Objective·To explore the correlation among perceived social support,rehabilitation self-efficacy and rehabilitation exercise adherence of in-patients after hip/knee arthroplasty,and examine the mediating role of rehabilitation self-efficacy in the correlation between perceived social support and rehabilitation exercise adherence.Methods·A convenience sampling method was used,and 141 post-total hip/knee arthroplasty inpatients in the bone and joint ward of the First Affiliated Hospital of Naval Medical University(Shanghai Changhai Hospital)from October 2021 to February 2023 were selected as the study subjects.The general demographic data,such as age and gender,and the information of disease and operation were assessed by using General Data Questionnaire.The adherence to rehabilitation exercise in patients after hip/knee arthroplasty was assessed by using the Rehabilitation Exercise Adherence Scale(REAS);the self-efficacy of rehabilitation exercise was assessed by using the Self-Efficacy for Rehabilitation Outcome Scale(SER);the social support level of individual subjective feelings of the patients was assessed by using the Perceived Social Support Scale(PSSS).Pearson's correlation analysis was used to test the correlation between the variables,and Bootstrap method was used to investigate the mediating role of rehabilitation self-efficacy in the correlation between perceived social support and rehabilitation exercise adherence.Results·A total of 167 questionnaires were distributed and 141 valid questionnaires were recovered,with a valid recovery rate of 84.4%.The age range of the 141 patients after hip/knee arthroplasty was 26?84 years old,and the average age was(64.75±10.74)years old.The total score of SER of the patients after hip/knee arthroplasty was(100.45±21.71),the total score of PSSS was(68.29±10.89),and the total score of REAS was(11.93±2.29).Pearson's correlation analysis results showed that there was a significant correlation between SER score and PSSS score,SER score and REAS score,and PSSS score and REAS score in patients after hip/knee arthroplasty.The mediation effect analysis showed that the indirect effect of perceived social support on rehabilitation exercise adherence was significant(effect value 0.033,95%CI 0.017?0.058,P<0.05),and the direct effect of perceived social support on rehabilitation exercise adherence was not significant(effect value 0.027,95%CI-0.008 ? 0.065,P>0.05).Conclusion·Perceived social support positively predicts rehabilitation exercise adherence,and rehabilitation self-efficacy fully mediates the correlation.Direct intervention in rehabilitation self-efficacy is superior to moderating the level of perceived social support.