title: Fractures of modern high nitrogen stainless steel cemented stems: cause, mechanism, and avoidance in 14 cases.
abstract: We present 14 cases of fracture of modern, high-nitrogen, stainless steel stems. Our clinical and radiological data suggest that heavy patients with small stems and poor proximal support are at risk for fracturing their implants. "Champagne-glass" canals can lead to the use of smaller stems often placed in varus, which can lead to cantilever bending and fatigue failure in the distal half of the stem. Metallurgical assessment of the retrieved high-nitrogen, stainless steel stems reveals microstructural inconsistencies that may contribute to their failure. Based on our findings, careful consideration and attention to technique is required when using stainless steel stems in patients with high body mass index or high weight. Technique is particularly important in femurs with champagne-glass canals.
authors.affiliation: Perth Orthopaedic Institute, Nedlands, Perth, Western Australia.
authors.forename: Piers J
authors.initials: PJ
authors.lastname: Yates
authors.forename: Nasir A
authors.initials: NA
authors.lastname: Quraishi
authors.forename: Allan
authors.initials: A
authors.lastname: Kop
authors.forename: Donald W
authors.initials: DW
authors.lastname: Howie
authors.forename: Clare
authors.initials: C
authors.lastname: Marx
authors.forename: Eric
authors.initials: E
authors.lastname: Swarts
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation*; D001696:Biomechanical Phenomena; D015992:Body Mass Index; D001835:Body Weight; D001843:Bone Cements; D005260:Female; D005269:Femur; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008669:Metallurgy; D009584:Nitrogen / Q000032:analysis; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013193:Stainless Steel
chemical_list: D001843:Bone Cements; D013193:Stainless Steel; D009584:Nitrogen