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Pagani NR, LeRoy TE, Menendez ME, Stoker GE, Lococo DV, Nairus JG. Gross Trunnion Failure of a Type 1 Taper After Metal-on-Polyethylene Total Hip Arthroplasty: A Report of 2 Cases. JBJS Case Connect 2021; 11:01709767-202106000-00133. [PMID: 34166254 DOI: 10.2106/jbjs.cc.21.00098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
CASE We describe 2 cases of gross trunnion failure (GTF) in males with Centers for Disease Control and Prevention Class 3 obesity 10 years after metal-on-polyethylene total hip arthroplasty (THA) with a titanium-alloy femoral stem and Type 1 taper. One patient received a large diameter cobalt-chromium femoral head, whereas the other received a smaller diameter head, both with high-offset femoral stems. CONCLUSION This is the first report of GTF involving the Echo Bi-Metric femoral stem after metal-on-polyethylene THA, and surgeons should consider the potential complication of GTF when using this specific femoral stem with metal heads in obese male patients.
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Affiliation(s)
- Nicholas R Pagani
- Department of Orthopaedic Surgery, New England Baptist Hospital, Boston, Massachusetts
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Avila JD, Bandyopadhyay A. Zirconia-Toughened Alumina Coated Ti6Al4V via Additive Manufacturing. MATERIALS LETTERS 2021; 291:129577. [PMID: 33692601 PMCID: PMC7939135 DOI: 10.1016/j.matlet.2021.129577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
CoCr alloy-based femoral heads have failed prematurely due to galvanic-induced corrosion when coupled with a titanium hip stem. Coupling a titanium based-femoral head with the titanium hip stem is ideal in addressing this failure mode. Ti6Al4V (Ti64) alloy was reinforced with zirconia-toughened alumina (ZTA) by directed-energy deposition (DED)-based additive manufacturing (AM) to address that concern. Preliminary materials processing work resulted in failed samples due to cracking, porosity, and delamination. After careful parameter optimization, a Ti64+5wt.%ZTA (5ZTA) composition produced a metallurgically sound and coherent interface, minimal porosity, and bulk structures. Hardness was observed to increase by 27%, normalized wear rate reduced by 25%, and contact resistance increased during in vitro tribological testing along with faster surface re-passivation.
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Fokter SK, Zajc J, Merc M. Interchangeable neck failures of bi-modular femoral stems in primary total hip arthroplasty cannot be predicted from serum trace element analysis. INTERNATIONAL ORTHOPAEDICS 2020; 45:877-881. [PMID: 32935199 DOI: 10.1007/s00264-020-04812-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 09/11/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Revision of a well-fixed stem due to unexpected modular neck fracture is a catastrophe for the patient and a challenge for the surgeon. This study aimed to test the possibility of predicting interchangeable neck fracture from serum levels of the stem/neck alloy-consisting metals. MATERIALS AND METHODS Nineteen patients at high risk for interchangeable neck fracture were randomly selected out of a cohort of 680 bimodular stems made from Ti6Al4V alloy. Serum levels of titanium, aluminium and vanadium were determined. Nine age- and gender-matched patients were used as controls. RESULTS Mean serum levels of Ti were 6.04 ± 2.52 μg/L, of Al 3.89 ± 1.68 μg/L and of V 0.07 ± 0.04 μg/L in the high-risk group, and 8.22 ± 4.74 μg/L, 4.99 ± 3.98 μg/L and 0.27 ± 0.44 μg/L in the low-risk group, respectively. No statistically significant differences were found between the groups. DISCUSSION Interchangeable neck fracture of bimodular femoral stems cannot be predicted from serum trace element analysis.
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Affiliation(s)
- Samo K Fokter
- Department for Orthopaedic Surgery, University Medical Centre Maribor, 5 Ljubljanska Street, SLO-2000, Maribor, Slovenia.
| | - Jan Zajc
- Faculty of Medicine, University of Maribor, 8 Taborska Street, SLO-2000 Maribor, Slovenia
| | - Matjaž Merc
- Department for Orthopaedic Surgery, University Medical Centre Maribor, 5 Ljubljanska Street, SLO-2000, Maribor, Slovenia
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Avila JD, Alrawahi Z, Bose S, Bandyopadhyay A. Additively Manufactured Ti6Al4V-Si-Hydroxyapatite composites for articulating surfaces of load-bearing implants. ADDITIVE MANUFACTURING 2020; 34:101241. [PMID: 32432027 PMCID: PMC7236886 DOI: 10.1016/j.addma.2020.101241] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Directed-energy deposition (DED)-based additive manufacturing (AM) was explored for composite development using silicon (Si) and hydroxyapatite (HA) in Ti-6Al-4V (Ti64) matrix for articulating surfaces of load-bearing implants. Specifically, laser engineered net shaping (LENS™), a commercially available DED-based AM technique, was used to fabricate composites from premixed-feedstock powders. The AM'd composites proved to not only improve upon Ti64's mechanical properties but also produced an in-situ Si-based tribofilm during tribological testing that minimized wear induced damage. Additionally, it was found that with the introduction of Si, titanium silicides and vanadium silicides were formed; allowing for 114% increased hardness, decreased coefficient of friction (COF) and a reduction of wear rate of 38.1% and 48.7%, respectively. The produced composites also displayed a positive shift in open-circuit potential (OCP) during linear wear, along with a reduction in the change of OCP from idle to linear wear conditions. Additionally, contact resistance (CR) values increased with a maximum value of 1500 ohms due to the formation of Si-based tribofilm on the wear surface. Such composite development approach using DED-based AM can open up the possibilities of innovating next-generation implants that are designed and manufactured via multi-material AM.
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Lützner J, Günther KP, Postler A, Morlock M. Metal Ion Release after Hip and Knee Arthroplasty - Causes, Biological Effects and Diagnostics. ZEITSCHRIFT FUR ORTHOPADIE UND UNFALLCHIRURGIE 2019; 158:369-382. [PMID: 31820432 DOI: 10.1055/a-0929-8121] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
All metal implants in human bodies corrode which results in metal ions release. This is not necessarily a problem and represents for most patients no hazard. However, if a critical metal ion concentration is exceeded, local or rarely systemic problems can occur. This article summarizes the mechanisms of metal ion release and its clinical consequences. Several situations can result in increased metal ion release: metal-on-metal hip arthroplasties with increased wear, increased micromotion at taper interfaces, direct metal-metal contact (polyethylene wear, impingement), erroneously used metal heads after ceramic head fracture. Possible problems are in most cases located close to the concerned joint. Furthermore, there are reports about toxic damage to several organs. Most of these reports refer to erroneously used metal heads in revisions after a broken ceramic head. There is currently no evidence of carcinogenic or teratogenic effects of implants but data is not sufficient to exclude possible effects. Cobalt and chromium blood levels (favorably in whole blood) should be measured in patients with suspected elevated metal ions. According to current knowledge levels below 2 µg/l seem to be uncritical, levels between 2 and 7 µg/l are considered borderline with unknown biological consequences and levels above 7 µg/l indicate a local problem which should be further diagnosed. Metal ion levels always need to be interpreted together with clinical symptoms and imaging results.
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Affiliation(s)
- Jörg Lützner
- University Center of Orthopaedics and Trauma Surgery, TU Dresden
| | | | - Anne Postler
- University Center of Orthopaedics and Trauma Surgery, TU Dresden
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Martin AJ, Jenkins DR, Van Citters DW. Role of corrosion in taper failure and head disassociation in total hip arthroplasty of a single design. J Orthop Res 2018; 36:2996-3003. [PMID: 29978908 DOI: 10.1002/jor.24107] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 07/01/2018] [Indexed: 02/04/2023]
Abstract
Modular junctions have been associated with corrosion in total hip arthroplasty. In a small number of cases, disassociation of the femoral head from the stem following gross wear of the taper has been reported. The purpose of this study was to investigate the role of corrosion in the development of mechanical changes leading to disassociation. Twenty-one retrieved stems and heads of one design previously reported with head disassociation were identified in an IRB-approved database. Components were scored for corrosion and measured for material loss. Stem alloy hardness was measured. Parametric and non-parametric statistics were performed (α < 0.05). Seven of twenty-one stems demonstrated gross material loss of the stem taper and head disassociation. The maximum linear depth (MLD) of material loss on stem tapers without dissociation and all head bores was 7.63 ± 6.04 and 63.76 ± 60.83 μm, respectively. Hardness of the stem material was statistically distinct, but similar to other stem materials. Results suggest material loss via corrosion at the head bore loosens the taper lock, allowing relative motion leading to abrasive wear of the stem taper. All cases of disassociation occurred at greater than 65 months with a minimum of 50 μm of loss at on the head bore. It may be warranted to survey patients with systems reporting head disassociation; for this system, including recalled heads, risk appears to begin after 6 years in vivo. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2996-3003, 2018.
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Affiliation(s)
- Audrey J Martin
- Thayer School of Engineering, Dartmouth College, 14 Engineering Dr., Hanover 03755, New Hampshire
| | | | - Douglas W Van Citters
- Thayer School of Engineering, Dartmouth College, 14 Engineering Dr., Hanover 03755, New Hampshire
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Krull A, Morlock MM, Bishop NE. Factors influencing taper failure of modular revision hip stems. Med Eng Phys 2018; 54:65-73. [PMID: 29500122 DOI: 10.1016/j.medengphy.2018.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/19/2018] [Accepted: 02/11/2018] [Indexed: 10/17/2022]
Abstract
Stem modularity of revision hip implant systems offers the advantage of the restoration of individual patient geometry but introduces additional interfaces, which are subjected to repetitive bending loading and have a propensity for fretting corrosion. The male stem taper is the weakest part of the modular junction due to its reduced cross section compared to the outside diameter of the stem. Taper fractures can be the consequence of overloading in combination with corrosion. The purpose of this study was to assess the influence of implant design factors, patient factors, and surgical factors on the risk of taper failure of the modular junction of revision stems. An analytical bending model was used to estimate the strength of the taper connection for pristine, fatigued and corroded conditions. Additionally, a finite element contact model of the taper connection was developed to assess the relative motion and potential for surface damage at the taper interface under physiological loading for varyied assembly and design parameters. Increasing the male taper diameter was shown to be the most effective means for increasing taper strength but would require a concurrent increase in the outer implant diameter to limit a greater risk of total surface damage for a thinner female taper wall. Increasing the assembly force decreases the total surface damage but not local magnitudes, which are probably responsible for crack initiation. It is suggested that in unfavourable loading conditions a monobloc implant system will reduce the risk of failure.
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Affiliation(s)
- A Krull
- TUHH - Hamburg University of Technology, Institute of Biomechanics, Denickestrasse 15, 21073 Hamburg, Germany.
| | - M M Morlock
- TUHH - Hamburg University of Technology, Institute of Biomechanics, Denickestrasse 15, 21073 Hamburg, Germany
| | - N E Bishop
- HAW - Hamburg University of Applied Science, Fakulty of Life Sciences, Department of Biomedical Engineering, Ulmenliet 20, 21033 Hamburg, Germany
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Krull A, Morlock MM, Bishop NE. The Influence of Contamination and Cleaning on the Strength of Modular Head Taper Fixation in Total Hip Arthroplasty. J Arthroplasty 2017. [PMID: 28625686 DOI: 10.1016/j.arth.2017.05.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Intraoperative interface contamination of modular head-stem taper junctions of hip implants can lead to poor fixation strength, causing fretting and crevice corrosion or even stem taper fracture. Careful cleaning before assembly should help to reduce these problems. The purpose of this study was to determine the effect of cleaning (with and without drying) contaminated taper interfaces on the taper fixation strength. METHODS Metal or ceramic heads were impacted onto titanium alloy stem tapers with cleaned or contaminated (fat or saline solution) interfaces. The same procedure was performed after cleaning and drying the contaminated interfaces. Pull-off force was used to determine the influence of contamination and cleaning on the taper strength. RESULTS Pull-off forces after contamination with fat were significantly lower than those for uncontaminated interfaces for both head materials. Pull-off forces after application of saline solution were not significantly different from those for uncontaminated tapers. However, a large variation in taper strength was observed, pull-off forces for cleaned and dried tapers were similar to those for uncontaminated tapers for both head materials. CONCLUSION Intraoperative contamination of taper interfaces may be difficult to detect but has a major influence on taper fixation strength. Cleaning of the stem taper with saline solution and drying with gauze directly before assembly allows the taper strength of the pristine components to be achieved. Not drying the taper results in a large variation in pull-off forces, emphasizing that drying is essential for sufficient and reproducible fixation strength.
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Affiliation(s)
- Annika Krull
- Institute of Biomechanics, Hamburg University of Technology, Hamburg, Germany
| | - Michael M Morlock
- Institute of Biomechanics, Hamburg University of Technology, Hamburg, Germany
| | - Nicholas E Bishop
- Institute of Biomechanics, Hamburg University of Technology, Hamburg, Germany; Department of Medical Technology, Faculty of Life Science, HAW Hamburg University of Applied Sciences, Hamburg, Germany
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Fokter SK, Moličnik A, Kavalar R, Pelicon P, Rudolf R, Gubeljak N. Why do some titanium-alloy total hip arthroplasty modular necks fail? J Mech Behav Biomed Mater 2016; 69:107-114. [PMID: 28064103 DOI: 10.1016/j.jmbbm.2016.12.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 11/08/2016] [Accepted: 12/19/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND Increased modularity in total hip arthroplasty (THA) through extra junction between the neck and the femoral stem is gaining popularity among orthopaedic community. However, the advantage of the additional junction is shadowed by an increased risk of mechanical failure. The aim of this study was to describe the exact mechanism of fracture of the modular femoral neck in an uncemented stem. METHODS Clinical, metallurgical, and mechanical analysis including finite-element modelling and elemental-sensitive tissue analysis with the micro-PIXE method was performed on two patients treated with fully modular primary THA made from Titanium alloy of the same oval taper-cone design. In patient A revision was performed 7.8 years after the unilateral primary procedure because of modular femoral neck fracture, while patient B was left-side revised 15 years after the bilateral primary procedure because of aseptic loosening of the femoral stem. RESULTS Body weight was 30% higher and the arm of implanted modular femoral neck was 51% longer in patient A compared to patient B. Therefore, the stress ratio on the modular femoral neck of patient A was calculated to be 2.45 times higher than in patient B, preventing cold welding and producing taper damage and degradation at the neck-stem junction. Large clusters of metallic debris containing Titanium and Vanadium from the alloy were present in the periprosthetic soft tissues of patient A. CONCLUSIONS Patients with higher body mass index treated with fully modular Ti-alloy THA may be at increased risk to experience catastrophic failure of the device. Orthopaedic surgeons should avoid using long necks whenever possible, as these are especially prone to develop a vicious circle starting with the fretting process and crevice corrosion at the taper-cone connection, leading to crack initiation and crack propagation, accelerated by the increased vulnerability of the Ti-alloy in biologic media, ultimately ending as fracture at the typical site. Serum Ti concentration may represent a rough estimation of taper degradation and patients with elevated levels should be warned and followed accordingly.
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Affiliation(s)
- Samo K Fokter
- Department of Orthopaedics, University Medical Centre, Maribor, Slovenia.
| | - Andrej Moličnik
- Department of Orthopaedics, University Medical Centre, Maribor, Slovenia
| | - Rajko Kavalar
- Department of Pathology, University Medical Centre, Maribor, Slovenia
| | | | - Rebeka Rudolf
- Faculty of Mechanical Engineering, University of Maribor, Slovenia; Zlatarna Celje, d.d., Celje, Slovenia
| | - Nenad Gubeljak
- Faculty of Mechanical Engineering, University of Maribor, Slovenia
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