Total knee replacements can be done either preserving or substituting for the posterior cruciate ligament. In the United States approximately 60% of knee replacements are done using posterior cruciate substituting implants and approximately 40% utilize a posterior cruciate retaining implant. Both have equal track records and the differences are primarily surgeon preference.

With regard to tibial components, there are options between fixed bearing tibial components and mobile bearing or rotating platform implants. Both types of implants have similar success in the elderly individual up to 15 to 20 years followup. Both types of knee replacement allow rotation of the knee, which is a normal component of knee range of motion.

There are some laboratory and theoretical advantages to the use of mobile bearing inserts in younger individuals who anticipate a functional use greater than 20-plus years. Longer follow up will determine if the theoretical advantages become reality.