In a study presented at the knee society during the 75th annual American Academy of Orthopaedic Surgeons meeting in San Francisco, California, in March 2008, improvement after total knee replacement was studied in 2,645 primary unilateral knee replacements. While significant pain relief was reported in over 95% of patients, the functional improvement was affected by several patient attributes. Lower functional gains were associated with a five year increase in patient age over the average, BMI of greater than 40 (defined as clinically morbidly obese), and patients with lower quadricep strength. While the majority pf patients obtained good pain relief, the amount of functional improvement is adversely affected by the patients’ age, weight, preoperative strength, and psychological profile, as patients with issues related to depression also scored lower on the functional gains.
