Impact of two types of expectancy on recovery from total knee replacement surgery (TKR) in adults with osteoarthritis.

This study examines the impact of 2 classes of psychological variables--expectancies for the future and self-efficacy--on recovery of function and reduction in symptomatology among individuals seeking total knee replacement surgery (TKR). The authors collected outcome measures (SF-36, WOMAC, Clinician assessments) prior to surgery, 4-6 weeks after surgery, and 6 months postsurgery for surgery patients and controls. Linear trend analyses by group gauged the impact of the surgical intervention on recovery, revealing significant improvements over time on physical health outcomes for the surgery patients not attained by controls. In addition, two classes of psychosocial variables--expectancies and efficacy beliefs--predicted the extent of gains in physical and mental health outcomes among those patients who elected to have surgery. When initial status was controlled, between 9 and 13 percent of the variance in TKR outcomes was due to expectations and efficacy. These results point to the importance of psychosocial variables in recovery of function and reduced symptoms after knee surgery.