Evaluation of the Success of Non-Cemented Porous and HA Coated Metal-UHMWPE Total Hip Implant Systems

2004 ◽  
pp. 33-40
Author(s):  
Sheila Rao ◽  
Adam Leckey
Keyword(s):  
Hip Implant ◽  
Total Hip ◽  
Coated Metal

Redesign of the Femoral Stem for a Total Hip Arthroplasty for Additive Manufacturing

2018 ◽  
Author(s):  
Bradley Hanks ◽  
Shantanab Dinda ◽  
Sanjay Joshi
Keyword(s):  
Additive Manufacturing ◽  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Lattice Structure ◽  
Stress Shielding ◽  
Patient Specific ◽  
Hip Implants ◽  
Hip Implant ◽  
Total Hip ◽  
Multiple Materials

Total hip arthroplasty (THA) is an increasingly common procedure that replaces all or part of the hip joint. The average age of patients is decreasing, which in turn increases the need for more durable implants. Revisions in hip implants are frequently caused by three primary issues: femoral loading, poor fixation, and stress shielding. First, as the age of hip implant patients decreases, the hip implants are seeing increased loading, beyond what they were traditionally designed for. Second, traditional implants may have roughened surfaces but are not fully porous which would allow bone to grow in and through the implant. Third, traditional implants are too stiff, causing more load to be carried by the implant and shielding the bone from stress. Ultimately this stress shielding leads to bone resorption and implant loosening. Additive manufacturing (AM) presents a unique opportunity for enhanced performance by allowing for personalized medicine and increased functionality through geometrically complex parts. Much research has been devoted to how AM can be used to improve surgical implants through lattice structures. To date, the authors have found no studies that have performed a complete 3D lattice structure optimization in patient specific anatomy. This paper discusses the general design of an AM hip implant that is personalized for patient specific anatomy and proposes a workflow for optimizing a lattice structure within the implant. Using this design workflow, several lattice structured AM hip implants of various unit cell types are optimized. A solid hip implant is compared against the optimized hip implants. It appears the AM hip implant with a tetra lattice outperforms the other implant by reducing stiffness and allowing for greater bone ingrowth. Ultimately it was found that AM software still has many limitations associated with attempting complex optimizations with multiple materials in patient specific anatomy. Though software limitations prevented a full 3D optimization in patient specific anatomy, the challenges associated such an approach and limitations of the current software are discussed.

Effect of Stem Positioning on Biomechanical Performance of a Novel Cementless Short-Stem Canine Total Hip Implant

2021 ◽  
Author(s):  
Natalie Jean Worden ◽  
Kristian J. Ash ◽  
Nathaniel R. Ordway ◽  
Mark Miller ◽  
Kenneth A. Mann ◽  
...  
Keyword(s):  
Femoral Neck ◽  
Ex Vivo ◽  
Peak Load ◽  
Relative Size ◽  
Peak Torque ◽  
Torsional Stiffness ◽  
Short Stem ◽  
Hip Implant ◽  
Total Hip ◽  
Implant Size

Abstract Objective The aim of this study was to evaluate the effect of stem positioning on the biomechanical performance of a novel, collared, short-stem total hip implant under compression and torsion ex vivo. Study Design Six canine cadaveric femurs were implanted with a collared short-stem femoral implant. Canal flare index (CFI), stem angle, absolute and relative cut heights and relative size were measured radiographically and used as independent variables. Biomechanical performance of the construct was evaluated using physiologic loading (loading) and supraphysiologic loading (failure) protocols. Results During loading protocols, compressive stiffness was influenced by absolute cut height (p = 0.018). During failure protocols, peak torque was influenced by CFI (p = 0.004) and craniocaudal relative size (p = 0.005). Peak load and torsional stiffness were not impacted by any of the radiographic variables (p > 0.05). Three of six femurs developed longitudinal fractures originating at the medial calcar at the time of failure. Conclusion The biomechanical performance of the collared short-stem implant was positively impacted by preserving more of the femoral neck, having a higher CFI and using a smaller implant size relative to the femoral neck isthmus.

Aseptic Loosening of Total Hip Implant: Mechanisms of Osteolysis and Potential Therapy

2010 ◽  
Vol 17 (3) ◽  
pp. 82-88
Author(s):  
M A Berglezov ◽  
Tat'yana Mikhaylovna Andreeva ◽  
M A Berglezov ◽  
T M Andreeva
Keyword(s):  
Aseptic Loosening ◽  
Hip Implant ◽  
Total Hip

scholarly journals The Design Improvement of Hip Implant for Total Hip Replacement (THR)

2008 ◽  
Vol 20 (1) ◽  
pp. 107-113
Author(s):  
Solehuddin Shuib ◽  
◽  
Barkawi Sahari ◽  
Amran Ahmed Shokri ◽  
Chew Soon Chai ◽  
...  
Keyword(s):  
Total Hip Replacement ◽  
Hip Replacement ◽  
Hip Implant ◽  
Design Improvement ◽  
Total Hip

Evaluation of femoral head damage during canine total hip replacement

2003 ◽  
Vol 16 (03) ◽  
pp. 184-190 ◽  
Author(s):  
H. Powell ◽  
A. Kohm ◽  
J. J. Lannutti ◽  
J. Dyce ◽  
I. Wood
Keyword(s):  
Electron Microscopy ◽  
Femoral Head ◽  
Total Hip Replacement ◽  
Hip Replacement ◽  
Polyethylene Wear ◽  
Optical Profilometry ◽  
Total Hip ◽  
Coated Metal ◽  
Hip Reduction ◽  
Scanning Electron

SummaryThree types of hip skids and a Hohmann retractor technique were used to facilitate reduction of the prosthesis in cadaveric canine total hip replacement. The degree of damage to the femoral head was evaluated using scanning electron microscopy and optical profilometry. Standard metal and ME-92 coated metal hip skids caused severe regional scratching of the femoral head. Morphologically similar scratch patterns were also identified on femoral heads retrieved from clinical patients. Use of a plastic coated skid or the Hohmann retractor technique had no perceptible effect on surface finish, and therefore either method is acceptable in clinical practice. The use of metal hip skids cannot be recommended for hip reduction as the resultant pattern of femoral head scratching is likely to be associated with early and severe polyethylene wear.

The fully hydroxyapatite-coated total hip implant

1996 ◽  
Vol 11 (5) ◽  
pp. 534-542 ◽  
Author(s):  
Ravishankar Vedantam ◽  
C. Ruddlesdin
Keyword(s):  
Hip Implant ◽  
Total Hip

Biological Fixation of a Porous-Coated, Metal-Backed Acetabular Component in Canine Total Hip Arthroplasty

1988 ◽  
Vol 01 (03/04) ◽  
pp. 141-145
Author(s):  
J. Schatzker ◽  
G. Sumner-Smith ◽  
V. L. Fornasier ◽  
J. R. Cockshutt
Keyword(s):  
Bone Ingrowth ◽  
Fibrous Tissue ◽  
Tissue Response ◽  
Surface Replacement ◽  
Cobalt Chromium ◽  
Biological Fixation ◽  
Total Hip ◽  
Coated Metal ◽  
Cobalt Chromium Molybdenum ◽  
Acetabular Components

A total hip surface replacement was successfully performed on eight adult dogs, using a porous-coated, cobalt-chromium- molybdenum alloy acetabular resurfacing component fixed to the acetabulum with 3.5 mm cortical screws. Functional, radiological, histological and fluorochrome labelling studies were used to assess tissue response to the implant. At four months after implantation, seven of the acetabular components were anchored with well organized fibrous tissue. Bone ingrowth had occurred in three components. Failures appeared to be due to technical difficulties encountered during the surgical procedure.

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