Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation: Neuromodulation of the Femoral Nerve for Postoperative Analgesia Following Ambulatory Anterior Cruciate Ligament Reconstruction: A Proof of Concept Study

Abstract

Objectives: The purpose of this prospective proof of concept study was to investigate the feasibility of using percutaneous peripheral nerve stimulation of the femoral nerve to treat pain in the immediate postoperative period following ambulatory anterior cruciate ligament reconstruction with a patellar autograft.

Materials and methods: Preoperatively, an electrical lead (SPRINT, SPR Therapeutics, Inc., Cleveland, OH, USA) was percutaneously implanted with ultrasound guidance anterior to the femoral nerve caudad to the inguinal crease. Within the recovery room, subjects received 5 min of either stimulation or sham in a randomized, double-masked fashion followed by a 5-min crossover period, and then continuous active stimulation until lead removal postoperative Day 14-28. Statistics were not applied to the data due to the small sample size of this feasibility study.

Results: During the initial 5-min treatment period, subjects randomized to stimulation (n = 5) experienced a slight downward trajectory (decrease of 7%) in their pain over the 5 min of treatment, while those receiving sham (n = 5) reported a slight upward trajectory (increase of 4%) until their subsequent 5-min stimulation crossover, during which time they also experienced a slight downward trajectory (decrease of 11% from baseline). A majority of subjects (80%) used a continuous adductor canal nerve block for rescue analgesia (in addition to stimulation) during postoperative Days 1-3, after which the median resting and dynamic pain scores remained equal or less than 1.5 on the numeric rating scale, respectively, and the median daily opioid consumption was less than 1.0 tablet.

Conclusions: This proof of concept study demonstrates that percutaneous femoral nerve stimulation is feasible for ambulatory knee surgery; and suggests that this modality may be effective in providing analgesia and decreasing opioid requirements following anterior cruciate ligament reconstruction. clinicaltrials.gov: NCT02898103.

Keywords: Ambulatory surgery; neuromodulation; outpatient surgery; percutaneous peripheral nerve stimulation; postoperative analgesia.

© 2018 The Authors. Neuromodulation: Technology at the Neural Interface published by Wiley Periodicals, Inc. on behalf of International Neuromodulation Society.

Figures

Figure 1

The percutaneous peripheral nerve stimulation equipment used for this study: A 12.5 cm, 20 g needle with a preloaded helically coiled monopolar insulated electrical lead (Panel a; MicroLead, SPR Therapeutics, Inc., Cleveland, OH, USA; illustration used with permission from Brian M. Ilfeld, MD, MS); and, a stimulator attached to the surface return electrode (Panel b; SPR Therapeutics, Inc., Cleveland, OH, USA; illustration used with permission from Brian M. Ilfeld, MD, MS). The power source (battery) for the pulse generator is integrated into the white surface return electrode pad.

Figure 2

Effects of percutaneous peripheral nerve stimulation of the femoral nerve on surgical pain within the recovery room immediately following anterior cruciate ligament reconstruction with a patellar autograft. Subjects were randomized to receive 5 min of either electric current (“stimulation”; n = 5) or sham (n = 5) in a double‐masked fashion (Treatment Period A) followed by a 5‐min crossover period (Treatment Period B). Stimulation was subsequently delivered to all subjects (n = 10) for 30 additional minutes. Data presented as means at each time point with the original pain scores measured using the numeric rating scale. Given the relatively small sample size, statistics were not applied to the data. The group that received stimulation during the initial treatment has data shown in ghost during the subsequent period because peripheral nerve stimulation has a “carryover” effect and these data points are therefore difficult to interpret. The yellow star indicates that five subjects initiated their local anesthetic perineural infusion during this period of time.

Figure 3

Pain at rest during percutaneous peripheral nerve stimulation of the femoral nerve following anterior cruciate ligament reconstruction with a patellar autograft. Each circle represents one subject, and the median for each time point is denoted with a horizontal line.

Figure 4

Pain with movement during percutaneous peripheral nerve stimulation of the femoral nerve following anterior cruciate ligament reconstruction with a patellar autograft. Each circle represents one subject, and the median for each time point is denoted with a horizontal line.

Figure 5

Opioid requirements during percutaneous peripheral nerve stimulation of the femoral nerve following anterior cruciate ligament reconstruction with a patellar autograft. Each circle represents one subject, and the median for each time point is denoted with a horizontal line.