Efficacy of Paraffin Bath Therapy in Hand Osteoarthritis: A Single-Blinded Randomized Controlled Trial

Abstract Objective To evaluate the efficacy of paraffin bath therapy on pain, function, and muscle strength in patients with hand osteoarthritis. Design Prospective single-blinded randomized controlled trial. Setting Department of physical medicine and rehabilitation in a university hospital. Participants Patients with bilateral hand osteoarthritis (N=56). Interventions Patients were randomized into 2 groups with a random number table by using block randomization with 4 patients in a block. Group 1 (n=29) had paraffin bath therapy (5 times per week, for 3-week duration) for both hands. Group 2 (n=27) was the control group. All patients were informed about joint-protection techniques, and paracetamol intake was recorded. Main Outcome Measures The primary outcome measures were pain (at last 48h) at rest and during activities of daily living (ADL), assessed with a visual analog scale (0–10cm) at 12 weeks. The secondary outcome measures were the Australian Canadian Osteoarthritis Hand Index (AUSCAN) and the Dreiser Functional Index (DFI), used for subjective functional evaluation, loss of range of motion (ROM), grip and pinch strength, painful and tender joint counts, and paracetamol intake. A researcher blind to group allocation recorded the measures for both hands at baseline, 3 weeks, and 12 weeks at the hospital setting. Results At baseline, there were no significant differences between groups in any of the parameters ( P >.05). After treatment, the paraffin group exhibited significant improvement in pain at rest and during ADL, ROM of the right hand, and pain and stiffness dimensions of the AUSCAN ( P .05). The control group showed a significant deterioration in right hand grip and bilateral lateral pinch and right chuck pinch strength ( P