Modularity of total hip prosthesis and its tribological implications

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Liliana-Laura Badita ◽  
Virgil Florescu ◽  
Constantin Tiganesteanu ◽  
Lucian Capitanu
Keyword(s):  
Femoral Head ◽  
Hip Prosthesis ◽  
Femoral Stem ◽  
Fretting Wear ◽  
Fretting Corrosion ◽  
Content Type ◽  
Hip Prostheses ◽  
Total Hip ◽  
Starting Point ◽  
Modular Prostheses

Purpose The study aims to analyze the fretting phenomenon, manifested at the taper junctions of modular total hip prostheses (THP). Modularity of prostheses implies the micro-movement occurrence. Fractures can arise as a result of the fretting cracking of the prostheses components, affecting durability of modular THPs. Fretting corrosion is associated with the decrease in the clinical acceptance of hip modular implants. Design/methodology/approach Starting from the fretting phenomenon influence on modularity, monoblock THPs and prostheses with modular femoral head recovered from some review surgeries were investigated. Modular prostheses have a taper junction femoral head – femoral stem neck. Investigation consisted in the analysis of fretting wear and fretting corrosion, of the femoral heads’ taper and of the femoral stems’ trunnions. Findings The main result was that the micro-movement that provokes the fretting of the femoral head-femoral stem taper junction analyzed does not have the same direction. It is manifesting in the direction of the axis of the femoral head taper, around this axis or as a composed movement. The authors suspect that this is due to the different design of the taper. In this way, the inclination of the stem’s trunnion into the head hole has a different angular misalignment and may cause greater damages of the taper. Originality/value This result can be a starting point from the improvement of the future taper junctions design that will improve the quality, durability and modularity of THPs.

Influence of the taper on the fretting wear of the femoral stem-femoral head taper junction in total hip prosthesis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lucian Capitanu ◽  
Liliana-Laura Badita ◽  
Constantin Tiganesteanu ◽  
Virgil Florescu
Keyword(s):  
Femoral Head ◽  
Hip Prosthesis ◽  
Femoral Stem ◽  
Fretting Wear ◽  
Linear Wear ◽  
Total Hip Prosthesis ◽  
Content Type ◽  
Wear Rates ◽  
Total Hip ◽  
Femoral Heads

Purpose The purpose of this paper is to study the roughness effect on the fixation of taper junction components and surfaces wear in terms of taper surface design. The roughness of the femoral heads’ taper and of the femoral stems’ trunnions can influence the fretting wear of the taper junction. Design/methodology/approach It was analysed whether a microgrooved taper surface of the femoral stem trunnion improves the fixation and reduces the wear rate at the taper junction of the hip prosthesis. Two models have studied: a femoral head with a smooth tapered surface combined with a microgrooved stem trunnion and a femoral head with a smooth tapered surface combined with a trunnion that had a smooth surface of the tapered. To compare the wear evolution between these two models, a computerised finite element model of the wear was used. Findings The results obtained after analysis carried out during millions of loading cycles showed that the depth of the linear wear and the total material loss were higher for the femoral heads joined with microgrooved trunnions. The main conclusion of this paper is that the smooth surfaces of the taper and of the trunnions will ensure a better fixation at the taper junction, and therefore, will reduce the volumetric wear rates. Originality/value A higher fixation of the taper junction will reduce the total hip prosthesis failure and, finally, it will improve the quality and durability of modular hip prostheses.

Range of Motion Caused by Design of the Total Hip Prosthesis

1988 ◽  
Vol 29 (6) ◽  
pp. 701-704 ◽  
Author(s):  
K. Herrlin ◽  
G. Selvik ◽  
H. Pettersson ◽  
L. Lidgren
Keyword(s):  
Range Of Motion ◽  
Hip Prosthesis ◽  
Femoral Stem ◽  
Clinical Material ◽  
Prosthetic Design ◽  
Total Hip Prosthesis ◽  
Hip Prostheses ◽  
Total Hip ◽  
Total Hip Prostheses

In a clinical material of total hip prostheses, a study was performed of the range of femoral motion until impingement occurred between the neck of the femoral stem and the rim of the acetabular socket. The results were compared with the physiologic range of motion, and the clinically relevant motion restriction was measured. Restriction was most common in flexion. There was a correlation between the prosthetic design and the restriction due to impingement.

scholarly journals Spontaneous Early Intraprosthetic Dislocation of 22 mm Skirted Femoral Head in Dual Mobility Hip Prosthesis: A Case Report

2021 ◽  
Vol 11 (5) ◽  
Author(s):  
Gur Aziz Singh Sidhu ◽  
Amit Kotecha ◽  
Sanjay Mulay ◽  
Neil Ashwood
Keyword(s):  
Case Report ◽  
Femoral Head ◽  
Revision Surgery ◽  
Hip Prosthesis ◽  
Weight Bearing ◽  
Femoral Stem ◽  
Acetabular Cup ◽  
Dual Mobility ◽  
Metal Head ◽  
Intraprosthetic Dislocation

Introduction: There is a trend for increasing use of dual mobility hip designs for both primary and revision hip arthroplasty settings. It provides dual articular surfaces along with increased jump distance to increase the stability of construct. However, this design has some unique complications of its own which surgeons should be aware of especially intraprosthetic dislocation (IPD). Case Report: A 76-year-old lady presented to clinic with painful hip hemiarthroplasty after fracture neck of femur. She underwent revision surgery with dual mobility uncemented acetabular cup and femoral stem was retained as it was well fixed. She was mobilizing well and around 5 weeks post her surgery, developed pain in hip region and difficulty in weight-bearing. Radiographs showed eccentric position of femoral neck in the socket. A diagnosis of IPD was established and revision surgery was planned. Intraoperatively, metal head had dislocated from the polyethylene head and both components were resting in the acetabular socket. No macroscopic erosion of acetabulum was noticed. The polyethylene component and femoral head were retrieved. With previous failed dual mobility, decision was made to achieve stability with larger head size and lipped liner posteriorly. Conclusion: IPD is a rare occurrence and unique complication to dual mobility implants. This report highlights that patients can have IPD without fall or trauma. Keywords: Intraprosthetic dislocation, dual mobility cup, dislocation, total hip replacement.

The Porous-Coated Anatomic (PCA) Total Hip Prosthesis

1994 ◽  
Vol 4 (2) ◽  
pp. 69-74
Author(s):  
P. Farsetti ◽  
R. Caterini ◽  
V. Barletta ◽  
A. E. Guarnieri ◽  
E. Ippolito
Keyword(s):  
Hip Prosthesis ◽  
Bone Ingrowth ◽  
Gluteus Medius ◽  
Radiographic Examination ◽  
Total Hip Prosthesis ◽  
Rating Score ◽  
Hip Prostheses ◽  
Total Hip ◽  
Total Hip Prostheses

Thirty uncemented porous-coated anatomic (PCA) total hip prostheses were implanted in 27 patients. The average age at the time of surgery was 54 years, and the average follow-up was 4.5 years. The average hip rating score was 88 points. Three patients had thigh pain at follow-up and fifteen had a mild limp, related to a weakness of the gluteus medius and minimus. On radiographic examination, we observed a good bone ingrowth of the implant in all patients. No aseptic loosening was radiographically demonstrated. No relationship was found between pain in the thigh and the various radiographic parameters studied (ra-diodense lines, sclerosis, varus position of the stem).

scholarly journals Comparison of four parameters to assess acetabular dysplasia and acetabular dysplasia rates in primary hip osteoarthritis patients: A study in Turkish population

2018 ◽  
Vol 26 (2) ◽  
pp. 230949901876803 ◽  
Author(s):  
Oktay Adanir ◽  
Gazi Zorer
Keyword(s):  
Femoral Head ◽  
Acetabular Dysplasia ◽  
Hip Prosthesis ◽  
Hip Osteoarthritis ◽  
High Rate ◽  
Femoral Head Coverage ◽  
Coverage Ratio ◽  
Total Hip ◽  
Center Edge ◽  
Age At Surgery

Introduction: Hip osteoarthritis is an important orthopedic problem frequently observed in the elderly. Acetabular dysplasia (AD) is one of the pathologies that cause coxarthrosis. Nearly 20–45% of primary or idiopathic hip osteoarthritis is linked to AD. In our country, there are few studies on this topic. We measured the center–edge (CE) angle, Sharp’s angle, acetabular depth, and femoral head coverage ratio on pelvis anteroposterior radiographs of patients with primary coxarthrosis and calculated the dysplasia rates. Patients and method: Age at surgery and sex of the patients; and CE angle, Sharp’s angle, acetabular depth, and femoral head coverage ratio for both operated and opposite hips were evaluated in 223 total hip prosthesis–performed patients with coxarthrosis. Also the distribution of mean age at surgery, sex of patients, dysplasia rates of operated hips, and bilateral dysplasia rates were calculated. Results: The right to left ratio of operated hips was 104/119. Female to male ratio was 163/60 (2.7/1), for those with CE angle below 20° it was 123/30 (4.1/1), and it was 40/30 (1.3/1) with CE angle above 20°. Mean age of patients at surgery was 56.9 (±11.4) years. CE angle less than 20° was found in 68.6% of patients, acetabulum depth less than 9 mm was found in 75.3%, Sharp’s angle was more than 45° in 65.9%, and femoral head coverage ratio was less than 70% in 70.3% of patients. Conclusions: We identified a high rate of AD in primary coxarthrosis patients undergoing total hip arthroplasty in the study population.

scholarly journals Impact of stem design and cementation on postoperative femoral antetorsion in 227 patients with total hip arthroplasty (THA)

2020 ◽  
Vol 49 (12) ◽  
pp. 2001-2009
Author(s):  
Tim Fischer ◽  
Christoph Stern ◽  
Benjamin Fritz ◽  
Patrick O. Zingg ◽  
Christian W. A. Pfirrmann ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Hip Prosthesis ◽  
Femoral Stem ◽  
Stem Design ◽  
Femoral Antetorsion ◽  
Total Hip ◽  
Posterior Condylar ◽  
Lower Variability

Abstract Objective In total hip arthroplasty (THA), surgeons attempt to achieve a physiological antetorsion. However, postoperative antetorsion of the femoral stem is known to show large variabilities. The purpose of this study was to assess whether postoperative antetorsion is influenced by stem design or cementation. Materials and methods This retrospective study included 227 patients with a hip prosthesis with five different stem designs (S1: short curved, S2 and S3: standard straight, S4: standard straight collared, S5: cemented straight), who had metal suppressed 1.5T-MRI of the hip between February 2015 and October 2019. Measurement of femoral antetorsion was done independently by two fellowship-trained radiologists on axial images by measuring the angle between the long axis of the femoral neck and the posterior condylar tangent of the knee. Measured angles in the different groups were compared using the t test for independent samples. Results The cementless collared stem S4 showed the highest antetorsion with 18.1° (± 10.5°; range –10°–45°), which was significantly higher than the antetorsion of the collarless S3 with 13.3° (± 8.4°; − 4°–29°) and the cemented S5 with 12.7° (± 7.7°; − 3°–27°) with p = 0.012 and p = 0.007, respectively. S1 and S2 showed an antetorsion of 14.8° (± 10.0°; 1°–37°) and 14.1° (± 12.2°; − 20°–41°). The torsional variability of the cementless stems (S1–4) was significantly higher compared with that of the cemented S5 with a combined standard deviation of 10.5° and 7.7° (p = 0.019). Conclusion Prosthesis design impacts the postoperative femoral antetorsion, with the cementless collared stem showing the highest antetorsion. Cemented stems demonstrated significantly lower variability, suggesting the lowest rate of inadvertent malrotation.

Femoral Anteversion and Restricted Range of Motion in Total Hip Prostheses

1988 ◽  
Vol 29 (5) ◽  
pp. 551-553 ◽  
Author(s):  
K. Herrlin ◽  
H. Pettersson ◽  
G. Selvik ◽  
L. Lidgren
Keyword(s):  
Range Of Motion ◽  
Femoral Component ◽  
Hip Prosthesis ◽  
Femoral Anteversion ◽  
Restricted Range ◽  
Total Hip Prosthesis ◽  
Hip Prostheses ◽  
Total Hip ◽  
Total Hip Prostheses

Impingement of the neck of the stem on to the rim of the socket may cause dislocation of the total hip prosthesis. The role of femoral anteversion in the occurrence of such impingement was analyzed in a clinical material of total hip prostheses with and without dislocation. A low femoral anteversion was linked to a clinically relevant reduction of the range of motion due to impingement and dominated in the group with dislocations. Impingement is minimized by inserting the femoral component in 10° to 20° of anteversion.

scholarly journals Assessment of the contact stress distribution dependent on functional and design parameters after total hip arthroplasty

2009 ◽  
pp. 43-53
Author(s):  
Emmanuel Rixrath ◽  
Sylvie Wendling-Mansuy ◽  
Patrick Chabrand
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Hip Prosthesis ◽  
Distribution Model ◽  
Design Parameters ◽  
Geometrical Parameters ◽  
Hip Prostheses ◽  
Total Hip ◽  
Dynamic Loading Conditions ◽  
Contact Stress Distribution

A numerical model was developed to assess the contact stress distribution in total hip prosthesis as a function of geometrical parameters such as the clearance between the bearing surfaces, the inclination and thickness of the UHMWPE cup. The contact stress distribution model proposed is submitted to static loading considering the maximal force during gait and jogging. The results shows that the magnitude of the maximal contact stress remains constant for inclination values in the range of [0-35°] and increase significantly with the cup clearance and liner thickness for inclination values in the range of [35°-65°]. This model could be improved by considering other factors such as friction and dynamic loading conditions. This approach would permit to bring new perspectives for studying the long-term behaviour of total hip prostheses.

scholarly journals Some Hard or Soft Coatings to Protect the Pristine Biometallic Substrates under Fretting-Corrosion Solicitations: What Should Be the Best Solution?

Lubricants ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 55
Author(s):  
Jean Geringer ◽  
Vincent Fridrici ◽  
Haohao Ding ◽  
Kyungmok Kim ◽  
T. Taylor ◽  
...  
Keyword(s):  
Hip Prosthesis ◽  
Femoral Stem ◽  
Hard Coatings ◽  
Mechanical Degradation ◽  
Diamond Like Carbon ◽  
Metallic Ions ◽  
Fretting Corrosion ◽  
Metallic Parts ◽  
Peek Coating ◽  
Metal Friction

Under tribological conditions in aqueous medium, the contact of materials does involve some degradations of materials. Especially friction under small reciprocal displacement, i.e., fretting corrosion, is occurring; this topic has been highlighted since the 80′s regarding hip implants. Hip prosthesis is assembled from three parts: femoral stem, neck and head. Fretting corrosion or friction corrosion between metallic parts first involves some degradation of the oxides layers. This step is governed by mechanics and it is related to some few minutes. Afterwards the corrosion occurrs enhanced by mechanical degradation. As well focused some oxides and some metallic ions are related to biocompatibility issues. Some strategies are available in order to avoid metal against metal friction and/or fretting. Some hard coatings and some smooth coatings were investigated. The first one is diamond-like carbon (DLC), and the second is a polyetheretherketone (PEEK), polymeric one. The investigations were focused on fretting corrosion solicitations of Ti-6Al-4V vs. Ti-6Al-4V + coating. DLC as a coating delays the corrosion degradation. The PEEK coating does not promote any corrosion degradation of the metallic counter part and more generally any wear.

Sign in / Sign up

Export Citation Format

Share Document