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.

Phenolysis for Advanced Shoulder Osteoarthritis: A Case Series of a Novel Ultrasound-Guided Approach to Anterior and Posterior Glenohumeral Articular Nerve Branches.

INTRODUCTION: The shoulder is one of the joints most affected by osteoarthritis, with a prevalence of almost 20% in adults over 65 years of age. Various treatments have been proposed to control osteoarthritis pain, including radiofrequency, pulsed and thermal, and recently cryoanalgesia. We propose in this series of cases a new approach to analgesic therapy with chemical denervation with phenol. MATERIALS AND METHOD: Patients who underwent phenolysis for shoulder osteoarthritis at our institutions in Italy and Australia between August 2022 and May 2023 were included. All patients included in our report provided written consent for publication. This chemical neurolysis technique consisted of two injections. First, the anterior shoulder capsule was denervated by a modified deep SHAC (Shoulder Anterior Capsule) approach to cover the anterior terminal articular branches of the axillary nerve, lateral pectoral nerve, and subscapularis nerve. Second, the posterior shoulder capsule was denervated by a posterior glenoid approach to cover the terminal articular branches of the suprascapular nerve (SSN).  Results: We included a total of 11 patients in this case series. Ten of 11 patients were affected by shoulder osteoarthritis, of which three had rotator cuff tendinopathy and three had full-thickness cuff tears. One patient had chronic subluxation of a shoulder prosthesis. After treatment, all patients significantly reduced pain immediately after treatment and, two weeks later, recovered joint movement and improved quality of life. No adverse events or loss of motor function following treatment. CONCLUSION: We presented a novel chemical approach to shoulder denervation, which was shown to be another effective way of improving pain and function in advanced glenohumeral arthritis.

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.

Transcutaneous pulsed radiofrequency treatment for patients with shoulder pain booked for surgery: a double-blind, randomized controlled trial.

Shoulder pain is the third most common musculoskeletal problem and accounts for 5% of general practitioner consultations. Although many treatments are described, there is no consensus on optimal treatment and up to 40% of patients still have pain 12 months after initially seeking help for pain. Previously, the effect of transcutaneous pulsed radiofrequency treatment (TCPRFT) was evaluated in a retrospective audit that showed good pain relief for a mean 395 days and justified this randomized sham controlled trial. In this study, 51 patients entered into a randomized double-blinded, placebo controlled study of TCPRFT. Patients were assessed at 4 and 12 weeks by a blinded observer and compared with baseline. We observed sustained reductions in pain at night, pain with activity, and functional improvement at 4 and 12 weeks with active but not sham TCPRFT. The 25 subjects who received active treatment showed statistically significant reductions of 24/100 in pain at night and 20/100 of pain with activity at 4 weeks and 18/100 and 19/100, respectively, at 12 weeks from baseline. Statistically significant lower Brief Pain Inventory pain and function scores (4 and 12 weeks), improved pain self-efficacy (4 weeks), Oxford Shoulder scores (12 weeks), and internal rotation (12 weeks) were seen. Pain at both rest and shoulder elevation were not improved by active treatment. No complications were seen. This study of a simple, low risk, outpatient treatment confirms the findings of our earlier study of TCPRFT for knee pain and shoulder pain audit that transcutaneous pulsed radiofrequency treatment may help some people with painful shoulders.

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.

The addition of a small-dose ketamine infusion to tramadol for postoperative analgesia: a double-blinded, placebo-controlled, randomized trial after abdominal surgery.

BACKGROUND: There are few data on combining ketamine with tramadol for postoperative analgesia in humans. We tested the hypothesis that adding ketamine to tramadol would improve analgesia after major abdominal surgery. METHOD: In this double-blind, randomized, controlled trial, adult patients (n = 120) having elective laparotomy were randomly assigned to a ketamine group (intraoperative ketamine 0.3 mg/kg and postoperative infusion at 0.1 mg x kg(-1) x h(-1) or control group (equivalent volume/rate of normal saline). All patients received intraoperative tramadol 3 mg/kg and a tramadol infusion (0.2 mg x kg(-1) x h(-1) for 48 h postoperatively and had morphine patient-controlled analgesia available for rescue analgesia. RESULTS: The ketamine group had less pain at rest (P = 0.01) and with movement (P = 0.02) and required less morphine (P = 0.003) throughout the 48-h study period. In the 0-24 h period, ketamine improved subjective analgesic efficacy (P = 0.008), was less sedating (P = 0.03), and required fewer physician interventions to manage severe pain (P = 0.01). Hallucinations were more common in ketamine patients, but other side effects were similar. CONCLUSION: Small-dose ketamine was a useful addition to tramadol and morphine after major abdominal surgery.