Twenty-year survivorship of a cemented mobile bearing Total Knee Arthroplasty

Abstract

Background: Increasing numbers of Total Knee Arthroplasty (TKA) operations are carried out worldwide each year. This brings with it an ever-increasing revision burden and it is therefore important to appreciate both the functional outcome and survivorship of established arthroplasties when considering new designs. We aim to evaluate the long-term survivorship of a fully cemented mobile bearing Total Knee Arthroplasty.

Methods: This study prospectively analyses the 20-year survivorship of a cohort of 487 consecutive patients who underwent cemented TKA under the care of a single surgeon using the Low Contact Stress (LCS) rotating platform (RP) implant. These patients were followed up prospectively with patient reported and functional outcomes recorded at regular intervals postoperatively.

Results: Five hundred and forty-two consecutive primary TKAs were carried out in 487 patients. A total of 139 knees (25.6%) were reviewed at 20 years post-operation. Overall cumulative survivorship, using revision for any reason as primary endpoint, was 98.0%. Mean Knee Society Scores for the patient cohort were 87.3 (Clinical score) and 52.5 (Functional score). Eleven (2.0%) were revised within 20 years - two for aseptic loosening, two for unexplained pain, five secondary patellar resurfacings for anterior knee pain, one for late infection and one liner exchange following spin-out.

Conclusion: This series demonstrates excellent survivorship and satisfactory outcome of a cemented mobile bearing TKA at 20 years.

Keywords: Cemented; Low Contact Stress (LCS); Mobile bearing; Outcomes; Survivorship; Total Knee Arthroplasty (TKA).