scholarly journals Microsection analysis of cortical form-fit of a custom femoral component in total hip arthroplasty: an in vitro study

2012 ◽  
Vol 4 (3) ◽  
pp. 31 ◽  
Author(s):  
Ulf Gunther Leichtle ◽  
Carmen Ina Leichtle ◽  
Franz Martini
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Stress Shielding ◽  
Femoral Stem ◽  
In Vitro Study ◽  
Limited Information ◽  
Total Hip ◽  
Custom Made ◽  
Diamond Saw

Custom femoral components have been developed for total hip arthroplasty to maximize cortical form-fit and thereby to reduce the problems of stress shielding and aseptic loosening. Limited information is available about how much endosteal cortical contact can actually be achieved with these expensive implants. The aim of this study was therefore to verify the exact cortical contact of a custom made stem using microsections and comparing it to a standard stem with similar design. In 8 human femurs (3 matched pairs and 2 separate specimens), custom femoral prostheses (Adaptiva; 5 femurs: 3 matched and 2 separate) and conventional femoral prostheses (Alloclassic; 3 matched femurs) were implanted. Endosteal cortical contact was determined from CAD planning drafts and microsections cut from the specimens with a diamond saw. Microsection analysis of the paired femurs showed that contact between prosthesis and bone varied clearly along the length of the femoral stem. Total cortical contact was con- siderably greater in custom prostheses than conventional prostheses (custom, 47%; conventional, 32%), but markedly less than the total contact predicted by the manufacturer (84% to 90%). The custom prosthesis had more lateral cortical contact on CAD planning drafts (cortical contact: medial, 60%; lateral, 53%) than on specimen microsections after implantation (medial, 64%; lateral, 24%). In summary, the philosophy of anchorage of both prostheses types could be confirmed. However, areas of cortical contact of the custom made prosthesis were considerably smaller compared to the pre-operative planning.

Early to medium-term outcomes of uncemented ceramic-bearing total hip arthroplasty in teenagers for paediatric hip conditions

2020 ◽  
Vol 102-B (11) ◽  
pp. 1491-1496
Author(s):  
Pranai K. Buddhdev ◽  
Ivor S. Vanhegan ◽  
Tahir Khan ◽  
Aresh Hashemi-Nejad
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Femoral Stem ◽  
Adolescent And Young Adult ◽  
Medium Term ◽  
Total Hip ◽  
Custom Made ◽  
The Mean ◽  
Custom Made Prostheses

Aims Despite advances in the treatment of paediatric hip disease, adolescent and young adult patients can develop early onset end-stage osteoarthritis. The aims of this study were to address the indications and medium-term outcomes for total hip arthroplasty (THA) with ceramic bearings for teenage patients. Methods Surgery was performed by a single surgeon working in the paediatric orthopaedic unit of a tertiary referral hospital. Databases were interrogated from 2003 to 2017 for all teenage patients undergoing THA with a minimum 2.3 year follow-up. Data capture included patient demographics, the underlying hip pathology, number of previous surgeries, and THA prostheses used. Institutional ethical approval was granted to contact patients for prospective clinical outcomes and obtain up-to-date radiographs. In total, 60 primary hips were implanted in 51 patients (35 female, 16 male) with nine bilateral cases. The mean age was 16.7 years (12 to 19) and mean follow-up was 9.3 years (2.3 to 16.8). Results The most common indication for teenage hip arthroplasty was avascular necrosis secondary to slipped upper femoral epiphysis (31%; n = 16). Overall, 64% of patients (n = 33) had undergone multiple previous operations. The survival at follow-up was 97%; two patients required revision for aseptic loosening (one femoral stem, one acetabular component). Both patients had fused hips noted at the time of arthroplasty. A further two patients had radiolucent lines but were asymptomatic. At latest follow-up the mean Oxford Hip Score was 44 (31 to 48) and a Visual Analogue Scale measurement of 1.5, indicating satisfactory function. Conclusion Operating on this cohort can be complicated by multiple previous surgeries and distorted anatomy, which in some cases require custom-made prostheses. We have demonstrated a good outcome with low revision rate in this complex group of patients. Cite this article: Bone Joint J 2020;102-B(11):1491–1496.

scholarly journals Fully porous 3D printed titanium femoral stem to reduce stress-shielding following total hip arthroplasty

2016 ◽  
Vol 35 (8) ◽  
pp. 1774-1783 ◽  
Author(s):  
Sajad Arabnejad ◽  
Burnett Johnston ◽  
Michael Tanzer ◽  
Damiano Pasini
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Stress Shielding ◽  
Femoral Stem ◽  
Total Hip ◽  
3D Printed

scholarly journals Application Of A Thermodynamic-Based Model To Investigate Bone Remodeling After Total Hip Arthroplasty Using Different Hip Implants

2021 ◽  
Author(s):  
Alireza Sayyidmousavi
Keyword(s):  
Total Hip Arthroplasty ◽  
Bone Remodeling ◽  
Mechanical Loading ◽  
Hip Arthroplasty ◽  
Stress Shielding ◽  
Irreversible Thermodynamics ◽  
Total Hip ◽  
Finite Element Software ◽  
Custom Made ◽  
Hip Stems

A new thermodynamic-based model for bone remodeling is introduced. This model is based on chemical kinetics and irreversible thermodynamics in which bone is treated as a self-organizing system capable of exchanging matter, energy and entropy with its surroundings. Unlike the previous works in which mechanical loading is regarded as the only stimulus for bone remodeling, this model establishes a coupling between mechanical loading and the chemical reactions involved in the process of bone remodeling. This model is then incorporated to the finite element software ANSYS in the form of a macro to study bone remodeling after total hip arthroplasty with four different implants: Custom-made titanium, composite, Exceter and Omnifit hip stems. Numerical computations of bone density distribution after total hip arthroplasty indicate that the Omnifit implant with carbon fiber polyamide 12 composite results in minimum resorption in the proximal femur and consequently minimum bone loss due to stress shielding.

Equivalent wear performance of dual mobility bearing compared with standard bearing in total hip arthroplasty: in vitro study

2016 ◽  
Vol 41 (3) ◽  
pp. 521-527 ◽  
Author(s):  
Gaël Gaudin ◽  
André Ferreira ◽  
Romain Gaillard ◽  
Jean Louis Prudhon ◽  
Jacques H. Caton ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
In Vitro Study ◽  
Vitro Study ◽  
Wear Performance ◽  
Dual Mobility ◽  
Total Hip

Femoral cement extraction in revision total hip arthroplasty – an in vitro study comparing computer-assisted freehand-navigated cement removal to conventional cement extraction

2015 ◽  
Vol 60 (6) ◽  
Author(s):  
Torsten Mumme ◽  
Max Julian Friedrich ◽  
Henrik Rode ◽  
Sascha Gravius ◽  
Stefan Andereya ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Conventional Method ◽  
Hip Arthroplasty ◽  
In Vitro Study ◽  
Computer Assisted ◽  
Measured Temperature ◽  
Time Saving ◽  
Total Hip ◽  
Cement Removal

AbstractRevision surgery of cemented femoral stems in total hip arthroplasty is gaining more and more importance, but cement removal in revision hip arthroplasty may be technically challenging. Conventional manual cement removal can be time consuming and be associated with complications such as cortical perforation, fracture, or bone loss. The aim of this study was to investigate the practicability of computer-navigated cement removal.In anThe mean time for cement removal was 29±5 min for the conventional method and 32±8 min for the freehand-navigated cement removal. Here, excepting the preparatory examinations, the navigated cement removal only took 13±5 min. The measured temperature during polymerization was 36±5°C and during navigated cement removal was 37±8°C. In the distal part of the femur, cement removal was more accurate with the conventional method compared to the navigated one.The freehand-navigated cement removal, with the exception of the preparatory examinations, is time saving compared to the conventional method. However, a potential for technical development especially for the milling device and accuracy exist.

scholarly journals Application Of A Thermodynamic-Based Model To Investigate Bone Remodeling After Total Hip Arthroplasty Using Different Hip Implants

2021 ◽  
Author(s):  
Alireza Sayyidmousavi
Keyword(s):  
Total Hip Arthroplasty ◽  
Bone Remodeling ◽  
Mechanical Loading ◽  
Hip Arthroplasty ◽  
Stress Shielding ◽  
Irreversible Thermodynamics ◽  
Total Hip ◽  
Finite Element Software ◽  
Custom Made ◽  
Hip Stems

A new thermodynamic-based model for bone remodeling is introduced. This model is based on chemical kinetics and irreversible thermodynamics in which bone is treated as a self-organizing system capable of exchanging matter, energy and entropy with its surroundings. Unlike the previous works in which mechanical loading is regarded as the only stimulus for bone remodeling, this model establishes a coupling between mechanical loading and the chemical reactions involved in the process of bone remodeling. This model is then incorporated to the finite element software ANSYS in the form of a macro to study bone remodeling after total hip arthroplasty with four different implants: Custom-made titanium, composite, Exceter and Omnifit hip stems. Numerical computations of bone density distribution after total hip arthroplasty indicate that the Omnifit implant with carbon fiber polyamide 12 composite results in minimum resorption in the proximal femur and consequently minimum bone loss due to stress shielding.

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