Design parameters and the material coupling are decisive for the micromotion magnitude at the stem–neck interface of bi-modular hip implants

Jauch, S.Y.; Huber, Gerd; Haschke, Henning; Sellenschloh, Kay; Morlock, Michael M.

doi:10.1016/j.medengphy.2013.11.009

Cited by 46 publications

(29 citation statements)

References 28 publications

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“…2). Micromotion at the neck-stem junction results in abrasion and fretting corrosion [17,18]. Chemomechanical stress is reported to be higher in titanium modular necks compared with cobalt-chromium bimodular necks.…”

Section: Discussionmentioning

confidence: 99%

High Risk of Failure With Bimodular Femoral Components in THA

Pour

Borden

Murayama

et al. 2016

Clinical Orthopaedics &Amp; Related Research

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Background The bimodular femoral neck implant (modularity in the neck section and prosthetic head) offers several implant advantages to the surgeon performing THAs, however, there have been reports of failure of bimodular femoral implants involving neck fractures or adverse tissue reaction to metal debris. We aimed to assess the results of the bimodular implants used in the THAs we performed. Questions/purposes We asked: (1) What is the survivorship of the PROFEMUR 1 bimodular femoral neck stems? (2) What are the modes of failure of this bimodular femoral neck implant? (3) What are the major risk factors for the major modes of failure of this device?Methods Between 2003 and 2009, we used one family of bimodular femoral neck stems for all primary THAs (PRO-FEMUR 1 Z and PROFEMUR 1 E). During this period, 277 THAs (in 242 patients) were performed with these implants. One hundred seventy were done with the bimodular PROFE-MUR 1 E (all are accounted for here), and when that implant was suspected of having a high risk of failure, the bimodular PROFEMUR 1 Z was used instead. One hundred seven THAs were performed using this implant (all are accounted for in this study). All bearing combinations, including metal-on-metal, metal-on-polyethylene, and ceramic-on-ceramic, are included here. Data for the cohort included patient demographics, BMI, implant dimensions, type of articular surface, length of followup, and C-reactive protein serum level. We assessed survivorship of the two stems using Kaplan-Meier curves and determined the frequency of the different modes of stem failure. For each of the major modes of failure, we performed binary logistic regression to identify associated risk factors. Results Survivorship of the stems, using aseptic revision as the endpoint, was 85% for the patients with the PROFE-MUR 1 E stems with a mean followup of 50 months (range, 1-125 months) and 85% for the PROFEMUR 1 Z with a mean followup of 50 months (range, 1-125 months)(95% CI, 74-87 months). The most common modes of failure were loosening (9% for the PROFEMUR 1 E), neck fracture (6% for the PROFEMUR 1 Z and 0.6% for the PROFEMUR 1 E), metallosis (1%), and periprosthetic fracture (1%). Only the bimodular PROFEMUR 1 E was associated with femoral stem loosening (odds ratio [OR] =1.1; 95% CI, 1.04-1.140; p = 0.032). Larger head (OR = 3.2; 95% CI, 0.7-14; p = 0.096), BMI (OR = 1.19; 95% CI, 1-1.4; p = 0.038) and total offset (OR = 1.83; 95% CI, 1.13-2.9; p = 0.039) were associated with neck fracture.

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Section: Discussionmentioning

confidence: 99%

High Risk of Failure With Bimodular Femoral Components in THA

Pour

Borden

Murayama

et al. 2016

Clinical Orthopaedics &Amp; Related Research

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“…Nominally the 12/14 taper has been used over the past 20 years, which suggests the taper angle has not changed, but little is known about the machining tolerances of tapers and trunnions among the different manufacturers. In dual modular stems, material coupling and the taper design are also crucial for the micromotion magnitude at the stem-neck junction with titanium neck adapters having significantly higher interface micromotions than those with CoCr adapters [29]. The additional stem-neck junction in dual modular stems has been associated with increased damage at the head-stem junction [22].…”

Section: What Clinical Problems Have Been Reported In Patients With Mmentioning

confidence: 99%

What is the Trouble With Trunnions?

Esposito¹,

Wright²,

Goodman³

et al. 2014

Clin Orthop Relat Res

112

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“…Despite the fact that the precise failure mechanism at taper interfaces is not yet completely elucidated, it is undisputed that micromotion between the adjacent implant components plays a role for this clinical concern [9,[25][26][27][28]. Previous experimental [28][29][30][31][32][33] and numerical studies [34,35] have evaluated micromotion at taper interfaces: the documented values report a large range from a few microns to more than 40 µm indicating that several factors such as, the prosthesis geometry, manufacturing tolerances of the taper, the location of the taper connection (headstem or stem-neck), taper surface topography and the assembly conditions may influence the micromotion levels [28][29][30][31][32]35]. These may be linked to changes in the location and size of the taper contact area [36] and the assembly force.…”

Section: Introductionmentioning

confidence: 99%

Effect of trunnion roughness and length on the modular taper junction strength under typical intraoperative assembly forces

Jauch-Matt

Miles

Gill

2017

Medical Engineering & Physics

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Modular hip implants are at risk of fretting-induced postoperative complications most likely initiated by micromotion between adjacent implant components. A stable fixation between ball head and stem-neck taper is critical to avoid excessive interface motions. Therefore, the aim of this study was to identify the effect of trunnion roughness and length on the modular taper strength under typical intraoperative assembly forces. Custom-made Titanium trunnions (standard/mini taper, smooth/grooved surface finish) were assembled with modular Cobalt-chromium heads by impaction with peak forces ranging from 2kN to 6kN. After each assembly process these were disassembled with a materials testing machine to detect the pull-off force as a measure for the taper strength. As expected, the pull-off forces increased with rising peak assembly force (p < 0.001). For low and moderate assembly forces, smooth standard tapers offered higher pull-off forces compared to grooved tapers (p < 0.038). In the case of an assembly force of 2kN, mini tapers showed a higher taper strength than standard ones (p=0.037). The results of this study showed that smooth tapers provided a higher strength for taper junctions. This higher taper strength may reduce the risk of fretting-related complications especially in the most common range of intraoperative assembly forces.

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Design parameters and the material coupling are decisive for the micromotion magnitude at the stem–neck interface of bi-modular hip implants

Cited by 46 publications

References 28 publications

High Risk of Failure With Bimodular Femoral Components in THA

High Risk of Failure With Bimodular Femoral Components in THA

What is the Trouble With Trunnions?

Effect of trunnion roughness and length on the modular taper junction strength under typical intraoperative assembly forces

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