J. Denise Power

Background: Despite broad calls to consider sex-specific effects in treatment/intervention studies, this remains a persistent gap. This study sought to identify presurgery factors associated with pain and physical function following hip and knee total joint arthroplasty (TJA) for osteoarthritis, specifically adopting a sex-stratified approach. Methods: Questionnaires were patient-completed presurgery: sociodemographic and health-related characteristics, anxiety and depression symptoms, neuropathic-like pain symptoms, multijoint involvement, and opioid use. Pain and physical function were captured presurgery and 1 year postsurgery. Study outcomes: pain and function status scores at 1 year and their percentage change (presurgery to 1 year postsurgery). Associations between presurgery factors and outcomes were assessed by sex-stratified multivariable linear regressions. Findings were contrasted against a sex-adjusted approach (i.e. one analysis in combined male/female sample). Results: Sample (45% hip, 55% knee): 787 female patients and 640 male patients. Among male patients only: Depressive symptoms were associated with worse pain and function status, and less pain improvement (β = −8.6% [−17.4%, 0.3%]), as were lower education and living alone. Among female patients only: Anxiety symptoms were associated with worse pain and function status and less pain (β = −7.7% [−14.3%, −1.0%) and functional improvement (β = −8.5% [−14.4%, −2.6%]), as was greater multijoint burden. The negative effect of neuropathic-like pain symptoms was greater in male patients than female patients. Sex-adjusted findings suggested sex had no consequence. Conclusions: Several factors uniquely influenced TJA outcomes by sex. Simple sex-adjustment may miss important effects. This has broad implications, including for patient education, decision making, prognostic/comparative effectiveness study design, and development/improvement of prediction algorithms. Though TJA focused, we hypothesize that sex differences are likely relevant in other clinical populations. Level of Evidence: Prognostic Level I . See Instructions for Authors for a complete description of levels of evidence.

Few studies have examined diabetes impact on total joint arthroplasty (TJA) outcomes, with variable findings. We investigated the association between diabetes and post-TJA physical function and pain, examining whether diabetes impact differs by sex and BMI. Patient sample completed questionnaires within 3 months prior to hip or knee TJA for osteoarthritis (OA) and 1-year post-surgery. Surgical ‘non-response’ was defined as < 30% improvement in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and physical function at 1-year. Two adjusted logistic regression models were estimated: (1) excluding, (2) including an interaction between diabetes, sex and BMI. The sample (626 hip, 754 knee) was 54.9% female, had mean BMI of 30.1, 13.0% reported diabetes. In adjusted models excluding an interaction, diabetes was not associated with non-response. However, a significant 3-way interaction (physical function: p = 0.003; pain: p = 0.006) between diabetes, sex, and BMI was found and was associated with non-response: non-response probability increased with increasing BMI in men with diabetes, but decreased with increasing BMI in women in diabetes. Findings suggest uncertainty in diabetes impact may be due to differential impacts by sex and BMI. A simple consideration of diabetes as present vs. absent may not be sufficient, with implications for the large TJA population.

Objective: To assess the impact of diabetes on physical and mental health status, as well as patient satisfaction, one-year following knee and hip total joint arthroplasty (TJA) for osteoarthritis (OA). Methods: Participants were 626 hip and 754 knee TJA patients. Pre-surgery data were collected on socio-demographics and health status. The 12-item Short Form Health Survey (SF-12) was collected pre- and one year post-surgery, and physical (PCS) and mental component (MCS) summary scores computed. One-year patient satisfaction was also recorded. Four regression models tested the effect of diabetes on: 1) PCS change score; 2) MCS change score; 3) achieving minimal clinically important improvement (MCII) on PCS; and 4) patient satisfaction (‘Somewhat or Very Satisfied’ vs. ‘Somewhat or Very Dissatisfied’). An interaction between surgical joint and diabetes was tested in each model. Results: Self-reported diabetes prevalence was 13.0% (95% CI: 11.2%-14.7%) and was more common in knee 16.1% (95% CI: 13.4%-18.7%) than hip 9.3% (95% CI: 7.0%-11.5%) patients. In adjusted analyses, change scores were 2.3 units less on the PCS for those with diabetes compared to those without (p = 0.005). Patients with diabetes were about half as likely to achieve MCII as patients without diabetes (p = 0.004). Diabetes was not significantly associated with satisfaction or changes in MCS scores. Diabetes effects did not differ by surgical joint. Conclusions: Findings support that diabetes has a negative impact on improvements in physical health after TJA. Considering the growing prevalence of OA and diabetes in the population, our findings support the importance of perioperative screening and management of diabetes in patients undergoing TJA.