Effect of Selected Ppsychological Factors During the Postoperative Rehabilitation Process After Total Knee or Hip Replacement

Purpose: The aim of this study was to evaluate the effect of psychological factors (rehabilitation motivation, social support and locus of control) on the postoperative outcomes pain and physical function after total knee or hip replacement.
Materials and Methods: In this longitudinal observational study with four assessment events, 59 subjects (average age 66.8 years +/-9.1 years; 45.8% female) after knee or hip replacement were asked to complete the WOMAC questionnaire on admission, on discharge as well as four and twelve weeks after discharge from the rehabilitation centre. All participants completed three additional questionnaires to measure the psychological factors rehabilitation motivation, social support and locus of control on admission and four weeks after discharge.
Results: Analyses of covariances showed an important influence of the psychological construct rehabilitation motivation on pain on admission, on discharge and twelve weeks after discharge as well as on physical function on all four measurement events. A weak effect of locus of control (externality) on pain was found on admission and four weeks after discharge. Regression analyses for the dependent variable pain allowed an explanation of the variance in the subscale rehabilitation motivation at all four measurement events between 25% to 29% by the independent variable negative influence of rehabilitation motivation. For the dependent variable physical function up to 26% of the scoring variances in all measurements could be explained by the subscale rehabilitation motivation.
Conclusion: Psychological factors, especially the psychological construct rehabilitation motivation, showed an effect on the postoperative outcome such as pain and physical function after a total knee or hip replacement.