Residual hip dysplasia in children: osseous and cartilaginous acetabular angles to guide further treatment—a pilot study

Abstract

PurposeIn case of residual hip dysplasia (RHD) in children, pelvic radiographs are sometimes insufficient to precisely evaluate the entire coverage of the femoral head, when trying to decide on the need for further reconstructive procedures.MethodsThis study retrospectively compares the bony and the cartilaginous acetabular angle of Hilgenreiner (HTE) of 60 paediatric hips on pelvic MRI separated in two groups. Group 1 included 31 hips with RHD defined by a bony HTE > 20°. Group 2 included 27 hips with a HTE < 20°. They were compared by introducing a new ratio calculated from the square of cartilaginous HTE above the bony HTE on frontal MRI. The normal upper limit for this acetabular angle ratio was extrapolated from the published normal values of cartilaginous HTE and bony HTE in children.ResultsThe acetabular angle ratio was statistically significantly increased in the hips with RHD with a mean value of 7.1 ± 4.7 compared to the hips in the control group presenting a mean value of 2.1 ± 1.9 (p < 0.00001).ConclusionsThis newly introduced ratio seems to be a helpful tool to orientate the further treatment in children presenting borderline RHD.

Timing of Repeat Ultrasound Examination in Treatment of Stable Developmental Dysplasia of the Hip

“…Furthermore, a considerable proportion of patients with stable dysplastic hips do develop residual dysplasia. 21 , 26 This is echoed in the results of the present study. Therefore, there is a need for a better understanding of the working mechanism of Pavlik treatment as well as increased ability to separate hips that would benefit from treatment, from those that will have a favorable course without.…”

What is the association between MRI and conventional radiography in measuring femoral head migration?

“…CMP derives its measurements from the cartilaginous edge of the roof of the acetabulum, but how this measurement relates to the stability of the hip and the prognosis of DDH is currently unknown. Other measurements based on the cartilaginous edge of the acetabulum have been proposed, most notably the cartilaginous acetabular index (CAI), which is increased in DDH (Li et al 2012) and has been proposed as a guiding measurement in the selection of patients for surgical treatment in borderline RAD cases (Merckaert et al 2019). This could mean a future role for CAI as predictor of the developmental potential of the hip and may show promise for measurements sharing the same anatomical landmarks such as the CMP.…”

“… 2012 ) and has been proposed as a guiding measurement in the selection of patients for surgical treatment in borderline RAD cases (Merckaert et al. 2019 ). This could mean a future role for CAI as predictor of the developmental potential of the hip and may show promise for measurements sharing the same anatomical landmarks such as the CMP.…”

The Use of Bovine Xenogeneic Bone Graft for Dega Pelvic Osteotomy in Children with Hip Dysplasia: A Retrospective Study of 147 Treated Hips

“…The AA decreases to 15 ± 5.5° during the first 4 years of life and then it remains stable until full hip ossification at maturity. Special values of the AA with regard to the exact patient age are listed in corresponding tables, for example, by Tönnis and Bunken [ 14 , 15 , 16 ]. The centre-edge angle was originally described by Wiberg in 1939 [ 17 ].…”