Femoral vectoring for hip dysplasia in neonates
Estadístiques de LA Referencia / Recolecta
Inclou dades d'ús des de 2022
Cita com:
hdl:2117/192350
Tipus de documentText en actes de congrés
Data publicació2013
EditorCIMNE
Condicions d'accésAccés obert
Tots els drets reservats. Aquesta obra està protegida pels drets de propietat intel·lectual i
industrial corresponents. Sense perjudici de les exempcions legals existents, queda prohibida la seva
reproducció, distribució, comunicació pública o transformació sense l'autorització del titular dels drets
Abstract
The biomechanical factors influencing the reduction of dislocated hips with the
Pavlik harness in patients of developmental hip dysplasia (DDH) were studied and simulated
using a three-dimensional Finite Element Method (FEM) computer model.
We identified five hip adductor muscles as key mediators in the prognosis of reduction for
DDH, and determined the non-dimensional force contribution of each muscle in the direction
necessary to achieve hip reduction for subluxated and fully dislocated hip joints.
Results indicate that the effects of the muscles studied are functions of the severity of
DDH. For an abducted and flexed subluxated hip, the Pectineus, Adductor Brevis, proximal
Adductor Magnus, and Adductor Longus muscles aid reduction, while the portions of the
Adductor Magnus muscle with middle and distal femoral insertion contribute negatively. For
a fully dislocated hip all muscles contribute detrimentally.
Consequently, our study points at the adductor muscles as the mediators of reductions of
subluxated hips, and suggests the need for external traction to bring fully dislocated hips over
the posterior acetabulum and labrum. Additionally, the reduction process of dysplastic hips
was found to occur in two phases: (1) Release phase and (2) Reduction phase, and the muscles
studied act distinctively in each phase. Moreover, we performed a cadaveric dissection to
study the 3-dimensional orientation of the iliopsoas tendon in different hip configurations, and found that in hip abduction and flexion this tendon is likely not an obstruction to DDH
reductions.
We also report on the development of an improved three-dimensional anatomical computer
model of the hip and femora of a 10-week old female infant for further study of hip dysplasia
and other conditions of the hip using dynamic simulations and the Finite Element Method.
This model was generated by combining CT-scans from four human subjects, as well as
muscle positional data. It was segmented to encompass the distinct cartilaginous regions of
infant anatomy, as well as the different regions of cortical and cancellous bone; these
properties were retrieved from the literature.
This engineering computer model of an infant anatomy is being employed f or ( 1) t he
development of an anatomy-based finite element and dynamics computer model for
simulations of hip dysplasia reductions using novel treatment approaches, (2) the
determination of a path of least resistance in reductions of hip dysplasia based on a minimum
potential energy approach, (3) the study of the mechanics of hyperflexion of the hip as
alternative treatment for late-presenting cases of hip dysplasia, and (4) a comprehensive
investigation of the effects of femoral anteversion angle (AV) variations in reductions of hip
dysplasia.
This study thus reports on an interdisciplinary effort between orthopedic surgeons and
mechanical engineers to apply engineering fundamentals to solve medical problems. The
results of this research are clinically relevant in pediatric orthopaedics.
ISBN978-84-941407-6-1
Fitxers | Descripció | Mida | Format | Visualitza |
---|---|---|---|---|
Coupled-2013-42 ... ring for hip dysplasia.pdf | 1,461Mb | Visualitza/Obre |