Novel approach for peripheral subcutaneous field stimulation for the treatment of severe, chronic knee joint pain after total knee arthroplasty

Abstract

The objective of this study is to present a novel approach for the treatment of severe, chronic knee joint pain following total knee arthroplasty utilizing peripheral subcutaneous field stimulation and discuss the role of this treatment modality in patients with symptoms that are refractory to conventional pharmacologic, surgical, and physical therapies. Presented are two case reports of patients with chronic intractable knee pain where peripheral nerve stimulation via a permanent neurostimulating implant was introduced successfully. Both patients presented with persistent knee pain, for greater than one year, after having had total knee arthroplasty. The patients' symptoms failed to be alleviated by a variety of interventions including non-steroidal anti-inflammatory drugs (NSAIDS), oral antidepressants, membrane stabilizers, opioids, physical therapy, surgical revisions, manipulation under anesthesia, local anesthetic patches, and transcutaneous electrical nerve stimulation. In each case, direct stimulation of the knee was achieved utilizing a peripheral nerve stimulator via a periarticular approach. Neuromodulation daily has produced both significant pain relief and functional improvement. Significant decreases in pain visual analog scale (VAS) scores and improvement in functional capacity were observed during the stimulation trial and during the follow-up after permanent implantation. The mean VAS score changed dramatically. Introduction of a peripheral subcutaneous field stimulation directly to the painful knee area is a novel and simple procedure that was extremely effective for the relief of pain and may provide a breakthrough in the treatment of chronic intractable knee pain following total knee arthroplasty. The periarticular approach has several advantages, including only small incisions over the lateral and medial knee, proximal thigh and abdomen resulting in minimal strain on the lead array with flexion and extension contributing to overall stability of this system.