Abstract
Purpose: The purpose of this work was to report mid-term results of a series of 162 total knee prostheses with an all-polyethylene plateau.
Material and methods: Between 1989 and 1995, 162 posterior stabilised cemented HLS2 total knee prostheses with an all-polyethylene plateau were implanted during first intention arthroplasties performed by the same surgeon. 142 prostheses were reviewed at more than one year, three patients died, and 17 were lost to follow-up (10%). Clinical results were assessed with the IKS criteria. Complete x-ray data included pangonograms. Mean follow-up was 4.5 years.
Results: Ninety-six percent of the patients were satisfied or very satisfied and 95% had no pain or mild pain. Mean flexion was 114°. The mean postoperative knee score was 81/100 and mean function score was 64/100. Radiographic findings showed the good position of the implants with mean AFT at 178.6°, mean AFm at 89.1° and mean ATm at 89°. There were eight failures (4.9%) requiring replacement of a component, two for frontal laxity, three for patellar fracture, one for infection, one for aseptic loosening, and one for an oversized tibial plateau. Two revision procedures were performed without implant replacement, one for pain (biopsy) and one for arthrolysis.
Discussion: These 162 prostheses with an all-polyethyl-ene plateau were retained among a consecutive series of 893 HLS prostheses. We compared the present results with those of the metal-backed prostheses implanted in this series and with data in the literature. We found a significant correlation between the presence of tibial lucent lines and postoperative alignment defects, explained by the type of tibial component, in these 162 all-polyethyl-ene plateau prostheses. These lucent lines did not progress with time and had no clinical consequence.
Conclusion: Clinial and radiological results with total knee prostheses with an all-polyethylene plateau, i.e. without metal backing, were very good in this series. We analysed our experience in comparison with the literature, focusing on the advantages and disadvantages of these two types of components.
The abstracts were prepared by Docteur Jean Barthas. Correspondence should be addressed to him at Secrétariat de la Société S.O.F.C.O.T., 56 rue Boissonade, 75014 Paris.
