Here’s what they did

The authors searched a number of electronic databases for randomized controlled trials (RCTs) concerning patients with knee OA studies reporting the pain outcome of patients. Included studies had to compare any electrical stimulation therapies with control interventions (sham or blank) or with each other.

Electric stimulation therapies included; high-frequency transcutaneous electrical nerve stimulation (h-TENS), low-frequency transcutaneous electrical nerve stimulation (l-TENS), neuromus- cular electrical stimulation (NMES), interferential current (IFC), pulsed electrical stimulation (PES), and noninvasive interactive neurostimulation (NIN).

They independently assessed the 27 included studies for methodologicaal quality.  They also used Bayesian network meta-analysis (more on this later) to combine both the direct and indirect evidence on treatment effectiveness.

Here’s what they found

• Six kinds of electrical stimulation therapies – high-frequency transcutaneous electrical nerve stimulation (h-TENS), low-frequency transcutaneous electrical nerve stimulation (l-TENS), neuromus- cular electrical stimulation (NMES), interferential current (IFC), pulsed electrical stimulation (PES), and noninvasive interactive neurostimulation (NIN)
• Interferential current (IFC) is the only significantly effective treatment in terms of both pain intensity and change pain score at last follow-up time point when compared with the control group.
• IFC showed the greatest probability of being the best option among the six treatment methods in pain relief.
• High frequency TENS achieved a significantly lower pain intensity compared with the control group
• The evidence of heterogeneity and the limitation in sample size of some studies could be a potential threat to the validity of result
• Seven trials reported adverse effects – mainly skin rashes during PES

Note to readers:

• IFC delivers alternating medium-frequency current (4,000 Hz) through superficial electrodes placed on the skin
• TENS is a form of electroanalgesia based on the gate control theory of pain perception65, which delivers biphasic pulsed currents through two electrodes

The authors concluded

Interferential current (IFC) seems to be the most promising pain relief treatment for the management of knee OA.

The Musculoskeletal Elf’s view

This systematic review used a network meta-analysis. So just what is a network meta-analysis? It is a statistical technique that allows in- direct comparisons of interventions among primary trials. In this study, the effect of pain management was expressed as the stan- dard mean differences (SMD) among different treatment arms.

A positive value represents a better pain relief effect and a negative value indicates less pain intensity after treatment. In this paper IFC achieved a significantly lower pain intensity compared with the control group (SMD: 0.92, 95% CI: 1.72, 0.05), and so did high frequency TENS (SMD: 0.78, 95% CI: 1.34, 0.22).

What do you think?

• Do you use electrical stimulation for OA knee?
• If so will these results affect your selection of type?
• If you didnt use electrical stimulation before will you consider it now?

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Links

• Electrical stimulation for pain relief in knee osteoarthritis: systematic review and network meta-analysis. Zeng C Osteoarthritis Cartilage. 2015 Feb;23(2):189-202. doi: 10.1016/j.joca.2014.11.014. Epub 2014 Nov 26.