Metal-on-Metal Hip Arthroplasty in Patients Thirty Years of Age or Younger

Yoo

Clinical Orthopaedics &Amp; Related Research

et al. 2012

Background THA in patients younger than 30 years presents challenges because of uncertainties regarding the long-term survivorship of prostheses. Alumina-on-alumina bearings, which exhibit little long-term wear, may be a reasonable option but the long-term survivorship is unknown. Questions/Purposes We determined (1) the survival rate of alumina-on-alumina bearings in patients younger than 30 years after a 10-year followup, (2) the incidence of audible hip clicking and squeaking, (3) radiographic evidence of osteolysis, and (4) the effects on pregnancy, childbirth, and career choice. Methods We retrospectively reviewed 62 patients who had 75 THAs with alumina-on-alumina bearings followed more than 10 years (average, 11.5; range, 10-13.5 years). Mean patient age at the time of surgery was 24 years (range, 18-30 years). All operations were performed using the same cementless implant at a single center. We determined survival, presence of osteolysis, and function (Harris hip score, WOMAC).

Section: Discussionmentioning

confidence: 92%

Section: Discussionmentioning

confidence: 99%

Alumina-on-alumina THA Performed in Patients Younger Than 30 Years: A 10-year Minimum Followup Study

Yoo

Clinical Orthopaedics &Amp; Related Research

et al. 2012

Clinical Orthopaedics &Amp; Related Research

“…The Harris hip score was reported in 12 studies with a mean postoperative score of 84.5 (range, 17-100) at an average followup of 7.5 years. The Merle d'Aubigne score was used in three studies with an average of 16.5 (range, [8][9][10][11][12][13][14][15][16][17][18] at mean followup of 15 years. Clinical outcomes were similar between Group I and Group II (average Harris hip score was 84.4 at mean followup of 7.7 years and 84.6 at mean followup of 7.4 years, respectively; p = 0.5).…”

Section: Resultsmentioning

confidence: 99%

Has Total Hip Arthroplasty in Patients 30 Years or Younger Improved? A Systematic Review

Adelani

Keeney

Palisch

et al. 2013

111

“…MoM bearings have been further developed for surface replacement in order to preserve bone on the femoral side5, 6 and for larger head sizes to achieve enhanced range of motion and stability 7, 8. These designs were often targeted at younger, more active patients 9, 10. However, adverse conditions such as implant malpositioning can lead to edge loading or head‐cup rim contact, and produce high contact stress causing elevated wear 11.…”

Section: Introductionmentioning

confidence: 99%

Effect of microseparation on contact mechanics in metal‐on‐metal hip replacements—A finite element analysis

2014

Some early failures of metal‐on‐metal (MoM) hip replacements associated with elevated wear have caused concerns for the use of this bearing combination. Simulator studies have shown that microseparation and its associated rim contact and edge loading may produce the most severe wear in MoM bearings. It is generally recognized that this high wear can be attributed to the high contact stress of the head on the rim of the cup. In this study, an improved finite element contact model that incorporates an elastic‐perfectly plastic material property for cobalt‐chrome alloy of the metal bearing was developed in an attempt to provide an accurate prediction of the stress and strain for the rim contact. The effects of the microseparation displacement (0.1−2 mm), cup inclination angle (25−65°) and cup rim radius (0.5−4 mm) on the contact stress/strain were investigated. The results show that a translational displacement >0.1 mm under a load >0.5 kN can produce a highly concentrated contact stress at the surface of the cup rim which can lead to plastic deformation. This study also suggests that the magnitude of translational displacement was the major factor that determined the severity of the contact conditions and level of stress and strain under microseparation conditions. Future studies will address the effect of surgical translational and rotational malposition and component design on the magnitude of microseparation, contact stress and strain and severity of wear. © 2014 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1312–1319, 2015.