RESEARCH REPORT PLATFORM PRESENTATION

FUNCTIONAL OUTCOMES AFTER TOTAL JOINT ARTHROPLASTY: COMPARISON OF PATIENTS WITH AND WITHOUT DIABETES. Amusat N¹, Jones A¹, Beaupre L², Scot S³, Warren S¹; ¹Faculty of Rehabilitation Medicine, University of Alberta. ²Orthopedic Research, Capital Health, Edmonton. ³Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta

PURPOSE: Current rates of Total Joint Arthroplasty (TJA) are increasing among the elderly; as is the prevalence of diabetes mellitus (DM). The effect of DM on short-term function after TJA has not been clearly elucidated. The aim of this study was to evaluate the effect of DM on 6-month functional outcomes in a patient population who received TJA. RELEVANCE: Dysfunction is one of the primary clinical problems for patients with TJA. Diabetes has been associated with dysfunction in the general population, but this relationship has not been established in patients with TJA. PARTICIPANTS: Seven hundred and fifteen patients who received primary elective total hip (n = 307) or knee arthroplasty (n = 408). METHODS: This is a secondary analysis, which was part of a larger prospective longitudinal study. Patients were evaluated within a month prior to surgery and 6-months after receiving TJA. Self reported function was measured using the function subscale of the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index. ANALYSIS: Student t-tests (both independent and paired) were used to compare WOMAC 6-month function between patients with and without diabetes. Multiple regression analysis was used to assess impact of diabetes status on function controlling for relevant medical characteristics (joint pain and function, co-morbidity, Body Mass Index (BMI), in-hospital complications, depression and type of joint operation). RESULTS: The mean age for the 82 patients who had diabetes was 67 years (SD 9.5) and 53% were female. There were no differences in demographics, baseline joint pain and function, and overall post-operative complications between patients with and without DM. There were more DM patients with hypertension (70% vs. 44%), circulatory (20% vs. 13%), heart (26% vs. 21%), kidney (8.5% vs. 3%) and eyes problem (31% vs. 35%). Patients with DM had more co-morbid conditions (mean 3.55, SD 2.0), higher BMI (mean 34.2, SD 6.4), and fewer were discharged home (52%). The mean (SD) baseline WOMAC function was 51.9 (17.4) and 49.1 (17.5) respectively for patients with and without DM (P>0.05). All patients irrespective of diabetes status had significant improvement (29%) in WOMAC function (P < 0.001). Function at 6-months was significantly lower for patients with diabetes (mean 23.9, SD 17.5) than patients without diabetes (mean 18.5, SD 14.3), but the difference was not clinically meaningful. Diabetes status was not significant in explaining 6-month WOMAC function after adjusting for relevant medical characteristics (P = 0.16, R2 = 0.12). CONCLUSIONS: Although patients with DM had more co-morbid conditions, it did not appear to influence their baseline or postoperative function when compared with patients without DM. Diabetes status was not a significant determinant of short-term functional outcome after TJA in this community-based cohort. IMPLICATIONS: Diabetes status alone is not a reason to expect poor functional outcomes when planning rehabilitation care after TJA. KEYWORDS: WOMAC Function, Total Joint Arthroplasty, Diabetes Mellitus. FUNDING ACKNOWLEDGEMENTS: This study was funded by the Alberta Heritage Foundation for Medical Research, Royal Alexandra Foundation, University of Alberta Hospital Foundation, and the Edmonton Orthopaedic Research Trust.

ETHICS COMMITTEE: Health Research Ethics Board of the University of Alberta.Canada.