Sarah R. Robbins
TORONTO — A 6-week intervention comprised of five conservative intervention strategies was associated with improved functionality among patients with thumb osteoarthritis, according to findings presented here.
However, Sarah R. Robbins, PhD, of the University of Sydney in Australia, and colleagues, acknowledged that the intervention combination failed to improve pain parameters.
“Hand OA is the most common type of OA, and the OA in the base of the thumb is particularly challenging, since most of the activities we do on a daily basis involve this joint,” she said. “The problem is that no particular intervention has been proven to be effective for patients with base of the thumb OA. There are no clinical practice guidelines available, either.”
Robbins noted that common clinical practice for this patient population involves a combination of conservative approaches. In the current study, the group aimed to define the efficacy of 6 weeks of such a strategy — including a hand splint, diclofenac sodium 1% gel, hand exercises and advice on how to protect the joint — on pain and functionality.
Pain was assessed using the Visual Analog Scale (VAS), and the researchers measured functionality using the Functional Index for Hand Osteoarthritis (FIHOA) score. The analysis included 102 patients randomly assigned the combination approach and 102 control patients who only received joint protection guidance.
The final analysis included 96 patients in the intervention arm and 99 controls. Robbins noted that protocols called for a 1:1 study design powered for superiority of the intervention. “These patients were followed up for 12 weeks, even though the intervention last only 6 weeks,” Robbins said.
Results showed that for VAS pain score, the absolute difference between intervention and control was -4.2 (P = .19) at 6 weeks, and -8.6 (P = .01) at 12 weeks.
For FIHOA, the difference was -1.7 (P < .01) at 6 weeks and -2.4 (P < .01) at 12 weeks.
“We can see that the intervention group had greater improvement in outcomes at 6 weeks in comparison to controls,” Robbins said. “The difference was even greater at 12 weeks.”
The researchers then asked patients how their functionality and pain improved over the course of the study. Results of this analysis showed that while functionality demonstrated clinical improvement, pain did not.
“Six weeks of combined conservative therapies provided a clinically meaningful improvement in function but not in pain,” Robbins noted. “Longer interventions might be required to reach clinically meaningful benefits in pain; I say that because we saw a better improvement in 12 weeks.” —by Rob Volansky
Robbins SR, et al. Abstract #14. Presented at: OARSI 2019 World Congress on Osteoarthritis; May 2-5; Toronto, Canada.
Disclosure: Robbins reports no relevant financial disclosures.