Sex differences in knee-related symptoms, psychological factors and quality of life in runners who have had knee surgery

      Introduction: Many people who sustain a knee injury and undergo surgery choose to continue or start running. Previous reports indicate that women have worse patient-reported outcomes than men following knee surgery. However, little is known about sex differences in patient-reported outcomes for people who have chosen to participate in running post knee surgery. We aimed to compare self-reported knee-related symptoms, psychological factors and quality of life between women and men running athletes with a history of knee surgery.
      Methods: A convenience sample of 103 running athletes (18-50years, run ≥10km/week and ≥3 sessions/week), with a history of knee surgery were recruited. Participant characteristics collected included age, sex, height, body mass, and weekly running frequency and total distance. Knee-related symptoms were assessed using six subscales of the Knee injury and Osteoarthritis Outcome Score (KOOS), including (i) pain; (ii) symptoms; (iii) function during activities of daily living; (iv) sports and recreational activities; (v) quality of life; and, (vi) patellofemoral joint symptoms, the Tampa Scale for Kinesiophobia and the Knee Self-Efficacy Scale. Independent t-tests were performed to compare outcomes between women and men. Effect sizes were calculated using Cohen’s d.
      Results: Female runners (n=32, 34.5 years, 63.7kg, 1.7m) had lower body mass and height compared to male runners (n=71, 35.2 years, 77.1kg, 1.8m), but were of similar age, and reported similar running frequency/distance and time post-surgery. Compared to men, women reported worse KOOS-symptoms (mean difference -5.39, 95%CI 10.81, 0.02; effect size -0.42), function during activities of daily living (-2.63, 95%CI -4.99, -0.26; effect size -0.47), and patellofemoral joint symptoms (-5.43, 95%CI -10.68, -0.17; effect size -0.44). There was no sex-differences observed for KOOS quality of life or sport and recreational subscales, kinesiophobia or knee self-efficacy.
      Discussion: Women with a history of knee surgery had evidence of worse self-reported outcomes than men, but it is unclear why. Our findings highlight the need to evolve our understanding and management of women who have chosen to participate in running post knee surgery, in particular focusing on improving their knee-related symptoms and function. (i) Why do women have inferior outcomes? (ii) Do women need a specific and more targeted rehabilitation approach pre- or post-operatively than men to enhance outcomes? Such knowledge would be of practical value for coaches, athletes, and health professionals to optimise sex-specific training and treatment strategies.
      Conflict of interest statement: My co-authors and I acknowledge that we have no conflict of interest of relevance to the submission of this abstract.