Influence of material coupling and assembly condition on the magnitude of micromotion at the stem–neck interface of a modular hip endoprosthesis

Jauch, S.Y.; Huber, Gerd; Hoenig, Elisa; Baxmann, M.; Grupp, Thomas M.; Morlock, Michael M.

doi:10.1016/j.jbiomech.2011.04.007

Cited by 116 publications

(66 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The combination of a small trunnion and lower modulus alloy results in this particular stem design offering the lowest flexural rigidity at the femoral trunnion of any of the 85 stems analyzed (Table 4) and may be a cause for concern. However, corrosion is a multifactorial process that depends not only on these mechanical causes, but also on other factors such as the method of manufacture and intraoperative assembly [3,5,16,21,26,27].…”

Section: Discussionmentioning

confidence: 99%

Modern Trunnions Are More Flexible: A Mechanical Analysis of THA Taper Designs

Porter

Urban

Jacobs

et al. 2014

Clin Orthop Relat Res

View full text Add to dashboard Cite

Background There is renewed concern surrounding the potential for corrosion at the modular head-neck junction to cause early failure in contemporary THAs. Although taper corrosion involves a complex interplay of many factors, a previous study suggested that a decrease in flexural rigidity of the femoral trunnion may be associated with an increased likelihood of corrosion at retrieval. Questions/purposes By analyzing a large revision retrieval database of femoral stems released during a span of three decades, we asked: (1) how much does flexural rigidity vary among different taper designs; (2) what is the contribution of taper geometry alone to flexural rigidity of the femoral trunnion; and (3) how have flexural rigidity and taper length changed with time in this group of revised retrievals? Methods A dual-center retrieval analysis of 85 modular femoral stems released between 1983 and 2012 was performed, and the flexural rigidity and length of the femoral trunnions were determined. These stems were implanted between 1991 and 2012 and retrieved at revision or removal surgery between 2004 and 2012. There were 10 different taper designs made from five different metal alloys from 16 manufacturers. Digital calipers were used to measure taper geometries by two independent observers. Results Median flexural rigidity was 228 N-m 2 ; however, there was a wide range of values among the various stems spanning nearly an order of magnitude between the most

show abstract

Section: Discussionmentioning

confidence: 99%

Modern Trunnions Are More Flexible: A Mechanical Analysis of THA Taper Designs

Porter

Urban

Jacobs

et al. 2014

Clin Orthop Relat Res

View full text Add to dashboard Cite

show abstract

“…Although the neck-stem junction was too strong to allow manual disassembly, micromotion occurred. Of note, it is our practice to take great care with dry assembly of the neck-stem junction on the back table [16]. We selected the best neck option based on preoperative 3D CT findings [9].…”

Section: Discussionmentioning

confidence: 99%

Adverse tissue reaction to corrosion at the neck-stem junction after modular primary total hip arthroplasty

Gkagkalis¹,

Mettraux²,

Omoumi³

et al. 2015

Orthopaedics & Traumatology: Surgery & Research

View full text Add to dashboard Cite

Complications related to the neck-stem junction of modular stems used for total hip arthroplasty (THA) are generating increasing concern. A 74-year-old male had increasing pain and a cutaneous reaction around the scar 1 year after THA with a modular neck-stem. Imaging revealed osteolysis of the calcar and a pseudo-tumour adjacent to the neck-stem junction. Serum cobalt levels were elevated. Revision surgery to exchange the stem and liner and to resect the pseudo-tumour was performed. Analysis of the stem by scanning electron microscopy and by energy dispersive X-ray and white light interferometry showed fretting corrosion at the neck-stem junction contrasting with minimal changes at the head-neck junction. Thus, despite dry assembly of the neck and stem on the back table at primary THA, full neck-stem contact was not achieved, and the resulting micromotion at the interface led to fretting corrosion. This case highlights the mechanism of fretting corrosion at the neck-stem interface responsible for adverse local tissue reactions. Clinical and radiological follow-up is mandatory in patients with dual-modular stems.

show abstract

“…Surgical assembly technique such as the force and angle at which the surgeon impacts the femoral head onto the stem taper [32] and the presence of fluid or debris on the taper surfaces during surgical assembly [16,21] can negatively affect the taper's initial stability. Material alloy of the head and stem taper also plays a role because different corrosion and fretting processes can occur depending on the material couple [18,19].…”

Section: Introductionmentioning

confidence: 99%