Evaluation of the effectiveness of low frequency magnetic field treatment in patients with knee osteoarthritis – a randomized single-blind clinical trial

Background
Knee osteoarthritis (KOA) also named as gonarthrosis, is one of the most common of all degenerative joint diseases. Ongoing research is being carried out to find effective, less expensive, and non-invasive treatments for KOA, including physiotherapy. Magnetotherapy is a treatment commonly used in the field of physiotherapy and may be clinically applicable in KOA.

Aim
This study aimed to evaluate the effectiveness of low-frequency magnetic field treatment in patients with KOA.

Material and methods
Thirty individuals with diagnosed KOA took part in the study. The participants were randomly assigned into 2 groups: study group I underwent magnetotherapy sessions and control group II was placebo. Simple randomization and single-blind method were applied. Magnetotherapy included 15 sessions. The Lysholm Knee Score (LKS), Visual Analogue Scale (VAS), and goniometer measurement of knee flexion range of motion (ROM) were used in the study. Surveys and measurements were administered on the first and last day of the treatment. Results were assessed based on 3 statistical analyses performed using IBM SPSS Statistics 23. Wilcoxon's test, Mann-Whitney U test, Chi-square, and Spearman's correlation were used.

Results
In the experimental group, the knee flexion ROM was improved after the treatments, with most people experiencing reduced pain (VAS) and improved function (LKS), whereas in the control group, a large number of subjects showed no significant changes. The results revealed that in the experimental and control groups, knee flexion ROM was associated with better function both before and after therapy and with less pain. Moreover, pain level (VAS) was strongly and negatively correlated with functional status (LKS).

Conclusions
Magnetotherapy is useful in reducing pain and improving the mobility and functional status of the knee joint in patients with KOA.