Excellent Survival of All-polyethylene Tibial Components in a Community Joint Registry

The advantages of the monoblock design and lower cost have prompted renewed interest in the all-polyethylene tibia in total knee arthroplasty. We prospectively followed patients with all-polyethylene tibial total knee arthroplasties over a 14-year period. Since 1991, 443 total knee arthroplasties using an all-polyethylene tibia component were implanted by 12 surgeons in four hospitals associated with a community registry. One of three designs was used in over 98% of cases. The mean age of the patient population was 77 years and 78% were female. Ninety-three patients died with their prosthesis intact. Three revisions were performed on this population with mean followup of 66.3 months (range, 0-158 months). Kaplan-Meier survival analysis revealed 99.4% survival at 14.3 years with revision for any reason as the end point. With aseptic loosening or wear as the revision reason, survival is 99.7% at 14.3 years. Total knee arthroplasty with one of the three contemporary congruent all-polyethylene tibia designs used in this registry performed extremely well in this population; savings for this group (compared to those with a metal-backed component) was estimated at $729 per case. If all patients older than 75 years of age in our registry had received an all-polyethylene tibia, the estimated savings for the implant alone would have been $1.28 million.

Level of Evidence: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.