The Effectiveness and Safety of Genicular Nerve Radiofrequency Ablation for the Treatment of Recalcitrant Knee Pain Due to Osteoarthritis: a Comprehensive Literature Review

Bedside ultrasound-guided genicular nerve block with corticosteroids and lignocaine for knee osteoarthritis improves pain and participation, and is safe in inpatient rehabilitation: a retrospective case series

Background

Knee osteoarthritis (OA) is a common joint disorder that causes significant pain and disability. It can affect individuals undergoing inpatient rehabilitation, interfering with their participation in therapy and clinical improvement. While there are various treatment options available for this condition, such as the intra-articular corticosteroid injection, not all patients are suitable and symptoms may persist despite multimodal analgesia. The ultrasound-guided genicular nerve block (US GNB) induces analgesia by targeting the genicular nerves around the knee, and has emerged as a safe and effective intervention option. This is the first effort to document its application in the inpatient rehabilitation setting.

Methods

This was a retrospective case series. We reviewed the medical records of inpatients undergoing rehabilitation who underwent the US GNB for disabling knee OA between July 1, 2022, and August 31, 2023. The primary outcome was improvement in rehabilitation participation based on physiotherapist notes in the week following the procedure. Secondary outcomes were pain by visual analogue scale (VAS), ambulation distance, and the Western Ontario and McMaster Universities Arthritis Index (WOMAC), at pre-discharge, 1-month, and 3-month follow-up timepoints. Safety and adverse events were also retrospectively reviewed.

Results

Nine patients were consented for recruitment in our study. Eight of them showed improvement in pain and/or participation in therapy. There were significant improvements in VAS scores (median change -3) and improvements in ambulation distance (median increase 8 m) between pre-injection and pre-discharge phases. However, these did not persist at the longer follow-up visits. There were no serious adverse events although 3 patients had recurrent pain at later dates, and required further procedures or surgical referral.

Conclusions

The US GNB is safe to perform for inpatients undergoing rehabilitation who experience pain from knee OA. We found that in nearly all patients, there was clinical improvement in their pain and participation in therapy. It can be an effective alternative when other analgesia options are less desirable or available, and can help to keep patients progressing on the road to recovery.

Chemical neurolysis of genicular nerves for chronic non-cancer knee pain: a scoping review

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 events, 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 September 4, 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 were extracted by 2 independent reviewers using an electronic database.

RESULTS

Eight studies were included in this review (including 1 randomized controlled trial), comprising 192 patients. Of the 8 studies, 4 used phenol, 3 used alcohol, and 1 used either alcohol or phenol for chemical neurolysis. Fluoroscopy, ultrasound guidance, or both were used for nerve target identification. All studies demonstrated that chemical neurolysis resulted in improved pain 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 is limited by study heterogeneity and small sample sizes. High-quality randomized controlled trials are required to clarify the selection of appropriate nerve targets and choice of image guidance and to compare with other ablative modalities.

STUDY REGISTRATION

Open Science Framework (https://osf.io/jg8wh).

Cryoneurolysis for non-cancer knee pain: A scoping review

Background and objective

Cryoneurolysis involves percutaneous insertion of a cryoprobe induced to extremely cold temperatures to disrupt peripheral nerve conduction. The primary objective of this scoping review is to summarize and critically appraise the current evidence for the benefits and safety of cryoneurolysis for non-cancer knee pain. The secondary objective is to describe the variations in cryoneurolysis techniques used.

Methods

MEDLINE, EMBASE, PubMed, Cochrane Library, and Web of Science were searched from their inception to February 2023 for any primary literature investigating the use of cryoneurolysis for non-cancer-related knee pain. Data was extracted for study characteristics, intervention characteristics, and clinical outcomes.

Results

Fourteen studies were identified, including three randomized controlled trials, four retrospective cohort studies, and seven case studies/series. Two studies included knee osteoarthritis patients, three studies included non-specific chronic knee pain patients; and nine studies included pre- or post-total knee arthroplasty patients. Ten studies targeted the infrapatellar branch of the saphenous nerve while the remaining four studies did not report the nerve targeted. Studies consistently demonstrated improvements in pain, function, quality of life, and opioid consumption. Most adverse events were mild and self-limiting. Considerable variations in technique parameters were observed.

Conclusions

Cryoneurolysis is a promising intervention to improve outcomes in non-cancer knee pain populations, particularly in mild-to-moderate knee osteoarthritis and pre-total knee arthroplasty populations. However, cryoneurolysis for knee pain remains largely investigational as more high-quality randomized controlled trials are required to further elucidate efficacy as well as optimal nerve selection and technique.

Extended-release triamcinolone provides prolonged relief for patients who failed standard corticosteroid injection for knee osteoarthritis; a pragmatic retrospective study

Objective

Identify if extended-release triamcinolone has a longer duration of action in a cohort of patients who have had limited duration of relief from prior corticosteroid injection.

Design

Retrospective analysis of patients with knee osteoarthritis.

Setting

Academic outpatient musculoskeletal practice.

Subjects

One hundred and fifty patients (age 67.5 ​± ​13.7, 68.2% female) with knee osteoarthritis who had subjectively insufficient relief from a standard corticosteroid injection.

Methods

Ultrasound-guided knee injections of extended-release triamcinolone were administered to all patients by experienced practitioners. The primary outcome measure was comparative duration of subjective relief from extended-release triamcinolone, compared to the patients' duration from their prior standard corticosteroid injection. The secondary outcome was the duration of relief from extended-release triamcinolone.

Results

Patients reported 7.1 ​± ​8.7 additional weeks of relief from extended-release triamcinolone (t ​= ​6.50, p ​< ​0.001), with lower Kellgren-Lawrence score being the only factor associated with increased comparative duration of relief (B ​= ​-2.39, p ​= ​0.042). No factors were associated with duration of pain relief from extended-release triamcinolone.

Conclusions

This retrospective study suggests that injection of extended-release triamcinolone is associated with prolonged pain relief in patients who have had insufficient duration of pain relief from a standard corticosteroid injection. Those with lower Kellgren-Lawrence grades were more likely to have an increased comparative duration of relief.

Procedural Approach to Ultrasound-Guided Geniculate Nerve Blockade for Knee Pain in Patients with OA

ABSTRACT

Ultrasound-guided genicular nerve block can provide excellent pain control for patients with knee OA. This procedure has the advantage of providing sensory blockade with concomitant sparing of motor compromise, which is observed when the femoral and its lateral femoral cutaneous branches are blocked. Once the geniculate nerve of interest is identified, the operator can use ultrasound guidance to surround nerve fascicles with an injectate mixture of anesthetic and corticosteroid, yielding decreased pain sensation at the joint capsule. Given the role of the geniculate nerve in providing sensory innervation to the joint capsule and knee ligaments, blockade of this nerve can serve as a useful tool for managing patients with acute knee pain secondary to OA.

Functional Outcomes and Physical Performance of Knee Osteoarthritis Patients After Ultrasound-Guided Genicular Nerve Radiofrequency Ablation

OBJECTIVE

To elucidate the effectiveness of ultrasound-guided genicular nerve radiofrequency ablation in alleviating pain as well as its effects on functional outcomes, quality of life and physical performance in knee osteoarthritis patients.

DESIGN

Prospective observational study.

SETTING

Patients were recruited within one community hospital.

SUBJECTS

Patients with knee osteoarthritis.

METHODS

The subjects underwent ultrasound-guided radiofrequency ablation of genicular nerves after showing a positive response to a diagnostic block. Outcome assessments were performed at baseline and at 2 and 12 weeks posttreatments using the 36-item Short Form Health Survey (SF-36), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and a physical performance evaluation including balance tests, quadriceps muscle strength test, two-minute walking test and knee joint proprioception test.

RESULTS

Thirteen out of 38 patients were eligible for genicular nerve radiofrequency ablation. There were significant improvements from baseline to posttreatment in the numeric rating scale score, physical health domain score of SF-36, and pain and stiffness domain scores of the WOMAC. Regarding physical performance, the step test result significantly improved over the 12 weeks of follow-up. On the other hand, no significant deteriorations in the single leg stance test, isokinetic quadriceps muscle strength test, knee joint proprioception test or two-minute walking test results were observed after radiofrequency ablation of genicular nerves.

CONCLUSIONS

Radiofrequency ablation of genicular nerves may significantly alleviate pain and improve functional outcomes in knee osteoarthritis patients. More importantly, static balance control and quadriceps muscle strength were preserved and there was a change of proprioception in the good direction.