There is increasing evidence that successful optimization of electrode position, amplitude and frequency parameters in a dynamically changing pattern may well be the key critical to successful therapeutic outcomes. The InterX is a device that provides such non-invasive interactive neurostimulation (NIN), optimizing all three stimulation parameters in a high amplitude, high density manner without penetrating too deeply into the tissue and without soliciting uncomfortable muscle contractions.
The InterX device operates by scanning the tissue to determine its impedance and to use the electrical characteristic of the skin to identify and target optimal treatment points. As stimulation is performed, the impedance of the skin under the electrode changes and is sensed by the device through the completed electrical circuit which in turn automatically varies the waveform parameters. Different preset stimulation patterns are selected in subsequent therapy sessions to prevent physiological accommodation and each of these presets automatically delivers a varying frequency to ensure optimal effects. The presets in this study varied the frequency from 15-360 pulses per second using a mixture of burst, variable and amplitude modulated parameters.
The delivery of NIN through the Flexible Array Electrode is effective for the management of pain in this population of patients, supporting previous literature pertaining to the handheld application of NIN in the post-surgical setting. The InterX is designed to optimize treatment point location, amplitude and frequency to ensure better clinical results and this technological aspect is maintained in this application. The clinical benefit of NIN therapy with the InterX device as a supplement to the standard in-house rehabilitative protocol allows patients suffering pain to regain function quicker, especially if their pain levels are particularly high. Even though subjects with more severe pain and more ROM-restriction were randomly assigned to the InterX group, the subjects receiving NIN therapy with InterX fared much better clinically with significantly reduced pain levels and improvements in ROM compared to control subjects. The implications of these findings are that patients suffering severe pain following TKR struggle to get sufficient relief from the standard of care of medications and that the inclusion of NIN therapy into the standard of care will offer greater and more consistent pain control, without the need for increased medication even with the worst cases.