{"title":"A Mathematical Evaluation of the Effects of the Head and Neck Diameter on the Arc of Motion and the Implications in Total Hip Arthroplasty","authors":"","doi":"10.1016/j.artd.2024.101556","DOIUrl":null,"url":null,"abstract":"<div><h3>Background</h3><div>Instability following total hip arthroplasty (THA) is a leading cause of revisions. Our objective was to evaluate the options that the surgeon has, to gain inherent stability with the use of conventional large femoral and dual mobility systems, and how the arc of motion (AOM) and jump distances (JDs) vary between them.</div></div><div><h3>Methods</h3><div>The head sizes examined spanned from 22 mm-54 mm, and neck sizes spanned from 10 mm-14 mm. Autodesk Fusion 360 is full-scale computer-aided designsoftware that can run simulations to validate a design. It was employed to calculate the AOM for each model. The JD was calculated with varying head sizes and 10- and 20-degree highwall liners.</div></div><div><h3>Results</h3><div>Increasing head sizes from 22, 28, 32-36 mm showed a considerable increase in the AOM for every neck size; however, there was substantially less of an increase with head sizes larger than 36 mm. As neck sizes increased from 10-14 mm, the AOM decreased. The JD increased substantially with the addition of 10- and 20-degree highwall liners.</div></div><div><h3>Conclusions</h3><div>Both classical THA and the dual mobility systems achieve greater AOM than an anatomical normal hip. As the head diameter increases, the AOM and the JD increases. Increases in head size improve range of motion; however, head sizes over 36-40 mm gain little regarding component stability. The more durable and thinner modern polyethylene liners allow for larger conventional femoral heads. When considering between a classical THA or a dual mobility system, the minimal gains with increasing the head size in using a dual mobility system may be far outweighed by the increase in directional stability offered by the large head THA with highwall liners.</div></div>","PeriodicalId":37940,"journal":{"name":"Arthroplasty Today","volume":null,"pages":null},"PeriodicalIF":1.5000,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Arthroplasty Today","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2352344124002413","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ORTHOPEDICS","Score":null,"Total":0}
引用次数: 0
Abstract
Background
Instability following total hip arthroplasty (THA) is a leading cause of revisions. Our objective was to evaluate the options that the surgeon has, to gain inherent stability with the use of conventional large femoral and dual mobility systems, and how the arc of motion (AOM) and jump distances (JDs) vary between them.
Methods
The head sizes examined spanned from 22 mm-54 mm, and neck sizes spanned from 10 mm-14 mm. Autodesk Fusion 360 is full-scale computer-aided designsoftware that can run simulations to validate a design. It was employed to calculate the AOM for each model. The JD was calculated with varying head sizes and 10- and 20-degree highwall liners.
Results
Increasing head sizes from 22, 28, 32-36 mm showed a considerable increase in the AOM for every neck size; however, there was substantially less of an increase with head sizes larger than 36 mm. As neck sizes increased from 10-14 mm, the AOM decreased. The JD increased substantially with the addition of 10- and 20-degree highwall liners.
Conclusions
Both classical THA and the dual mobility systems achieve greater AOM than an anatomical normal hip. As the head diameter increases, the AOM and the JD increases. Increases in head size improve range of motion; however, head sizes over 36-40 mm gain little regarding component stability. The more durable and thinner modern polyethylene liners allow for larger conventional femoral heads. When considering between a classical THA or a dual mobility system, the minimal gains with increasing the head size in using a dual mobility system may be far outweighed by the increase in directional stability offered by the large head THA with highwall liners.
期刊介绍:
Arthroplasty Today is a companion journal to the Journal of Arthroplasty. The journal Arthroplasty Today brings together the clinical and scientific foundations for joint replacement of the hip and knee in an open-access, online format. Arthroplasty Today solicits manuscripts of the highest quality from all areas of scientific endeavor that relate to joint replacement or the treatment of its complications, including those dealing with patient outcomes, economic and policy issues, prosthetic design, biomechanics, biomaterials, and biologic response to arthroplasty. The journal focuses on case reports. It is the purpose of Arthroplasty Today to present material to practicing orthopaedic surgeons that will keep them abreast of developments in the field, prove useful in the care of patients, and aid in understanding the scientific foundation of this subspecialty area of joint replacement. The international members of the Editorial Board provide a worldwide perspective for the journal''s area of interest. Their participation ensures that each issue of Arthroplasty Today provides the reader with timely, peer-reviewed articles of the highest quality.