Graphic Analysis of Femoral Growth in Young Children with Perthes' Disease

Abstract

A cohort of 20 children, younger than 5.5 years at the time of onset of unilateral Perthes' disease, were studied by computer graphic analysis. Graphic outlines derived from each child's series of anterior posterior radiographs of the pelvis and hips were aligned on layers in a computer application such that changes over time could be directly visualized and measured. In these young children, injury to the cartilaginous growth mechanisms accounted for almost all of the abnormal change in the shape of the proximal femur; growth abnormalities had been established by the time of initial radiographs and persisted both as constant growth-rate change and growth-direction change until skeletal maturity. Despite the similar degree of radiographic bone necrosis, outcomes differed, and the specific growth aberrations were highly unique to the individual. At the time of the most recent radiographs, among the diseased hips 7 had spherical femoral heads larger than the normal side, eight had elliptical femoral heads congruent with the acetabulum, and five had elliptical femoral heads with a flat area congruent with the acetabulum. The study did not provide evidence to support a logic for brace or surgical treatment of young children with Perthes' disease.

3‐dimensional metrics of proximal femoral shape deformities in Legg–Calvé–Perthes disease and slipped capital femoral epiphysis

“…In LCPD, the average displacement was substantial in the femoral head (15.1±2.7mm), the greater trochanter (4.7±1.3mm), and the femoral neck (8.2±1.1mm). These results are consistent with descriptions of LCPD in the literature 20,22,40 , but additionally provide quantitative, region-specific displacement values that may be useful as guidelines for surgical bone resection. Within the anterosuperior femoral head region of LCPD femurs, maximum strains were in the anterolateral to posteromedial directions, quantitatively supporting the idea that material within LCPD femoral heads flow towards regions of lower pressure 51,52 .…”

“…The progression of LCPD and SCFE shape deformities has been extensively described in 2-D from longitudinal radiographic studies 14,17,20,40 . However, quantification of 3-D deformation relative to the normal femur at landmark locations is essential for delineating normal and aberrant growth biomechanics.…”

“…The SSM-biomechanics metrics of displacement and strain are two complementary indices that allow a better understanding of shape changes in disease in the context of continuum mechanics. The progression of LCPD and SCFE shape deformities has been extensively described in 2-D from longitudinal radiographic studies 14,17,20,40 . However, quantification of 3-D deformation relative to the normal femur at landmark locations is essential for delineating normal and aberrant growth biomechanics.…”

Computer-assisted design model to evaluate the outcome of combined osteotomies in Legg-Calvé-Perthes disease

“…Several studies ( 31 , 32 ) described the deformation of the proximal femur in different ways. Chan et al ( 24 ) found that the deformation mainly occurs in the femoral head and neck instead of the greater trochanter; stress concentration in the anterosuperior portion of the femoral head was observed in their study which made the deformed head shift laterally.…”

Magnetic Resonance Imaging in Legg-Calvè-Perthes Disease

“…Because of the difficulty in investigating the physis, the question regarding the responsibility of its impairment in the deformity of the hip still remains controversial. [12][13][14][15][16][17] At this moment, some investigators have decided that there is no sufficient reliability of prognostics criteria and it must be useful to explore a new way.…”