Early Experience With a Novel Miniaturized Spinal Cord Stimulation System for the Management of Chronic Intractable Pain of the Back and Legs.

INTRODUCTION: A novel, spinal cord stimulation (SCS) system with a battery-free miniaturized implantable pulse generator (IPG) was used in this feasibility study. The system uses an external power source that communicates bidirectionally with the IPG (< 1.5 cm3). Human factors, subject comfort, and effects on low back and leg pain were evaluated in this first-in-human study. MATERIALS AND METHODS: A prospective, multicenter, open-label clinical trial was initiated to evaluate the safety and performance of a novel miniaturized stimulator in the treatment of chronic, intractable leg and low-back pain. Eligible subjects were recruited for the study and gave consent. Subjects who passed the screening/trial phase (defined as ≥ 50% decrease in pain) continued to the long-term implant phase and were followed up at predefined time points after device activation. Interim clinical and usability outcomes were captured and reported at 90 days. RESULTS: Results of 22 subjects who chose a novel pulsed stimulation pattern therapy using the battery-free IPG (< 1.5 cm3) are described here. At 90-days follow-up, the average pain reduction was 79% in the leg (n = 22; p < 0.0001) and 76% in the low back (n = 21; p < 0.0001) compared with baseline. Responder rates (≥ 50% pain relief) at 90 days were 86% in leg pain (19/22) and 81% in low-back pain (17/21). Subjects rated the level of comfort of the external wearable power source to be 0.41 ± 0.73 at 90 days on an 11-point rating scale (0 = very comfortable, 10 = very uncomfortable). DISCUSSION: These interim results from the ongoing study indicate the favorable efficacy and usability of a novel, externally powered, battery-free SCS IPG (< 1.5 cm3) for leg and low-back pain. Study subjects wore the external power source continuously and found it comfortable, and the system provided significant pain relief. These preliminary findings warrant further investigation. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is ACTRN12618001862235.

Three-Dimensional Printing: An Aid to Epidural Access for Neuromodulation.

OBJECTIVE: The case report details to use of three-dimensional (3D) printing as an aid to neuromodulation. METHODS: A patient is described in whom previous attempts at spinal neuromodulation had failed due to lack of epidural or intrathecal access, and the use of a 3D printed model allowed for improved planning and ultimately, success. RESULTS: Successful spinal cord stimulation was achieved with the plan developed by access to a 3D model of the patient's spine. CONCLUSION: Neuromodulation techniques can provide the optimal analgesic techniques for individual patients. At times these can fail due to lack of access to the site for intervention, in this case epidural access. 3D printing may provide additional information to improve the likelihood of access when anatomy is distorted and standard approaches prove difficult.

Treating Chronic, Intractable Pain with a Miniaturized Spinal Cord Stimulation System: 1-Year Outcomes from the AUS-nPower Study During the COVID-19 Pandemic.

Purpose: Spinal cord stimulation (SCS) is a highly effective treatment for chronic neuropathic pain. Despite recent advances in technology, treatment gaps remain. A small SCS system with a miniaturized implantable pulse generator (micro-IPG; <1.5 cm3 in volume) and an externally worn power source may be preferred by patients who do not want a large, implanted battery. We report here the long-term outcomes from the first-in-human study evaluating the safety and performance of a new neurostimulation system. Patients and Methods: This was a prospective, multi-center, open-label, single-arm study to evaluate this SCS system, in the treatment of chronic, intractable leg and low-back pain. Consented subjects who passed screening continued on to the long-term phase of the study. One-year, patient-reported outcomes (PRO's) such as pain (Numeric Rating Scale, NRS), functional disability, quality of life, and mood were captured. Results: Twenty-six (26) evaluable subjects with permanent implants were included in this analysis. The average leg pain NRS score decreased from 6.8 ± 1.2 at baseline to 1.1 ± 1.2 at the end of the study (p < 0.001), while the average low-back pain NRS score decreased from 6.8 ± 1.2 to 1.5 ± 1.2 (p < 0.001). The responder rate (proportion with ≥50% pain relief) was 91% in the leg(s) and 82% in the low back. There were significant improvements in functional disability (Oswestry Disability Index) and in mood (Beck Depression Inventory), demonstrating a 46% and 62% improvement, respectively (p < 0.001). Eleven-point Likert scales demonstrated the wearable to be very comfortable and very easy to use. Conclusion: There were considerable challenges conducting a clinical study during the COVID-19 pandemic, such as missed study programming visits. Nevertheless, subjects had significant PRO improvements through 1-year. The small size of the implanted device, along with a proprietary waveform, may allow for improved SCS outcomes and a drop in incidence of IPG-pocket pain.

Transcutaneous application of pulsed radiofrequency treatment for shoulder pain.

UNLABELLED: We report a retrospective audit of transcutaneous pulsed radiofrequency treatment therapy (TCPRFT) for shoulder pain over a 4-year period. METHODS: Electronic and manual case review revealed that TCPRFT had been performed on 13 patients, with 15 painful shoulders, using a single treatment session between 2006 and 2010 in an outpatient setting. RESULTS: Of the 15 shoulders treated, 10 (two-thirds) had pain relief for over 3 months with an average pain score reduction of 6.1 of 10 and an average duration of pain relief of 395 days. Two experienced pain relief of < 3 months with an average reduction in pain score of 4.3 of 10 and an average duration of effect of 11 days. Three cases experienced no pain relief from the treatment. SUMMARY: These results suggest TCPRFT may provide clinically useful pain relief and be another treatment modality for shoulder pain. Our findings justifies further research, and we are proceeding with a double-blind placebo randomized controlled studies to determine the efficacy of TCPRFT in chronic shoulder pain.

Transcutaneous pulsed radiofrequency treatment in patients with painful knee awaiting total knee joint replacement.

OBJECTIVE: Our study was designed to determine if transcutaneous-pulsed radiofrequency treatment (TCPRFT) was able to reduce the pain experienced by patients awaiting total knee joint replacement (TKJR). We conducted a randomized, double-blinded, placebo controlled trial of TCPRFT in patients referred for TKJR to our hospital's Orthopedic Outpatient Clinic. METHODS: Patients on the waiting list for assessment for TKJR were invited to participate and were examined in the clinic if they satisfied the inclusion criteria. Patients were randomized to receive active or sham TCPRFT. The alteration in pain and function of the treated knee after a single TCPRFT was assessed at examination at 1 and 4 weeks using visual analog pain score (VAS) at rest and after 20 and 400 m walks. RESULTS: The results of 50 patients showed a statistically significant reduction in VAS at 1 and 4 weeks compared with baseline in the group who received active treatment. We also demonstrated what is considered a clinically significant improvement in this group that became more pronounced at week 4 compared with week 1 and also more after a 400 m walk compared with a 20 m walk. Maximum improvement observed in group data was 19/100 VAS. Patients receiving sham treatment showed no statistically significant improvement. DISCUSSION: We believe this to be the first report of a controlled study of TCPRFT. This pilot study shows a benefit of the technique that justifies future research.

Randomized, double blinded comparative trial of intradermal injections of lignocaine versus N-saline around the knee to relieve pain in patients awaiting total knee replacement.

OBJECTIVES: We report a randomized, double-blinded comparative study assessing the efficacy of local anesthetic with N-saline intradermal blocks around the knee to reduce pain and improve patient satisfaction while waiting for a total knee joint replacement. METHODS: Patients were offered involvement in this study while on the hospital waiting list for a knee replacement. Eligible patients, after completing a prestudy assessment, received an average of 6.3 (range: 1 to 10) intradermal injections of 0.5 mL either saline or 1% lignocaine injections into tender points around the knee. Patients were assessed at 2 hours and 1 week after the injections. Pain was assessed using 0 to 100 visual analog pain scale. Global perceived effect (satisfaction) was measured on a 7-point Likert scale. RESULTS: Thirty-two of 34 patients attended at 1-week assessment, 24 (75%) felt that they were improved, and 8 (25%) considered they were unchanged or worse. In both the saline and lignocaine groups, 12 of 16 patients felt that they had improved. N-saline proved as effective as lignocaine in reducing knee pain when injected intradermally. Seventy-five percent of patients were improved at 1 week.