Conservative treatments have no clinically beneficial effect on thumb pain

A combination of conservative treatments offered patients with thumb base osteoarthritis “small to medium and potentially clinically beneficial effects on hand function but not pain,” researchers wrote in JAMA Internal Medicine.

Leticia A. Deveza, MD, PhD, a rheumatology specialist at the Institute of Bone and Joint Research at The University of Sydney, and colleagues wrote that recommended conservative treatments for thumb base osteoarthritis consist of education and training in ergonomic fundamentals; receiving a splint; exercises geared toward muscle strength, joint mobility and stability; and NSAIDs, preferably topical ones.

“Nevertheless, individually, these treatments usually only provide small benefits to patients,” the researchers wrote. “A more effective conservative treatment strategy for thumb base osteoarthritis is lacking.”

Deveza and colleagues recruited 204 patients aged older than 40 years in Australia with symptomatic and radiographic evidence of thumb base osteoarthritis. The patients rated their pain as six or higher on the Functional Index for Hand Osteoarthritis and averaged 40 or greater on the 0- to 100-mm visual analog scale.

The patients were randomly assigned in a 1:1 ratio to receive either the intervention — which included up to 12 weeks of education on self-management and ergonomics principles, a base-of-thumb splint, hand exercises and a supply of Voltaren Emulgel (diclofenac sodium gel, GlaxoSmithKline) — or just education on ergonomic fundamentals and self-management.

Both cohorts attended two individual, face-to-face treatment sessions with a physiotherapist at baseline and week 2. At 12 weeks, patients in the comparator cohort were given instructions on how to use the treatments “as per the intervention group.” Throughout the study, patients from either group could use the pain medications they were taking prior to study enrollment and/or acetaminophen or paracetamol as a rescue medication.

Deveza and colleagues wrote that at week 6, hand function improved “significantly more” among the 195 patients who remained in the intervention cohort compared with the 194 patients who were still in the comparator cohort (between-group difference = –1.7 units; 97.3% CI, –2.9 to –0.5). This trend was sustained at 12 weeks (between-group difference = –2.4 units; 95% CI, –3.5 to –1.3).

Pain scores between the cohorts improved “similarly” at week 6 (between-group difference = –4.2 mm; 97.3% CI, –11.3 to 3). At week 12, the reduction in pain was “significantly greater” in the intervention cohort (between-group difference = –8.6 mm; 95% CI, –15.2 to –2).

However, the researchers concluded that the intervention’s “effects on pain were smaller and clinically no better than education alone.”

During the trial, 34 “nonserious” adverse events occurred — all of them in the intervention group, but most were skin reactions to the gel and exercise-related pain incidents that “resolved with no sequelae,” according to the researchers.

“These results provide clinicians with evidence for efficacy of a relatively safe conservative intervention for patients with thumb base osteoarthritis,” they said.