"Floating total knee": ipsilateral periprosthetic fractures of the distal femur and proximal tibia after total knee arthroplasty.

UNLABELLED: Currently, there are more than 300000 primary total knee arthroplasty (TKA) performed annually in the United States. It is estimated that 0.3% to 2.5% of these patients will sustain a periprosthetic fracture in association with a TKA [Haidukewych GJ, Jacofsky DJ, Hanssen AD. Treatment of periprosthetic fractures around a total knee arthroplasty. J Knee Surg 2003;16:111]. The first report of a periprosthetic fracture involving a TKA occurred in 1977 [Callaghan JJ. Periprosthetic fractures of the acetabulum during and following total hip arthroplasty. Instr Course Lect 1998;47:231]. The majority of periprosthetic fractures associated with a TKA are distal femoral fractures [Berry D. EPIDEMIOLOGY: hip and knee. In: Callaghan J, Duncan C, editors. Periprosthetic fractures after major joint replacement. Philadelphia: WB Saunders; 1999. p. 183]. Periprosthetic tibial fractures are rare and usually involve the medial tibial plateau in the presence of a loose component [Rand JA, Coventry MB. Stress fractures after total knee arthroplasty. J Bone Joint Surg Am 1980;62:226, Hanssen AD, Stuart MJ]. Treatment of periprosthetic tibial fractures. Clin Orthop 2000; p. 91]. The following case report describes the management of simultaneous ipsilateral distal femoral and proximal tibial periprosthetic fractures associated with a TKA. The patient was informed that data concerning the case would be submitted for publication. To our knowledge, this "floating total knee" injury has not been previously reported.