Abstract
Introduction
One of the main considerations in the revision TKR setting is deciding on the level of constraint to be utilized once the bone defects have been reconstructed. There is a fear that employing a maximally constrained insert could compromise long term results. We report on a consecutive series of full tibial and femoral component revisions all treated with a maximally conforming insert and followed for a minimum of 5 years.
Materials and Methods
The study group consisted of 76 consecutive revision TKR in 76 patients where both the femur and the tibia were revised. 4 patients died and 6 were lost to follow up. Final cohort had an average age of 70 years, average BMI of 31 and there were 39 males in the group. Average time to revision was 7 years (range 1–10 years) and the reasons for revision included infection in 28, aseptic loosening 26, osteolysis and poly wear in 9 and 13 other. All were treated with the same revision system and an identical maximally conforming tibial rotating platform insert and followed for an average of 7 years (range 5–14 years).
Results
one patient required additional surgery during the study period for a patella fracture. There were no manipulations. Average Knee Society Scores increased from an average of 55 to 89 at final follow up. No implants were loose or at risk of loosening and no knee sustained any mechanical complications related to the insert.
Conclusion
Despite fears to the contrary, we did not identify any issues in using a maximally constrained insert in this consecutive group of revision total knee patients. It is unclear if the fact that these inserts were of a rotating platform design is important. In this group of revision TKRs, using the maximal level of constraint did not appear to negatively influence outcome at mid-term follow up.
