Background: There have been a limited number of studies of total
knee arthroplasties with durations of follow-up of fifteen years, but we are
not aware of any involving modular fixed-bearing posterior cruciate-retaining
Methods: A consecutive series of 139 total knee arthroplasties in
109 patients (average age, sixty-seven years), performed by one surgeon using
a nonconforming posterior cruciate-retaining prosthesis, was followed for
fifteen years or longer. Forty-five patients (fifty-nine knees) were examined
at a minimum of fifteen years postoperatively, fifty-seven patients (seventy
knees) had died, five patients (eight knees) were too ill to return for
assessment, and two patients (two knees) were considered lost to follow-up.
The patients were assessed clinically with use of the Knee Society clinical
rating system, and the knees were assessed radiographically. Survivorship
analysis was performed with use of worst-case-scenario analysis and with
failure defined as a reoperation for any reason.
Results: There were five reoperations, four of which were performed
because of wear of the polyethylene insert. In addition, one loose cemented
femoral component was revised at fifteen years. The survival rate without
revision or a need for any reoperation was 92.6% at fifteen years. The mean
Knee Society score and functional score at fifteen years were 96 and 78
points, respectively. The prevalence of radiolucent lines was 13%, with 2%
around the femur, 11% around the tibia, and none around the patella. None of
these lines were clinically relevant. There was no evidence of progressive
radiolucent lines, and there was one case of asymptomatic femoral
Conclusions: In this single-surgeon series, modular fixed-bearing
posterior cruciate-retaining total knee arthroplasties had good clinical and
radiographic results with excellent survivorship for up to fifteen years.
These results are comparable with those in long-term studies of posterior
stabilized implants and of prostheses with mobile-bearing and nonmodular
Level of Evidence: Therapeutic Level IV. See Instructions
to Authors for a complete description of levels of evidence.