Long-term use of a splint at night reduces pain and disability in people with osteoarthritis at the base of the thumb

Question

Does use of a splint at night improve pain and disability in people with osteoarthritis at the base of the thumb (OABT)?

Design

Randomised, controlled trial with concealed allocation.

Setting

Two tertiary hospitals in France.

Participants

Patients were recruited from tertiary clinics or private practices. Inclusion criteria were pain at the base of the thumb 30 mm or greater on a visual analogue scale (VAS) from 0 (no pain) to 100 mm, age 45–75 years, radiographic evidence of OABT, and either trapeziometacarpal joint enlargement or closure of the first web. Post-traumatic osteoarthritis, inflammatory and crystal arthritis, neurological conditions, trauma, surgery and collagen diseases were exclusion criteria. Randomisation of 112 participants allotted 57 to the intervention group and 55 to a control group.

Interventions

Both groups received usual care, at the discretion of the general practitioner or rheumatologist. In addition, a rigid splint was custom made for participants in the intervention group by an occupational therapist. It covered the base of the thumb and the thenar eminence but not the wrist. These participants were advised to wear it at night for one year, and encouraged to contact the therapist if they felt the splint needed adjustment, if pain increased while wearing the splint, or if they had adverse effects, eg, skin erosion.

Outcome measures

The primary outcome was the change in pain on the VAS at one month. Secondary outcome measures were disability at one month, and pain and disability at twelve months. Disability was measured with Cochin Hand Functional Scale from 0 (low disability) to 90, and on another VAS (100 mm = high perceived disability). Participants also rated their perceived global improvement and underwent clinical and radiological measures: pinch strength, pain during pinch, thumb mobility, closure of the first web, and blinded assessment of radiological progression of osteoarthritis.

Results

98 (87%) participants completed the study. No significant between-group differences in any outcomes were observed at one month. At 12 months, however, the intervention group showed significantly greater reductions in pain (by 14 mm, 95% CI 5 to 23), in Cochin scores (by 6 points, 95% CI 2 to 11), and in perceived disability (by 13 mm, 95% CI 4 to 22). The groups did not significantly differ on the remaining secondary outcomes.

Conclusion

For patients with OABT, night splinting had no effect on pain and disability at 1 month but both improved at 12 months.