P-073 - (Poster #73) Peripheral Nerve Stimulation HF-EMC Technology to Power an Implanted Neurostimulator with a Separate Receiver for the Treatment of Chronic Knee Pain after Total Knee Replacement: A 12 month Retrospective Study

Knee pain, due to osteoarthritis, is one of the most challenging painful conditions which can be treated with knee replacement surgery if conservative and interventional pain therapies fail. The condition becomes even more challenging if the pain continues after the knee replacement.

Our study presents cases that were treated with Peripheral Nerve Stimulation HF-EMC Technology for treating patients after knee replacement surgery who failed all other pain management modalities.

Purpose/Objectives:

The primary objective of this retrospective review was to examine the responder rate (proportion of subjects experiencing greater than 50% relief) and changes in pain scores after the trial procedure. Secondary objectives included changes in pain scores from at least one month after permanent implantation and adverse event occurrences.

Methods:

A retrospective review was conducted to assess baseline and follow-up parameters. Inclusion criteria included subjects 18 years or older with residual chronic knee pain after total knee replacement. Exclusion criteria included subjects with another active implanted device for pain management. The 11-point Verbal Rating Scale (VRS) was used to assess pain scores. All subjects were implanted with a permanent Freedom PNS system at the infrapatellar saphenous nerve (IPS).

Results:

At the end of the 7-day trial period, all 7 (100%) subjects reported more than 50% pain relief, with mean pain scores reducing from 9.5±0.5 to 1.3±0.5 (86%; p< 0.001). The average VRS score at 1-month post-permanent implant decreased to 2.9±0.9 (69%; p< 0.001). Six subjects reported mean VRS of 3.5±2.1 (63%; p< 0.001) at three months. Five subjects reported a mean VRS of 3.8±2.2 (60%; p< 0.001)  with four subjects reporting a mean pain score of 4 (58%; p< 0.001)  after 12 months. All subjects reported improved mobility and quality of life. No adverse events were reported.

Conclusions/Implications for future research and/or clinical care:

Peripheral nerve stimulation at the infrapatellar saphenous nerve with the Freedom PNS System demonstrates efficacy and safety in managing chronic knee pain after total knee replacement (TKR). This approach holds promise for patients with residual chronic pain after surgery, warranting further investigation and consideration in clinical practice.