Knee Arthroplasty Results in Obese Patients

Abstract

Purpose: This research was undertaken to evaluate the effects of excessive body weight on the results of total knee arthroplasty (TKA).
Patients and methods: The senior one of us (N.G.) performed 32 TKA in severely obese patients between 1992-1995. The mean age was 62 years (54-77) and mean follow-up time was 38 (25-69) months. The preoperative diagnosis was primary osteoarthrosis in 12, rheumatoid arthritis in four and post-traumatic arthrosis in two patients. TKA was performed bilaterally in 14 patients at the same anesthetic session. 'Electrooligograph Body Composition Analysis System' that measure lean body mass and fat percentage was used for all patients.
Results: According to Hospital for Special Surgery Knee Rating Scale scores of the obese patients did not differ from the non-obese patients at the same follow-up term but ambulation and rehabilitation period that is necessary to resume daily living activities took longer. In obese patients, frequency of patellar complaints were higher than non-obese patients.
Discussion: It is well known that the incidence of failure of fixation of the prosthesis and wear of polyethylene components are the most important problems in overweight patients. However, the activity level of obese patients tend to be more sedentary and less cyclic loading is applied to components. This may be the major factor in obtaining a better result than expected in this follow-up period.