Deviation of the centre of rotation of the femoral head in dysplastic hip joints
- PDF / 860,522 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 24 Downloads / 194 Views
ORIGINAL ARTICLE
Deviation of the centre of rotation of the femoral head in dysplastic hip joints Hironobu Hoshino1 · Hiroki Furuhashi1 · Yuta Shimizu1 · Yukihiro Matsuyama1 Received: 23 April 2020 / Accepted: 12 August 2020 © Springer-Verlag France SAS, part of Springer Nature 2020
Abstract Objective Hip instability may be based not only on some mismatch between the size of the femoral head and acetabulum but also on the deviation of the centre of rotation of the femoral head. The aim of this study was to compare the differences between the centre of rotation of the femoral head and that of the acetabulum in normal and dysplastic hips. Materials and methods Thirty dysplastic hips and 30 control hips without dysplastic hip were included in this study. Computed tomography data were imported into three-dimensional analysis software. The sphere radius of the acetabulum, the sphere radius of the femoral head, and the deviation of the centre of rotation of the femoral head from that of the acetabulum were analysed. Results The sphere radii of the acetabulum and femoral head were significantly larger in dysplastic hips. Distances between the centre of rotation of the acetabulum and that of the femoral head were significantly larger in dysplastic group than in control group. The centre of rotation of the femoral head was significantly deviated anterosuperiorly in dysplastic hips. We found significant negative correlations between centre–edge angle and the distance between the centre of rotation of the acetabulum and that of the femoral head in all subjects. Conclusion In dysplastic hip joints, the centre of rotation of the femoral head was more deviated anterosuperiorly from that of the acetabulum than in normal hip joints even in static condition, which might be clinically associated with the microinstability in dysplastic hips. Keywords Acetabular dysplasia · Sphere · Hip instability · Three-dimensional analysis
Introduction Patients with dysplastic hip present with morphologic abnormalities such as insufficient acetabular coverage of the femoral head, shallow acetabular concavity, and maloriented acetabulum [1–3]. The clinical condition of dysplastic hips may be associated with the dynamic instability of the hip joint in addition to the mechanical loading by less acetabular coverage of the femoral head. Hip instability is generally defined as extraphysiologic hip motion [4]. However, there are no suitable measurements of hip instability. The normal hip joint is a highly constrained concentric ball joint. It moves in all directions smoothly if the * Hironobu Hoshino hhoshi@hama‑med.ac.jp 1
Department of Orthopaedic Surgery, Hamamatsu University School of Medicine, 1‑20‑1 Handayama, Hamamatsu 431‑3192, Japan
sphere size of the acetabulum is almost the same as that of the femoral head and the location of the centre of rotation of the acetabulum is almost the same as that of the femoral head. Several studies have demonstrated that the relationship between the femoral head and acetabulum is not perfectly cong
Data Loading...
