scholarly journals Effect of femoral head size on the wear of metal on metal bearings in total hip replacements under adverse edge‐loading conditions

2012 ◽  
Vol 101B (2) ◽  
pp. 213-222 ◽  
Author(s):  
Mazen Al‐Hajjar ◽  
John Fisher ◽  
Sophie Williams ◽  
Joanne L. Tipper ◽  
Louise M. Jennings
Keyword(s):  
Femoral Head ◽  
Head Size ◽  
Loading Conditions ◽  
Femoral Head Size ◽  
Total Hip ◽  
Total Hip Replacements ◽  
Metal On Metal ◽  
Edge Loading ◽  
Hip Replacements

scholarly journals The Performance of Mixed Manufacturer Metal On Metal Total Hip Replacements

2017 ◽  
Vol 7 (2) ◽  
Author(s):  
Richard Barker Cook ◽  
Jeremy M. Latham ◽  
Robert J.K. Wood
Keyword(s):  
Femoral Head ◽  
Hip Resurfacing ◽  
Normal Range ◽  
Material Loss ◽  
Total Hip ◽  
Loss Analysis ◽  
Total Hip Replacements ◽  
Metal On Metal ◽  
Hip Replacements ◽  
Stem Damage

Using a femoral head from one manufacturer on the stem of another manufacturer poses the risk that the taper interface between the components may not contact correctly and the performance of the joint will be impaired. The cohorts in this study are a combination of modular Birmingham Hip Resurfacing (BHR) and Adept femoral heads on CPT stems. The study reviews the geometry of the taper interfaces to establish if the taper clearance angles was outside of the normal range for other taper interfaces. In addition the rates of material loss from the bearings and taper and a ranking of the stem damage were reviewed to determine if the levels of loss were above that seen for other similar joints. The material loss analysis demonstrated that the rates or levels of loss from the bearings, taper and stem were no different to levels published for manufacturer matched joints and in many cases were lower. The results demonstrate that the taper clearance angles for the mixed manufacturer joints (BHR-CPT: 0.067 to -0.116, Adept-CPT: 0.101 to -0.056) were within the range of other studies and manufacturer matched clearances (0.134 to -0.149).Using components from different manufacturers has not in this instance increased the level of material loss from the joints, when compared to other similar manufacturer matched joints.

scholarly journals Comparison between component designs with different femoral head size in metal-on-metal total hip arthroplasty; multicenter randomized prospective study

2015 ◽  
Vol 12 (4) ◽  
pp. 228-236 ◽  
Author(s):  
Wataru Ando ◽  
Kengo Yamamoto ◽  
Takashi Atsumi ◽  
Satoshi Tamaoki ◽  
Kazuhiro Oinuma ◽  
...  
Keyword(s):  
Femoral Head ◽  
Total Hip Arthroplasty ◽  
Prospective Study ◽  
Hip Arthroplasty ◽  
Head Size ◽  
Femoral Head Size ◽  
Total Hip ◽  
Metal On Metal

scholarly journals Femoral Head Size Does Not Affect Ion Values in Metal-on-Metal Total Hips

2010 ◽  
Vol 469 (6) ◽  
pp. 1642-1650 ◽  
Author(s):  
Mitchell Bernstein ◽  
Alan Walsh ◽  
Alain Petit ◽  
David J. Zukor ◽  
John Antoniou
Keyword(s):  
Femoral Head ◽  
Head Size ◽  
Femoral Head Size ◽  
Metal On Metal

Robotic-Arm Assisted Total Hip Arthroplasty Results in Smaller Acetabular Cup Size in Relation to the Femoral Head Size: A Matched-Pair Controlled Study

2017 ◽  
Vol 27 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Carlos Suarez-Ahedo ◽  
Chengcheng Gui ◽  
Timothy J. Martin ◽  
Sivashankar Chandrasekaran ◽  
Parth Lodhia ◽  
...  
Keyword(s):  
Femoral Head ◽  
Head Size ◽  
Robotic Arm ◽  
Matched Pair ◽  
Femoral Head Size ◽  
Acetabular Cup ◽  
Acetabular Bone ◽  
Head Diameter ◽  
Total Hip ◽  
Femoral Head Diameter

Purpose To compare the acetabular component size relative to the patient's native femoral head size between conventional THA (CTHA) approach and robotic-arm assisted THA (RTHA) to infer which of these techniques preserved more acetabular bone. Methods Patients were included if they had primary osteoarthritis (OA) and underwent total hip replacement between June 2008 and March 2014. Patients were excluded if they had missing or rotated postoperative anteroposterior radiographs. RTHA patients were matched to a control group of CTHA patients, in terms of preoperative native femoral head size, age, gender, body mass index (BMI) and approach. Acetabular cup size relative to femoral head size was used as a surrogate for amount of bone resected. We compared the groups according to 2 measures describing acetabular cup diameter ( c) in relation to femoral head diameter ( f): (i) c-f, the difference between cup diameter and femoral head diameter and (ii) ( c-f)/ f, the same difference as a fraction of femoral head diameter. Results 57 matched pairs were included in each group. There were no significant differences between groups for demographic measures, femoral head diameter, or acetabular cup diameter (p>0.05). However, measures (i) and (ii) did differ significantly between the groups, with lower values in the RTHA group (p<0.02). Conclusions Using acetabular cup size relative to femoral head size as an approximate surrogate measure of acetabular bone resection may suggest greater preservation of bone stock using RTHA compared to CTHA. Further studies are needed to validate the relationship between acetabular cup size and bone loss in THA.

Comparision of Cup Anteversion and Tilt Effects on Dislocation Propensity for Small-Head-Size Total Hip Replacements

2000 ◽  
Author(s):  
Mark E. Nadzadi ◽  
Douglas R. Pedersen ◽  
John J. Callaghan ◽  
Thomas D. Brown
Keyword(s):  
Range Of Motion ◽  
Three Dimensional ◽  
Element Model ◽  
Head Size ◽  
Modular System ◽  
Total Hip ◽  
Total Hip Replacements ◽  
Apparent Stiffness ◽  
Hip Replacements ◽  
Laboratory Examinations

Abstract While dislocation is a leading cause of total hip replacement failure, empirical observations far outnumber systematic laboratory examinations of this phenomenon. A previously validated three-dimensional, non-linear, contact finite element model was used to study how surgical placement affects dislocation propensity. The computational model employed a widely used 22mm modular system, and examined range of motion prior to impingement as well as peak moment developed to resist dislocation under a typical leg-crossing maneuver. Results were compared to a previous study of an otherwise similar 26mm modular head system, using the same formulation. Similar trends occurred. Increasing tilt and/or anteversion increased both the range of motion and the peak resisting moment, while apparent stiffness seemed to be unaffected. Further, impingement range of motion was independent of head size, but peak resisting moment was nearly 25% less for the 22mm head sizes.

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