration percentage (MP) were measured. 50 radiographs were randomly selected for analysis of interrater reliability by three raters using the intraclass correlation coefficient (ICC). The correlations between PAMP/MP and pelvic obliquity were analyzed with Pearson correlation coefficients. Results - The interrater reliability for all 3 measurements was high (ICCs 0.88-0.97). The correlation between the high side of the pelvic obliquity and the difference between right and left hip displacement was higher for PAMP (r = 0.70) than for MP (r = 0.41). Interpretation - The new PAMP measurement showed high interrater reliability and a higher correlation with pelvic obliquity than MP. We suggest the use of PAMP at least in hips with a pelvic obliquity exceeding 5°.

Figures

Figure 1a.
Figure 1a.
Pelvic obliquity in a 12-year-old girl with cerebral palsy in GMFCS level IV. Measurement of migration percentage (MP). MP = a/b × 100. MP =46% in the left hip and 32% in the right hip.
Figure 1b.
Figure 1b.
Measurement of pelvic obliquity (PO). PO =15°, left side elevated.
Figure 1c.
Figure 1c.
Measurement of pelvic adjusted migration percentage (PAMP). PAMP =59% in the left hip and 15% in the right hip.
Figure 2.
Figure 2.
Number of pelvic radiographs related to the degree of PO. Negative value = left side of pelvis elevated, positive value = right side of pelvis elevated.
Figure 3.
Figure 3.
Difference between MP in the right and left hip related to PO. Negative PO value = left side of pelvis elevated, positive PO value = right side of pelvis elevated.
Figure 4.
Figure 4.
Difference between PAMP on the right and left hip related to PO. Negative PO value = left side of pelvis elevated, positive PO value = right side of pelvis elevated.

References

    1. Alriksson-Schmidt A I, Arner M, Westbom L, Krumlinde-Sundholm L, Nordmark E, Rodby-Bousquet E, et al. . A combined surveillance program and quality register improves management of childhood disability. Disabil Rehabil 2017; 39: 830–6.
    1. Dobson F, Boyd R N, Parrott J, Nattrass G R, Graham H K. Hip surveillance in children with cerebral palsy: impact on the surgical management of spastic hip disease. J Bone Joint Surg Br 2002; 84: 720–6.
    1. Evans J D. Straightforward statistics for the behavioral sciences. Pacific Grove, CA: Brooks/Cole Publishing; 1996.
    1. 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: 20-year results of a population-based prevention programme. Bone Joint J 2014; 96-B: 1546–52.
    1. Heidt C, Hollander K, Wawrzuta J, Molesworth C, Willoughby K, Thomason P, et al. . The radiological assessment of pelvic obliquity in cerebral palsy and the impact on hip development. Bone Joint J 2015; 97-B: 1435–40.
    1. Kalen V, Bleck E E. Prevention of spastic paralytic dislocation of the hip. Dev Med Child Neurol 1985; 27: 17–24.
    1. Letts M, Shapiro L, Mulder K, Klassen O. The windblown hip syndrome in total body cerebral palsy. J Pediatr Orthop 1984; 4: 55–62.
    1. Lonstein J E, Beck K. Hip dislocation and subluxation in cerebral palsy. J Pediatr Orthop 1986; 6: 521–526.
    1. McGraw K O, Wong S P. Forming inferences about some intraclass correlation coefficients. Psychological Methods 1996; 1: 30–46.
    1. Miller F, Slomczykowski M, Cope R, Lipton G E. Computer modeling of the pathomechanics of spastic hip dislocation in children. J Pediatr Orthop 1999; 19: 486–92.
    1. Palisano R, Rosenbaum P, Walter S, Russell D, Wood E, Galuppi B. Development and reliability of a system to classify gross motor function in children with cerebral palsy. Dev Med Child Neurol 1997; 39: 214–23.
    1. Porter D, Michael S, Kirkwood C. Patterns of postural deformity in non-ambulant people with cerebral palsy: what is the relationship between the direction of scoliosis, direction of pelvic obliquity, direction of windswept hip deformity and side of hip dislocation? Clin Rehabil 2007; 21: 1087–96.
    1. Reimers J. The stability of the hip in children: a radiological study of the results of muscle surgery in cerebral palsy. Acta Orthop Scand 1980; (Suppl 184): 1–100.

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