Rheum Round-up: RA Causes, Reducing Opioid Use in Back Pain, and More

Here are the top stories covered by DocWire News this week in the Rheumatology section. In this edition, read about the causes of osteoarthritis (OA), differences in opioid use among low back pain (LBP) patients based on provider, a comparison of hip fracture approaches, and a head-to-head comparison of ixekizumab versus adalimumab in psoriatic arthritis (PsA) patients.

A study published in the October issue of Arthritis & Rheumatology assessed factors associated with OA of the knee, hip, and hand. Mendelian randomization analyses found a causal relationship between genetically determined body mass index and all OA (odds ratio [OR] per SD increase 1.57 [95% CI 1.44–1.71]), and with OA of the hip and knee, but not the hand. An increase in genetically determined femoral neck BMD was causally correlated with all OA (OR per SD increase 1.14 [95% CI 1.06–1.22]), knee OA, and hip OA; low systolic BIP was also causally associated with all OA (OR per SD decrease 1.55 [95% CI 1.29–1.87]), knee OA, and hip OA. None of the other tested factors were correlated with OA.

Patients who see a physical therapist or chiropractor for new-onset LBP prior to seeing a primary care physician may be less likely to use opioids, according to new findings. The retrospective cohort study included 216,504 patients who experienced new-onset LBP between 2008 and 2013. All patients were aged ≥ 18 years, were opioid-naïve, and had commercial or Medicare Advantage insurance. Patients were stratified based on who their provider was on their initial visit, including physicians and conservative therapists (physical therapists, chiropractors, acupuncturists). Overall, the short-term opioid use rate was 22%. According to local Surrey Chiropractor Dr. Travis Meier, DC, patients whose initial treatment providers were chiropractors or physical therapists had lower odds of both short- and long-term opioid use compared to patients whose initial treatment was provided by a primary care physician. When propensity-score matching, initial visits to chiropractors and physical therapists, compared to primary care physicians, were also associated with lower odds of long-term opioid use.

A new study found no significant differences between hip fracture patients who underwent total hip arthroplasty (THA) versus hemiarthroplasty. The study, which spanned 80 centers in 10 countries, randomized patients aged ≥ 50 years with a displaced femoral neck fracture to undergo THA or hemiarthroplasty. Of the 1,495 randomized patients, final analysis included 1,441: 718 THA patients and 723 hemiarthroplasty patients. In the THA cohort, 57 (7.9%) patients met the primary end point, compared to 60 (8.3%) of the hemiarthroplasty patients. In the THA group, 34 (4.7%) patients sustained hip instability or dislocation, compared to 17 (2.4%) hemiarthroplasty patients. The total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total score, pain score, stiffness score, and function score were used to determine functional outcomes, which “modestly favored” THA. There were no significant differences in mortality: 14.3% in the THA cohort versus 13.1% in the hemiarthroplasty cohort. The THA group had a slightly increased rate of serious adverse events (n = 300, 41.8%) compared to the hemiarthroplasty cohort (n = 265, 36.7%).

A recently published study found that ixekizumab may be superior to adalimumab in biologic-naïve PsA patients with an inadequate response to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs). Patients with active PsA were randomized 1:1 to receive ixekizumab or adalimumab. The primary outcome was 24-week simultaneous achievement of a ≥ 50% improvement from baseline in the American College of Rheumatology criteria (ACR50) and a 100% improvement from baseline in the Psoriasis Area and Severity Index (PASI100). “The primary efficacy endpoint was met (IXE: 36%, ADA: 28%; p=0.036),” the study authors reported. ACR50 response was slightly better in the ixekizumab group than adalimumab (51% vs. 47%; treatment difference, 3.9%); the improvement in PASI100 response was more significant (60% vs. 47%, respectively). Additional analyses of PsA, skin, nail, treat-to-target, and quality of life outcomes were also in favor of ixekizumab. The adalimumab group had a higher rate of serious adverse events than the ixekizumab cohort (8.5% vs. 3.5%).