UCSF

Objective

Ankylosing spondylitis (AS) and psoriatic arthritis (PsA) often affect the hip and/or knee. If effective, treatments might reduce risk of total hip or total knee arthroplasty (THA/TKA). We evaluated risk of THA/TKA related to use of medical therapies in AS/PsA.

Methods

We conducted a nested case-control study using 1994-2018 data from the OptumLabs Data Warehouse, which includes deidentified medical and pharmacy claims, laboratory results, and enrollment records for commercial and Medicare Advantage enrollees. Among those with AS/PsA, THA/TKA cases were matched up to 4 controls by sex, age, AS/PsA diagnosis, diagnosis year, insurance type, obesity, and prior THA/TKA. We assessed AS/PsA treatment 6 months prior to THA/TKA, including disease-modifying antirheumatic drugs (DMARDs) and tumor necrosis factor inhibitors (TNFi), alone or in combination, stratified by nonsteroidal antiinflammatory drug (NSAID) use. We evaluated the relation of treatment to risk of THA/TKA using conditional logistical regression with adjustment for confounders.

Results

Among 16,748 adults with AS, there were 444 THA/TKA cases and 1613 matched controls. Among 34,512 adults with PsA, there were 1003 cases and 3793 controls. Adjusted ORs for treatment category and THA/TKA ranged from 0.60 to 1.92; however, none were statistically significant. Results were similarly null in several sensitivity analyses.

Conclusion

Odds of THA/TKA were not reduced with any combinations of NSAIDs, DMARDs, or TNFi among persons with AS or PsA. Given current utilization patterns in this population of US adults with AS and PsA, these medical therapies did not appear to be associated with less end-stage peripheral joint damage.