title: Bilateral fatigue fracture of the femoral components in a cruciate-retaining cementless total knee prosthesis.
abstract: This article reports a case of bilateral fatigue fracture of the femoral components in a cruciate-retaining uncemented total knee arthroplasty (TKA). A 75-year-old woman (height, 158 cm; weight, 72 kg; body mass index, 29.2) had undergone one-stage bilateral TKA for osteoarthritis 11 years previously at the author's institution. Surgery was performed using an uncemented Flexible Nichidai Knee. Equal tension of the collateral ligaments and normal mechanical axis were achieved during the primary procedure. The patient was an ardent lover of the game of badminton and had higher activity levels with daily playing. At 8 years postoperatively, she started complaining of mild pain in both knees. The pain gradually increased, and at 11 years postoperatively, she had difficulty walking. Anteroposterior radiographs showed narrowing of the medial joint space, indicating wear of the polyethylene insert. Lateral radiographs showed signs of broken implants in both knees. There were no signs of gross implant loosening or osteolysis. One-stage revision surgery was performed, and the knees were converted to cemented posterior-stabilized TKAs. At revision, the bilateral femoral components were found to be fractured at the junction between the trochlear flange and the medial condyle, anteriorly to the medial peg. The polyethylene insert showed mild wear at the medial middle portion. In the majority of case reports, stress fractures of the femoral component have predominantly affected the medial condyle, following uncemented implantation of fixed-bearing knees. In this case, failure of bone ingrowth in uncemented components, higher body mass index, and a higher athletic activity led to fatigue fracture of the femoral components.
authors.affiliation: Department of Orthopedic Surgery, Nihon University School of Medicine, Tokyo, Japan. ssaito@med.nihon-u.ac,jp
authors.forename: Shu
authors.initials: S
authors.lastname: Saito
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Tokuhashi
authors.forename: Takao
authors.initials: T
authors.lastname: Ishii
authors.forename: Sei
authors.initials: S
authors.lastname: Mori
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Hosaka
authors.forename: Keinosuke
authors.initials: K
authors.lastname: Ryu
authors.forename: Gen
authors.initials: G
authors.lastname: Suzuki
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D001843:Bone Cements; D002484:Cementation; D005260:Female; D005264:Femoral Fractures / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D015775:Fractures, Stress / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery; D006304:Health Status; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery; D007720:Knee Prosthesis; D016348:Osseointegration; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery; D016119:Posterior Cruciate Ligament; D011475:Prosthesis Failure; D011859:Radiography; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012086:Reoperation
chemical_list: D001843:Bone Cements