title: New type of hip arthroplasty failure related to modular femoral components: breakage at the neck-stem junction.
abstract: Total hip replacements (THR) with modular femoral components (stem-neck interface) make it possible to adapt to extramedullary femoral parameters (anteversion, offset, and length) theoretically improving muscle function and stability. Nevertheless, adding a new interface has its disadvantages: reduced mechanical resistance, fretting corrosion and material fatigue fracture. We report the case of a femoral stem fracture of the female part of the component where the modular morse taper of the neck is inserted. An extended trochanteric osteotomy was necessary during revision surgery because the femoral stump could not be grasped for extraction, so that a long stem had to be used. In this case, the patient had the usual risk factors for modular neck failure: he was an active overweight male patient with a long varus neck. This report shows that the female part of the stem of a small femoral component may also be at increased failure risk and should be added to the list of risk factors. To our knowledge, this is the first reported case of this type of failure.
authors: Service de chirurgie orthopédique et traumatologique, centre hospitalier général de Longjumeau, 159, rue du Président-François-Mitterrand, BP 125, 91161 Longjumeau cedex 01, France. Electronic address: philippe.wodecki@ch-longjumeau.fr.
authors: P
authors: P
authors: Wodecki
authors: D
authors: D
authors: Sabbah
authors: G
authors: G
authors: Kermarrec
authors: I
authors: I
authors: Semaan
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods; D005500:Follow-Up Studies; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008875:Middle Aged; D050177:Overweight; D057068:Periprosthetic Fractures / Q000175:diagnosis / Q000601:surgery*; D011474:Prosthesis Design; D011475:Prosthesis Failure; D020127:Recovery of Function; D012086:Reoperation / Q000379:methods; D013314:Stress, Mechanical; D016896:Treatment Outcome
keywords: Failure; Fretting corrosion; Modular neck; Revision; Stem fracture; Total hip arthroplasty