The Use of Stems for Morbid Obesity in Total Knee Arthroplasty.

Morbidly obese patients undergoing total knee arthroplasty have worse functional outcomes and implant survival, and increased revision rates compared with nonobese patients. In addition to increased medical comorbidities and difficult exposure, increased stress on the tibial implant and altered kinematics of knee motion contribute to aseptic loosening and medial collapse. Increased implant fixation, including use of a stemmed tibial implant, may be a way to help avoid these complications. While there is limited data on tibial stems in the morbidly obese patients specifically, cemented stemmed tibial implants should be strongly considered in these patients, especially if bone quality is poor. The initial increased cost of a stemmed implant can be justified in this high-risk patient population to minimize the risk of costly revisions related to compromised tibia component fixation.