First Report on All-Poly Knee Replacements in Younger Patients

This is the first study to report on the results of an all plastic (polyethylene) knee replacement for patients younger than 60 years old.

Total knee implants have gone through major design changes over the years. Metal backing for the lower leg (tibial) portion of the implant was used in the 1980s. Surgeons thought this type of material was stronger with less wear and tear on the bone.

By the 1990s metal backed tibial implants were standard in most total knee replacements. Another 10 years and it's clear that there's a downside to this type of implant called backside wear.

This refers to the underside of the tibial plate as it comes in contact with the bone. Severe bone break down called osteolysis from the metal backed implant is a problem. The pendulum has swung back toward using all plastic (polyethylene) implant parts.

The results of this study show good results with the all-poly model in adults ages 47 to 60 years old. All patient were followed up for at least two years. Some were seen for up to 11 years. This shows the all-poly is made to last even in younger, active patients.



References: Amar S. Ranawat, MD, et al. Experience with an All-Polyethylene Total Knee Arthroplasty in Younger, Active Patients with Follow-up from 2 to 11 Years. In The Journal of Arthroplasty. October 2005. Vol. 20. No. 7. Suppl. 3. Pp. 7-11.