Abstract
BIOLOGICS DISCONTINUATION AND BMI PREDICT RA FLARE RISK AFTER HIP AND KNEE ARTHROPLASTY
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Background: Immunosuppressive medications are often stopped prior to arthroplasty to mitigate infection risk, but this may increase the risk of disease flares post surgery in patients with rheumatoid arthritis (RA).
Objectives: To describe rates, characteristics, and risk factors for flare after total hip (THA) and total knee (TKA) arthroplasty surgery.
Methods: Pre- and post-operative characteristics were examined in 58 RA patients undergoing TKA/THA. Perioperative medication use was standard of care: biologics were stopped before surgery, while steroids and methotrexate (MTX) continued. Clinicians evaluated RA clinical characteristics, on average, 0–2 weeks before and 6 weeks post-surgery. Post-surgery, patients completed weekly questions about RA symptoms, impact, and flare status using the OMERACT Flare Questionnaire. Baseline characteristics were compared using t-tests and chi-square, and multivariate logistic regression was used to identify baseline characteristics associated with post-surgical RA flares.
Results: Of 68 patients, 10 (15%) were flaring prior to surgery and were excluded. 88% met 2010/1987 RA criteria; those who did not meet criteria were included by rheumatologist diagnosis. Patients had a mean [SD] age of 61 [12], BMI of 30.6 [7.2], and RA duration of 16 [12] yrs. 59 (87%) were female, 53 (78%) were white, 33 (49%) were having THA, and 35 (52%) were on biologics. 35 (60%) had flared by 6 weeks post surgery. At baseline, flarers had significantly (p<.05) higher BMI, higher disease activity indicators (DAS28, RAPID3), inflammatory markers (ESR, CRP), and pain, and more were undergoing THA and used biologics (Table 1). After controlling for age, surgical joint, and baseline DAS28, the odds of flaring by 6 weeks post-surgery were significantly higher in patients who had discontinued biologics (OR 14.9, 95% CI 2.0, 112.0) or were obese (OR 6.0, 95% CI 1.1, 33.0).
Table 1. Characteristics of RA patients who did and did not flare in the first 6 weeks post hip or knee arthroplasty (N=58)
Flare (n=35)No Flare (n=23)Significance
Age (yrs)58.2 (13.5)63.9 (10.4)0.073
Female Sex32 (91%)18 (78%)0.155
BMI32.6 (7.2)28.6 (6.5)0.040
Minority Race10 (29%)2 (9%)0.099
Hip arthroplasty22 (63%)6 (26%)0.006
HOOS39.8 (21.9)52.2 (22)0.230
KOOS44.0 (27.5)44.9 (14.2)0.914
RA Duration (yrs)16.4 (12.0)16.1 (13.2)0.920
DAS284.1 (1.2)2.9 (1.3)0.001
RAPID316.0 (4.1)13.2 (5.4)0.032
ESR (mm/hr)23.9 (20.2)11.0 (11.2)0.003
CRP (mg/dl)2.3 (3.6)0.9 (0.8)0.043
MD Global4.1 (1.6)3.3 (1.9)0.092
Patient Global5.1 (1.9)4.0 (2.5)0.064
Pain (10mm VAS)7.0 (2.0)5.7 (2.7)0.053
MD HAQ3.9 (1.6)3.5 (1.5)0.282
Biologics24 (69%)7 (30%)0.004
MTX20 (57%)14 (61%)0.778
Data shown as mean (SD) or n (%).
Conclusions: Flares are frequent in RA patients undergoing arthroplasty, particularly THA. Discontinuing biologics and obesity significantly increased the risk of flaring post-arthroplasty.
Acknowledgement: This study was supported by the Clinical Translational Science Center (CTSC) (UL1-TR000457–06).
Disclosure of Interest: None declared
DOI: 10.1136/annrheumdis-2016-eular.2190Citation: Annals of the Rheumatic Diseases, volume 75, supplement 2, year 2016, page 219Session: Rheumatoid arthritis - comorbidity and clinical aspects
(Poster Presentations )
5 organizations
Organization
Hospital for Special SurgeryOrganization
Mcgill University, Montreal, CanadaOrganization
New York Genome Center