Dislocation of posterior-stabilized mobile-bearing knee prosthesis. A case report

Knee. 2006 Dec;13(6):478-82. doi: 10.1016/j.knee.2006.07.002. Epub 2006 Sep 7.

Abstract

Spin-out of mobile-bearing knees is a significant early complication of mobile-bearing total knee arthroplasty. Dislocation of the cam-post mechanism of fixed-bearing posterior-stabilized knees occurs more rarely. We have observed an unusual case of dislocation of posterior-stabilized rotating-platform total knee arthroplasty, which has both a cam-post mechanism and rotating platform. A 65-year-old man with knee osteoarthritis and cervical spondylotic myelopathy underwent total knee arthroplasty using a mobile-bearing prosthesis. The dislocation, which occurred 4 days postoperatively, could not be reduced by closed manipulation. However, spontaneous reduction occurred 6 days after the dislocation, which did not recur. A gap mismatch or trapezoidal-shaped gaps may lead to dislocation or spin-out of the bearing insert. This case illustrates that dislocation of a posterior-stabilized mobile-bearing total knee arthroplasty can occur, and both quadriceps deficiency and ligament laxity may contribute to the risk of dislocation.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Arthroplasty, Replacement, Knee*
  • Humans
  • Knee Prosthesis*
  • Male
  • Osteoarthritis, Knee / surgery
  • Prosthesis Design
  • Prosthesis Failure*