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The Effectiveness of Fluoroscopically-Guided Genicular Nerve Radiofrequency Ablation for the Treatment of Chronic Knee Pain Due to Osteoarthritis: A Systematic Review
Abstract
The objective was to determine the effectiveness of fluoroscopically-guided genicular nerve radiofrequency ablation (RFA) for painful knee osteoarthritis. Primary outcome measure was improvement in pain after six months. Secondary outcomes included Oxford Knee Score (OKS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Two reviewers independently assessed publications before October 10, 2020. The Cochrane Risk of Bias Tool and Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system were used. 199-publications were screened, and nine were included. Six-month success rates for >=50% pain relief after RFA ranged from 49-74%. When compared to intraarticular steroid injection (IAS), the probability of success was 4.5 times higher for RFA (RR = 4.58 [95% CI 2.61, 8.04]). When RFA was compared to hyaluronic acid injection (HA), the probability of treatment success was 1.8 times higher (RR = 1.88 [95% CI 1.38, 2.57]). Group mean OKS and WOMAC scores improved in participants receiving genicular RFA compared to IAS and HA. According to GRADE there is moderate quality evidence that fluoroscopically-guided genicular RFA is effective for reducing pain associated with knee osteoarthritis at minimum of six months. Further research is likely to have an important impact on the current understanding of the long-term effectiveness of this treatment.
... When results from all clinical studies are evaluated, regardless of the RFA modality employed, successful outcomes have been reported in between 30% and 74% of OA patients at 6 months. [120][121][122][123][124][125][126] When RF of the genicular nerves is compared to intra-articular injections in knee OA, the results from systematic reviews are contradictory. One reported the probability of benefit after RF to be 4.5 times higher compared to IACS and 1.8 times higher compared to IAHA, while another showed no significant difference in effect between IA injections, RF ablation, and genicular artery embolization. ...
... One reported the probability of benefit after RF to be 4.5 times higher compared to IACS and 1.8 times higher compared to IAHA, while another showed no significant difference in effect between IA injections, RF ablation, and genicular artery embolization. 125,127 There seem to be differences in the efficacy between the three RF modalities. Conventional RF treatment was shown to be superior to pulsed RF in OA knee pain in an RCT, which is consistent with comparisons for other joints. ...
... Systematic reviews report the RF intervention to be safe with limited non-severe adverse events. 125,126,160,161 T A B L E 1 Summary of evidence for interventional management of chronic knee OA. ...
Introduction: Chronic knee pain is defined as pain that persists or recurs over 3 months. The most common is degenerative osteoarthritis (OA). This review represents a comprehensive description of the pathology, diagnosis, and treatment of OA of the knee. Methods: The literature on the diagnosis and treatment of chronic knee pain was retrieved and summarized. A modified Delphi approach was used to formulate recommendations on interventional treatments. Results: Patients with knee OA commonly present with insidious, chronic knee pain that gradually worsens. Pain caused by knee OA is predominantly nociceptive pain, with occasional nociplastic and infrequent neuropathic characteristics occurring in a diseased knee. A standard musculoskeletal and neurological examination is required for the diagnosis of knee OA. Although typical clinical OA findings are sufficient for diagnosis, medical imaging may be performed to improve specificity. The differential diagnosis should exclude other causes of knee pain including bone and joint disorders such as rheumatoid arthritis, spondylo-and other
... When results from all clinical studies are evaluated, regardless of the RFA modality employed, successful outcomes have been reported in between 30% and 74% of OA patients at 6 months. [120][121][122][123][124][125][126] When RF of the genicular nerves is compared to intra-articular injections in knee OA, the results from systematic reviews are contradictory. One reported the probability of benefit after RF to be 4.5 times higher compared to IACS and 1.8 times higher compared to IAHA, while another showed no significant difference in effect between IA injections, RF ablation, and genicular artery embolization. ...
... One reported the probability of benefit after RF to be 4.5 times higher compared to IACS and 1.8 times higher compared to IAHA, while another showed no significant difference in effect between IA injections, RF ablation, and genicular artery embolization. 125,127 There seem to be differences in the efficacy between the three RF modalities. Conventional RF treatment was shown to be superior to pulsed RF in OA knee pain in an RCT, which is consistent with comparisons for other joints. ...
... Systematic reviews report the RF intervention to be safe with limited non-severe adverse events. 125,126,160,161 T A B L E 1 Summary of evidence for interventional management of chronic knee OA. ...
Introduction: Chronic knee pain is defined as pain that persists or recurs over 3 months. The most common is degenerative osteoarthritis (OA). This review represents a comprehensive description of the pathology, diagnosis, and treatment of OA of the knee. Methods: The literature on the diagnosis and treatment of chronic knee pain was retrieved and summarized. A modified Delphi approach was used to formulate recommendations on interventional treatments. Results: Patients with knee OA commonly present with insidious, chronic knee pain that gradually worsens. Pain caused by knee OA is predominantly nociceptive pain, with occasional nociplastic and infrequent neuropathic characteristics occurring in a diseased knee. A standard musculoskeletal and neurological examination is required for the diagnosis of knee OA. Although typical clinical OA findings are sufficient for diagnosis, medical imaging may be performed to improve specificity. The differential diagnosis should exclude other causes of knee pain including bone and joint disorders such as rheumatoid arthritis, spondylo-and other
... As more complete descriptions of knee joint neuroanatomy emerge, conventional GRFN protocols have been expanded to capture additional sensory targets and account for anatomic variation [11,12]. The majority of clinical outcome studies indicate that GRFN effectively reduces pain and improves function in patients with painful knee OA [13][14][15], with the most recent literature indicating that expanded GRFN protocols likely improve outcomes beyond that of the originally proposed technique [12,[16][17][18][19]. Although there are case reports of complications such as pes anserine tendon injury, septic arthritis, skin burns, and periarticular hematomas [20][21][22][23], GRFN is generally regarded as a safe and well-tolerated procedure [24]. ...
... Inclusion criteria were patients aged 18-80 years with painful knee OA or persistent post-TKA pain with at least one positive (≥50% pain relief) prognostic genicular nerve block prior to their GRFN procedure. Detailed descriptions of the genicular nerve block and GRFN procedural techniques were previously published [15]. Exclusion criteria included inability or refusal to participate in a phone call-based standardized outcome survey and missing or low (≤3 points) baseline Numeric Pain Rating Scale (NPRS) scores within two months before the index GRFN. ...
... In a retrospective analysis of 31 patients who underwent GRFN, the procedure was shown on average to provide greater than 60% pain relief in patients for as long as 6 months [14]. In a systematic review, Fogarty et al. reported that 49-74% of participants achieved ≥50% pain relief at 6 months after undergoing GRFN treatment, which outperformed IA injections of steroid and hyaluronic acid, respectively [15]. Approximately half of patients in the present study reported a ≥50% reduction in NPRS score at an average follow-up time of 23.4 ± 11.3 months post-GRFN, suggesting that patients who undergo GRFN in "real-world" practice can be expected to report a similar rate of treatment success to that observed in clinical trials, particularly when expanded lesioning protocols are utilized. ...
Background
Genicular radiofrequency neurotomy (GRFN) is an effective treatment for a subset of individuals with chronic knee pain. Previous studies demonstrate that Medicare and Medicaid beneficiaries report worse outcomes following various interventional procedures compared with commercially insured patients.
Objective
Evaluate the association of payer type on GRFN treatment outcomes.
Methods
Consecutive patients who underwent GRFN at a tertiary academic center were contacted for participation. Demographic, clinical, and procedural characteristics were collected from electronic medical records. Outcome data were collected by standardized telephone survey at 6–12 months, 12–24 months and ≥24 months. Treatment success was defined as ≥50% numerical pain rating scale (NPRS) score reduction from baseline. Data were analyzed using descriptive statistics for demographic, clinical, and procedural characteristics. Logistic and Poisson regression analyses were performed to examine the association of variables of interest and pain reduction.
Results
One hundred thirty-four patients treated with GRFN (mean 65.6 ± 12.7 years of age, 59.7% female) with a mean follow-up time of 23.3 ± 11.3 months were included. Payer type composition was 48.5% commercial (n = 65), 45.5% Medicare (n = 61), 3.7% Medicaid (n = 5), 1.5% government (n = 2), and 0.8% self-pay (n = 1). Overall, 47.8% of patients (n = 64) reported ≥50% NPRS score reduction after GRFN. After adjusting for age, follow-up duration, Kellgren-Lawrence osteoarthritis grade, baseline opioid use, antidepressant/antianxiety medication use, history of knee replacement, and number of RFN lesions placed, the logistic regression model showed no statically significant association between payer type and treatment outcome (OR = 2.11; 95% CI = 0.87, 5.11; p = 0.098).
Discussion/conclusion
In this study, after adjusting for demographic, clinical, and procedural characteristics, we found no association between payer type and treatment success following GRFN. This observation contrasts findings from other interventional studies reporting an association between payer category and treatment success.
... Genicular nerve radiofrequency ablation (GnRFA) has emerged as a promising intervention for both knee OA pain resistant to conservative management and for chronic post-TKA pain [12,13]. Continuous radiofrequency ablation (GnRFA) methods offers an avenue for disrupting neural pathways associated with knee pain via targeted heat-related coagulation of axons [14][15][16][17]. ...
... GnRFA is an evidence-based technique supported by multiple prospective cohort studies and randomized controlled trials (RCTs) [12,13,31,32]; however, there are variable practice patterns and GnRFA techniques. There has been no peer-reviewed publication quantifying these variations in real-world clinical practice. ...
Introduction
Chronic knee pain often results from degenerative conditions such as knee osteoarthritis (OA) and can worsen after surgical interventions like total knee arthroplasty (TKA). Knee OA affects approximately 86 million individuals globally, leading to decreased function, mobility limitations, and disability. While TKA is a common surgical treatment for refractory knee OA, though up to 20 % of patients experience chronic post-operative knee pain worse than their pre-operative pain. Genicular nerve radiofrequency ablation (GnRFA) has emerged as a promising intervention for knee OA pain unresponsive to conservative management and for chronic post-TKA pain. GnRFA is an evidence-based technique supported by multiple prospective cohort studies and randomized controlled trials (RCTs). However, practice patterns and GnRFA techniques vary, and no peer-reviewed publication has yet quantified these variations in real-world clinical practice.
Objective
This study aims to understand the practice patterns of interventional pain physicians regarding patient selection, use of prognostic blocks, imaging, nerve targets, GnRFA types, and GnRFA techniques in treating knee pain secondary to OA or persistent post-TKA pain.
Methods
An anonymous 29-question survey was distributed via electronic mail to members of the International Pain and Spine Intervention Society (IPSIS) from January 16, 2024, to February 29, 2024. The survey assessed practice patterns related to patient selection, prognostic block use, and GnRFA techniques. Data were collected and stored using REDCap software, with descriptive statistics calculated.
Results
A total of 150 completed surveys were analyzed, representing a completion rate of 2.0 % of surveys sent, 3.5 % of emails opened, and 56.8 % of those who clicked on the survey link. Respondents generally use common selection protocols regarding OA grade (Kelgren-Lawrence 3 and 4), duration of failed conservative care (3–6 months), a single anesthetic block paradigm, and use of fluoroscopic guidance for the GnRFA procedure. More variability was reported between respondents regarding the volume of anesthetic used during prognostic blocks, the threshold to consider a prognostic block “positive,” the technology used, and nerves targeted during the GnRFA procedure.
Conclusion
The study provides valuable insights into the current practice patterns of GnRFA among interventional pain physicians. While there is consensus on some aspects of patient selection and procedural techniques, significant variability exists in prognostic block protocols and nerve targets for GnRFA. These findings highlight the need for further research to explore the long-term efficacy and safety of GnRFA and to standardize techniques and protocols across different practice settings, ultimately improving patient outcomes and quality of life. The low response rate may limit generalizability, and the survey did not include data on active tip sizes used for ablation or whether other procedures should be exhausted before resorting to GnRFA. Additionally, a survey to IPSIS membership only may not fully represent a diverse cohort of pain management specialists, potentially introducing sampling bias. Future studies should include members from a broader range of professional organizations to enhance representativeness.
... Since Choi et al. first introduced radiofrequency ablation (RFA) as a technique to alleviate chronic knee pain secondary to osteoarthritis (OA) in 2011 [1], genicular nerve RFA has emerged as a popular procedure to treat knee pain [2,3]. Due to the complex innervation of the knee joint, RFA for knee joint pain can be challenging, especially for pain localized at the inferior lateral quadrant (ILQ) of the anterior aspect of the knee. ...
... Genicular nerve ablations have been utilized as effective modalities for patients with intractable knee pain refractory to other conservative treatments [1][2][3]7]. Most sensory nerve branches of the knee are not near the motor nerves, except for the recurrent fibular nerve. ...
... In the literature, the effectiveness of RFA therapies for managing persistent pain syndromes has been widely examined. Techniques such as genicular nerve radiofrequency ablation for knee osteoarthritis, nerve ablation for foot and ankle pain, and ultrasound-guided ablation for sural neuralgia have shown successful outcomes in various anatomical regions [29][30][31]. These methods have proven particularly effective in cases where conservative treatments have failed, providing significant pain relief and functional improvement. ...
This study aimed to compare the effectiveness of Pulsed Radiofrequency Ablation (PRFA) and surgery for treating chronic plantar fasciitis, focusing on pain relief and functional outcomes.
A prospective study involved 30 patients with chronic plantar fasciitis unresponsive to 12 months of conservative treatment. Patients were divided into PRFA (n = 17) and surgical (n = 13) groups. Clinical evaluations were conducted preoperatively and at three, six and 12 months postoperatively using VAS, AOFAS, FFI, and RMS scores. Radiological measurements assessed foot structure impact.
Both PRFA and surgery significantly reduced pain and improved function. PRFA had a shorter operative time and quicker return to activities (p < 0.001). At 3 months, PRFA showed superior VAS, FFI, and RMS scores (p < 0.05). Long-term outcomes were similar. No major complications occurred, but minor complications were higher in the surgical group (p < 0.01).
PRFA is a minimally invasive, effective treatment for chronic plantar fasciitis with quicker recovery and lower complication rates compared to surgery. Both treatments offer comparable long-term benefits. Further studies are needed to confirm these findings.
... In reality, outcomes are often poorer after revision TKR compared with primary TKR; nearly half of patients report severe chronic post-operative pain [7]. Genicular nerve radiofrequency ablation (GNRFA) has emerged as a popular and effective procedure to treat arthritic knee pain [8][9][10]. ...
Background
Genicular nerve radiofrequency ablation (GNRFA) is a popular and effective procedure to treat arthritic knee pain. For refractory arthritic pain that fails conservative treatment, total knee arthroplasty (TKA) has been an excellent option. Unfortunately, 15–30% of people who undergo a TKA continue to experience pain and stiffness in the knee. The treatment options for post-TKA knee pain are limited. Pain providers have been trialing GNRFA on this pain condition. However, convincing evidence of its efficacy in treating post-TKA pain is still lacking.
Methods
This is a retrospective study of 73 patients who had undergone genicular nerve RFA, 46 (63.01%) with osteoarthritic pain, and 27 (36.99%) with post-TKA pain. We compared the outcomes (pain relief, function, and complications) between these two groups at 3 months and 6 months after RFA.
Results
Before RFA, there was no significant difference in initial pain and functional level between these two groups. After RFA, the two groups had comparable pain relief at 3 months (p = 0.68) and 6 months (p = 0.53), and similar functionality at 3 months (p = 0.36) and 6 months (p = 0.65).
The overall success rate (≥50% pain relief after RFA) was 80.82%, 95% CI: 70.34%–88.22% (osteoarthritic group 80.43%, 95% CI: 66.83%–89.35%, post-TKA 81.48%, 95% CI: 63.30%–91.82%, P = 0.91) at 3-month follow-up and 56.16%, 95% CI: 44.76%–66.95% (osteoarthritic group 56.52%, 95% CI: 42.25%–69.79%, post-TKA 55.56%, 95% CI: 37.31%–72.41%, P = 0.94) at 6-month follow-up.
There were no reported complications in either group.
Conclusions
Genicular Nerve Radiofrequency Ablation (GNRFA) holds the potential to be equally effective for both post-TKA knee pain and osteoarthritic knee pain.
... Dr. Devor adroitly highlights the limitations of genicular nerve radiofrequency ablation (RFA), which stem not only from not targeting enough of the "extrinsic" nerve supply in many of the early studies [10][11][12], but also from possible failure to interrupt the intrinsic innervation. However, it is axiomatic that all intrinsic innervation stems from extrinsic innervation, which is easier to identify and target. ...
... Subsequent studies and systematic reviews have confirmed these findings, showing that genicular radiofrequency ablation (RFA) is superior to alternative nonsurgical interventions, such as intra-articular corticosteroids, intra-articular hyaluronic acid, and oral nonsteroidal anti-inflammatory drugs, in terms of pain, function, and composite patientreported outcomes from 3-12 months. 11,12 However, patient selection and GNRFA technical methods need to be refined compared with original descriptions, particularly given recent negative studies that have shown unfavorable outcomes when fewer coagulation zones were used, as opposed to expanded lesioning protocols based on improved understanding of the knee neuroanatomy. [13][14][15][16][17][18][19][20] Expanded protocols, targeting additional sensory nerves beyond the classic targets, and performance of multiple ablations at specific sites appear to be associated with an increased probability of treatment success. ...
... In a double-blind, randomized controlled study by Choi et al. [5], the 50% success rate with genicular RFA was 59% at three months. In a systematic review evaluating the efficacy of genicular RFA, at least 50% success rates at six months were reported to be between 49% and 74% [9]. Despite similarities in the success rates, there are some differences between phenol neurolysis and RFA in terms of complications, duration, and cost. ...
Background
Genicular nerve neurolysis with phenol and radiofrequency ablation (RFA) are two interventional techniques for treating chronic refractory knee osteoarthritis (KOA) pain. This study aimed to compare the efficacy and adverse effects of both techniques.
Methods
Sixty-four patients responding to diagnostic blockade of the superior medial, superior lateral, and inferior medial genicular nerve under ultrasound guidance were randomly divided into two groups Group P (2 mL phenol for each genicular nerve) and Group R (RFA 80°C for 60 seconds for each genicular nerve). The numeric rating scale (NRS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used to evaluate the effectiveness of the interventions.
Results
RFA and phenol neurolysis of the genicular nerves provided effective analgesia within groups at 1 week, 1 month, and 3 months compared to baseline. There was no significant difference between the groups in terms of NRS and WOMAC scores at all measurement times. At the 3rd month follow-up, 50% or more pain relief was observed in 53.1% of patients in Group P and 50% of patients in Group R. The rate of transient paresthesia was 34.4% in Group P and 6.3% in Group R, and this was significantly higher in Group P.
Conclusions
Neurolysis of the genicular nerves with both RFA and phenol is effective in the management of KOA pain. Phenol may be a good alternative to RFA. Further studies are needed on issues such as dose adjustment to prevent transient paresthesia response.
... Subsequent studies and systematic reviews have confirmed these findings, showing that genicular radiofrequency ablation (RFA) is superior to alternative nonsurgical interventions, such as intra-articular corticosteroids, intra-articular hyaluronic acid, and oral nonsteroidal anti-inflammatory drugs, in terms of pain, function, and composite patientreported outcomes from 3-12 months. 11,12 However, patient selection and GNRFA technical methods need to be refined compared with original descriptions, particularly given recent negative studies that have shown unfavorable outcomes when fewer coagulation zones were used, as opposed to expanded lesioning protocols based on improved understanding of the knee neuroanatomy. [13][14][15][16][17][18][19][20] Expanded protocols, targeting additional sensory nerves beyond the classic targets, and performance of multiple ablations at specific sites appear to be associated with an increased probability of treatment success. ...
Background:
Genicular nerve radiofrequency ablation (GNRFA) is an effective treatment for chronic knee pain. However, there has been minimal investigation of real-world, long-term outcomes and factors that predict treatment success following GNRFA.
Objectives:
Evaluate the effectiveness of GNRFA for chronic knee pain in a real-world population and identify predictive factors.
Methods:
Consecutive patients who underwent GNRFA at a tertiary academic center were identified. Demographic, clinical, and procedural characteristics were collected from the medical record. Outcome data was numeric rating scale (NRS) pain reduction and Patient Global Impression of Change (PGIC). Data were collected by standardized telephone survey. Predictors of success were evaluated using Logistic and Poisson regression analyses.
Results:
Of the 226 total patients identified, 134 (65.6 ± 12.7; 59.7% female), mean follow-up time of 23.3 ± 11.0 months were successfully contacted and analyzed. 47.8% (n = 64; 95%CI: 39.5-56.2) and 61.2% (n = 82; 95%CI: 52.7-69.0) reported ≥50% NRS reduction and ≥2 point NRS reduction, respectively. 59.0% (n = 79; 95%CI: 50.5-66.9) reported "much improved" on the PGIC questionnaire. Higher Kellgren and Lawrence (KL) osteoarthritis grade (2-4 compared to 0-1), no baseline opioid, antidepressant, or anxiolytic medication use, and >3 nerves targeted were associated with a greater likelihood of treatment success (p < 0.05).
Conclusion:
In this real-world cohort, approximately half of the participants experienced clinically meaningful improvements in knee pain after GNRFA at an average follow-up time of nearly 2 years. More advanced osteoarthritis (KL Grade 2-4), no opioid, antidepressant, or anxiolytic medication use, and >3 nerves targeted were associated with higher likelihood of treatment success.
... We did not detect any significant adverse events after the procedure. Most previous studies about genicular nerve RFA did not report any major adverse events 45 , while some studies found only mild localized side effects. 17 Nevertheless, there were some case reports about some serious side effects of genicular nerve RFA, including knee hematoma or hemarthrosis, septic arthritis, severe skin burn, tendon injury, and complex regional pain syndrome (CRPS). ...
Objective: When patients with chronic osteoarthritis (OA) knee pain do not respond to conservative treatment and are not suitable for knee arthroplasty, radiofrequency ablation (RFA) of the genicular nerve is probably an alternative treatment. This study aimed to evaluate the efficacy and safety of genicular nerve ablation in severe osteoarthritic knee pain patients. Materials and Methods: Patients with severe chronic OA knee pain were recruited and performed a genicular nerve block (GNB). The patients’ demographic data, numerical rating scale (NRS) at rest and on movement, Thai Oxford knee score (Thai OKS), Thai knee injury and osteoarthritis outcome score physical function short form (Thai KOOS-PS), timed up and go test, brief pain inventory, fall evaluation, and EuroQol 5D-5L were recorded. For the positive block patients (≥50% pain relief for 24 hours), genicular nerve RFA was performed under fluoroscopic or ultrasound guidance. All patients were followed up at the 1st, 3rd, 6th, 9th and 12th months. Results: 21 patients were included in the study, but only 17 were completely followed up for 12 months. At the 12th month, genicular nerve RFA reduced the mean NRS on movement from 7.9±1.6 to 4.0±2.6 (p=0.005), improved knee function (Thai OKS from 18.8±5.3 to 28.5±10.1; p=0.006), but did not significantly improve quality of life (EuroQol-5D-5L from 0.43±0.20 to 0.69±0.33; p=0.130). No adverse events were observed. Conclusion: Genicular nerve radiofrequency ablation in severe chronic OA knee patients demonstrated significant pain relief and functional improvement for up to 12 months without serious adverse events.
... A recent 11-patient case series by Koshi et al. utilized a 7-lesion approach to the SMGN, SLGN, IMGN, NVM, Fig. 2. Quality Assessment of Controlled Intervention Studies using NHLBI Tool. Interventional Pain Medicine xxx (xxxx) xxx NVI, and NVL using a three-tined electrode in which the 91% of the patients reported >50% improvement of knee pain at month 1 follow-up [47,56,57]. This strengthens the notion that an increased number of targets may be warranted for a more complete pain relief protocol. ...
... Multiple prospective trials and systematic reviews have now demonstrated the effectiveness of genicular nerve radiofrequency Abbreviations: Genicular nerve radiofrequency ablation, (GNRFA); superomedial genicular nerve, (SMGN); superolateral genicular nerve, (SLGN); inferomedial genicular nerve, (IMGN); nerve to vastus medialis, (NVM); nerve to vastus lateralis, (NVL); nerve to vastus intermedius, (NVI); recurrent fibular nerve, (RFN); patient global impression of change, (PGIC); Kellgren-Lawrence osteoarthritis score grade, (KL). ablation (GNRFA) for reducing chronic knee pain in patients with native knee osteoarthritis and after a total knee arthroplasty (TKA) [4][5][6][7][8][9]. GNRFA is a minimally invasive percutaneous procedure that utilizes thermal energy to coagulate sensory nerves that innervate the anterior knee capsule, thereby interrupting nociception. ...
Objective
Genicular nerve radiofrequency ablation (GNRFA) is an effective treatment option for chronic knee pain in native knee osteoarthritis and total knee arthroplasty (TKA) patients. Recent dissections have revealed significant variability in typical genicular nerve targets and other sensory nerves not included in previous studies. Early, short-term results suggest that more complete sensory denervation with GNRFA may result in more significant pain reduction; however, no long-term clinical outcome exists. We aim to present long-term clinical outcomes after an expanded GNRFA technique with a three-tined radiofrequency cannula.
Methods
Eleven consecutive patients with ≥6 months of knee pain underwent an expanded GNRFA protocol targeting the superomedial (SMGN), superolateral (SLGN), inferomedial genicular nerves (IMGN), in addition to the nerves to vastus medialis (NVM), lateralis (NVL), and intermedius (NVI). Long-term pain and impression of change outcomes were collected in a cross-sectional fashion.
Results
At ≥18 months (mean 24 months) post-GNRFA, 91% (95% CI = 59, 100%), 73% (95% CI = 46, 99%), and 9% (95% CI = 0, 26%) of patients reported ≥50%, ≥80%, and 100% pain relief, respectively. Additionally, 27% (95% CI = 1, 54%) and 64% (95% CI = 35, 92%) of individuals reported a PGIC score of 6 (“much improved”) and 7 (“very much improved”), respectively. The proportion of individuals who reported the MCID for the PGIC (score of ≥6) was 91% (95% CI = 59, 100%). There were no adverse events reported amongst the patients in this cohort. No patients progressed to surgery.
Conclusion
This single-arm cohort suggests that an expanded GNRFA protocol targeting SMGN, SLGN, IMGN, NVM, NVL, and NVI nerves with a three-tined electrode, resulted in significant long-term (≥18 months) improvements in pain and patient-perceived global improvement. Large, head-to-head trials are needed to establish whether this GNRFA protocol is superior to those used in previous clinical studies and those currently used more commonly in practice.
Objective
Chemical neurolysis of the genicular nerves is a treatment option for intractable non-cancer knee pain. This scoping review synthesizes the available literature on the effectiveness, adverse effects and procedural techniques of chemical neurolysis of genicular nerves for the management of knee pain.
Design
Scoping review.
Setting
All clinical and research settings.
Subjects
Adult participants with chronic non-cancer knee pain undergoing chemical neurolysis of genicular nerves.
Methods
A literature search in MEDLINE, EMBASE and Cochrane Library was conducted up to 4 September 2023. Articles were searched via terms and keywords relating to “knee”, “pain”, “knee osteoarthritis”, “ablation”, “alcohol”, “phenol” and “chemical neurolysis”. Included articles were full text primary studies and in English. Data was extracted using an electronic database by 2 independent reviewers.
Results
There were 8 studies included in this review (including 1 randomized controlled trial), comprising 192 patients. There were 4 studies that used phenol, 3 studies that used alcohol, and 1 study that used either alcohol or phenol for chemical neurolysis. Both fluoroscopy and/or ultrasound guidance were utilized for nerve target identification. All studies demonstrated that chemical neurolysis resulted in improved pain and/or functional outcomes, with no serious adverse events reported.
Conclusions
Chemical neurolysis of the genicular nerves is a promising treatment strategy for chronic knee pain. Interpretation of the available studies are limited by study heterogeneity and small sample sizes. High-quality randomized controlled trials are required to clarify the selection of appropriate nerve targets, choice of image guidance, and to compare with other ablative modalities.
In patients with symptomatic osteoarthritis knee (OAK), cryoneurolysis (CRYO) and cooled radiofrequency ablation (C-RFA) are reported to be effective and safe; however, they have not been compared directly. The objective of this study is to compare CRYO and C-RFA of the genicular nerve (GN) in terms of efficacy and safety profile in patients with Kellgren and Lawrence (KL) grade ≥ 3 OAK.
This single-centric, assessor-blinded, randomized, parallel-group, non-inferiority study will include 80 patients with KL grade ≥ 3 OAK. The patients with ≥ 50% pain relief on diagnostic block of three GNs will be randomized to one of the two groups, i.e., CRYO (n = 40) or C-RFA (n = 40). The three target GNs for the interventions will include: superior medial, superior lateral, and inferior medial. The primary outcome will be efficacy of CRYO or C-RFA at 2, 12, and 24 weeks post-procedure based on the 11-point Numerical Pain Rating Scale. The secondary outcomes will be functional improvement based on 12-item Oxford Knee Score and safety of both the procedures. The study is registered in the Clinical Trials Registry—India.
CRYO and C-RFA provide pain relief and improve functional outcome by preventing transmission of pain signals, though by distinct mechanisms. While C-RFA is an established treatment modality, recent evidence supports CRYO in patients with OAK. This study intends to demonstrate non-inferiority of CRYO against C-RFA, thereby supporting the use of CRYO as an additional treatment modality in patients with KL grade ≥ 3 OAK.
Background and objectives
Genicular nerve radiofrequency ablation (GNRFA) is an emerging procedure used to relieve pain from severe knee osteoarthritis. While there have been rare reports of significant complications, their incidence has not been well established. The objective of this study was to examine complication rates at 30 and 90 days post treatment as well as characterize opioid-prescribing patterns before and after treatment.
Methods
A large national database was queried to identify patients undergoing GNRFA from 2015 to 2022 and matched to control cohorts composed of patients receiving either intra-articular corticosteroid (CSI) or hyaluronic acid injection (HAI) of the knee. Complication rates at 30 and 90 days were analyzed. Opioid utilization was assessed in the 6 months before and after treatment.
Results
Rates of infection (0.1%, CI 0.02% to 0.5% vs 0.2%, CI 0.05% to 0.6%), septic arthritis (<0.1%, CI 0.003% to 0.4% vs 0.1%, CI 0.02% to 0.5%), deep vein thrombosis (2.0%, CI 1.3% to 2.7% vs 1.6%, CI 1.0% to 2.2%), pulmonary embolism (1.2%, CI 0.6% to 1.7% vs 1.3%, CI 1.1% to 2.5%), bleeding (<0.1%, CI 0.003% to 0.4% vs 0%, CI 0% to 0.3%), seroma (<0.1%, CI 0.003% to 0.4% vs 0.2%, CI 0.05% to 0.6%), nerve injury (0%, CI 0% to 0.3% vs 0%, CI 0% to 0.3%) and thermal injury (0%, CI 0% to 0.3% vs 0%, CI 0% to 0.3%) were not different between CSI and GNRFA cohorts at 30 days. Rate of swelling was significantly greater in the GNRFA cohort (9.4%, CI 7.6% to 10.4% vs 6.4%, CI 4.8% to 7.2%, p=0.003) at 30 days. At 90 days, rates of septic arthritis (0.1%, CI 0.02% to 0.5% vs 0.3%, CI 0.08% to 0.7%), deep vein thrombosis (3.1%, CI 2.1% to 3.8% vs 3.1%, CI 2.2% to 3.9%), pulmonary embolism (1.5%, CI 0.9% to 2.1% vs 1.8%, CI 1.2% to 2.5%), and nerve injury (0%, CI 0% to 0.3% vs <0.1%, CI 0.003% to 0.4%) were not significantly different.
Between HAI versus GNRFA cohorts, no significant differences were seen in rates of infection (0.3%, CI 0.08% to 0.07% vs 0.7%, CI 0.3% to 1.2%), septic arthritis (0.2%, CI 0.05% to 0.6% vs 0.4%, CI 0.2% to 0.9%), deep vein thrombosis (2.0%, CI 1.3% to 2.7% vs 1.9%, CI 1.2% to 2.7%), pulmonary embolism (1.5%, CI 0.9% to 2.2% vs 1.7%, CI 1.1% to 2.5%), bleeding (0.1%, CI 0.02% to 0.5% vs 0.2%, CI 0.05% to 0.6%), seroma (<0.1%, CI 0.03% to 0.4% vs 0%, CI 0% to 0.3%), nerve injury (0%, CI 0% to 0.3% vs 0%, CI 0% to 0.3%), swelling (14.0%, CI 11.6% to 15.1% vs 12.0%, CI 10.3% to 13.6%), and thermal injury (<0.1%, CI 0.03% to 0.4% vs <0.01%, CI 0.3% to 0.4%) at 30 days. Rates of infection (0.7%, CI 0.3% to 1.2% vs 1.4%, CI 0.9% to 2.1%), septic arthritis (0.3%, CI 0.1% to 0.8% vs 0.5%, CI 0.2% to 1.1%), deep vein thrombosis (3.6%, CI 2.6% to 4.4% vs 3.1%, CI 2.2% to 4.0%), pulmonary embolism (2.3%, CI 1.5% to 3.0% vs 2.1%, CI 1.4% to 3.0%) and nerve injury (0%, CI 0% to 0.3% vs 0.1%, CI 0.02% to 0.5%) were not significantly different at 90 days.
There were no significant differences in level of pretreatment opioid utilization although overall consumption in mean daily morphine equivalents was greater in the GNRFA cohort. Opioid utilization significantly increased in the first 30 days after ablation in patients with no prior opioid use compared to controls. In patients with some and chronic prior opioid use, opioid requirements were generally decreased in all treatment groups at 6 months with no clearly superior treatment in reducing opioid consumption.
Conclusion
Our study demonstrated that GNRFA possesses a safety profile similar to that of intra-articular injections although significant adverse events such as venous thromboembolism and septic arthritis may occur rarely. Although opioid utilization generally increased in the 30 days after ablation compared with intra-articular injection, similar reduction in opioid consumption at 6 months was seen in patients with prior opioid use in the ablation and control cohorts.
Background:
Monopolar radiofrequency ablation (MRFA) of the genicular nerves has been considered the main interventional treatment for chronic knee pain. However, the variable locations of these nerves could suggest that traditional MRFA of genicular nerves may be insufficient to cover the area needed to provide complete sensory denervation. For these reasons, some alternatives have been proposed to achieve an increase in the lesion area that offers better outcomes such a bipolar radiofrequency ablation (BRFA).
Objective:
To describe the efficacy and safety of the bipolar radiofrequency ablation (BRFA) of the genicular nerves in the patients with chronic knee pain.
Methods:
A retrospective study was conducted in the Pain Medicine Department. Institutional review board approval from the Hospital Ethical Committee and informed consent were obtained. We reviewed our database for BRFA of genicular nerves from January 2018 to December 2021 for patients with chronic knee pain. The cannulas were placed using ultrasound guidance (10 cm, 22-gauge and 10 mm active curved tip), and each pair of cannulas were subjected to BRFA for 90 seconds at 80∘C. Data analysis was conducted using T-test for paired variables (Visual analogue scale and EuroQol, an instrument intended to complement other forms of quality-of-life measures).
Results:
Twenty-five patients met inclusion criteria after excluding 7 based on the study design. The mean improvement of our patients according to the VAS was -3.98 (95%CI: -4.37 to -3.59) p< 0.0001 and EuroQol +0.416 (95%CI: 0.364 to 0.468) p< 0.0001. The mean duration of improvement was 8 (6-11) months after BRFA. There were no reported serious adverse events related to the procedure, only local pain for 24 to 48 hours in 3 patients.
Conclusions:
We can conclude that BRFA reduces procedural pain and increases the treatment area, providing more complete sensory denervation and improved clinical outcomes.
Radiofrequency (RF) is a minimally invasive technique for disrupting or altering nociceptive pathways to treat musculoskeletal neuropathic and nociplastic pain.
RF has been employed to treat painful shoulder, lateral epicondylitis, knee and hip osteoarthritis, chronic knee pain, Perthes disease, greater trochanteric pain syndrome, plantar fasciitis, and painful stump neuromas; it has also been employed before and after painful total knee arthroplasty and after anterior cruciate ligament reconstruction.
The benefits of RF include the following:it is safer than surgery; there is no need for general anaesthesia, thereby reducing adverse effects; it alleviates pain for a minimum of 3–4 months; it can be repeatable if necessary; and it improves joint function and minimizes the need for oral pain medication.
RF is contraindicated for pregnant women; unstable joints (hip, knee, and shoulder); uncontrolled diabetes mellitus; presence of an implanted defibrillator; and chronic joint infection (hip, knee, and shoulder).
Although adverse events from RF are unusual, potential complications can include infection, bleeding, numbness or dysesthesia, increased pain at the procedural site, deafferentation effect, and Charcot joint neuropathy.
Although there is a risk of damaging non-targeted neural tissue and other structures, this can be mitigated by performing the technique under imaging guidance (fluoroscopy, ultrasonography, and computed tomography).
RF appears to be a valuable technique for alleviating chronic pain syndromes; however, firm proof of the technique’s efficacy is still required.
RF is a promising technique for managing chronic musculoskeletal of the limbs pain, particularly when other techniques are futile or not possible.
Objective
Evaluate outcomes of genicular nerve chemical neurolysis (GChN) in a real-world population with chronic knee pain.
Design
Restrospective, observational cohort study
Setting
Tertiary academic medical center
Subjects
Consecutive patients who underwent GChN ≥three months prior.
Methods
Standardized surveys were collected by telephone that included the Numerical Rating Scale (NRS), opioid analgesic use, and Patient Global Impression of Change (PGIC). Age, sex, body mass index (BMI), duration of pain, history of arthroplasty, lack of effect from previous radiofrequency ablation, percentage relief from a prognostic block, and volume of phenol used at each injection site were extracted from charts. Descriptive statistics were calculated and logistic regression analyses were performed to identify factors influencing treatment outcome.
Results
At the time of follow-up post-GChN (mean 9.9±6.1 months), 43.5% (95%CI = 33.5, 54.1) of participants reported ≥50% sustained pain reduction. On the PGIC assessment, 45.9% (95%CI = 35.5, 56.7) of participants reported to be “very much improved”/“much improved.” Of 40 participants taking opioids at baseline, 11 (27.5%; 95%CI = 14.6, 43.9) ceased use. 46.3% of participants with a native knee treated reported ≥50% pain reduction, while 33.3% of participants with an arthroplasty in the treated knee reported this threshold of pain reduction (p = 0.326). Logistic regression analyses did not reveal associations between treatment success and any of the factors that we evaluated.
Conclusions
GChN may provide a robust and durable treatment effect in a subset of individuals with chronic knee pain with complicating factors traditionally associated with poor treatment outcomes such as those with pain refractory to radiofrequency ablation and/or following arthroplasty.
Background
Distal femur fractures account for approximately 3%–6% of all femoral fractures. Non-operative management may be an attractive option for the elderly with significant perioperative mortality risk. Adequate pain control is a major barrier to non-operative fracture management. Chemical neurolysis has been described for analgesic management of proximal hip fractures, however no description of interventional management of distal femur fracture exists in literature. We describe a case of phenol chemical neurolysis of genicular nerves in addition to injection at the site of fracture to provide effective analgesia for distal femur fracture.
Case presentation
A patient in their 90s with a witnessed mechanical fall sustained an intra-articular displaced fracture of the distal right femur shaft with extension into the distal femoral condyle. The patient elected to undergo non-surgical management given the high perioperative mortality risk. Acute pain service was involved and multimodal oral analgesics including opioids were insufficient in managing the patient’s pain. The addition of femoral nerve catheter local anesthetic infusion did not sufficiently improve analgesia. Phenol chemical neurolysis of the superolateral, superomedial, inferomedial genicular nerves and of the fracture site was offered and performed. Resting pain decreased from Numerical Rating Scale 5/10 to 0/10 on postprocedure day 1. This was sustained at the 2-month timepoint.
Conclusions
We report the successful use of phenol neurolysis of genicular nerves and the fracture site in an elderly patient with a conservatively managed distal femur fracture. These interventions resulted in improved analgesia and achieved prolonged duration of effect.
Genicular nerve radiofrequency ablation (GNRFA) is an effective treatment for chronic knee pain related to osteoarthritis. It is often utilized when conservative management has failed and patients wish to avoid arthroplasty, are poor surgical candidates due to co-morbid medical conditions, or in those suffering from persistent pain after arthroplasty. The classic targets for GNRFA include the superior lateral genicular nerve, superior medial genicular nerve, and inferior medial genicular nerve but multiple anatomic studies have demonstrated additional sensory innervation to the knee. In this research article, we propose an image-guided technique that can safely target the infrapatellar branch of the saphenous nerve which also provides sensory innervation to the anterior capsule. The proposed technique includes variations for conventional bipolar radiofrequency ablation, cooled radiofrequency ablation, dual-tined bipolar radiofrequency ablation, and monopolar radiofrequency ablation using a long axis approach. The described technique is based on updated anatomic studies and takes into account safety concerns such as thermal risk to the skin and/or pes anserine tendons and breaching of the synovial cavity. Future clinical research should be performed to confirm the safety and effectiveness of this specific approach.
Intro
Genicular nerve radiofrequency ablation (GNRFA) is an effective treatment for chronic knee pain related to osteoarthritis. It is often utilized when conservative management has failed and patients wish to avoid arthroplasty, are poor surgical candidates due to comorbid medical conditions, or in those suffering from persistent pain after arthroplasty. The classic targets for GNRFA include the superior lateral genicular nerve, superior medial genicular nerve, and inferior medial genicular nerve but multiple anatomic studies have demonstrated additional sensory innervation to the knee.
Objective
In this research article, we propose an image-guided technique that can safely target the infrapatellar branch of the saphenous nerve which also provides sensory innervation to the anterior capsule.
Proposal
The proposed technique includes variations for conventional bipolar radiofrequency ablation, cooled radiofrequency ablation, dual-tined bipolar radiofrequency ablation, and monopolar radiofrequency ablation using a long axis approach. The described technique is based on updated anatomic studies and takes into account safety concerns such as thermal risk to the skin and/or pes anserine tendons and breaching of the synovial cavity.
Conclusion
Future clinical research should be performed to confirm the safety and effectiveness of this specific approach.
Neurological interventions have taken on a significant role in interventional radiology (IR) practice. Indications fall under three main categories: (1) intraprocedural pain management, (2) cancer pain palliation, and (3) chronic non-cancer pain control. Short-term regional anaesthesia can be achieved with local anaesthetics, while longer-term pain control can be attained with radiofrequency neuromodulation (pulsed or otherwise) or thermal/chemical neurolysis. This review article summarises the therapeutic options, applications, and techniques of commonly used peripheral nerve and plexus interventions in IR.
Objective
Summarize the therapeutic pain-reducing effects of GnRF for refractory post-TKA knee pain. A secondary objective was to summarize improvements in physical function after GnRF.
Methods
A protocol was registered, and a database search conducted by an experienced librarian of all available studies in the English language up until November 3, 2021. Study inclusion criteria were randomized controlled trials (RCTs), prospective and retrospective longitudinal studies, cross-sectional studies, case series, case reports, studies involving adults ≥18 years of age, and studies written about the use of GnRF for the alleviation of chronic knee pain after receiving a TKA. The study quality and risk of bias was assessed using NHLBI Study Quality of Assessment Tools and Murad et al.’s Quality Assessment of Case Reports. Certainty in the evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach.
Results
A total of 229 studies were screened, 11 met the inclusion criteria, and 265 patients underwent GnRF. Study designs included 1 double-blind pragmatic RCT, 5 retrospective cohort studies, 2 retrospective case series, and 3 case reports. The overall study quality assessment demonstrated three studies had “good”, six “fair”, and two “poor” quality. There have been positive responses to GnRF for post-TKA chronic knee pain in a range of 30-100% of patients.
Conclusions
According to GRADE, there is limited evidence, associated with low certainty to support the use of GnRF to ameliorate chronic knee pain after TKA, largely due to inconsistency and risk of bias. The studies included in this review reported positive results in pain and disability, and relatively few adverse events.
Background:
Knee osteoarthritis is a painful and sometimes debilitating disease that often affects patients for years. Current treatments include short-lasting and often repetitive nonsurgical options, followed by surgical intervention for appropriate candidates. Cooled radiofrequency ablation (CRFA) is a minimally invasive procedure for the treatment of pain related to knee osteoarthritis. This trial compared the efficacy and safety of CRFA with those of a single hyaluronic acid (HA) injection.
Methods:
Two hundred and sixty subjects with knee osteoarthritis pain that was inadequately responsive to prior nonoperative modalities were screened for enrollment in this multicenter, randomized trial. One hundred and eighty-two subjects who met the inclusion criteria underwent diagnostic block injections and those with a minimum of 50% pain relief were randomized to receive either CRFA on 4 genicular nerves or a single HA injection. One hundred and seventy-five subjects were treated (88 with CRFA and 87 with HA). Evaluations for pain (Numeric Rating Scale [NRS]), function (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), quality of life (Global Perceived Effect [GPE] score and EuroQol-5 Dimensions-5 Level [EQ-5D-5L] questionnaire), and safety were performed at 1, 3, and 6 months after treatment.
Results:
Demographic characteristics did not differ significantly between the 2 study groups. A total of 158 subjects (76 in the CRFA group and 82 in the HA group) completed the 6-month post-treatment follow-up. In the CRFA group, 71% of the subjects had ≥50% reduction in the NRS pain score (primary end point) compared with 38% in the HA group (p < 0.0001). At 6 months, the mean NRS score reduction was 4.1 ± 2.2 for the CRFA group compared with 2.5 ± 2.5 for the HA group (p < 0.0001). The mean WOMAC score improvement at 6 months from baseline was 48.2% in the CRFA group and 22.6% in the HA group (p < 0.0001). At 6 months, 72% of the subjects in the CRFA group reported improvement in the GPE score compared with 40% in the HA group (p < 0.0001).
Conclusions:
CRFA-treated subjects demonstrated a significant improvement in pain relief and overall function compared with subjects treated with a single injection of HA. No serious adverse events related to either procedure were noted, and the overall adverse-event profiles were similar.
Level of evidence:
Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
Background:
Safe and effective non-surgical treatments are an important part of the knee osteoarthritis (OA) treatment algorithm. Cooled radiofrequency ablation (CRFA) and hyaluronic acid (HA) injections are two commonly used modalities to manage symptoms associated with knee OA.
Methods:
A prospective 1:1 randomized study was conducted in 177 patients comparing CRFA to HA injection with follow-ups at 1, 3, 6 and 12 months. HA subjects with unsatisfactory outcomes at 6-months were allowed to crossover and receive CRFA. Knee pain (numeric rating scale = NRS), WOMAC Index (pain, stiffness and physical function), overall quality of life (global perceived effect = GPE, EQ-5D-5 L), and adverse events were measured.
Results:
At 12-months, 65.2% of subjects in the CRFA cohort reported ≥50% pain relief from baseline. Mean NRS pain score was 2.8 ± 2.4 at 12 months (baseline 6.9 ± 0.8). Subjects in the CRFA cohort saw a 46.2% improvement in total WOMAC score at the 12-month timepoint. 64.5% of subjects in the crossover cohort reported ≥50% pain relief from baseline, with a mean NRS pain score of 3.0 ± 2.4 at 12 months (baseline 7.0 ± 1.0). After receiving CRFA, subjects in the crossover cohort had a 27.5% improvement in total WOMAC score. All subjects receiving CRFA reported significant improvement in quality of life. There were no serious adverse events related to either procedure and overall adverse event profiles were similar.
Conclusion:
A majority of subjects treated with CRFA demonstrated sustained knee pain relief for at least 12-months. Additionally, CRFA provided significant pain relief for HA subjects who crossed over 6 months after treatment.
Trial registration:
This trial was registered on ClinicalTrials.gov, NCT03381248. Registered 27 December 2017.
Objective:
The primary objective of this observational, prospective, multicenter study was to evaluate the long-term outcomes, including pain, function, and perceived effect of treatment, in cooled radiofrequency ablation (CRFA) subjects who have pain due to osteoarthritis (OA) of the knee.
Methods:
This analysis included a subset of subjects previously enrolled in a prospective, multicenter randomized study comparing the safety and effectiveness of CRFA and intra-articular steroid (IAS) injection in knee OA patients through 12 months, were contacted to participate in this extension study. Subjects were enrolled if they agreed to participate in up to two additional follow-ups, at 18- and 24-months.
Results:
Eighty-three subjects from the five participating sites received CRFA during the original study and were contacted for this extension study. Of the 33 subjects enrolled, 25 were evaluated at 18 months post-CRFA treatment, and their mean Numeric Rating Scale (NRS) score was 3.1 ± 2.7 with 12 subjects reporting ≥50% pain relief compared to baseline. At 24 months, 18 subjects reported a mean NRS score of 3.6 ± 2.8, with 11 demonstrating ≥50% pain relief. Functional improvement via Oxford Knee Score (OKS) continued to be present with an overall mean change from baseline of 26.0 ± 9.6 points at 18 months and 29.9 ± 10.4 points at 24 months.
Conclusion:
In this subset of subjects from a randomized controlled trial, CRFA provided sustained pain relief, improved function, and perceived positive effect through 24 months for subjects with OA knee pain with no safety concerns identified.
Background:
Genicular nerve radiofrequency ablation (RFA) is an intervention to treat patients with chronic knee pain who have failed previous conservative, pharmacologic, and surgical interventions. Vascular complications following interventional procedures of the knee are extremely rare. A delay in diagnosis may be detrimental for the viability of the affected limb and may ultimately require amputation.
Case presentation:
A 76-year-old man with a history of severe bilateral knee osteoarthritis and grade 4 chondromalacia presented to our clinic with refractory, severe bilateral knee pain and received a bilateral genicular nerve RFA. He returned 4 days later with right medial thigh pain and a magnetic resonance imaging study revealing a hematoma along the anteromedial aspect of the right distal femoral diaphysis measuring 13.3 × 4.5 × 3.0 cm. After collaboration between pain medicine and orthopedic surgery services, decision was made to treat patient conservatively with rest, compression, elevation, ice application, tramadol, and gabapentin, but with close follow-up and a low threshold to intervene with diagnostic and therapeutic angiography with embolization if bleeding worsened; he reported resolution of his pain after a 4-day and 1-month follow-up.
Conclusion:
This is the first report describing iatrogenic vascular injury in the knee after a genicular RFA procedure. Pain medicine physicians should be aware of the vascular anatomy of the knee, particularly paying close attention to variations after previous surgeries. Future trials should investigate modalities that minimize vascular complications including concomitant use of ultrasonography with fluoroscopy and other forms of RFA including pulsed or cooled RFA.
Background and objectives
As a follow-up to the 6-month report,12 this study investigated the analgesic effect of cooled radiofrequency ablation (CRFA) in patients with knee osteoarthritis (OA) 12 months postintervention and its ability to provide pain relief in patients who experienced unsatisfactory effects of intra-articular steroid injection (IAS).
Methods
Seventy-eight per cent (52/67) of patients originally treated with CRFA were evaluated at 12 months, while at 6 months post-IAS, 82% (58/71) of those patients crossed over to CRFA and assessed 6 months later.
Results
At 12 months, 65% of the original CRFA group had pain reduction ≥50%, and the mean overall drop was 4.3 points (p<0.0001) on the numeric rating scale. Seventy-five per cent reported ‘improved’ effects. The cross-over group demonstrated improvements in pain and functional capacity (p<0.0001). No unanticipated adverse events occurred.
Conclusions
This study demonstrates that analgesia following CRFA for OA knee pain could last for at least 12 months and could rescue patients who continue to experience intolerable discomfort following IAS.
Clinical trial registration
The ClinicalTrials.gov registration number for this study is NCT02343003 .
Background and Aims
Monopolar radiofrequency ablation (MRFA) of the genicular nerve is effective in managing chronic knee pain from osteoarthritis (OA); however, the procedure itself is associated with significant pain due to manipulation of electrode to localise tiny genicular nerves. We hypothesised that inserting two electrodes to target the genicular nerves [bipolar radiofrequency ablation (BRFA)] without sensory localisation can decrease the procedural pain with equal analgesic efficacy in treating knee pain.
Methods
Thirty patients with chronic knee pain due to OA were randomised to receive either MRFA (n = 15) or BRFA (n = 15), after having 50% pain relief with diagnostic genicular nerve block. Pain during the procedure (assessed by the Numeric Rating Scale [NRS]), time taken to do the procedure and complications were recorded. Knee pain was assessed by the Oxford Knee Score at baseline, 1 week, 1 month, 3 months and 6 months following the procedure.
Results
Patients in both groups had good pain relief, and no difference in pain relief and the duration of pain relief was seen between the two groups. The median (range) NRS for procedural pain was significantly lower in the bipolar group [3 (3–5)] than in the monopolar group [5 (3–7), P = 0.013]. There was no significant difference in procedure time and no complications were seen in either group.
Conclusion
BRFA is an effective alternative for ablation of genicular nerves in patients with knee pain due to OA. It causes less procedural pain compared with MRFA.
Background and objectives:
Osteoarthritis (OA) of the knee affects the aging population and has an associated influence on the health care system. Rigorous studies evaluating radiofrequency ablation for OA-related knee pain are lacking. This study compared long-term clinical safety and effectiveness of cooled radiofrequency ablation (CRFA) with intra-articular steroid (IAS) injection in managing OA-related knee pain.
Methods:
This is a prospective, multicenter, randomized trial with 151 subjects with chronic (≥6 months) knee pain that was unresponsive to conservative modalities. Knee pain (Numeric Rating Scale [NRS]), Oxford Knee Score, overall treatment effect (Global Perceived Effect), analgesic drug use, and adverse events were compared between CRFA and IAS cohorts at 1, 3, and 6 months after intervention.
Results:
There were no differences in demographics between study groups. At 6 months, the CRFA group had more favorable outcomes in NRS: pain reduction 50% or greater: 74.1% versus 16.2%, P < 0.0001 (25.9% and 83.8% of these study cohorts, respectively, were nonresponders). Mean NRS score reduction was 4.9 ± 2.4 versus 1.3 ± 2.2, P < 0.0001; mean Oxford Knee Score was 35.7 ± 8.8 vs 22.4 ± 8.5, P < 0.0001; mean improved Global Perceived Effect was 91.4% vs 23.9%, P < 0.0001; and mean change in nonopioid medication use was CRFA > IAS (P = 0.02). There were no procedure-related serious adverse events.
Conclusions:
This study demonstrates that CRFA is an effective long-term therapeutic option for managing pain and improving physical function and quality of life for patients with painful knee OA when compared with IAS injection.
Clinical trial registration:
ClinicalTrials.gov (NCT02343003).
Hyaluronic acid (HA) is a commonly prescribed treatment for knee pain resulting from osteoarthritis (OA). Although numerous HA products have been approved for use by the US Food and Drug Administration, the efficacy of HA injections for knee OA remains disputed with meta-analyses and societal clinical guidelines drawing disparate conclusions. The American Academy of Orthopaedic Surgeons (AAOS) recently published a best-evidence systematic review and concluded that available data did not support the routine use of HA for knee OA. The purpose of the current article is to highlight issues that confound interpretation of meta-analyses on HA for knee OA, to provide realistic estimates of the true efficacy of HA injections in knee OA, and to provide commentary on the methods and conclusions from the AAOS systematic review. In general, the clinical benefit of HA is underestimated using conventional meta-analytic techniques. When accounting for differential control group effects in HA studies, it can be reasonably concluded that HA injections may be beneficial to an appreciable number of patients with knee OA. In addition, the systematic review methodology used by AAOS was questionable due to exclusion of numerous relevant studies and inclusion of studies that used HAs not approved for use in the US, both of which underestimated the true efficacy of HA injections. Overall, the efficacy of HA injections for knee OA is likely better than previously reported. Future clinical trials and meta-analyses should account for differential control group effects in order to avoid the continued confusion surrounding HA injection efficacy.
This study aimed to perform genicular nerve RF neurotomy using two different imaging methods, fluoroscopy and ultrasound, and to compare the clinical effects and reliability of the two methods. Fifty patients with osteoarthritis were included in this study. Patients were randomly allocated into group 1 (fluoroscopy imaging) and group 2 (ultrasound imaging). Outcomes were measured using a pain scale (visual analog scale; VAS) and the Western Ontario and McMaster Universities (WOMAC) Index of Osteoarthritis. The application time in the ultrasound group (20.2 ± 6.4 min) was shorter than in the fluoroscopy group (25 ± 4.8 min) (p < 0.05). There was no difference in pain relief and functional status between the ultrasound and fluoroscopy groups. Decrease in VAS score and WOMAC total score in the first and third months was significant in both groups (p < 0.001). GNRFT under ultrasound guidance was easily applicable, safe and dynamic, and required no radiation to achieve the same benefit as the fluoroscopy-guided interventions.
Background
Chronic knee pain from osteoarthritis (OA) is common in the aging and the obese population. Radiofrequency ablation of the genicular nerves has been introduced as a potential surgery-sparing treatment for chronic knee pain from OA, yet only two outcome studies have been published and optimal patient selection for this procedure has not been established.
Objectives
We describe a standardized protocol for selecting patients for cooled radiofrequency ablation (C-RFA) of the genicular nerves, as well as the clinical outcomes of four patients ages 63-65 years.
Methods
The threshold for selection based on diagnostic genicular nerve block was ≥ 80% pain reduction. Following successful block, C-RFA of the genicular nerves was performed. Outcomes included pain, function, analgesic medication use, opioid use, and progression to total knee arthroplasty at a minimum of 6 month follow up.
Results
C-RFA of the genicular nerves after using the described selection protocol resulted in > 90% pain reduction, improved function and avoidance of surgery at 6 months in all four cases. All opioid and analgesic medication use decreased or was unchanged in all cases. No serious adverse events occurred.
Conclusions
The accompanying case series suggests that this protocol is deserving of randomized, prospective study.
To assess the validity of the Oxford Knee Score (OKS) for use in patients undergoing non-operative management for their knee osteoarthritis (OA) within the National Health Service (NHS).
Observational cohort study.
Single orthopaedic centre in England.
134 patients undergoing non-operative management for knee OA.
OKS, the Intermittent and Constant Osteoarthritis Pain (ICOAP), the Knee Injury and Osteoarthritis Score-Physical Function Short Form (KOOS-PS), at baseline and 3-month follow-up, transition item of change at 3 months.
The OKS summary scale and its pain and functional component subscales demonstrated good test-retest reliability (intraclass correlation coefficient 0.93, 0.91 and 0.92, respectively) and measurement precision which, allows its use with groups of patients with knee OA (research/audit) and with individuals (clinical practice). The results in this study were consistent with a priori set hypotheses about the relationship of OKS with other validated measures (KOOS-PS, ICOAP and short form 12 (SF-12)), which provided evidence of its construct validity and responsiveness. Confirmatory factor analysis confirmed the structural validity of OKS. However, there was a lack of satisfactory evidence of structural validity for ICOAP and KOOS. The minimum detectable change (MDC90) was ±6 for OKS (±16 for the Pain Component Score (OKS-PCS) and ±15 for the Functional Component Score (OKS-FCS)). Minimal important changes were ≈7 for OKS (≈17 for OKS-PCS and ≈11 for OKS-FCS) and minimal important differences were ≈6 for OKS (≈14 for OKS-PCS and ≈10 for OKS-FCS). These values were also calculated for ICOAP and KOOS-PS.
The OKS summary scale, together with its pain and functional component subscales, has excellent measurement properties when used with patients with knee OA undergoing non-operative treatment and is superior to ICOAP and KOOS-PS for this purpose. This evidence provides support for the validity of the use of OKS when used across the spectrum of knee OA disease severity, both in research and clinical practice.
Obesity is associated with an increasing prevalence of musculoskeletal complaints and pain. Obesity is a major risk factor for osteoarthritis (OA), and pain can manifest in load-bearing and nonload-bearing joints. The lumbar spine and the knee are 2 primary sites for pain onset in the obese patient. Irrespective of the weight loss method, reduction of body fat can lower the mechanical and inflammatory stressors that contribute to OA. Single or combined methods of weight loss including exercise, dietary modification, medications, and bariatric surgery are associated with lower joint pain and increased physical function. Methods of weight loss or maintenance in early years may reduce the life exposure of joints to the obesity induced stressors on load bearing joints.
Secondary analysis, pretreatment-posttreatment observational study.
To compare the reliability and responsiveness of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Knee Outcome Survey activities of daily living subscale (KOS-ADL), and the Lower Extremity Functional Scale (LEFS) in individuals with knee osteoarthritis (OA).
The WOMAC is the current standard in patient-reported measures of function in patients with knee OA. The KOS-ADL and LEFS were designed for potential use in patients with knee OA. If the KOS-ADL and LEFS are to be considered viable alternatives to the WOMAC for measuring patient-reported function in individuals with knee OA, they should have measurement properties comparable to the WOMAC. It would also be important to determine whether either of these instruments may be superior to the WOMAC in terms of reliability or responsiveness in this population.
Data from 168 subjects with knee OA, who participated in a rehabilitation program, were used in the analyses. Reliability and responsiveness of each outcome measure were estimated at follow-ups of 2, 6, and 12 months. Reliability was estimated by calculating the intraclass correlation coefficient (ICC2,1) for subjects who were unchanged in status from baseline at each follow-up time, based on a global rating of change score. To examine responsiveness, the standard error of the measurement, minimal detectable change, minimal clinically important difference, and the Guyatt responsiveness index were calculated for each outcome measure at each follow-up time.
All 3 outcome measures demonstrated reasonable reliability and responsiveness to change. Reliability and responsiveness tended to decrease somewhat with increasing follow-up time. There were no substantial differences between outcome measures for reliability or any of the 3 measures of responsiveness at any follow-up time.
The results do not indicate that one outcome measure is more reliable or responsive than another when applied to subjects with knee OA. We believe that all 3 instruments are appropriate outcome measures to examine change in functional status of patients with knee OA.J Orthop Sports Phys Ther 2012;42(8):716-723, Epub 8 March 2012. doi:10.2519/jospt.2012.4038.
Chronic osteoarthritis (OA) pain of the knee is often not effectively managed with current non-pharmacological or pharmacological treatments. Radiofrequency (RF) neurotomy is a therapeutic alternative for chronic pain. We investigated whether RF neurotomy applied to articular nerve branches (genicular nerves) was effective in relieving chronic OA knee joint pain. The study involved 38 elderly patients with (a) severe knee OA pain lasting more than 3 months, (b) positive response to a diagnostic genicular nerve block and (c) no response to conservative treatments. Patients were randomly assigned to receive percutaneous RF genicular neurotomy under fluoroscopic guidance (RF group; n=19) or the same procedure without effective neurotomy (control group; n=19). Visual analogue scale (VAS), Oxford knee scores, and global perceived effect on a 7-point scale were measured at baseline and at 1, 4, and 12weeks post-procedure. VAS scores showed that the RF group had less knee joint pain at 4 (p<0.001) and 12 (p<0.001) weeks compared with the control group. Oxford knee scores showed similar findings (p<0.001). In the RF group, 10/17 (59%), 11/17 (65%) and 10/17 (59%) achieved at least 50% knee pain relief at 1, 4, and 12 weeks, respectively. No patient reported a post-procedure adverse event during the follow-up period. RF neurotomy of genicular nerves leads to significant pain reduction and functional improvement in a subset of elderly chronic knee OA pain, and thus may be an effective treatment in such cases. Further trials with larger sample size and longer follow-up are warranted.
Introduction
Ultrasound (US)-guided radiofrequency ablation (RFA) of genicular nerves (GNs) is increasingly performed to manage chronic knee pain. The anatomical foundations supporting the choice of original targets for US-guided GN-RFA have been thoroughly improved by recent anatomical studies. Therefore, this study aimed to provide a new protocol with revised anatomical targets for US-guided GN-RFA and to assess their accuracy in a cadaveric model.
Materials and methods
Fourteen fresh-frozen cadaveric knees were used. After a pilot study with 4 knees, five consistent nerves were targeted in the other 10 knees with revised anatomical landmarks: superior medial genicular nerve (SMGN), superior lateral genicular nerve (SLGN), inferior medial genicular nerve (IMGN), recurrent fibular nerve (RFN) and the infrapatellar branch of the saphenous nerve (IPBSN). For each nerve, the lumen of radiofrequency (RF) cannula was prefilled with non-diffusible black paint, and then the cannula was inserted at the target site under US guidance. After US verification of correct placement, the stylet was introduced in the cannula to create a limited black mark on the tissues at the top of the active tip. Anatomical dissection was performed to assess for accuracy.
Results
The proportion of nerves directly found in contact with the black mark was 7/10, 8/10, 10/10 and 9/10 for the SMGN, SLGN, IMGN and RFN, respectively. The proportions of nerve captured by the theoretical largest monopolar RF lesions were 100% for the SMGN, IMGN and RFN, and IPBSN and 95% for SLGN. The mean distances from the center of the black mark to the targeted nerve were 2.1±2.2 mm, 1.0±1.4 mm, 0.75±1.1 mm and 2.4±4.5 mm for the SMGN, SLGN, IMGN and RFN, respectively.
Conclusion
US-guided GN-RFA with revised anatomical targets resulted in accurate capture of the five targeted nerves. This protocol provides precise sensory denervation of a larger panel of nerves, targeting those whose constancy regarding anatomical location has been clearly demonstrated. It is expected to improve the clinical outcomes.
Background and objectives:
Radiofrequency (RF) denervation of the superolateral genicular nerve (SLGN), superomedial genicular nerve (SMGN) and inferomedial genicular nerve (IMGN) is commonly used to manage chronic knee joint pain. However, knowledge of articular branches captured, using classical landmarking techniques, remains unclear. In order to enhance and propose new RF procedures that conceivably capture a greater number of articular branches, more detailed cadaveric investigation is required. The objectives were to (1) determine which articular branches are captured or spared using classical landmarking techniques, and (2) evaluate the anatomical feasibility of classical landmarking techniques using three-dimensional (3D) modeling technology.
Methods:
Ultrasound-guided classical superolateral/superomedial/inferomedial landmarking techniques were used to position RF cannulae in five specimens. The articular branches, bony and soft tissue landmarks, and cannula tip position, were meticulously dissected, digitized and modeled in 3D. Simulated lesions were positioned at the cannula tip, on the 3D models, to determine which articular branches were captured or spared. Capture rates of articular branches were compared.
Results:
In all specimens, classical superolateral/superomedial techniques captured the transverse deep branches of SLGN and SMGN, and articular branches of lateral and medial nerve to vastus intermedius, while sparing distal branches of SLGN/SMGN. The inferomedial technique captured anterior branches of IMGN while sparing the posterior and inferior branches.
Conclusions:
This study provides anatomical evidence supporting the effectiveness of classical landmarking for genicular nerve ablation; however, each technique resulted in sparing of articular branches. The extensive innervation of the knee joint suggests the use of supplementary landmarks to improve capture rates and potentially patient outcomes.
Interpreting randomized clinical trials (RCTs) is crucial to making decisions regarding the use of analgesic treatments in clinical practice. In this article, we report on an Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) consensus meeting organized by the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION), the purpose of which was to recommend approaches that facilitate interpretation of analgesic RCTs. We review issues to consider when drawing conclusions from RCTs, as well as common methods for reporting RCT results and the limitations of each method. These issues include the type of trial, study design, statistical analysis methods, magnitude of the estimated beneficial and harmful effects and associated precision, availability of alternative treatments and their benefit-risk profile, clinical importance of the change from baseline both within and between groups, presentation of the outcome data, and the limitations of the approaches used.
Introduction
The purpose of this study was to evaluate the efficacy and safety of adipose-derived stem cell (ADSC) or stromal vascular fraction (SVF) injections for knee osteoarthritis (OA) treatment by analyzing all randomized controlled trials dealing with this topic.
Materials and Methods
The following search terms were used in PUBMED, EMBASE, Scopus and the Cochrane Library Database on 14th November 2019: “adipose derived stem cell” OR “stromal vascular fraction” OR “SVF” OR “multipotent mesenchymal stromal cells” OR “stem cell” OR “derived stem cell” OR “autologous” AND “knee” OR “osteoarthritis” OR “chondral defect” OR “randomized” OR “controlled trial”. No time limit was given to publication date. We included randomized controlled trials (RCTs) based on the following criteria: (1) English studies; (2) patient population diagnosed with knee OA and treated with ADSCs or SVF injections; (3) comparison group treated with placebo, surgery or adjuvant injections, such as platelet rich-plasma or hyaluronic acid.
Results
Intra-articular injections of adipose stem cell therapy in the form of ADSC or SVF is a safe procedure for the treatment of knee OA, with good clinical and radiological outcomes in the early follow-up period (12-24 months). In addition, treatment with fat-derived cells showed a very low complication rate (16.15%) of which all were considered to be minor.
Conclusions
ADSCs and SVF seem to produce promising good to excellent clinical results for the treatment of knee OA. However, the length and modalities of follow-up in the different conditions are extremely variable. Nevertheless, it appears that the use of adipose-derived stem cells is associated with clinical and radiological improvements and minimal complication rates. To avoid bias deriving from the use of biological adjuvants or surgical procedures, randomized controlled trials comparing ADSCs or SVF and other treatments (for example platelet rich-plasma or hyaluronic acid injections) should be performed.
Aim: Cooled radiofrequency ablation (CRFA) has demonstrated efficacy in the management of knee pain caused by osteoarthritis. A typical procedure involves fluoroscopic placement of internally cooled radiofrequency probes to ensure the probes are located near target genicular nerves. Patients & methods: A new technique was developed to perform CRFA using ultrasound (US) guidance. Patient outcomes were reported using a telephone survey. Results: Ablation procedures were successfully performed using US guidance. A total of 51 patients were retrospectively identified for telephone screening. A total of 22 patients completed the telephone questionnaire. There were no safety concerns identified and the majority of patients reported satisfactory outcomes. Conclusion: Patient outcomes demonstrate that US-guided CRFA procedures provide pain relief and functional improvement. Further studies are needed to compare the efficacy of US-guided CRFA to fluoroscopy-guided CRFA procedures.
Background:
Cooled radiofrequency ablation (CRFA) in a randomized, prospective study demonstrated significantly greater improvements in pain, functional, and global outcome measures.
Objectives:
This large, real-life, retrospective study evaluated the long-term effectiveness of CRFA in the general chronic knee pain population.
Study design:
Retrospective electronic chart review.
Setting:
Outpatient private practice.
Methods:
After institutional review board approval, we reviewed data of 275 consecutive patients who had undergone a geniculate nerve block at a single-site pain practice between July 1, 2014 and July 1, 2017. A total of 44 patients had a negative response to the geniculate block, and 11 patients had long-term pain relief from the block and declined CRFA. Eight patients underwent knee surgery after the block, and 7 never followed up for further treatment. Finally, 205 patients had undergone CRFA, and 183 (89%) of them returned to provide data.
Results:
The average age of the 183 patients was 61 (28-95) years, body mass index 34 (18.5-57), and there were 105 women and 78 men. A total of 137 patients had unilateral knee pain, whereas 46 patients had bilateral knee pain. Eighty percent (146/183) reported at least one or more additional sources of chronic pain (back, shoulder, and others). The average opioid use at baseline was 50 mg morphine sulfate equivalents (median 30 mg). The average baseline pain scores were 8.5, which decreased to 2.2 after the geniculate local anesthetic block, and to 4.2 after CRFA. A total of 65% of the patients claimed > 50% pain relief, whereas 77% had 2 or more Visual Analog Scale points decrease, and 26 (14%) patients reported no pain at all after CRFA. The mean duration of > 50% pain relief after CRFA was 12.5 months (range 0-35 months). There was no significant decrease of opioid use. Patients who underwent a repeated procedure (n = 43) achieved a similar pain relief (P = 0.402). We could not find a statistical difference in geniculate CRFA outcomes between the group who had total knee arthroplasty (TKA; n = 21) and maintained chronic knee pain and patients who had no prior surgery (P = 0.542).
Limitations:
Retrospective nature of the study.
Conclusions:
This study demonstrates the clinical effectiveness of CRFA in the treatment of chronic knee pain from osteoarthritis, and even in those patients who maintained chronic knee pain after TKA. Our real-life data seems to agree with data previously published in a randomized controlled trial, despite the fact that this was quite a heterogenous patient population with various sources of chronic pain.
Key words:
Radiofrequency ablation, chronic knee pain, knee osteoarthritis.
Background and objectives
Genicular nerve blockade (GNB) and radiofrequency ablation (RFA) have recently emerged as treatment options for patients with chronic knee pain. However, an increasing number of anatomical studies and systematic reviews concluded that the anatomical basis for needle placement was unclear, incomplete and somewhat inaccurate. This study was designed to assess the accuracy of updated anatomical landmarks for fluoroscopy-guided blockade of the consistent genicular nerves in a cadaveric model.
Methods
Based on a comprehensive review of recent anatomical studies and prior dissection of 21 fresh cadaver knees, we defined bony landmarks with high likelihood of successful ablation of the five consistent genicular nerves (GN). We tested the accuracy of GNBs using the above-stated anatomical landmarks in 10 intact fresh cadaveric knees. Needle placement was guided by fluoroscopy and 0.5 mL of 0.1% methylene blue was injected at the site of each nerve. The knees were subsequently dissected to assess the accuracy of the injections. If the nerve was dyed with blue ink, the placement was considered accurate.
Results
The accuracy of our injections was 100% for the superior medial genicular nerve, inferior medial GN, infrapatellar branch of saphenous nerve and recurrent fibular nerve. The superior lateral GN was dyed in 90% of specimens.
Conclusion
This study provides physicians with precise anatomical landmarks for the five consistent GN for fluoroscopic-guided GNB. Our revised technique, which targets more nerves with increased accuracy, could potentially lead to improved therapeutic benefits on chronic knee pain.
Objective:
To determine if commonly used knee radiofrequency ablation (RFA) techniques would be able to completely denervate the knee joint.
Methods:
A comprehensive search of the literature on knee joint innervation was conducted using the databases Medline, Embase, and PubMed from inception through February 1, 2019. Google Scholar was also searched. Data on the origin, number of articular branches, course, distribution, and frequency of each nerve innervating the knee joint were extracted from the included studies and compared in order to identify variations.
Results:
Twelve studies of anterior knee joint innervation and six studies of posterior knee joint innervation were included. The anterior knee joint was innervated by 10 nerves and further subdivided into two parts (anteromedial and anterolateral) or four quadrants (superomedial, inferomedial, superolateral, and inferolateral) based on innervation patterns; the posterior knee joint was innervated by two or three nerves, most commonly via the popliteal plexus. There is a lack of precise, validated anatomic targets identifiable with fluoroscopy and ultrasound for knee diagnostic blocks and RFA. Only three of the 12 or potentially 13 nerves innervating the knee joint are targeted by commonly used knee RFA techniques.
Conclusions:
Commonly used knee RFA techniques would not be able to completely denervate the knee joint. It may not be necessary to capture all of the nerves, but only the nerves mediating a patient's pain. Further clinical studies are required to validate specific diagnostic blocks and evaluate clinical outcomes using rigorous diagnostic blocks and anatomically specific knee RFA techniques.
Context:
Amid extensive debate, evidence surrounding the use of platelet-rich plasma (PRP) for musculoskeletal injuries has rapidly proliferated, and an overall assessment of efficacy of PRP across orthopaedic indications is required.
Objectives:
(1) Does PRP improve patient-reported pain in musculoskeletal conditions? and (2) Do PRP characteristics influence its treatment effect?
Data sources:
MEDLINE, EMBASE, Cochrane, CINAHL, SPORTDiscus, and Web of Science libraries were searched through February 8, 2017. Additional studies were identified from reviews, trial registries, and recent conferences.
Study selection:
All English-language randomized trials comparing platelet-rich therapy with a control in patients 18 years or older with musculoskeletal bone, cartilage, or soft tissue injuries treated either conservatively or surgically were included. Substudies of previously reported trials or abstracts and conference proceedings that lacked sufficient information to generate estimates of effect for the primary outcome were excluded.
Study design:
Systematic review and meta-analysis.
Level of evidence:
Level 1.
Data extraction:
All data were reviewed and extracted independently by 3 reviewers. Agreement was high between reviewers with regard to included studies.
Results:
A total of 78 randomized controlled trials (5308 patients) were included. A standardized mean difference (SMD) of 0.5 was established as the minimum for a clinically significant reduction in pain. A reduction in pain was associated with PRP at 3 months (SMD, -0.34; 95% CI, -0.48 to -0.20) and sustained until 1 year (SMD, -0.60; 95% CI, -0.81 to -0.39). Low- to moderate-quality evidence supports a reduction in pain for lateral epicondylitis (SMD, -0.69; 95% CI, -1.15 to -0.23) and knee osteoarthritis (SMD, -0.91; 95% CI, -1.41 to -0.41) at 1 year. PRP characteristics did not influence results.
Conclusion:
PRP leads to a reduction in pain; however, evidence for clinically significant efficacy is limited. Available evidence supports the use of PRP in the management of lateral epicondylitis as well as knee osteoarthritis.
Background:
Fluoroscopically guided cooled genicular nerve radiofrequency ablation (RFA) is an increasingly performed procedure for chronic, refractory knee pain due to osteoarthritis. Traditionally, partial sensory denervation has been accomplished through ablation of the superomedial, superolateral, and inferomedial genicular nerves. However, recent cadaveric studies have demonstrated additional sensory nerves and significant anatomic variation that impact current protocols.
Objective:
We describe an updated cooled genicular nerve radiofrequency ablation protocol that accounts for varied nerve location of the superomedial, superolateral, and inferomedial genicular nerves, as well as capture of the terminal articular branches of the nerves to the vastus intermedius, vastus lateralis, and vastus medialis. Furthermore, we describe an adjusted technique for inferomedial genicular nerve capture that mitigates the risk of pes anserine tendon injury.
Design:
Technical report and brief literature review.
Methods:
Cadaveric studies relating to the sensory innervation of the anterior knee joint were reviewed, and a more accurate and comprehensive cooled genicular nerve radiofrequency ablation (CRFA) protocol is proposed.
Conclusions:
Based on recent, rigorous anatomic dissections of the knee, the proposed genicular nerve CRFA protocol will provide more complete sensory denervation and potentially improve clinical outcomes. Prospective studies will be needed to confirm the hypothesis that this protocol will result in improved effectiveness and safety of genicular nerve RFA.
Early evidence from clinical trials suggests effectiveness of fluoroscopically guided genicular nerve radiofrequency ablation (RFA) for the treatment of chronic knee pain due to osteoarthritis.1 One small sham‐controlled study has demonstrated efficacy of this procedure.2 Additionally, there is interest in the use of genicular RFA for the treatment of persistent chronic knee pain post‐total knee arthroplasty, though efficacy has yet to be demonstrated.3
Glucocorticoids remain widely used for many medical conditions, and fractures are the most serious common adverse event related to long-term glucocorticoid use. Glucocorticoid-induced osteoporosis (GIOP) develops in a time- and dose-dependent manner, but even at low doses, an increased risk of fragility fracture may be observed even within the first month of treatment. GIOP is mediated by multiple pathophysiologic mechanisms resulting in an inhibition of bone formation and an increase in bone resorption. The clinical assessment of GIOP has potential pitfalls since dual-energy X-ray absorptiometry (DXA) may underestimate the risk of fracture in patients treated with glucocorticoids. Many national organizations have developed guidelines for assessing fracture risk and treating patients with, or at risk for, GIOP. These groups advocate both antiresorptive agents and bone-forming agents based predominately on their efficacy in improving bone mineral density. Oral bisphosphonates are generally the first-line therapy for GIOP in most patients due to their proven efficacy, good safety, and low cost. For those patients at greater risk of fracture, teriparatide should be considered earlier, based on its ability to significantly reduce vertebral fractures when compared with alendronate. GIOP remains a major public health concern that is at least partially preventable with current and potential future therapeutic options.
BACKGROUND
It is known that South Australia (SA) has the highest rate of knee arthroscopy use of any state in Australia, however Level 1 evidence demonstrates that knee arthroscopy in patients with uncomplicated knee osteoarthritis confers no benefit. In SA, which patients are presenting with knee pain and what treatments are they receiving?
AIMS
To determine the prevalence, persistence and treatment modalities of knee pain in SA.
METHODS
This study analysed data from the North‐West Adelaide Health Study (1999‐2015), a longitudinal, population based cohort study of people aged 18 years and over (n=4060), initially randomly selected from the north‐west region of Adelaide, SA. It incorporated clinic assessments, self‐completed questionnaires and telephone interviews to collect demographic, anthropometric and biochemical data over 4 main stages (1, 2, 3 and NW15). Data were linked to Medical Benefits Scheme (MBS) data.
RESULTS
In stages 3 and NW15 of the NWAHS, 30‐35% of participants reported knee pain (n=803, 452). Demographic variables associated with knee pain included older age and lower educational level, while risk factors included obesity and high waist circumference. In the 12 months preceding NW15, 33% of participants with knee pain/stiffness consulted a GP for their knee pain, 10.2% an orthopaedic surgeon, and 12.6% a physiotherapist. Between 2011 and 2015, 3.0% the cohort underwent a knee arthroscopy, and 3.1% underwent knee magnetic resonance imaging.
CONCLUSION
Knee pain affects large proportions of the SA population. Knee pain was persistent with underuse of non‐pharmacological treatments and high use of specialist referral. This data supports the need for a national strategy to effectively manage osteoarthritis.
This article is protected by copyright. All rights reserved.
Background and objectives:
The knee joint is the most common site of osteoarthritis. While joint replacement is considered an ultimate solution, radiofrequency denervation may be contemplated in some cases. Radiofrequency ablation requires precise localization of the articular branches innervating the joint capsule. The objective of this cadaveric study was to determine the source, course, relationships, and frequency of articular branches innervating the anterior knee joint capsule.
Methods:
Fifteen knees were meticulously dissected. The number and origin of the articular branches were recorded, and their distribution defined by quadrants. Their relationships to anatomical landmarks were identified.
Results:
The articular branches terminated in 1 of the 4 quadrants with minimal overlap. In all specimens, the superolateral quadrant was innervated by the nerve to vastus lateralis, nerve to vastus intermedius, superior lateral genicular and common fibular nerves; inferolateral by the inferior lateral genicular and recurrent fibular nerves; superomedial by the nerve to vastus medialis, nerve to vastus intermedius and superior medial genicular nerve; and inferomedial by the inferior medial genicular nerve. In 3 specimens, the inferomedial quadrant also received innervation from the infrapatellar branch of saphenous nerve. All articular branches except the nerves to vastus lateralis and medialis course at the periosteal level.
Conclusions:
The frequency map of the articular branches provides an anatomical basis for the development of new clinical protocols for knee radiofrequency denervation and perioperative pain management.
Background and Objectives. Genicular nerve radiofrequency ablation is an effective treatment for
patients with chronic pain due to knee osteoarthritis; however, little is known about factors that predict
procedure success. The current study evaluated the utility of genicular nerve blocks to
predict the outcome of genicular nerve cooled radiofrequency ablation (cRFA) in patients with
osteoarthritis.
Methods. This randomized comparative trial included patients with chronic knee pain due to osteoarthritis.
Participants were randomized to receive a genicular nerve block or no block prior to cRFA. Patients receiving a prognostic block that demonstrated �50% pain relief for six hours received cRFA. The primary outcome
was the proportion of participants with �50% reduction in knee pain at sixmonths.
Results. Twenty-nine participants (36 knees) had cRFA following a prognostic block, and 25 patients (35 knees) had cRFA without a block. Seventeen participants (58.6%) in the prognostic block group and 16 (64.0%) in the no block group had �50% pain relief at six months (P=0.34). A 15-point decrease in the Western Ontario and McMaster Universities Osteoarthritis Index at six months was present in 17 of 29 (55.2%) in the prognostic block group and 15 of 25 (60%) in the no block group (P=0.36).
Conclusions. This study demonstrated clinically meaningful improvements in pain and physicalfunction up to six months following cRFA. A prognostic genicular nerve block using a local anesthetic volume of 1mL at each injection site and a threshold of�50% pain relief for subsequent cRFA eligibility did not improve the rate of treatment
success.
Background:
Studies of radiofrequency ablation (RFA) of genicular nerves have reportedly significantly decreased pain up to 3 months post ablation, but no longer term effects have been reported. We performed an analysis of long-term pain relief of 31 RFA procedures of the genicular nerves to analyze the degree of pain relief past 3 months, culminating at 6 months.
Study design:
Chart review and study design was approved by Newark Health Sciences Institutional Review Board (IRB). Chart review and follow-up was performed on all patients who underwent genicular nerve RFA during the period of February 2014 through August of 2015. During this inclusion period 41 genicular nerve RFAs were performed on 31 patients, 5 patients received RFA procedure in both knees. Patient follow-up was performed via telephone interview or in-office visit at least 3 months and 6 months post RFA.
Settings:
Procedures were performed in Medical Special Procedures at University Hospital in Newark, NJ, and the Pain Management Center at Overlook Medical Arts Center in Summit, NJ.
Methods:
Chart review and study design was approved by Newark Health Sciences IRB. Chart review was performed from February 2014 and continued through August 2015. Patient follow-up was conducted at 3 and at least 6 months post treatment to gauge degree of pain relief (0 - none, 100% - complete), their current day's pain score, other treatment modalities tried before RFA, and the medications used. Patients were asked to quantify their satisfaction with procedure length, pre-procedure anxiety, complications, and if they would recommend this procedure to others. Primary and secondary goals were the duration of pain relief after RFA, the quality of pain relief, and the efficacy of our approach for RFA of genicular nerves versus prior published techniques.
Results:
At 3 month follow-up, the average pain relief was 67% improvement from baseline knee pain, 0% being no relief and 100% being complete relief, and average 0 - 10 pain score was 2.9. At 6 month follow-up, of those who described pain relief at 3 months, 95% still described pain relief. This group's average percent pain relief was 64% and average day's 0 - 10 pain score 3.3.
Limitations:
Our study included a retrospective component in chart review followed by prospective follow-up, only 76% of patients were able to participate in the interview process. Furthermore, some patients suffered from other chronic pain ailments, most commonly chronic back pain, which at times disturbed the patient's ability to focus on solely knee pain.
Conclusions:
Based on patient interviews and data collection, RFA of genicular nerves can supply on average greater than 60% pain relief in our patient population for as long as 6 months.Key words: Osteoarthritis, knee osteoarthritis, chronic knee pain, radiofrequency ablation, nerve ablation, genicular nerves, long-term pain relief.
Importance
Synovitis is common and is associated with progression of structural characteristics of knee osteoarthritis. Intra-articular corticosteroids could reduce cartilage damage associated with synovitis but might have adverse effects on cartilage and periarticular bone.
Objective
To determine the effects of intra-articular injection of 40 mg of triamcinolone acetonide every 3 months on progression of cartilage loss and knee pain.
Design, Setting, and Participants
Two-year, randomized, placebo-controlled, double-blind trial of intra-articular triamcinolone vs saline for symptomatic knee osteoarthritis with ultrasonic features of synovitis in 140 patients. Mixed-effects regression models with a random intercept were used to analyze the longitudinal repeated outcome measures. Patients fulfilling the American College of Rheumatology criteria for symptomatic knee osteoarthritis, Kellgren-Lawrence grades 2 or 3, were enrolled at Tufts Medical Center beginning February 11, 2013; all patients completed the study by January 1, 2015.
Interventions
Intra-articular triamcinolone (n = 70) or saline (n = 70) every 12 weeks for 2 years.
Main Outcomes and Measures
Annual knee magnetic resonance imaging for quantitative evaluation of cartilage volume (minimal clinically important difference not yet defined), and Western Ontario and McMaster Universities Osteoarthritis index collected every 3 months (Likert pain subscale range, 0 [no pain] to 20 [extreme pain]; minimal clinically important improvement, 3.94).
Results
Among 140 randomized patients (mean age, 58 [SD, 8] years, 75 women [54%]), 119 (85%) completed the study. Intra-articular triamcinolone resulted in significantly greater cartilage volume loss than did saline for a mean change in index compartment cartilage thickness of −0.21 mm vs −0.10 mm (between-group difference, −0.11 mm; 95% CI, −0.20 to −0.03 mm); and no significant difference in pain (−1.2 vs −1.9; between-group difference, −0.6; 95% CI, −1.6 to 0.3). The saline group had 3 treatment-related adverse events compared with 5 in the triamcinolone group and had a small increase in hemoglobin A1c levels (between-group difference, −0.2%; 95% CI, −0.5% to −0.007%).
Conclusions and Relevance
Among patients with symptomatic knee osteoarthritis, 2 years of intra-articular triamcinolone, compared with intra-articular saline, resulted in significantly greater cartilage volume loss and no significant difference in knee pain. These findings do not support this treatment for patients with symptomatic knee osteoarthritis.
Trial Registration
ClinicalTrials.gov Identifier: NCT01230424
Background and objectives:
Radiofrequency ablation of genicular nerves has proved to be successful in relieving pain and incapacity caused by osteoarthritis of the knee. However, long-term efficacy of such a treatment remains to be assessed. The current study aimed to reproduce radiofrequency neurotomy of genicular nerves to manage gonarthrosis pain and disability and establish therapeutic response until 1 year after intervention.
Methods:
This single-center, prospective, observational, noncontrolled, longitudinal study included patients with grade 3 to 4 gonarthrosis suffering from intractable knee pain, scoring 5 or more on the visual analog scale (VAS) during >6 months. Therapy was based on ultrasound guided radiofrequency neurotomy of the superior medial, superior lateral and inferior medial genicular nerves. Visual analog scale and Western Ontario and McMaster Universities Osteoarthritis scores were assessed before therapy and at 1, 6, and 12 months following treatment.
Results:
Radiofrequency neurotomy of genicular nerves significantly reduced perceived pain (VAS) and disability (Western Ontario and McMaster Universities Osteoarthritis) in the majority of participants, without untoward events. The proportion of participants with improvement of 50% or greater in pretreatment VAS scores at 1, 6, and 12 months following intervention were 22/25 (88%), 16/25 (64%) and 8/25 (32%), respectively.
Conclusions:
Ultrasound-guided radiofrequency neurotomy of genicular nerves alleviates intractable pain and disability in the majority of patients with advanced Osteoarthritis of the knee. Such a treatment is safe and minimally invasive and can be performed in an outpatient setting. The beneficial effect of treatment started to decline after 6 months, but even 1 year after the intervention, 32% of patients reported 50% improvement or greater in pretreatment VAS scores.
Objective:
1) Do treatment effects differ between participants receiving manual therapy (MT) with exercise compared to subjects who don't, 2) are treatment effects sustained better when participants receive booster sessions compared to those who don't over a one year period in subjects with knee osteoarthritis (OA)?
Design:
Multi-center, 2x2 factorial randomized clinical trial. 300 participants with knee OA were randomized to 4 groups: exercise-no boosters (Ex), exercise-with boosters(Ex+B), manual therapy+exercise-no boosters(MT+Ex), manual therapy+exercise-with boosters(MT+Ex+B). The primary outcome was the Western Ontario and McMaster osteoarthritis index (WOMAC) at 1 year. Secondary outcomes included knee pain, physical performance tests, and proportions of participants meeting treatment responder criteria.
Results:
There were no differences between groups on the WOMAC at 1 year or on any performance-based measures. Secondary analyses indicated a) better scores on the WOMAC and greater odds of being a treatment responder at 9 weeks for participants receiving MT, b) greater odds of being a treatment responder at 1 year for participants receiving boosters. Exploratory interaction analysis suggested knee pain decreases for participants receiving boosters and increases for participants not receiving boosters from 9 weeks to 1 year.
Conclusions:
MT or use of boosters with exercise did not result in additive improvement in the primary outcome at 1 year. Secondary outcomes suggest MT may have some short term benefit, and booster sessions may improve responder status and knee pain at 1 year. However, the role of booster sessions remains unclear in sustaining treatment effects and warrants further study. Clinical Trials.gov (NCT01314183).
Objective:
Osteoarthritis (OA) is a disabling disease that produces severe morbidity reducing physical activity. Our position statement on treatment of knee OA with viscosupplementation injection [hyaluronic acid (HA)] versus steroid [intra-articular corticosteroid (IAS)] and placebo [intra-articular placebo (IAP)] is based on the evaluation of treatment effect by examining the number of subjects within a treatment arm that met the Outcome Measures in Rheumatoid Arthritis Clinical Trials-Osteoarthritis Research Society International (OMERACT-OARSI) criteria, which is different and more relevant than methods used in other reviews which examined if the average change across the treatment groups was clinically different.
Data sources:
We performed a systematic literature search for all relevant articles from 1960 to August 2014 in the MEDLINE, EMBASE, and Cochrane CENTRAL. We performed a network meta-analysis (NMA) of the relevant literature to determine if there is a benefit from HA as compared with IAS and IAP.
Main results:
Eleven articles met the inclusion criteria from the search strategy. On NMA, those subjects receiving HA were 15% and 11% more likely to respond to treatment by the OMERACT-OARSI criteria than those receiving IAS or IAP, respectively (P < 0.05 for both).
Conclusions:
In light of the aforementioned results of our NMA, the American Medical Society for Sport Medicine recommends the use of HA for the appropriate patients with knee OA.
Chronic knee pain is common in all age groups. Some patients who fail conservative therapy benefit from radiofrequency neurotomy. Knowledge of the anatomy is critical to ensure a successful outcome. The purpose of this study was to reanalyze the innervation to the anterior knee capsule from the perspective of the interventional pain practitioner.
The study included a comprehensive literature review followed by dissection of 8 human knees to identify the primary capsular innervation of the anterior knee joint. Photographs and measurements were obtained for each relevant nerve branch. Stainless-steel wires were placed along the course of each primary innervation, and radiographs were obtained.
Literature review revealed a lack of consensus on the number and origin of nerve branches innervating the anterior knee capsule. All dissections revealed the following 6 nerves: superolateral branch from the vastus lateralis, superomedial branch from the vastus medialis, middle branch from the vastus intermedius, inferolateral (recurrent) branch from the common peroneal nerve, inferomedial branch from the saphenous nerve, and a lateral articular nerve branch from the common peroneal nerve.Nerve branches showed variable proximal trajectories but constant distal points of contact with femur and tibia. The inferolateral peroneal nerve branch was found to be too close to the common peroneal nerve, making it inappropriate for radiofrequency neurotomy.
The innervation of the anterior capsule of the knee joint seems to follow a constant pattern making at least 3 of these nerves accessible to percutaneous ablation. To optimize clinical outcome, well-aligned radiographs are critical to guide lesion placement.
Patients with osteoarthritis (OA) are faced with a barrage of treatment options, from recommendations from friends and social media to medications prescribed by the primary care physician. The purpose of this article is to critically review current approaches to generalized or monoarticular OA based on available evidence and to illustrate multidisciplinary and multimodal treatment strategies for the management of OA. Treatment options assessed for efficacy include patient education; oral and topical pharmacological agents; complementary and alternative medicine; surgery; manual medicine; acupuncture; interventional procedures (corticosteroid injection, viscosupplementation, and pulsed radiofrequency); bracing; assistive devices; physical therapy; and physical modalities. Multidisciplinary and multimodal treatment strategies combined with early detection and prevention strategies provide the best benefit to patients. This review also illustrates that traditional and alternative modalities of treatment can be both synergistic and beneficial. Physicians should be aware of the variety of tools available for the management of OA and the associated symptoms. Those healthcare providers who can best individualize treatment plans for specific patients and inspire their patients to embrace healthy lifestyle modifications will achieve the best results.
Objective
This study aims to compare radiofrequency (RF) heat lesion size across electrodes and generator settings available for interventional pain management.Methods
Monopolar lesions are generated ex vivo in animal tissue using sharp cannulae with tip diameters 23, 22, 20, 18, 16 gauge; tip lengths 5, 6, 10, 15 mm; set temperatures 60, 70, 80, 90°C; set times 1, 1.5, 2, 3, 5, 10 minutes. Lesions are generated using the RRE electrode, cooled RF, and parallel-tip bipolar RF for comparison. Lesion sizes are assessed by automated photographic temperature inference from over 400 lesions, using multiple lesions per configuration.ResultsMonopolar lesion width and length increase with each factor (P < 0.001). Increasing cannula diameter from 22 to 16 gauge increases average lesion width 58–65% (3–4 mm) at 80°C and 2 minutes. Increasing temperature from 60°C to 90°C increases lesion width 108–152% at 2 minutes. Although dimensions grow most rapidly over the first minute, average lesion width is 11–20% larger at 2 minutes, and 23–32% larger at 3 minutes, compared with 1 minute. Lesion length extends distal and proximal to the tip, and exceeds tip length by 1–5 mm at 80°C and 2 minutes. Conventional 16 gauge cannulae at 80–90°C for 2–3 minutes generate lesions of average width similar to that produced by the cooled RF configuration proposed for sacroiliac joint denervation. Bipolar RF between parallel cannulae produces a rounded brick-shaped lesion of comparable shape to three sequential monopolar lesions generated using the same cannulae and generator settings.Conclusions
Tip gauge, tip length, temperature, and time substantially affect RF lesion size.
Treatment of Osteoarthritis of the Knee: Evidence-Based Guideline, 2nd Edition, is based on a systematic review of the current scientific and clinical research. This guideline contains 15 recommendations, replaces the 2008 AAOS clinical practice guideline, and was reevaluated earlier than the 5-year recommendation of the National Guideline Clearinghouse because of methodologic concerns regarding the evidence used in the first guideline. The current guideline does not support the use of viscosupplementation for the treatment of osteoarthritis of the knee. In addition, the work group highlighted the need for better research in the treatment of knee osteoarthritis.
Objective. A study is carried out of the spatial distribution and time dependence of electric and thermal fields in the tissue around a radiofrequency (RF) electrode used in pain therapy. Finite-element calculation of the fields is performed, and results are compared with ex vivo tissue data. Field predictions are made for continuous and for pulsed RF applications.
Design. A special RF cannula electrode is constructed with both macro and micro thermocouple sensors to measure both average and rapid, transitory temperature effects. Temperatures and impedances are recorded in liver and egg-white models using signal outputs from a commercially available RF lesion generator. These data are compared with the results of finite-element calculations using electric field equations and the bio-heat equation.
Results. Average and pulsatory temperatures at the RF electrode are measured. Rapid temperature spikes during pulsed RF bursts are observed. These data compared well with theoretical calculations using known electrical and thermal tissue parameters.
Conclusion. Continuous RF lesioning causes heat destruction of neurons. Pulsed RF lesioning (PRFL) produces heat bursts with temperatures in the range associated with destructive heat lesions. PRFL also produces very high electric fields that may be capable of disrupting neuronal membranes and function. Finite-element calculations agree substantially with the measured data, giving confidence to their predictions of fields around the RF electrode.
To update the American College of Rheumatology (ACR) 2000 recommendations for hip and knee osteoarthritis (OA) and develop new recommendations for hand OA.
A list of pharmacologic and nonpharmacologic modalities commonly used to manage knee, hip, and hand OA as well as clinical scenarios representing patients with symptomatic hand, hip, and knee OA were generated. Systematic evidence-based literature reviews were conducted by a working group at the Institute of Population Health, University of Ottawa, and updated by ACR staff to include additions to bibliographic databases through December 31, 2010. The Grading of Recommendations Assessment, Development and Evaluation approach, a formal process to rate scientific evidence and to develop recommendations that are as evidence based as possible, was used by a Technical Expert Panel comprised of various stakeholders to formulate the recommendations for the use of nonpharmacologic and pharmacologic modalities for OA of the hand, hip, and knee.
Both “strong” and “conditional” recommendations were made for OA management. Modalities conditionally recommended for the management of hand OA include instruction in joint protection techniques, provision of assistive devices, use of thermal modalities and trapeziometacarpal joint splints, and use of oral and topical nonsteroidal antiinflammatory drugs (NSAIDs), tramadol, and topical capsaicin. Nonpharmacologic modalities strongly recommended for the management of knee OA were aerobic, aquatic, and/or resistance exercises as well as weight loss for overweight patients. Nonpharmacologic modalities conditionally recommended for knee OA included medial wedge insoles for valgus knee OA, subtalar strapped lateral insoles for varus knee OA, medially directed patellar taping, manual therapy, walking aids, thermal agents, tai chi, self management programs, and psychosocial interventions. Pharmacologic modalities conditionally recommended for the initial management of patients with knee OA included acetaminophen, oral and topical NSAIDs, tramadol, and intraarticular corticosteroid injections; intraarticular hyaluronate injections, duloxetine, and opioids were conditionally recommended in patients who had an inadequate response to initial therapy. Opioid analgesics were strongly recommended in patients who were either not willing to undergo or had contraindications for total joint arthroplasty after having failed medical therapy. Recommendations for hip OA were similar to those for the management of knee OA.
These recommendations are based on the consensus judgment of clinical experts from a wide range of disciplines, informed by available evidence, balancing the benefits and harms of both nonpharmacologic and pharmacologic modalities, and incorporating their preferences and values. It is hoped that these recommendations will be utilized by health care providers involved in the management of patients with OA.
BACKGROUND: Knee pain is nearly twice as prevalent as hip pain in elderly people, yet knee replacement is far less common than hip replacement. AIM: To investigate whether systematic differences in the primary care management of hip versus knee problems might explain the disparate rates of joint replacement. DESIGN OF STUDY: Cross-sectional, population-based postal survey. SETTING: Random sample of 5500 Oxfordshire residents aged 65 years and above. METHOD: Screening questions were used to identify symptomatic individuals: During the past 12 months, have you had pain in or around either of your hips/knees on most days for 1 month or longer?. Standard (Lequesne) severity ratings were obtained for each hip and knee. Logistic regression was used to estimate odds ratios (ORs) for knee cases versus hip cases for selected healthcare services and attitudes toward replacement. RESULTS: Among 3341 responders, 212 hip cases and 612 knee cases were identified. Knee pain led to a GP consultation more often t
To estimate the lifetime risk of symptomatic knee osteoarthritis (OA), overall and stratified by sex, race, education, history of knee injury, and body mass index (BMI).
The lifetime risk of symptomatic OA in at least 1 knee was estimated from logistic regression models with generalized estimating equations among 3,068 participants of the Johnston County Osteoarthritis Project, a longitudinal study of black and white women and men age >or=45 years living in rural North Carolina. Radiographic, sociodemographic, and symptomatic knee data measured at baseline (1990-1997) and first followup (1999-2003) were analyzed.
The lifetime risk of symptomatic knee OA was 44.7% (95% confidence interval [95% CI] 40.0-49.3%). Cohort members with history of a knee injury had a lifetime risk of 56.8% (95% CI 48.4-65.2%). Lifetime risk rose with increasing BMI, with a risk of 2 in 3 among those who were obese.
Nearly half of the adults in Johnston County will develop symptomatic knee OA by age 85 years, with lifetime risk highest among obese persons. These current high risks in Johnston County may suggest similar risks in the general US population, especially given the increase in 2 major risk factors for knee OA, aging, and obesity. This underscores the immediate need for greater use of clinical and public health interventions, especially those that address weight loss and self-management, to reduce the impact of having knee OA.