Cemented long-stem revision total knee arthroplasty

Theoretical concerns about the use of cemented long-stemmed revision total knee arthroplasty include inducing stress shielding with adverse effects on prosthesis fixation. This study details the clinical outcome of 35 patients with 40 cemented long-stemmed kinematic stabilizer revision total knee arthroplasties at followup evaluation averaging 58.2 months (range, 24-111 months). Of these 40 revision arthroplasties, there were 25 long-stemmed tibial components and 38 long-stemmed femoral components. The Knee Society pain score improved from a preoperative value of 38 points (range, 4-80 points) to 83 points (range, 33-100 points) at last evaluation. The Knee Society function score improved from a preoperative value of 46 points (range, 5-100 points) to 64 points (range, 0-100 points) at last evaluation. Initial postoperative radiographs showed tibial bone-cement radiolucencies in 5 knees, but at final followup none of these radiolucencies had progressed. Radiolucencies developed in 5 additional tibial components by the time of final followup, but these were all incomplete and <1 mm in width. Two femoral components had initial postoperative radiolucencies. These radiolucencies remained stable in 1 knee, whereas the other knee had asymptomatic radiographic loosening. Incomplete radiolucencies of <1 mm developed in 3 additional femoral components at final followup. The incidence of tibial radiolucencies of 32% in the present study is similar to the incidence of radiolucencies with a nonstemmed revision cemented total knee arthroplasty, with the same prosthetic design, previously reported from the authors' institution. Despite theoretical concerns of stress shielding with adverse effects on prosthetic fixation, this clinical study did not find evidence to support those concerns, and thus provides a basis of future comparison with cementless press-fit intramedullary fixation systems used during revision total knee arthroplasty.