Patients with the systemic autoimmune disease Sjogren's syndrome who underwent joint replacement surgery were at increased risk for transfusions and for discharge to non-home settings, but not for serious complications such as post-surgical infection, a large U.S. cohort study found.
Elevated risks for needing in-hospital transfusions were observed among patients with Sjogren's syndrome compared with healthy controls, with odds ratios of 1.37 (95% CI 1.22-1.55) following total hip arthroplasty and 1.21 (95% CI 1.10-1.34) after total knee arthroplasty, according to Jasvinder A. Singh, MD, and John D. Cleveland, MD, both of the University of Alabama at Birmingham.
And while there also was an increased likelihood of being discharged to a rehabilitation or other inpatient facility after hip replacement, patients with Sjogren's syndrome were no more likely than healthy controls to develop infections, require revision surgery, or die, the researchers reported in BMC Musculoskeletal Disorders.
"An absence of an association of Sjogren's syndrome with post-arthroplasty infection, revision, or mortality should reassure patients with Sjogren's syndrome and surgeons that these risks are not increased post-arthroplasty," they wrote.
Sjogren's syndrome primarily afflicts older women, and is characterized by dryness of the lachrymal glands and systemic symptoms. It can develop on its own or as a complication of other autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, or scleroderma.
An increased risk for post-arthroplasty complications has been reported for certain other systemic autoimmune diseases, including rheumatoid arthritis and lupus, but it is unclear whether similar risks exist for Sjogren's syndrome, which has minimal effects on the joints but is associated with systemic inflammation and upregulation of proinflammatory cytokines.
To address this question, Singh and Cleveland analyzed data for the years 1998 to 2014 from the U.S. National Inpatient Sample, which represents 20% of the country's community hospital discharges.
During that time period, there were 4,116,485 primary total hip arthroplasties and 8,127,282 primary total knee arthroplasties. Of those, 6,222 and 12,772 hip and knee replacements were in patients with Sjogren's syndrome.
Mean age of the Sjogren's patients was 65. Compared with individuals without Sjogren's syndrome, those with the disorder more often were women and had a Deyo-Charlson comorbidity score of 2 or higher.
In one-third of patients, the Sjogren's syndrome was secondary to another disorder, most commonly systemic lupus erythematosus.
Multiple regression analyses controlled for various potential confounders, including age, sex, and comorbidities, while sensitivity analyses further adjusted for hospital size and location as well as for primary versus secondary Sjogren's syndrome.
Although a significantly higher risk was seen for discharge to a rehabilitation facility after hip replacement, such was not the case following knee replacement (OR 0.93, 95% CI 0.86-1.02).
No association was seen among Sjogren's patients with having a hospital stay longer than 3 days for either knee (OR 0.96, 95% CI 0.88-1.04) or hip (OR 0.99, 95% CI 0.88-1.12) replacement. Similar results were seen on sensitivity analyses (OR 0.97, 95% CI 0.89-1.05 and OR 1.00, 95% CI 0.89-1.12).
Moreover, no associations were seen for in-hospital complications other than transfusions for either knee or hip arthroplasty:
On sensitivity analyses, primary Sjogren's syndrome was associated with an elevated risk of requiring revision after total knee arthroplasty (OR 2.29, 95% CI 1.03-5.10) and secondary Sjogren's was linked with a greater likelihood of having a hospital stay longer than 3 days (OR 1.28, 95% CI 1.04-1.57) but a lower mortality risk (OR 0.62, 95% CI 0.51-0.76). The implications of these sensitivity findings are unclear and require additional study, according to the authors.
They suggested that the increased risk for transfusion among Sjogren's patients may relate to the anemia and cytopenia that can result from systemic inflammation, and that typical symptoms of fatigue and functional impairment may have contributed to the need for discharge to an inpatient facility among hip replacement patients.
"These findings can inform patients, providers, and policy-makers regarding the minimal impact of Sjogren's syndrome on post-primary total knee arthroplasty and total hip arthroplasty outcomes," they concluded.
A limitation of the study was the lack of information on the severity of Sjogren's symptoms.