Does short-wave diathermy increase the effectiveness of isokinetic exercise on pain, function, knee muscle strength, quality of life, and depression in the patients with knee osteoarthritis? A randomized controlled clinical study.

Background: Knee osteoarthritis (OA) is a painful condition causing disability and muscle weakness. Shortwave diathermy (SWD) is one of several physical therapy modalities and used predominantly as a pain reduction modality in the clinical practice. However, the efficacy of SWD in knee OA is still inconclusive.
Aim: The aim of this study was to determine if SWD increase the effectiveness of isokinetic exercise on pain, function, muscle strength, quality of life and depression in patients with OA.
Design: This was a randomised, controlled clinical trial.
Setting: Inpatient Physiotherapy Department.
Population: Forty women aged between 42 and 74 years, with a diagnosis of bilateral primary knee OA.
Methods: Patients were sequentially randomized into two groups. Group 1 (N.=20) received SWD and isokinetic muscular strengthening exercises. Group 2 (N.=20) served as control group and they received isokinetic exercises only. Both of the programs were performed three days a week, for a duration of four weeks, and a total of 12 sessions. Patients were assessed before treatment (BT), after treatment (AT), and at a three-month follow-up (F). Outcome measures included visual analogue scale, Western Ontario and McMaster University Osteoarthritis Index, six minute walking distance, isokinetic muscle testing, Short Form 36 and Beck depression index.
Results: The patients with OA in each group had significant improvements in pain, disability, depression, walking distance, muscle strength, and quality of life AT and F when compared with their initial status (P<0.05). There was no statistically significant difference between the groups according to all the parameters regarding the change scores between AT-BT test and F-BT test (P>0.05) except some isokinetic peak torque measurements (F-BT scores of extension right 60°, 120° and flexion right 60°).
Conclusion: Use of SWD in addition to isokinetic exercise program seems to have no further significant effect in terms of pain, disability, walking distance, muscle strength, quality of life and depression in patients with knee OA.
Clinical Rehabilitation Impact: Considering the time and cost of combination therapy is now, the isokinetic exercise program, as it is efficient, may be preferable for the treatment of knee OA, alone.