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The prognostic value of the head-shaft angle on hip displacement in children with cerebral palsy.

van der List JP, Witbreuk MM, Buizer AI, van der Sluijs JA - J Child Orthop (2015)

Bottom Line: II-III) (172° vs. 165°; p < 0.001).The HSA at two years is larger in hips that will displace and larger in children with higher GMFCS levels (IV-V).Prognostic study, level II.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Research Institute MOVE, VU University Medical Center, De Boelelaan 1117, P.O. Box 7057, 1081 HV, Amsterdam, The Netherlands, jpjvanderlistmd@gmail.com.

ABSTRACT

Background: Hip displacement is the second most common deformity in cerebral palsy (CP). The risk for hip displacement is related to the Gross Motor Function Classification System (GMFCS). Recently, the head-shaft angle (HSA) has been identified as a predictor for hip displacement and the aim of this study is to assess the predictive value of the HSA for hip displacement in CP.

Methods: In this retrospective cohort, we performed radiological measurements in 50 children on both hips. In children with GMFCS level II (30 hips), III (30 hips), IV (20 hips) and V (20 hips), we measured the HSA and migration percentage (MP) in three age intervals: age two years (T1), age four years (T2) and age seven years (T3).

Results: At T1, the HSA was larger (more valgus) in hips that will displace than in hips that will not displace (174° vs. 166°; p = 0.001) and was also larger in higher GMFCS levels (IV-V vs. II-III) (172° vs. 165°; p < 0.001). At T1, GMFCS [odds ratio (OR) 14.7; p = 0.001] and HSA (OR 1.102; p = 0.043) were predictors for hip displacement at T3, but at T2, MP (OR 1.071; p = 0.010) was the only predictor for hip displacement at T3.

Conclusions: The HSA at two years is larger in hips that will displace and larger in children with higher GMFCS levels (IV-V). At age two years, GMFCS and HSA are valuable predictors for hip displacement, but at the age of four years, only MP should be used in the prediction of hip displacement.

Level of evidence: Prognostic study, level II.

No MeSH data available.


Related in: MedlinePlus

Anteroposterior (AP) radiograph of the pelvis. Right hip: head-shaft angle (C) by measuring the medial angle between a line perpendicular to the proximal femoral epiphysis and a line through the middle of the femoral shaft. Left hip: the migration percentage (MP) is measured by a Hilgenreiner’s line (H) and three perpendicular lines. The MP is measured by A/B × 100 %
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Fig1: Anteroposterior (AP) radiograph of the pelvis. Right hip: head-shaft angle (C) by measuring the medial angle between a line perpendicular to the proximal femoral epiphysis and a line through the middle of the femoral shaft. Left hip: the migration percentage (MP) is measured by a Hilgenreiner’s line (H) and three perpendicular lines. The MP is measured by A/B × 100 %

Mentions: The two radiographic parameters, HSA and MP, were assessed at T1 (between 12 and 32 months), at T2 (between 36 and 60 months) and at T3 (between 72 and 96 months) in a total of 100 hips. We used the AP radiograph of pelvic and hip joints to measure the AP HSA and MP at these ages. Standardised radiographs were obtained with the patient supine, the pelvis symmetrically positioned with the spinae iliacae on equal height and straightened legs with 20° internal rotation. The HSA is measured on an AP radiograph according to Southwick [18] (Fig. 1) and his measurement has a maximal intrarater variability of 1.7 % and a maximal interrater variability of 1.8 % at the AP radiograph [19]. The MP, as described by Reimers [20], was used to measure the lateral displacement of the femoral head (Fig. 1). The MP is not influenced by rotation of the hip [20] and has an intrarater variability of 3.6 % and an interrater variability of 3.2 % [21, 22]. Because of the low intra- and interrater variability of both the HSA and the MP, the measurements were performed by the same examiner (JL) once. They were performed on the digital radiology system IMS Webviewer [23].Fig. 1


The prognostic value of the head-shaft angle on hip displacement in children with cerebral palsy.

van der List JP, Witbreuk MM, Buizer AI, van der Sluijs JA - J Child Orthop (2015)

Anteroposterior (AP) radiograph of the pelvis. Right hip: head-shaft angle (C) by measuring the medial angle between a line perpendicular to the proximal femoral epiphysis and a line through the middle of the femoral shaft. Left hip: the migration percentage (MP) is measured by a Hilgenreiner’s line (H) and three perpendicular lines. The MP is measured by A/B × 100 %
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4417736&req=5

Fig1: Anteroposterior (AP) radiograph of the pelvis. Right hip: head-shaft angle (C) by measuring the medial angle between a line perpendicular to the proximal femoral epiphysis and a line through the middle of the femoral shaft. Left hip: the migration percentage (MP) is measured by a Hilgenreiner’s line (H) and three perpendicular lines. The MP is measured by A/B × 100 %
Mentions: The two radiographic parameters, HSA and MP, were assessed at T1 (between 12 and 32 months), at T2 (between 36 and 60 months) and at T3 (between 72 and 96 months) in a total of 100 hips. We used the AP radiograph of pelvic and hip joints to measure the AP HSA and MP at these ages. Standardised radiographs were obtained with the patient supine, the pelvis symmetrically positioned with the spinae iliacae on equal height and straightened legs with 20° internal rotation. The HSA is measured on an AP radiograph according to Southwick [18] (Fig. 1) and his measurement has a maximal intrarater variability of 1.7 % and a maximal interrater variability of 1.8 % at the AP radiograph [19]. The MP, as described by Reimers [20], was used to measure the lateral displacement of the femoral head (Fig. 1). The MP is not influenced by rotation of the hip [20] and has an intrarater variability of 3.6 % and an interrater variability of 3.2 % [21, 22]. Because of the low intra- and interrater variability of both the HSA and the MP, the measurements were performed by the same examiner (JL) once. They were performed on the digital radiology system IMS Webviewer [23].Fig. 1

Bottom Line: II-III) (172° vs. 165°; p < 0.001).The HSA at two years is larger in hips that will displace and larger in children with higher GMFCS levels (IV-V).Prognostic study, level II.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Research Institute MOVE, VU University Medical Center, De Boelelaan 1117, P.O. Box 7057, 1081 HV, Amsterdam, The Netherlands, jpjvanderlistmd@gmail.com.

ABSTRACT

Background: Hip displacement is the second most common deformity in cerebral palsy (CP). The risk for hip displacement is related to the Gross Motor Function Classification System (GMFCS). Recently, the head-shaft angle (HSA) has been identified as a predictor for hip displacement and the aim of this study is to assess the predictive value of the HSA for hip displacement in CP.

Methods: In this retrospective cohort, we performed radiological measurements in 50 children on both hips. In children with GMFCS level II (30 hips), III (30 hips), IV (20 hips) and V (20 hips), we measured the HSA and migration percentage (MP) in three age intervals: age two years (T1), age four years (T2) and age seven years (T3).

Results: At T1, the HSA was larger (more valgus) in hips that will displace than in hips that will not displace (174° vs. 166°; p = 0.001) and was also larger in higher GMFCS levels (IV-V vs. II-III) (172° vs. 165°; p < 0.001). At T1, GMFCS [odds ratio (OR) 14.7; p = 0.001] and HSA (OR 1.102; p = 0.043) were predictors for hip displacement at T3, but at T2, MP (OR 1.071; p = 0.010) was the only predictor for hip displacement at T3.

Conclusions: The HSA at two years is larger in hips that will displace and larger in children with higher GMFCS levels (IV-V). At age two years, GMFCS and HSA are valuable predictors for hip displacement, but at the age of four years, only MP should be used in the prediction of hip displacement.

Level of evidence: Prognostic study, level II.

No MeSH data available.


Related in: MedlinePlus