Ankylosing Spondylitis Anti-TNF Drugs Decrease Need for Hip Replacement

In a poster presented at the 2016 American College of Rheumatology annual meeting in Washington, DC, researchers from Cedars-Sinai Medical Center tested the hypothesis that anti-tumor necrotic factor (TNFi) drugs could help delay hip deterioration in patients with ankylosing spondylitis (AS).

AS, a chronic inflammatory disease of the spine, is prevalent in 4% to 5% of those with chronic back pain, according to the Cleveland Clinic. In addition to non-steroidal anti-inflammatory dugs (NSAIDs), TNFi drugs like infliximab, golimumab, etanercept, and adalimumab are commonly prescribed treatments for the condition.

The Cedars-Sinai report asserts that 5% of patients with AS also have severe hip problems that require total hip arthroplasty (THA), but that it was previously unclear how TNFi treatments would impact the course of hip progression. They hypothesized that it would be of benefit.

For the study, 613 AS patients were administered at least two sets of hip radiographs. Assessed based on Bath Ankylosing Spondylitis Radiologic Index (BASRI) scores, a “progressor” was defined as a patient who saw a score change of two or more units between their initial radiograph and their fist follow-up. The median follow-up period was about 3 years, and “included patients with BASRI hip scores below 4 (n=579) for the progression analysis and selected a grade-2 BASRI score change to eliminate concerns associated with reliability for reading grade-1 scores,” according to the report.

Of the 576 patients included in the final report, 551 were found to be non-progressors compared to 25 progressors. They found no significant interaction between NSAID and TNFi use, and found that TNFi treatment lowered risk of hip disease progression (adjusted OR=0.02; p=0.003).