Lumbar medial branch (MB) radiofrequency ablation is a common intervention to treat facetogenic low back pain. The consensus among spine pain interventionalists is that capturing a greater length of the MB correlates with a longer duration of pain relief. Therefore, there has been interest in defining optimal needle angles to achieve parallel cannula placement. Presently, there is inconsistency regarding the optimal caudal needle angles.
The objectives of this study were to: 1) use a dissection-based 3D modelling methodology to quantify optimal caudal needle angles from cadaveric models; and 2) compare optimal cadaver-derived caudal needle angles with real-world patient-derived needle angles.
Eighteen formalin embalmed lumbosacral spine specimens were dissected, digitized, and modelled in 3D. Virtual needles were simulated and placed parallel with the L1-L5 MBs. Cadaver-derived caudal needle angles were measured from the high-fidelity 3D models with optimally placed virtual needles. Lateral fluoroscopic images of patients (n = 200) that received lumbar MB denervation were reviewed to measure patient-derived caudal needle angles (L3-L5 MB levels). Descriptive statistics were used to analyze the cadaver (L1-L5 MB levels) and patient-derived (L3-L5 MB levels) caudal needle angles. The cadaver and patient-derived mean caudal needle angles for L3-L5 MB levels were compared.
There was variability in the cadaver-derived mean caudal needle angles. The lowest mean caudal needle angle was the L1 MB level measured at 41.57 ± 8.56° (range: 27.14° - 53.96°). The highest was the L5 MB level with a mean caudal needle angle of 60.79 ± 8.55° (range: 46.97° - 79.74°). A total of 123 patients were included and 369 caudal needle angles (L3-L5 MB levels) were measured and analyzed. There was variability in the patient-derived mean caudal needle angles. The patient-derived mean caudal needle angles were 29.18 ± 8.77° (range: 11.80° - 61.31°), 33.34 ± 7.23° (range: 16.40° - 54.15°), and 49.08 ± 8.87° (range: 26.45° - 76.95°) for the L3, L4, and L5 MB levels, respectively. There was a significant difference in mean caudal needle angle between cadaver and patient-derived needle angles at the L3, L4, and L5 MB levels.
Analysis of cadaver-derived needle angles versus patient-derived data suggests optimization of lumbar MB denervation requires greater caudal angulation to achieve parallel needle placement. Further research is required to assess the clinical implications.
Percutaneous pain and spine procedures play an important diagnostic and therapeutic role in the treatment of various pain diagnoses. Accurate placement of needles or cannulae during these procedures is paramount to the success of these procedures.
The purpose of this study is to examine and quantify the amount of deflection of radiofrequency cannulae based on curved tip versus no curved tip, using a ballistic gel tissue simulant.
Six different types of cannulae commonly used for spinal and peripheral nerve ablations were selected, including 18, 20, and 22 gauge curved and straight radiofrequency cannulae. Ballistic gel samples were made in molds of 40 mm and 80 mm. Each cannula was mounted in a drill press to ensure accurate trajectory.
Curved RFA cannula had increased deflection when compared to straight cannula for 18-, 20-, and 22-gauge cannulae at a depth of 40 mm. Curved RFA cannula had increased deflection when compared to straight cannula for 20- and 22-gauge cannulae at a depth of 80 mm. Overall, the mean deflection for a curved cannula increased 1.9x for 20-gauge cannulae and 2.5x for 22-gauge cannulae when compared to a straight cannula.
For interventionalists, understanding the effects of needle or cannula shape is crucial for accurate placement. When a procedure requires additional steerability, additional deflection up to 2.5x obtained by placing a bend in the needle or cannula tip should be considered.
Chronic low back pain is a highly prevalent condition with multiple etiologies. Cluneal nerve neuropathy is an increasingly relevant condition in the management of this condition, and radiofrequency is an alternative management option.
A case series, which included four patients who underwent ultrasound-guided conventional radiofrequency intervention of the superior cluneal nerves, using a previously undescribed technique and direction of intervention.
Patients reported a 50–90 % improvement in pain and a functional benefit for their daily activities of more than 40 % at 4- and 10-week follow-up, with no adverse events following the intervention.
Continuous radiofrequency of the cluneal nerves is an interesting alternative in the management of this pathology of low back pain. The ultrasound technique described may be a management proposal with lower risk and adequate effectiveness.
Accuracy in the interpretation of data, and publication of studies regardless of outcomes are vital to the development of the scientific literature.
To determine the proportion of studies in the spine literature that report positive results.
Review article of studies published in nine major spine, pain, and physical medicine and rehabilitation (PM&R) journals from January 1, 2018–December 31, 2022.
Not applicable.
Articles that reported on pain and/or function from 2018 to 2022 in nine major journals were reviewed by two independent evaluators. The articles were graded as either positive or negative based on the authors’ own conclusions about their work.
Overall, 91 % [95 % CI 88–94 %] of all articles were reported to have positive results. No significant differences were found between the broad categories of spine, pain, and PM&R journals. When comparing different categories of treatments, there were lower rates of positive results from medication/supplement studies (54 % [95 % CI 27–81 %]) compared to studies of spine injections/interventions (95 % [95 % CI 91–99 %]) and those of surgery (100 % [95 % CI 96–100 %]), and a lower rate of positive results from studies on physical treatments (85 % [95 % CI 75–95 %]) compared to those of surgery (100 % [95 % CI 96–100 %]). Studies with placebo controls were less likely to report positive results (60 % [95 % CI 44–76 %]) compared to those that did not use placebo controls (96 % [95 % CI 94–98 %]).
Despite the vast majority of studies in the spine literature concluding positive results, the high disease prevalence of spine conditions and the enormous burden on the healthcare system remain.
Spinal cord stimulation (SCS) devices are routinely trialed to assess pain and functional improvement before permanent lead implantation. Lead migration is a common complication that may cause a loss of therapeutic effect in patients who may otherwise benefit from SCS. The timing of lead migration during the trial period is currently unknown.
We hypothesize that significant lead migration may occur early in the SCS trial period, such as postoperative day 1 or 2, which may allow for contact stimulation adjustment to prevent false negative trial results. As such, in this study, we aim to evaluate the incidence and distance of lead migration in early thoracic SCS trial period.
We performed a case series of 27 patients ≥19 years of age who received differential target multiplexed thoracic SCS trials for chronic neuropathic pain from July 1, 2020 to July 1, 2023. Patients with a neuropathic pain diagnosis failing medical treatment, without structural pathology limiting epidural access, and with psychiatric clearance for suitability are eligible for SCS trials at our center. Pre- and post-flexion radiographs taken immediately after implantation and on postoperative day 1 or 2 were examined to assess the distance of lead migration. Clinically significant lead migration was pre-defined as ≥ 10 mm.
The mean (SD) distances of epidural lead migration on postoperative day 1 or 2 were 18.2 (12.9) mm and 19.1 (13.3) mm for the cephalic and caudal leads, respectively. All migrations were caudad except for one trial. Clinically significant lead migration occurred in 20/27 (74 %) patients.
Clinically significant epidural lead migration occurs in the early SCS trial period.
Previous authors have described the anatomy of the superior cluneal nerves with medial, intermediate, and lateral branches as they pass over the iliac crest. Prior authors describe a technique for radiofrequency of the superior cluneal nerves with needle placement walking off of the superior border of the iliac crest with needle redirection by sensory testing and a monopolar radiofrequency lesion. This is a case report of a patient with sustained pain relief after performing a radiofrequency ablation of the superior cluneal nerves utilizing a bipolar palisade technique.