Article Text
Abstract
Background Whether restored mobility bestowed by Total Knee Arthroplasty (TKA) facilitates weight loss in rheumatoid arthritis (RA) patients has not been studied specifically [1] RA patients may face barriers to post-operative weight loss, such as corticosteroid use and upper extremity arthritis limiting rehabilitation [2] Clinicians need to counsel RA patients regarding expectations for weight loss after TKA.
Objectives To determine if significant weight loss occurred in overweight and obese RA patients 6-18 months after TKA compared to non-RA patients
Methods All TKAs done at Montefiore Medical Center from 2001-2012 were identified in the electronic medical record. The RA group was defined as patients with at least 2 visits with International Classification of Diseases, Ninth Revision (ICD9) code 714.0 for rheumatoid arthritis and a prescription for ≥1 disease modifying anti-rheumatic drug [3]. The non-RA group was defined as those without RA (714.0), spondyloarthritis (720.x, 696.1, 099.3), inflammatory bowel disease (555.x), or connective tissue disease (710.x). Peri-operative (30 days before to 7 days after) and post-operative (6-18 months after) weight (kg) and body mass index (BMI) (kg/m2) was obtained. Overweight (BMI ≥25-29.9) and obese (BMI ≥30.0) patients were included in the analysis [4]. Bivariate analysis compared baseline characteristics (demographics, Charlson comorbidity index [5]) and post-operative weight changes of RA and non-RA groups. Multivariate analysis adjusted for gender, ethnicity, race, and comorbidity index. Weight change of >±5% was considered clinically significant [6].
Results Using defined criteria, 46 RA and 1348 non-RA patients were identified. Of these, 14 (30%) RA and 331 (25%) non-RA were overweight; 31 (67%) RA and 894 (66%) non-RA were obese, p<0.218. Peri-operatively, RA patients were younger, with mean age of 60±10 years, compared to non-RA, 65±10, p<0.002. There was no difference in gender or comorbidity score between the groups. Post-operatively, 20% of RA patients and 20% of non-RA patients lost >5% of their peri-operative body weight, p<0.811. However, 24% of RA and 14% of non-RA gained >5% body weight, p<0.039. In a logistic regression model, age was a predictor of weight gain, p<0.044.
Conclusions A small minority of RA patients lost significant weight 6-18 months after TKA. In contrast, more RA patients gained significant weight, compared to non-RA patients. This data apprises clinicians who counsel RA patients regarding weight loss after TKA. Future studies can identify factors associated with significant weight change.
References
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Disclosure of Interest : None declared
DOI 10.1136/annrheumdis-2014-eular.3935