Investigation of a three-dimensional printed dynamic cervical spine model for anatomy and physiology education.

INTRODUCTION: Three-dimensional (3D) printing of anatomical structures is a growing method of education for students and medical trainees. These models are generally produced as static representations of gross surface anatomy. In order to create a model that provides educators with a tool for demonstration of kinematic and physiologic concepts in addition to surface anatomy, a high-resolution segmentation and 3D-printingtechnique was investigated for the creation of a dynamic educational model. METHODS: An anonymized computed tomography scan of the cervical spine with a diagnosis of ossification of the posterior longitudinal ligament was acquired. Using a high-resolution thresholding technique, the individual facet and intervertebral spaces were separated, and models of the C3-7 vertebrae were 3D-printed. The models were placed on a myelography simulator and subjected to flexion and extension under fluoroscopy, and measurements of the spinal canal diameter were recorded and compared to in-vivo measurements. The flexible 3D-printed model was then compared to a static 3D-printed model to determine the educational benefit of demonstrating physiologic concepts. RESULTS: The canal diameter changes on the flexible 3D-printed model accurately reflected in-vivo measurements during dynamic positioning. The flexible model also was also more successful in teaching the physiologic concepts of spinal canal changes during flexion and extension than the static 3D-printed model to a cohort of learners. CONCLUSIONS: Dynamic 3D-printed models can provide educators with a cost-effective and novel educational tool for not just instruction of surface anatomy, but also physiologic concepts through 3D ex-vivo modeling of case-specific physiologic and pathologic conditions.

The importance of teaching clinical anatomy in surgical skills education: Spare the patient, use a sim!

Anatomical knowledge is a key tenet in graduate medical and surgical education. Classically, these principles are taught in the operating room during live surgical experience. This puts both the learner and the patient at a disadvantage due to environment, time, and safety constraints. Educational adjuncts such as cadaveric courses and surgical skills didactics have been shown to improve resident confidence and proficiency in both anatomical knowledge and surgical techniques. However, the cost-effectiveness of these courses is a limiting factor and in many cases prevents implementation within institutional training programs. Anatomical simulation in the form of "desktop" three-dimensional (3D) printing provides a cost-effective adjunct while maintaining educational value. This article describes the anatomical and patient-centered approach that led to the establishment of our institution's 3D printing laboratory for anatomical and procedural education. Clin. Anat. 32:124-127, 2019. © 2019 Wiley Periodicals, Inc.

Ex vivo virtual and 3D printing methods for evaluating an anatomy-based spinal instrumentation technique for the 12th thoracic vertebra.

INTRODUCTION: Three-dimensional printing and virtual simulation both provide useful methods of patient-specific anatomical modeling for assessing and validating surgical techniques. A combination of these two methods for evaluating the feasibility of spinal instrumentation techniques based on anatomical landmarks has not previously been investigated. MATERIALS AND METHODS: Nineteen anonymized CT scans of the thoracic spine in adult patients were acquired. Maximum pedicle width and height were recorded, and statistical analysis demonstrated normal distributions. The images were converted into standard tessellation language (STL) files, and the T12 vertebrae were anatomically segmented. The intersection of two diagonal lines drawn from the lateral and medial borders of the T12 transverse process (TP) to the lateral border of the pars and inferolateral portion of the TP was identified on both sides of each segmented vertebra. A virtual screw was created and insertion into the pedicle on each side was simulated using the proposed landmarks. The vertebral STL files were then 3D-printed, and 38 pedicles were instrumented according to the individual posterior landmarks used in the virtual investigation. RESULTS: There were no pedicle breaches using the proposed anatomical landmarks for insertion of T12 pedicle screws in the virtual simulation component. The technique was further validated by additive manufacturing of individual T12 vertebrae and demonstrated no breaches or model failures during live instrumentation using the proposed landmarks. CONCLUSIONS: Ex vivo modeling through virtual simulation and 3D printing provides a powerful and cost-effective means of replicating vital anatomical structures for investigation of complex surgical techniques.

Intraoperative image-guided spinal navigation: technical pitfalls and their avoidance.

Spinal instrumentation has made significant advances in the last two decades, with transpedicular constructs now widely used in spinal fixation. Pedicle screw constructs are routinely used in thoracolumbar-instrumented fusions, and in recent years, the cervical spine as well. Three-column fixations with pedicle screws provide the most rigid form of posterior stabilization. Surgical landmarks and fluoroscopy have been used routinely for pedicle screw insertion, but a number of studies reveal inaccuracies in placement using these conventional techniques (ranging from 10% to 50%). The ability to combine 3D imaging with intraoperative navigation systems has improved the accuracy and safety of pedicle screw placement, especially in more complex spinal deformities. However, in the authors' experience with image guidance in more than 1500 cases, several potential pitfalls have been identified while using intraoperative spinal navigation that could lead to suboptimal results. This article summarizes the authors' experience with these various pitfalls using spinal navigation, and gives practical tips on their avoidance and management.

Best of both worlds: Use of robotic principles for placing navigated cervical and difficult upper thoracic pedicle screws, a technical nuance.

Navigated pedicle screw placement can be particularly challenging for cervical and upper thoracic levels in obese patients. This technical challenge can be compounded by the smaller diameter tools that can be flexible and therefore confound navigation. It is imperative to avoid excessive manipulation of surrounding tissues to maintain navigation accuracy in the mobile cervical spine.1 Robotic-assisted spinal approaches use firm guides to aid drilling and screw placement but are hindered by high costs with equipment acquisition.2,3 Here, we propose a technical nuance that combines robotic surgical principles with tools that are more readily available in many surgical departments. We present the case of a 64-year-old female with a chief complaint of neck pain, irradiating to the left worse than right arm and prior history of C5-7 anterior cervical discectomy and fusion (ACDF). Imaging showed multi-level degenerative disease and a solid prior C5-7 ACDF with grade I anterolisthesis at C7-T1 due to severe facet degeneration with severe left sided foraminal stenosis. Given failure of conservative management, the patient was brought to the operating room for left C7-T1 foraminotomy and C7-T1 posterior instrumented fusion. Here, we show the use of a tubular retractor fixed to the surgical bed for solid and reproducible trajectory for all of the tools to minimize the risk of surrounding tissue manipulation and its effect on navigation accuracy.

Single-Photon Emission Computed Tomography (SPECT-CT) as a Predictor of Pain Generators in Patients Undergoing Anterior Cervical Discectomy and Fusion (ACDF) for Axial Cervical Pain.

BACKGROUND: Axial neck pain is often associated with cervical instability, and surgical options are often reserved for patients with either neurological compromise or deformity of the spine. However, cervical facet arthropathy is often implicated with instability and the location of painful generators is often difficult to ascertain. Single-photon emission computed tomography (SPECT-CT) presents an adjunct to conventional imaging in the workup of patients with suspected facetogenic pain. We aimed to report our experience with patients undergoing anterior cervical discectomy and fusion (ACDF) guided by SPECT-CT for axial cervical pain. METHODS: We retrospectively identified all cases undergoing ACDF that presented with axial neck pain where correlating SPECT-CT high metabolism areas were identified. Patients were treated at a tertiary care institution between January 2018 and January 2021. Patients with positive radiotracer uptake pre-operatively were compared with patients undergoing ACDF without uptake on SPECT-CT. The pre- and post-operative patients who reported neck pain at one year were compared. RESULTS: Thirty-five patients were included in this retrospective cohort. The median pre- and post-intervention (at one-year follow-up) visual analog score (VAS) of patients undergoing ACDF without uptake on SPECT-CT was 7 and 3 (p<0.01), while the pre- and post-VAS for patients undergoing surgery with positive uptake on SPECT-CT was 8.5 and 0 (p<0.01). Improvement was significantly larger for patients undergoing SPECT-CT-guided ACDF (p=0.02). At one year after surgery, none of the assessed patients required additional surgical intervention. CONCLUSION: This case series represents the experience of our group to date with patients undergoing SPECT-CT-guided ACDF with results suggesting potential benefit in guiding fusion.

Frailty as a Predictor of Postoperative Morbidity and Mortality in Patients Aged 80 Years and Older Undergoing Instrumented Fusion.

BACKGROUND AND OBJECTIVES: Degenerative spine disease is a leading cause of disability, with increasing prevalence in the older patients. While age has been identified as an independent predictor of outcomes, its predictive value is limited for similar older patients. Here, we aimed to determine the most predictive frailty score of adverse events in patients aged 80 and older undergoing instrumented lumbar fusion. METHODS: We proceeded with a multisite (3 tertiary academic centers) retrospective review including patients undergoing instrumented fusion aged 80 and older from January 2010 to present. A composite end point encompassing 30-day return to operating room, readmission, and mortality was created. We estimated the area under the receiver operating characteristic curve for frailty scores (Modified Frailty Index-5 [MFI-5], Modified Frailty Index-11 [MFI-11], and Charlson Comorbidity Index [CCI]) in relation to that composite score. In addition, we estimated the association between each score and the composite end point by means of logistic regression. RESULTS: A total of 153 patients with an average age of 85 years at the time of surgery were included. We observed a 30-day readmission rate of 11.1%, reoperation of 3.9%, and mortality of 0.6%. The overall rate of the composite end point at 30 days was 25 (15.1%). The AUC for MFI-5 was 0.597 (0.501-0.693), for MFI-11 was 0.620 (0.518-0.723), and for CCI was 0.564 (0.453-0.675). The association between the scores and composite end point did not reach statistical significance for MFI-5 (odds ratio [OR] = 1.45 [0.98-2.15], P = .061) and CCI (OR = 1.13 [0.97-1.31], P = .113) but was statistically significant for MFI-11 (OR = 1.46 [1.07-2.00], P = .018). CONCLUSION: This is the largest study comparing frailty index scores in octogenarians undergoing instrumented lumbar fusion. Our findings suggest that while MFI-11 score correlated with adverse events, the predictive ability of existing scores remains limited, highlighting the need for better approaches to identify select patients at age extremes.

Transient Neuropathic Pain Following Mechanically Assisted Manipulation of the Spine: A Clinical Case Study.

We describe the case of a patient developing acute neuropathic pain in the sciatic nerve distribution following spinal manipulation. Manipulative treatment with an Activator Adjusting Instrument (AAI) was recommended and performed. Within 24 hours, the patient developed severe 10/10 pain originating from the left gluteal area at the site of one of the activator deployments with radiation all the way down his left leg to the foot. He was able to maintain distal left leg strength and sensation. Relief was achieved with subsequent physical therapy techniques to relax his deep gluteal muscles, raising the hypothesis of temporary injury to the deep gluteal muscles, with painful contractions resulting in gluteal region pain as well as sciatic nerve inflammation as the nerve passed through that region. This clinical case illustrates some of the perils and risks of spinal manipulation, particularly in the elderly, and the need for careful patient selection.

Hybrid Minimally Invasive Endoscopic Approach for Gaseous Protrusion Causing L5 Radiculopathy.

We present an illustrative case of a hybrid approach between minimally invasive and endoscopic spine surgery techniques. We utilized this hybrid approach for the first 3 cases to help diminish the learning curve as we started a spinal endoscopy program. The patient is an 85-year-old woman with a prior history of arthrodesis at L3-5. She presented with severe leg pain and imaging evidence of degenerative disk disease with disk protrusion in the extraforaminal zone at L5-S1. Computed tomography imaging shows the disk protrusion to be gaseous in nature. Given failure of conservative management and patient refusal for extension of her prior fusion, she was offered a combined minimally invasive navigated technique and endoscopic approach for far lateral diskectomy. After obtaining the correct trajectory, with confirmation by intraoperative fluoroscopy, microscopic visualization was used to identify the protruded disk and the exiting nerve root (Video 1). Given the difficult visualization, a 30-degree endoscopic probe was used, which enabled real-time visualization of the gaseous protrusion being released in the liquid medium. After decompression, microscopic visualization was used for confirmation, with the patient obtaining a good surgical outcome and complete relief of her presenting pain. This case illustrates the synergism between endoscopic and minimally invasive spine surgery techniques and the unique advantages of enabling visualization of spinal anatomy through a liquid medium with the use of an endoscope.1-3.

International Learner Perceptions, Educational Value, and Cost Associated With the Use of Start-to-Finish Surgical Simulation Compared With Cadaveric Models.

BACKGROUND: Graduate surgical education is highly variable across regions and institutions regarding case volume and degree of trainee participation in each case. Dedicated educational curriculum using cadaveric tissue has been shown to enhance graduate surgical training, however with associated financial and utility burden to the institution. OBJECTIVE: To investigate the utility of educational and cost applications of a novel method of combining mixed organic hydrogel polymers and 3-dimensional printed anatomic structures to create a complete "start-to-finish" simulation for resident education in spinal anatomy, instrumentation, and surgical techniques. METHODS: This qualitative pilot study investigated 14 international participants on achievement of objective and personal learning goals in a standardized curriculum using biomimetic simulation compared with cadaveric tissue. A questionnaire was developed to examine trainee evaluation of individual anatomic components of the biomimetic simulators compared with previous experience with cadaveric tissue. RESULTS: A total of 210 responses were acquired from 14 participants. Six participants originated from US residency education programs and 8 from transcontinental residency programs. Survey results for the simulation session revealed high user satisfaction. Score averages for each portion of the simulation session indicated learner validation of anatomic features for the simulation compared with previous cadaveric experience. Cost analysis resulted in an estimated savings of $10 833.00 for this single simulation session compared with previous cadaveric tissue sessions. CONCLUSION: The results of this study indicate a strong potential of establishing biomimetic simulation as a cost-effective and high-quality alternative to cadaveric tissue for the instruction of fundamental spine surgical techniques.

Robotic-Assisted vs Nonrobotic-Assisted Minimally Invasive Transforaminal Lumbar Interbody Fusion: A Cost-Utility Analysis.

BACKGROUND: Management of degenerative disease of the spine has evolved to favor minimally invasive techniques, including nonrobotic-assisted and robotic-assisted minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). Value-based spending is being increasingly implemented to control rising costs in the US healthcare system. With an aging population, it is fundamental to understand which procedure(s) may be most cost-effective. OBJECTIVE: To compare robotic and nonrobotic MIS-TLIF through a cost-utility analysis. METHODS: We considered direct medical costs related to surgical intervention and to the hospital stay, as well as 1-yr utilities. We estimated costs by assessing all cases involving adults undergoing robotic surgery at a single institution and an equal number of patients undergoing nonrobotic surgery, matched by demographic and clinical characteristics. We adopted a willingness to pay of $50 000/quality-adjusted life year (QALY). Uncertainty was addressed by deterministic and probabilistic sensitivity analyses. RESULTS: Costs were estimated based on a total of 76 patients, including 38 undergoing robot-assisted and 38 matched patients undergoing nonrobot MIS-TLIF. Using point estimates, robotic surgery was projected to cost $21 546.80 and to be associated with 0.68 QALY, and nonrobotic surgery was projected to cost $22 398.98 and to be associated with 0.67 QALY. Robotic surgery was found to be more cost-effective strategy, with cost-effectiveness being sensitive operating room/materials and room costs. Probabilistic sensitivity analysis identified robotic surgery as cost-effective in 63% of simulations. CONCLUSION: Our results suggest that at a willingness to pay of $50 000/QALY, robotic-assisted MIS-TLIF was cost-effective in 63% of simulations. Cost-effectiveness depends on operating room and room (admission) costs, with potentially different results under distinct neurosurgical practices.

Minimally Invasive Transforaminal Lumbar Interbody Fusion: Cost of a Surgeon's Learning Curve.

BACKGROUND: Minimally invasive transforaminal interbody fusion has become an increasingly common approach in adult degenerative spine disease but is associated with a steep learning curve. We sought to evaluate the impact of the learning experience on mean procedure time and mean cost associated with each procedure. METHODS: We studied the first 100 consecutive minimally invasive transforaminal interbody fusion procedures of a single surgeon. We performed multivariable linear regression models, modeling operating time, and costs in function of the procedure order adjusted for patients' age, sex, and number of surgical levels. The number of procedures necessary to attain proficiency was determined through a k-means cluster analysis. Finally, the total excess operative time and total excess cost until obtaining proficiency was evaluated. RESULTS: Procedure order was found to impact procedure time and mean costs, with each successive case being associated with progressively less procedure time and cost. On average, each successive case was associated with a reduction in procedure time of 0.97 minutes (95% confidence interval 0.54-1.40; P < 0.001) and an average adjusted reduction in overall costs of $82.75 (95% confidence interval $35.93-129.57; P < 0.001). An estimated 58 procedures were needed to attain proficiency, translating into an excess procedure time of 2604.2 minutes (average of 45 minutes per case), overall costs associated with the learning experience of $226,563.8 (average of $3974.80 per case), and excess surgical cost of $125,836.6 (average of $2207.66 per case). CONCLUSIONS: Successive cases were associated with progressively less procedure time and mean overall and surgical costs, until a proficiency threshold was attained.

Interactive Neurosurgery Lecture Series: A Global Education Platform of Tele-Teaching During the Coronavirus Disease 2019 Pandemic and Beyond.

OBJECTIVE: To explore the worldwide impact of a virtual neurosurgery-neuroscience lecture series on optimizing neurosurgical education with tele-teaching. METHODS: A retrospective analysis was performed from our Zoom database to collect data from October 15, 2020, to December 14, 2020, and from September 27, 2021, to December 13, 2021. A comparative analysis of participants in the 2 different time frames was performed to investigate the impact of tele-teaching on neurosurgical education worldwide. To evaluate participant satisfaction, the yearly continuing medical education reports of 2020-2021 were analyzed. Data related to the distribution of lectures by subspecialties were also described. RESULTS: Among the 11 lectures of the first period, 257 participants from 17 countries in 4 different continents were recorded, with a mean of 64 (standard deviation = 9.30) participants for each meeting; 342 attendees participated from 19 countries in 5 continents over the 11 lectures of the second part, with an average of 82.8 (standard deviation = 14.04) attendees; a statistically significant increase in participation between the 2 periods was identified (P < 0.001) A total of 19 (2020) and 21 (2021) participants submitted the continuing medical education yearly survey. More than 86.4% of overall responses considered the lectures "excellent." The main topics reported during lectures in 2020-2021 were related to brain tumors (33.7%) and education (22.1%). CONCLUSIONS: The COVID-19 pandemic has increased the need to introduce new educational approaches for teaching novel ways to optimize patient care. Our multidisciplinary Web-based virtual lecture series could represent an innovative tele-teaching platform in neurosurgical training.

SPECT-CT as a Predictor of Pain Generators in Patients Undergoing Intra-Articular Injections for Chronic Neck and Back Pain.

BACKGROUND: The ability to accurately predict pain generators for chronic neck and back pain remains elusive. OBJECTIVE: We evaluated whether injections targeted at foci with uptake on single-photon emission computerized tomography-computed tomography (SPECT-CT) were associated with improved outcomes in patients with chronic neck and back pain. METHODS: A retrospective review was completed on patients undergoing SPECT-CT for chronic neck and back pain between 2016 and 2020 at a tertiary academic center. Patients' records were reviewed for demographic, clinical, imaging, and outcomes data. Only those patients who had facet injections after SPECT-CT were included in this evaluation. Patients undergoing injections targeted at foci of abnormal radiotracer uptake were compared with patients without uptake concerning immediate positive response, visual analog scale, and the need for additional injection or surgery at the target level. RESULTS: A total of 2849 patients were evaluated with a SPECT-CT for chronic neck and back pain. Of those, 340 (11.9%) patients received facet joint injections after SPECT-CT. A propensity score regression analysis adjusted for age, gender, body mass index, hypertension, multiple target injections, and injection location showed uptake targeted injections not being associated with an improved immediate positive response (odds ratio: 0.64; 95% confidence interval: 0.34-1.21; P = 0.172). In patients with a failed facet injection preceding SPECT-CT, adding SPECT-CT to guide facet injections was associated with a decrease in visual analog scale pain scores 2 weeks after injection (P = 0.018), particularly when changes were made to the facets being targeted (P = 0.010). CONCLUSION: This study suggests that there is benefit with SPECT-CT specially to guide facet injections after failed prior facet injections.

Spinal cord stimulator--trial lead migration study.

OBJECTIVES: Investigate whether percutaneous spinal cord stimulator (SCS) leads migrate significantly during a 3-day trial, and determine whether the skin anchoring method influences lead migration. MATERIAL AND METHODS: Twenty patients were prospectively enrolled. Ten leads were anchored with suture and tape and 10 were anchored with tape only. A standardized X-ray protocol of lead position was obtained immediately following lead placement and upon completion of the trial. RESULTS: Using a standardized method, SCS leads were measured and movement was calculated. The average movement for leads anchored with tape only was 8.72 mm (SD=5.77), inferiorly; while movement for leads anchored with suture and tape was 24.49 mm (SD=11.3), inferiorly. A t-test revealed a significant difference between the groups (t=3.9, P=0.001). CONCLUSIONS: Percutaneous SCS trial electrodes migrate significantly, inferiorly, during a 3-day trial. Anchoring the trial electrodes to the skin with a suture and tape results in significantly greater inferior migration when compared with anchoring the lead with tape only.

Establishing a Cost-Effective 3-Dimensional Printing Laboratory for Anatomical Modeling and Simulation: An Institutional Experience.

SUMMARY STATEMENT: Three-dimensional (3D) printing is rapidly growing in popularity for anatomical modeling and simulation for medical organizations across the world. Although this technology provides a powerful means of creating accurately representative models of anatomic structures, there remains formidable financial and workforce barriers to understanding the fundamentals of technology use, as well as establishing a cost- and time-effective system for standardized incorporation into a workflow for simulator design and anatomical modeling. There are many factors to consider when choosing the appropriate printer and accompanying software to succeed in accomplishing the desired goals of the executing team. The authors have successfully used open-access software and desktop fused deposition modeling 3D printing methods to produce more than 1000 models for anatomical modeling and procedural simulation in a cost-effective manner. It is our aim to share our experience and thought processes of implementing 3D printing into our anatomical modeling and simulation workflow to encourage other institutions to comfortably adopt this technology into their daily routines.

Image-Guided Right T10 Costotransverse Joint Resection for Costotransversitis: Operative Technique and Nuances: 2-Dimensional Operative Video.

We describe the operative approach and management for costotransverse joint inflammation in a 49-yr-old man with worsening midthoracic pain radiating to the right paraspinal area. He underwent physical therapy with no relief of his symptoms. Thoracic spine magnetic resonance imaging (MRI) revealed severe arthritic changes involving the right T10 costotransverse joint. Scoliosis X-rays showed a dextroconvex curvature in the midthoracic spine, without any significant imbalance. Single-photon emission computed tomography (SPECT) scan revealed focal increased uptake of the right T10 costotransverse joint. T10 costotransverse joint lidocaine injection did not provide any relief. We performed a computed tomography (CT)-guided biopsy, which was negative for malignancy and also cultures were negative. MRI revealed a significant enhancement in this area and the patient's C-reactive Protein was elevated. Decision was made to perform open biopsy and costotransverse joint resection. We present a case of minimally invasive, image-guided costotransverse joint resection, which has not been described in the literature. The right T10 costotransverse joint was dissected out with the image-guided dilator, and tubular retractors were inserted. Under the microscope, using the image-guided drill, the right T10 costotransverse joint was drilled out. The lateral aspect of the right T10 process was drilled out as well as the medial-dorsal aspect of the right T10 rib. The patient recovered from surgery well with abatement of his preoperative thoracic pain, which remained abated at 6-mo follow-up. This case highlights the complex technical nuances of this procedure, and the importance of a thorough preoperative evaluation with a bone SPECT scan to help localize the pain generator. Patient consented for the procedures and for the publication of the video.

Perioperative Comparison of Robotic-Assisted Versus Fluoroscopically Guided Minimally Invasive Transforaminal Lumbar Interbody Fusion.

OBJECTIVE: Robotic surgical systems have been developed to improve spine surgery accuracy. Studies have found significant reductions in screw revision rates and radiation exposure with robotic assistance compared with open surgery. The aim of the present study was to compare the perioperative outcomes between robot-assisted (RA) and fluoroscopically guided (FG) minimally invasive (MI) transforaminal lumbar interbody fusion (TLIF) performed by a single surgeon. METHODS: The present retrospective cohort study analyzed all patients with lumbar degenerative disease who had undergone MI-TLIF by a single surgeon from July 2017 to March 2020. One group had undergone FG MI-TLIF and one group had undergone RA MI-TLIF. RESULTS: Of the 101 patients included in the present study, 52 had undergone RA MI-TLIF and 49, FG MI-TLIF. We found no statistically significant differences in the operative time (RA, 241 ± 69.3 minutes; FG, 246.2 ± 56.3 minutes; P = 0.681). The mean radiation time for the RA group was 32.8 ± 28.8 seconds, and the mean fluoroscopy dose was 31.5 ± 30 mGy. The RA radiation exposure data were compared with similar data for the FG MI-TLIF group in a previous study (59.5 ± 60.4 mGy), with our patients' radiation exposure significantly lower (P = 0.035). The postoperative complications and rates of surgical revision were comparable. CONCLUSIONS: Our results have demonstrated that RA MI-TLIF provides perioperative outcomes comparable to those with FG MI-TLIF. A reduced radiation dose to the patient was observed with RA compared with FG MI-TLIF. No differences were noted between the RA and FG cohorts in operative times, complication rates, revision rates, or length of stay.

Initial Results of Precision Treatment of Postoperative Cerebrospinal Fluid Leak with Ultrasound-Guided Epidural Blood Patch.

BACKGROUND: Incidental durotomy, a known complication of spinal surgery, can lead to persistent cerebrospinal fluid leak and pseudomeningocele if unrecognized or incompletely repaired. We describe the use of ultrasound to visualize the site of durotomy, observe the aspiration of the pseudomeningocele, and guide the precise application of an ultrasound-guided epidural blood patch (US-EBP), under direct visualization in real time. METHODS: A retrospective review was performed to determine demographic, procedural, and outcome characteristics for patients who underwent US-EBP for symptomatic postoperative pseudomeningocele. RESULTS: Overall, 48 patients who underwent 49 unique episodes of care were included. The average age and body mass index were 60.5 (±12.6) years and 27.8 (±4.50) kg/m2, respectively. The most frequent index operation was laminectomy (24.5%), and 36.7% of surgeries were revision operations. Durotomy was intended or recognized in 73.4% of cases, and the median time from surgery to symptom development was 7 (interquartile range 4-16) days. A total of 61 US-EBPs were performed, with 51.0% of patients experiencing resolution of their symptoms after the first US-EBP. An additional 20.4% were successful with multiple US-EBP attempts. Complications occurred in 14.3% of cases, and the median clinical follow-up was 4.3 (interquartile range 2.4-14.5) months. CONCLUSIONS: This manuscript represents the largest series in the literature describing US-EBP for the treatment of postoperative pseudomeningocele. The success rate suggests that routine utilization of US-guided EBP may allow for targeted treatment of pseudomeningoceles, without the prolonged hospitalization associated with lumbar drains or the risks of general anesthesia and impaired wound healing associated with surgical revision.

Painful medial branch neuroma treated with minimally invasive medial branch neurectomy.

STUDY DESIGN: Case report. OBJECTIVE: To report an unusual complication following lumbar facet radiofrequency denervation and describe a successful, minimally invasive treatment of a presumed medial branch neuroma. SUMMARY OF BACKGROUND DATA: Radiofrequency medial branch neurotomy is a common procedure for the treatment of mechanical back pain. Deafferentation injury and neuroma formation is well known and reported following chemical, surgical, and cryoablation neurolysis; however, it is thought to be rare with radiofrequency ablation. When this problem is encountered, treatment options appear to be limited. Further radiofrequency ablations may be ineffective and indeed may cause further injury. METHODS: A 17-year-old male who sustained a traumatic fracture of the right L3-4 facet joint presented with increasing back pain after multiple radiofrequency ablations of the medial branches of the L2 and L3 dorsal rami. The description of the back pain, initially nociceptive in nature, had become progressively neuropathic with clear focal areas of allodynia and hyperesthesia. Further medial branch radiofrequency denervation was found to be ineffective. RESULTS: Diagnostic block of the right medial branch of the L2 dorsal ramus provided the patient with total relief of pain. This was followed by a minimally invasive open surgical ablation of the L2 medial branch neuroma using three-dimensional, fluoroscopy-based image guidance. At 7 months of follow-up, the patient reported complete resolution of pain, discontinuation of all pain medications, and return to all previous physical activities. CONCLUSION: Deafferentation injury is a rare but recognized complication of chemical, surgical, and thermal neuroablation. This case report presents a rare instance of presumed neuroma formation following multiple radiofrequency ablations for the treatment of facet-generated mechanical back pain. Open and minimally invasive medial branch neurectomy resulted in complete resolution of pain and return to baseline function.