Nerve regeneration after radiofrequency application

Randomized Placebo-Controlled Trial of 60-Day Percutaneous Peripheral Nerve Stimulation Treatment Indicates Relief of Persistent Postoperative Pain, and Improved Function After Knee Replacement

OBJECTIVES

Total knee arthroplasty (TKA) is an effective surgery for end-stage knee osteoarthritis, but chronic postoperative pain and reduced function affect up to 20% of patients who undergo such surgery. There are limited treatment options, but percutaneous peripheral nerve stimulation (PNS) is a promising nonopioid treatment option for chronic, persistent postoperative pain. The objective of the present study was to evaluate the effect of a 60-day percutaneous PNS treatment in a multicenter, randomized, double-blind, placebo-controlled trial for treating persistent postoperative pain after TKA.

MATERIALS AND METHODS

Patients with postoperative pain after knee replacement were screened for this postmarket, institutional review board-approved, prospectively registered (NCT04341948) trial. Subjects were randomized to receive either active PNS or placebo (sham) stimulation. Subjects and a designated evaluator were blinded to group assignments. Subjects in both groups underwent ultrasound-guided placement of percutaneous fine-wire coiled leads targeting the femoral and sciatic nerves on the leg with postoperative pain. Leads were indwelling for eight weeks, and the primary efficacy outcome compared the proportion of subjects in each group reporting ≥50% reduction in average pain relative to baseline during weeks five to eight. Functional outcomes (6-minute walk test; 6MWT and Western Ontario and McMaster Universities Osteoarthritis Index) and quality of life (Patient Global Impression of Change) also were evaluated at end of treatment (EOT).

RESULTS

A greater proportion of subjects in the PNS groups (60%; 12/20) than in the placebo (sham) group (24%; 5/21) responded with ≥50% pain relief relative to baseline (p = 0.028) during the primary endpoint (weeks 5-8). Subjects in the PNS group also walked a significantly greater distance at EOT than did those in the placebo (sham) group (6MWT; +47% vs -9% change from baseline; p = 0.048, n = 18 vs n = 20 completed the test, respectively). Prospective follow-up to 12 months is ongoing.

CONCLUSIONS

This study provides evidence that percutaneous PNS decreases persistent pain, which leads to improved functional outcomes after TKA at EOT.

Percutaneous radiofrequency ablation and endoscopic neurotomy for lumbar facet joint syndrome: are they good enough?

OBJECTIVE

Lumbar facet joint (LFJ) syndrome is one of the common causes of low back pain (LBP). There are different views on percutaneous and endoscopic radiofrequency. The purpose of this systematic review and meta-analysis is to explore the therapeutic effect of radiofrequency ablation on LBP originating from LFJ and compare the therapeutic effect of percutaneous radiofrequency ablation and endoscopic neurotomy.

METHODS

We included randomized controlled trials which compared the efficiency of percutaneous radiofrequency ablation and conservative treatment (sham procedures, facet joint injection, physiotherapy, exercise, or oral medication) or compared the efficiency of percutaneous radiofrequency ablation and endoscopic neurotomy for LFJ syndrome. We searched in PubMed and Web of Science from inception to March 27, 2023. Meta-analysis was performed using RevMan 5.4 software.

RESULTS

A total of 11 randomized controlled trials were included. Among them, nine studies were used for evaluating efficiency of percutaneous radiofrequency ablation, and two studies were used for evaluating efficiency of endoscopic neurotomy. Pooled data from two studies reporting outcomes at 1 year did not show a benefit from facet joint denervation by comparing the percutaneous radiofrequency ablation and conservative treatment (standardized mean difference (SMD) = -0.87, 95% confidence interval (CI) [-2.10, 0.37], P = 0.17). There was no significant difference between percutaneous radiofrequency ablation and endoscopic neurotomy at 1-month follow-up (mean difference (MD) = -0.13, 95%CI [-0.18, -0.44], P = 0.41). At 12-month follow-up the pain relief in the endoscopic neurotomy was significantly better than that in the percutaneous radiofrequency ablation group (MD = 1.98, 95%CI [1.60, 2.36], P < 0 .0001).

CONCLUSION

The LBP was significantly relieved shortly after percutaneous radiofrequency ablation. Compared with percutaneous radiofrequency ablation, endoscopic neurotomy seems to have a longer effect. A longer follow-up period is needed to confirm its effectiveness.

Does additional extracorporeal shock wave therapy improve the effect of isolated percutaneous radiofrequency coblation in patients with insertional Achilles tendinopathy? Study protocol for a randomized controlled clinical trial

BACKGROUND

No conclusive evidence recommends a prior treatment for insertional Achilles tendinopathy (IAT). It is theorized that both percutaneous radiofrequency coblation and extracorporeal shockwave therapy (ESWT) relieve pain within the insertion. However, no clinical evidence shows that either treatment promotes the regeneration of the tendon or if the combination of these 2 interventions offers better function and less pain than one therapy.

METHODS

The study is a randomized, controlled trial with patients allocated in a 1:1 ratio to one of two parallel groups. Patients with insertional Achilles tendinopathy who are not satisfied with the effect of conservative treatment will be screened. A minimum of 38 patients will be enrolled after deciding to participate in the trial on an informed basis. Then the intervention group and the control group perform radial ESWT and sham-ESWT respectively at 6 months after percutaneous radiofrequency coblation. The primary outcome will be the Victorian Institute of Sports Assessment Achilles (VISA-A) Score. Secondary outcome measures will be Foot and Ankle Outcome Score (FAOS) scale, visual analog scale (VAS), Tegner Score, and MRI ultra-short echo time (UTE) T2* value. The assessments will occur in 6 months, 1 year, and 2 years, post-operatively. The differences between the 2 groups will be conducted as intention-to-treat basis.

DISCUSSION

We aim to investigate if radiofrequency coblation associated with ESWT can provide more encouraging imaging findings as well as functional and clinical outcomes regarding the treatment of the IAT comparing to the single radiofrequency coblation treatment.

TRIAL REGISTRATION

ChiCTR1800017898; pre-results. Registered on 20 August 2018.

Nonoperative Management of the Achilles Tendon Insertion

Insertional Achilles tendinopathy can be a very challenging clinical syndrome with various nonoperative measures typically attempted before surgical intervention. Associated complications are known with surgical repair and can be limb altering. Owing to the longevity of clinical symptoms before clinical presentation, changing the pathophysiologic process and halting the inflammatory changes becomes paramount. Here we discuss nonoperative techniques and updates in the foot and ankle literature.

Changes in the gene expression in mouse astrocytes induced by pulsed radiofrequency: A preliminary study

Glial cells, both astrocytes and microglia, play important roles in the induction and maintenance of neuroinflammation resulting in neuropathic pain. Pulsed radiofrequency (PRF) is applied to various nerves for the treatment of pain, although the molecular mechanism underlying its effects is still unclear. We herein investigated the genomic effects of PRF on a mouse cultured astrocyte cell line. PRF was applied to the cultured astrocytes in 20-msec pulses of 480 kHz every 500 msec, delivered at the rate of 2 Hz, for 30 min. PRF increased the expression of 2,431 genes and decreased that of 209 genes. Among these genes, 435 genes were upregulated >10-fold and 89 genes >30-fold, while no genes showed a 10-fold decrease in expression. A gene ontology analysis using the list of >10-fold upregulated genes showed that PRF treatment activated immune responses. A pathway analysis using the Kyoto Encyclopedia of Gene and Genomes with the same list detected seven pathways related to neuropathic pain. These findings suggest that PRF improves neuropathic pain via neuroimmunomodulation.

Radiofrequency Microdebridement as an Adjunct to Arthroscopic Surgical Treatment for Recalcitrant Gluteal Tendinopathy: A Double-Blind, Randomized Controlled Trial

Background:

Recalcitrant greater trochanteric pain is increasingly recognized as an indication for surgical intervention. The arthroscopic approach has become rapidly more common than the open alternative.

Hypothesis:

Patients undergoing radiofrequency microdebridement (RFMD) as an adjunct to arthroscopic gluteal bursectomy (AGB) and iliotibial band release (ITBR) will experience better functional improvement than AGB and ITBR alone at 1 year.

Study Design:

Randomized controlled trial; Level of evidence, 2.

Methods:

A total of 33 patients with failed nonoperative treatment of gluteal tendinopathy were randomly allocated to undergo AGB/ITBR or AGB/ITBR + RFMD. Full-thickness tears were excluded. The primary outcome measure was the modified Harris Hip Score (mHHS) at 52 weeks. Secondary outcome measures included the mHHS, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analog scale (VAS) for pain, and 12-item Short Form Health Survey (SF-12), which were evaluated at 0, 6, 12, 24, and 52 weeks. Statistical significance was defined as P < .05.

Results:

A total of 33 participants (33 hips; 30 female and 3 male; mean age, 58 years) were randomized; 16 patients underwent AGB/ITBR + RFMD, and 17 underwent AGB/ITBR. Participants’ functionality improved in both groups at all time intervals. The mean mHHS score improved from 57.49 ± 10.61 to 77.76 ± 18.40 (P = .004) and from 58.98 ± 12.33 to 79.96 ± 18.86 (P = .001) at 52 weeks in the AGB/ITBR and AGB/ITBR + RFMD groups, respectively, although there was no statistically significant difference between groups. There were no device-related adverse events.

Conclusion:

AGB/ITBR led to significant improvements in patients with recalcitrant gluteal tendinopathy. In this small RCT, the addition of RFMD showed no additional benefit to AGB/ITBR but provided a safe adjunct for the surgical management of recalcitrant gluteal tendinopathy.

Registration:

NCT01562366 (ClinicalTrials.gov identifier).

Endoscopic Plantar Fasciotomy vs Open Radiofrequency Microtenotomy for Recalcitrant Plantar Fasciitis

BACKGROUND

Although usually self-limiting, around 10% of patients develop recalcitrant plantar fasciitis despite conservative treatment. In such cases, operative intervention can be offered. Traditionally, plantar fasciotomy has been the treatment of choice, but recently, there has been a push for more minimally invasive approaches. Radiofrequency microtenotomy has also been increasingly used as a treatment option. In this study, we compare the outcomes of endoscopic plantar fasciotomy and open radiofrequency microtenotomy.

METHODS

Patients treated in our institution with either procedure between 2007 and 2015 were included and interviewed at baseline and 3 months, 6 months, and 12 months postoperatively using the American Orthopaedic Foot & Ankle Society (AOFAS) and 36-item Medical Outcomes Short Form (SF-36) questionnaires. They were asked questions to evaluate their expectation and satisfaction postoperatively. Demographic and clinicopathological data were prospectively collected from clinical charts and electronic records.

RESULTS

There was no difference in either treatment arms preoperatively and an overall improvement in all functional outcomes postoperatively. However, patients who had endoscopic plantar fasciotomy fared better at 3 months compared to patients who underwent open microtenotomy with the visual analog score component of the AOFAS hindfoot score (HINDVAS) and the social functioning and role-functioning-emotional reaching statistical significance ( P = .027, P = .03, and P = .03, respectively). There was no difference in functional outcomes at 6 or 12 months postoperatively.

CONCLUSION

Endoscopic plantar fasciotomy was associated with an earlier improvement in functional outcome in our study. However, both treatments had equivalent outcomes at 1-year follow-up, suggesting that either method is reasonable in the treatment of chronic plantar fasciitis.

LEVEL OF EVIDENCE

Level III, comparative study.

Comparison of Clinical Efficacy Among Endoscopy-Assisted Radio-Frequency Ablation, Extracorporeal Shockwaves, and Eccentric Exercises in Treatment of Insertional Achilles Tendinosis

BACKGROUND

We sought to compare clinical efficacy among endoscopy-assisted radio-frequency ablation under local anesthesia, extracorporeal shockwaves (ESWs), and eccentric exercises in treating insertional Achilles tendinosis.

METHODS

In this retrospective study, 78 patients diagnosed as having unilateral insertional Achilles tendinosis were enrolled. These participants underwent endoscopy-assisted radio-frequency ablation, ESWs, and eccentric calf muscle exercises between March 1, 2006, and February 28, 2011. Clinical efficacy was evaluated by the visual analog scale (VAS), the American Orthopaedic Foot and Ankle Society (AOFAS) ankle/hindfoot scale, and the Victorian Institute of Sport Assessment-Achilles (VISA-A) scale before and after treatment.

RESULTS

Before treatment, there were no statistically significant differences in VAS, AOFAS ankle/hindfoot scale, and VISA-A scale scores among the different groups (all P > .05). For the endoscopy and ESW groups, VAS, AOFAS ankle/hindfoot scale, and VISA-A scale scores were significantly improved after 18 months of treatment (all P < .05). The VAS, AOFAS ankle/hindfoot scale, and VISA-A scale scores in the endoscopy group were significantly higher than those in the ESW and eccentric exercise groups after 18 months of therapy (all P < .05).

CONCLUSIONS

Combined with synovectomy and tendon debridement, endoscopy-assisted radio-frequency ablation yields better clinical efficacy compared with ESWs in treating insertional Achilles tendinosis.

The anabolic effect of plasma-mediated ablation on the intervertebral disc: stimulation of proteoglycan and interleukin-8 production

BACKGROUND CONTEXT

Plasma-mediated radiofrequency-based ablation (coblation) is an electrosurgical technique currently used for tissue removal in a wide range of surgical applications, including lumbar microdiscectomy. In vitro and in vivo studies have shown the technique to alter the expression of inflammatory cytokines in the disc, increasing the levels of interleukin-8 (IL-8), which may promote maturation and remodeling of the disc matrix.

PURPOSE

To better understand the effect of coblation treatment, this study characterizes the temporal and spatial pattern of healing after stab injury to the rabbit intervertebral disc, with and without plasma-mediated radiofrequency treatment.

PATIENT SAMPLE

A total of 23 New Zealand white rabbits.

STUDY DESIGN

Annular and nuclear stab injuries.

OUTCOME MEASURES

Sandwich enzyme-linked immunosorbent assay evaluated the concentrations of cytokines tumor necrosis factor-α, IL-1β, and IL-8. Histopathologic evaluations were performed on whole discs and end plates. Tissue sections were stained with Safranin-O to evaluate nucleus pulposus and annulus fibrosus proteoglycan content and with Alcian blue for extracellular proteoglycan content. Intradiscal leakage pressure was evaluated by injecting methylene blue dye into the nucleus.

METHODS

Animals underwent annular and nuclear stab injuries on three consecutive lumbar discs (L2-L3 to L4-L5). The three levels were randomly assigned into one of the three groups for treatment with a plasma-mediated radiofrequency ablation device (TOPAZ; ArthroCare Corp., Austin, TX, USA): active treatment of the nucleus only (SN); active treatment of both nucleus and annulus (SNA); sham treatment. Unstabbed/untreated discs from L5-L6 (n=5) served as normal controls. Animals were euthanized at 4, 8, and 28 days postsurgery.

RESULTS

Tumor necrosis factor-α was detected in sham discs at 4 and 8 days, but not in coblation groups (SN or SNA); IL-1β was below detection in all three treatment groups. Interleukin-8 levels increased in all treatment groups at 4 and 8 days compared with normal control, peaking at 4th day for sham and SN groups and 8th day (p>.3) for the SNA group (a 2.5-fold increase). Pressure measurements revealed higher leakage in the SN group, but no statistically significant differences. Histopathology showed higher proteoglycan production by 28 days in the SNA and SN groups compared with sham. All three treatment groups showed ruptured annular fibers from the stab injury, but maintained the overall architecture. Remnants of notochordal tissue within the nucleus were evident in all treatment groups at 4 and 8 days, but were only found in sham group by 28 days. At this time, unlike the normal or sham controls, the nucleus of SN and SNA discs had fibrocartilaginous tissue with chondrocyte-like cells. Significant differences in the disc architecture grade were only noted when comparing normal controls with other groups by 28 days (p<.001).

CONCLUSIONS

Plasma-mediated radiofrequency ablation appears to have an anabolic effect on disc cells, stimulating proteoglycan and IL-8 production and maintaining annulus architecture. Coblation treatment appears to reduce cellular response to proinflammatory stimuli and restore overall disc architecture that may prove beneficial in a number of degenerative disc paradigms. Further studies are encouraged to investigate the therapeutic effect of the technique.

Is percutaneous radiofrequency coblation for treatment of Achilles tendinosis safe and effective?

Insertional Achilles tendinosis results in isolated pain at the Achilles tendon insertion site due to intratendinous degeneration. When conservative measures fail, surgical treatment may be necessary. Radiofrequency coblation has been suggested to be an effective procedure for treatment of tendon pathologies. Percutaneous execution of this procedure is very simple as well as minimally invasive, and thus if effective, would be an excellent alternative to an open treatment of insertional Achilles tendinopathy. A review of 47 cases with this percutaneous technique was conducted. In our relatively short-term follow-up (mean = 8.6 months, SD = 9.71, range 1 to 40), the incidence of reoperation was 14.9% (7/47). Rupture of the Achilles tendon was identified in 3 (6.4%) patients. Our cohort had a relatively high body mass index (mean = 37.1, SD = 6.96, range 24.3 to 52.8). We recommend surgeons to be cautious about selecting this procedure in similar, high body mass index patient cohorts for treatment of Achilles tendinosis.

Fascial incision and adhesiolysis combined with radiofrequency microtenotomy in treatment of chronic midportion Achilles tendinopathy

BACKGROUND AND AIMS

Achilles tendinopathy is a common problem that can cause disturbing symptoms in activities of daily living as well as prevent sports activities. The purpose of this study was to evaluate the effects of fascial incision and adhesiolysis combined with radiofrequency microtenotomy in treatment of chronic midportion Achilles tendinopathy.

MATERIAL AND METHODS

Twenty-four patients were included in this study. The cases were studied retrospectively. The mean age of the patients was 54 years (range, 39 to 72) and there were 12 women and 12 men. A final evaluation was done at an average of 30 months (range, 18 to 45) after surgery, including radiofrequency microtenotomy.

RESULTS

In all cases the Nirschl Pain Phase Scale of Athletic Overuse Injuries score improved and the difference was statistically significant (p < 0.0001). The patients themselves rated the result excellent in 14 cases and good in 10 cases.

CONCLUSION

Fascial incision and adhesiolysis combined with radiofrequency microtenotomy seems to be a useful alternative in treatment of chronic midportion Achilles tendinopathy in cases of unsuccessful non-operative treatment.

New options in the management of tendinopathy

Tendon injuries can be acute or chronic, and caused by intrinsic or extrinsic factors, either alone or in combination. Tendinopathies are a common cause of disability in occupational medicine and account for a substantial proportion of overuse injuries in sports. Tendinopathy is essentially a failed healing response, with haphazard proliferation of tenocytes, abnormalities in tenocytes, with disruption of collagen fibres and subsequent increase in noncollagenous matrix. The scientific evidence base for managing tendinopathies is limited. What may appear clinically as an "acute tendinopathy" is actually a well advanced failure of a chronic healing response in which there is neither histologic nor biochemical evidence of inflammation. In this review we report the new options for the management of tendinopathy, including eccentric exercises, extracorporeal shockwave therapy, injections (intratendinous injections of corticosteroids, aprotinin, polidocanol platelet-rich plasma, autologous blood injection, high-volume injections) and surgery. Open surgery aims to excise fibrotic adhesions, remove areas of failed healing and make multiple longitudinal incisions in the tendon to detect intratendinous lesions, and to restore vascularity and possibly stimulate the remaining viable cells to initiate cell matrix response and healing. New surgical techniques aim to disrupt the abnormal neoinnervation to interfere with the pain sensation caused by tendinopathy. These procedures are intrinsically different from the classical ones in present use, because they do not attempt to address directly the pathologic lesion, but act only to denervate them. They include endoscopy, electrocoagulation, and minimally invasive stripping. Further randomized controlled trials are necessary to clarify better the best therapeutic options for the management of tendinopathy.

Radiofrequency coblation for chronic foot and ankle tendinosis

PURPOSE

To evaluate outcomes of radiofrequency coblation for chronic tendinosis of the foot and ankle tendons.

METHODS

Records of 7 men and 8 women (16 feet) aged 27 to 65 years who underwent radiofrequency coblation for chronic tendinosis (combined with other procedures for other pathology) of the Achilles, posterior tibial, and peroneal tendons were retrospectively reviewed. The visual analogue scale (VAS) for pain status, the Short Form (SF-36) questionnaire for quality of life, and the American Orthopaedic Foot and Ankle Society (AOFAS) scores for functional status of the patients were determined pre- and post-operatively.

RESULTS

All patients reported significant reduction in pain at 3 months, with more than 63% attaining VAS scores of 0 at 6 months. AOFAS scores were significantly improved at both 3 and 6 months. Most components of SF-36 scores improved at 6 months except those for general health and role emotional; only those for bodily pain improved significantly. At postoperative month 3 and 6 respectively, 93 and 100% of the patients had their expectations met, whereas 93 and 88% had good-to-excellent satisfaction. There were no major complications.

CONCLUSIONS

Radiofrequency coblation for chronic tendinosis of the foot and ankle achieves good short-term outcomes and pain relief. It may be combined with other procedures for maximal benefit.

Pulsed radiofrequency effects on the lumbar ganglion of the rat dorsal root: a morphological light and transmission electron microscopy study at acute stage

Since the dorsal root ganglia represent the first structure of pain modulation, they are the target of the newest therapies of neuropathic pain. Between these, pulsed radiofrequency (PRF) has been described among the promising non-invasive methods. Although the results encourage the clinical use of this procedure, their mechanism of action is still unclear. Aim of our study was to analyze acute effects of PRF on the rat lumbar ganglion and on nervous fibres running inside it. Clinical works describe PRF treatment as a technique without any visible neurological deficit. The few disposable histological works are contractictory: some describe no signs of cellular damage and some demonstrate visible intracellular modifications. A total of 20 male Wistar rats were deeply anesthesized. Ten were positioned in a stereotactic system, and exposed to PRF at 2 Hz for 30 s after exposition of paravertebral muscles and positioning of a stimulation needle on left L4 ganglion. The other ten were used as controls. After 1 h, the left dorsal root ganglions L3, L4, L5 of the 20 animals were explanted, fixed in 2.5% Karnowsky solution and prepared for light and transmission electron microscopy. At light microscopy no differences between treated and control animals were observed; at transmission electron microscopy, instead, it was possible to observe that T gangliar cells contained an abnormal abundant smooth reticulum with enlarged cisternae and numerous vacuoles; myelinated axons presented pathological features and their myelin coverage was not adherent. Instead, unmyelinated axons appeared normal in shape and dimension and the Schwann cells surrounding it had intact plasmamembrane. Our results, obtained at acute stage, reveal that the PRF procedure should destroy the myelin envelope of nervous fibres. Further future studies, at chronic stage, should give other information on the prognosis of the myelinic damage.