Sometimes, patients with painful knee osteoarthritis do not get sufficient pain relief with conservative treatments and do not want (or are not suitable candidates for) arthroplasty. Now, with the advent of genicular nerve radiofrequency ablation (GNRFA), such patients have another option.
As described in a recent issue of JBJS Essential Surgical Techniques, GNRFA has been shown to provide consistent pain relief for 3 to 6 months. Using heat generated from electricity delivered via fluoroscopically guided needle electrodes, the procedure denatures the proteins in the 3 genicular nerves responsible for transmitting knee pain. Although there is a paucity of high-quality studies on the efficacy of this procedure, one study found that, on average, GNRFA led to improvement of >60% from baseline knee pain for at least 6 months.
In the authors’ practice, GNFRA is generally not repeated if it is ineffective the first time, but the procedure has been shown to be safe when administered repeatedly in patients who respond well. Proper positioning of the electrodes is essential, but the authors caution that without ample experience, “it may be difficult to isolate the exact anatomic location of ≥1 of the genicular nerves.”
General anesthesia is not required for the procedure, which is commonly performed by interventional pain specialists. Despite theoretical concerns, no Charcot-type joints have been reported after GNRFA. The authors emphasize, however, that the procedure provides temporary relief at best; it does not eliminate the potential for nerve regrowth and does not alter the arthritic disease process. Even more importantly, GNRFA needs to be studied with higher-level clinical research designs, ideally an adequately powered sham/placebo-controlled randomized trial.
For more information about JBJS Essential Surgical Techniques, watch this video featuring JBJS Editor-in-Chief Dr. Marc Swiontkowski.
Orthopaedists are seeing an increasing number of active, young patients with hip pain. A study by May et al. in the March 20, 2019 issue of The Journal of Bone & Joint Surgery strongly suggests that osteoid osteoma (OO)—a small, benign tumor characterized by dense sclerotic bone tissue—should not be overlooked in the differential diagnosis when working up these patients.
The authors identified and reviewed the records of 50 children and adolescents (mean age of 12.4 years) at their tertiary-care pediatric center who had received a diagnosis of OO within or around the hip between 2003 and 2015. Nighttime hip and/or thigh pain (90%) and symptom relief with NSAIDs (88%) were common clinical findings.
Sclerosis/cortical thickening was visible in 58% of the radiographs. Perilesional edema and a radiolucent nidus was found on all 43 of the available CT scans, leading the authors to conclude that “CT scans provide definitive diagnosis” of OO.
Unfortunately, 46% of these patients initially received an alternative diagnosis, the most common of which was femoroacetabular impingement (FAI), and a delay in diagnosis of >6 months occurred in 43% of patients. The authors note that concerns regarding radiation exposure have led some clinicians to order MRI rather than CT when evaluating pediatric hip disorders, but this study found that identifying an OO nidus with MRI was not as accurate as doing so with CT.
Regarding treatment, among the 41 patients who ultimately underwent percutaneous radiofrequency ablation (RFA) to treat OO, 93% achieved complete post-RFA symptom resolution. Complications from RFA occurred in 7% of patients who underwent the procedure.
Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.
This month, OrthoBuzz asked Chad Krueger, MD, JBJS Deputy Editor for Social Media, to select the five most clinically compelling findings from among the more than 25 studies cited in the June 20, 2018 Specialty Update on Spine Surgery.
—A Level-III retrospective analysis found that patients who received a preoperative cervical epidural steroid injection prior to an anterior cervical discectomy and fusion or a posterior cervical fusion had a significantly greater risk of postoperative infection than those who did not receive a preoperative steroid injection.1 Prospective studies are needed to further clarify the perioperative infection risk associated with cervical epidural steroid injections.
—A Level-II randomized pilot trial comparing titanium-coated PEEK interbody spacers with non-coated PEEK spacers among 40 patients who underwent transforaminal lumbar interbody fusion found that patients in both groups had 92% fusion at 3 months, with no significant between-group differences in pain and disability outcomes.2
—A Level-II randomized study of 108 patients who underwent lumbar discectomy compared outcomes among those who experienced 2 weeks versus 6 weeks of postoperative activity restriction. At the 1-year follow-up there was a nonsignificant difference in recurrent herniation (11% in the 2-week group versus 7% in the 6-week group) and no significant between-group differences in pain or disability scores.3
RF Ablation for Chronic Low Back Pain
—A Level-II meta-analysis involving 454 patients with chronic low back pain found that those who underwent radiofrequency (RF) lumbar-facet denervation had significantly reduced VAS back pain compared to a group that underwent a sham procedure or epidural block. Those in the denervation group who benefited most were those who had responded favorably to an initial diagnostic facet block.4
Adolescent Idiopathic Scoliosis
—A Level-II study assessing the ability of surface topography to evaluate spinal deformity in children with adolescent idiopathic scoliosis followed 45 patients for 1 year. This method plus radiography allowed researchers to determine mild curves with strong negative predictive value and sensitivity. The authors estimated that surface topographic analyses could reduce patient exposure to ionizing radiation by eliminating 31% of surveillance radiographs in these patients.5
- Cancienne JM, Werner BC, Puvanesarajah V, Hassanzadeh H, Singla A, Shen FH, Shimer AL. Does the timing of preoperative epidural steroid injection affect infection risk after ACDF or posterior cervical fusion?Spine (Phila Pa 1976). 2017 Jan 15;42(2):71-7.
- Rickert M, Fleege C, Tarhan T, Schreiner S, Makowski MR, Rauschmann M, Arabmotlagh M. Transforaminal lumbar interbody fusion using polyetheretherketone oblique cages with and without a titanium coating: a randomised clinical pilot study. Bone Joint J.2017 Oct;99-B(10):1366-72.
- Bono CM, Leonard DA, Cha TD, Schwab JH, Wood KB, Harris MB, Schoenfeld AJ. The effect of short (2-weeks) versus long (6-weeks) post-operative restrictions following lumbar discectomy: a prospective randomized control trial. Eur Spine J.2017 Mar;26(3):905-12. Epub 2016 Nov 2.
- Lee CH, Chung CK, Kim CH. The efficacy of conventional radiofrequency denervation in patients with chronic low back pain originating from the facet joints: a meta-analysis of randomized controlled trials. Spine J.2017 Nov;17(11):1770-80. Epub 2017 May 30.
- Hong A, Jaswal N, Westover L, Parent EC, Moreau M, Hedden D, Adeeb S. Surface topography classification trees for assessing severity and monitoring progression in adolescent idiopathic scoliosis. Spine (Phila Pa 1976).2017 Jul 1;42(13):E781-7.