title: Fracture at the stem-condylar junction of a modular femoral prosthesis in a varus-valgus constrained total knee arthroplasty.
abstract: We present a rare case of fracture of the modular femoral component in a varus-valgus constrained total knee arthroplasty (TKA) prosthesis which occurred 2 years after implantation. Both femoral and tibial components underwent a second revision using a constrained hinged TKA. Laboratory analysis revealed insufficient metaphyseal bone stock in association with inadequate cement mantle incorporation which made implant fixation solely reliant on the intramedullary stem construct. It was therefore hypothesized that high repetitive stresses over the junction of the modular component led to the fracture.
  
  
  METHODS
  Case report, Level IV.
authors.affiliation: 4th Department of Orthopaedic Surgery, Asclepeion Voulas General Hospital, V. Paulou 01 Str, 16673 Attiki, Greece. drdnikol@hotmail.com
authors.forename: D D
authors.initials: DD
authors.lastname: Nikolopoulos
authors.forename: I G
authors.initials: IG
authors.lastname: Polyzois
authors.forename: E A
authors.initials: EA
authors.lastname: Magnissalis
authors.forename: P F
authors.initials: PF
authors.lastname: Bernard
authors.forename: I V
authors.initials: IV
authors.lastname: Michos
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D017760:Bone Malalignment / Q000209:etiology / Q000601:surgery; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000601:surgery; D007720:Knee Prosthesis; D011183:Postoperative Complications / Q000601:surgery; D011475:Prosthesis Failure / Q000209:etiology*; D012086:Reoperation