Abstract
The ultracongruent insert has been used since 1991 beginning with the Natural-Knee, then manufactured by Sulzermedica. It has posterior stabilising ability with the 12.5mm anterior build up with a significantly more congruent articulation. This translates to higher contact areas and theoretically lower wear. The higher central eminence provides some medial lateral stability. This style insert is now available from at least seven different manufacturers.
The first study was reported in the 2000 Journal of Arthroplasty with Hofmann et al., comparing 100 ultracongruent inserts with 100 PCL sparing inserts with an average five-year follow up. Knee scores and range of motion were similar or no dislocations or subluxations were noted. We found this bone sparing since there is no box cut and requires less time for surgery. This insert provided excellent stability in all ranges of motion.
Indications for this surgery are deficiency or compromise of the PCL.
Contraindications are attenuation or absence of either one or both collateral ligaments where a more constrained device is suggested.
