Total dislodgement of the femoral component following cemented total knee arthroplasty: a case report

Total dislodgement of the components, which is the most severe form of loosening, has hitherto been unreported following total knee arthroplasty. An eighty-four-year-old woman presented with complaints of pain and sensation of insecurity of her right knee after cemented total knee arthroplasty. On physical examination, a clunk was elicited during movements of the knee; however, radiographs appeared normal except for a separated fragment of the medial femoral condyle. Further examination with varus and valgus stress tests under fluoroscopic control showed dislodgement of the femoral component, which was only apparent on stress radiographs. She underwent revision cemented total knee arthroplasty and her complaints disappeared completely within a follow-up period of three years. This case illustrates the need for stress radiographs when standard radiographs are normal in the face of a high suspicion of loosening.