Publications by authors named "Juan S Uribe"

174 Publications

Biomechanics of open versus minimally invasive deformity correction:​ comparison of stability and rod strain between pedicle subtraction osteotomy and anterior column realignment.

J Neurosurg Spine 2021 Jul 2:1-9. Epub 2021 Jul 2.

1Department of Neurosurgery and.

Objective: Anterior column realignment (ACR) is a new minimally invasive approach for deformity correction that achieves a degree of lordosis similar to that obtained with pedicle subtraction osteotomy (PSO). This study compared the biomechanical profiles of ACR with PSO using range of motion (ROM) and posterior rod strain (RS) to gain insight into the ACR technique and the necessary surgical strategies to optimize longevity and stability.

Methods: An in vitro biomechanical study using standard flexibility testing (7.5 Nm) was performed on 14 human cadaveric specimens, separated into 2 groups similar in age, sex, bone mineral density, and intact ROM. For group 1 (n = 7, instrumented L1-S1), a 30° ACR was performed at L3-4. For group 2 (n = 7, instrumented T12-S1), a 30° L3 PSO was performed. Specimens were subjected to nondestructive loads in flexion, extension, axial rotation, lateral bending, and compression. Conditions tested were 1) intact, 2) pedicle screw with 2 rods (PSR), 3) ACR or PSO with 2 rods (+2R), and 4) ACR or PSO with 4 rods (+4R). Primary outcome measures of interest were ROM stability and posterior RS at L3-4.

Results: No difference was observed between groups in lumbar lordosis (p = 0.83) or focal angular lordosis at L3-4 (p = 0.75). No differences in stability were observed between ACR+2R and PSO+2R (p ≥ 0.06);​ however, ACR+2R was significantly less stable than PSR in flexion and extension (p ≤ 0.02), whereas PSO+2R was less stable than PSR only in extension (p = 0.04). ACR+4R was more stable than ACR+2R in flexion, extension, left axial rotation, and compression (p ≤ 0.02). PSO+4R was more stable than PSO+2R only in extension (p = 0.04). Both ACR+2R and PSO+2R resulted in significant increases in RS in flexion and extension compared with PSR (p ≤ 0.032). RS in flexion and extension decreased significantly for ACR+4R versus ACR+2R and for PSO+4R versus PSO+2R (p ≤ 0.047). PSO+2R yielded lower RS than ACR+2R in compression (p = 0.03). No differences existed in RS between ACR+4R and PSO+4R (p ≥ 0.05).

Conclusions: Although ACR appeared to be slightly more destabilizing than PSO using traditional 2R fixation, both techniques resulted in significant increases in posterior RS. The 4R technique increased stability in ACR and decreased RS in both ACR and PSO but may be more beneficial in ACR. Longer-term clinical studies are needed to appropriately identify the durability of the ACR technique in deformity correction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.12.SPINE201306DOI Listing
July 2021

Adjacent-segment effects of lumbar cortical screw-rod fixation versus pedicle screw-rod fixation with and without interbody support.

J Neurosurg Spine 2021 Jun 18:1-7. Epub 2021 Jun 18.

Objective: Cortical screw-rod (CSR) fixation has emerged as an alternative to the traditional pedicle screw-rod (PSR) fixation for posterior lumbar fixation. Previous studies have concluded that CSR provides the same stability in cadaveric specimens as PSR and is comparable in clinical outcomes. However, recent clinical studies reported a lower incidence of radiographic and symptomatic adjacent-segment degeneration with CSR. No biomechanical study to date has focused on how the adjacent-segment mobility of these two constructs compares. This study aimed to investigate adjacent-segment mobility of CSR and PSR fixation, with and without interbody support (lateral lumbar interbody fusion [LLIF] or transforaminal lumbar interbody fusion [TLIF]).

Methods: A retroactive analysis was done using normalized range of motion (ROM) data at levels adjacent to single-level (L3-4) bilateral screw-rod fixation using pedicle or cortical screws, with and without LLIF or TLIF. Intact and instrumented specimens (n = 28, all L2-5) were tested using pure moment loads (7.5 Nm) in flexion, extension, lateral bending, and axial rotation. Adjacent-segment ROM data were normalized to intact ROM data. Statistical comparisons of adjacent-segment normalized ROM between two of the groups (PSR followed by PSR+TLIF [n = 7] and CSR followed by CSR+TLIF [n = 7]) were performed using 2-way ANOVA with replication. Statistical comparisons among four of the groups (PSR+TLIF [n = 7], PSR+LLIF [n = 7], CSR+TLIF [n = 7], and CSR+LLIF [n = 7]) were made using 2-way ANOVA without replication. Statistical significance was set at p < 0.05.

Results: Proximal adjacent-segment normalized ROM was significantly larger with PSR than CSR during flexion-extension regardless of TLIF (p = 0.02), or with either TLIF or LLIF (p = 0.04). During lateral bending with TLIF, the distal adjacent-segment normalized ROM was significantly larger with PSR than CSR (p < 0.001). Moreover, regardless of the types of screw-rod fixations (CSR or PSR), TLIF had a significantly larger normalized ROM than LLIF in all directions at both proximal and distal adjacent segments (p ≤ 0.04).

Conclusions: The use of PSR versus CSR during single-level lumbar fusion can significantly affect mobility at the adjacent segment, regardless of the presence of TLIF or with either TLIF or LLIF. Moreover, the type of interbody support also had a significant effect on adjacent-segment mobility.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.11.SPINE20977DOI Listing
June 2021

Biomechanical effects of a novel posteriorly placed sacroiliac joint fusion device integrated with traditional lumbopelvic long-construct instrumentation.

J Neurosurg Spine 2021 Jun 18:1-10. Epub 2021 Jun 18.

1Department of Neurosurgery, Spinal Biomechanics Laboratory, and.

Objective: S2-alar-iliac (S2AI) screw fixation effectively ensures stability and enhances fusion in long-segment constructs. Nevertheless, pelvic fixation is associated with a high rate of mechanical failure. Because of the transarticular nature of the S2AI screw, adding a second point of fixation may provide additional stability and attenuate strains. The objective of the study was to evaluate changes in stability and strain with the integration of a sacroiliac (SI) joint fusion device, implanted through a novel posterior SI approach, supplemental to posterior long-segment fusion.

Methods: L1-pelvis human cadaveric specimens underwent pure moment (7.5 Nm) and compression (400 N) tests in the following conditions: 1) intact, 2) L2-S1 pedicle screw and rod fixation with L5-S1 interbody fusion, 3) added S2AI screws, and 4) added bilateral SI joint fixation (SIJF). The range of motion (ROM), rod strain, and screw bending moments (S1 and S2AI) were analyzed.

Results: S2AI fixation decreased L2-S1 ROM in flexion-extension (p ≤ 0.04), L5-S1 ROM in flexion-extension and compression (p ≤ 0.004), and SI joint ROM during flexion-extension and lateral bending (p ≤ 0.03) compared with S1 fixation. SI joint ROM was significantly less with SIJF in place than with the intact joint, S1, and S2AI fixation in flexion-extension and lateral bending (p ≤ 0.01). The S1 screw bending moment decreased following S2AI fixation by as much as 78% in extension, but with statistical significance only in right axial rotation (p = 0.03). Extending fixation to S2AI significantly increased the rod strain at L5-S1 during flexion, axial rotation, and compression (p ≤ 0.048). SIJF was associated with a slight increase in rod strain versus S2AI fixation alone at L5-S1 during left lateral bending (p = 0.048). Compared with the S1 condition, fixation to S2AI increased the mean rod strain at L5-S1 during compression (p = 0.048). The rod strain at L5-S1 was not statistically different with SIJF compared with S2AI fixation (p ≥ 0.12).

Conclusions: Constructs ending with an S2AI screw versus an S1 screw tended to be more stable, with reduced SI joint motion. S2AI fixation decreased the S1 screw bending moments compared with fixation ending at S1. These benefits were paired with increased rod strain at L5-S1. Supplementation of S2AI fixation with SIJF implants provided further reductions (approximately 30%) in the sagittal plane and lateral bending SI joint motion compared with fixation ending at the S2AI position. This stability was not paired with significant changes in rod or screw strains.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.11.SPINE201540DOI Listing
June 2021

Emerging Technologies in Spinal Surgery: Ultra-Low Radiation Imaging Platforms.

Oper Neurosurg (Hagerstown) 2021 06;21(Suppl 1):S39-S45

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.

Background: Spine surgery has seen tremendous growth in the past 2 decades. A variety of safety, practical, and market-driven needs have spurred the development of new imaging technologies as necessary tools for modern-day spine surgery. Although current imaging techniques have proven satisfactory for operative needs, it is well-known that these techniques have negative consequences for operators and patients in terms of radiation risk. Several mitigating techniques have arisen in recent years, ranging from lead protection to radiation-reducing protocols, although each technique has limits. A hitherto-problematic barrier has been the fact that efforts to diminish radiation emission come at the cost of reduced image quality.

Objective: To describe new ultra-low radiation imaging modalities that have the potential to drastically reduce radiation risk and minimize unacceptable adverse effects.

Methods: A literature review was performed of articles and studies that used either of 2 ultra-low radiation imaging modalities, the EOS system (EOS-Imaging S.A., Paris, France) and LessRay (NuVasive, San Diego, CA).

Results: Both ultra-low radiation imaging modalities reduce radiation exposure in the preoperative and perioperative settings. EOS provides 3-dimensional reconstructive capability, and LessRay offers intraoperative tools that facilitate spinal localization and proper visual alignment of the spine.

Conclusion: These novel radiation-reducing technologies diminish patient and surgeon exposure, aid the surgeon in preoperative planning, and streamline intraoperative workflow.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ons/opaa324DOI Listing
June 2021

"Disruptive Technology" in Spine Surgery and Education: Virtual and Augmented Reality.

Oper Neurosurg (Hagerstown) 2021 06;21(Suppl 1):S85-S93

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.

Background: Technological advancements are the drivers of modern-day spine care. With the growing pressure to deliver faster and better care, surgical-assist technology is needed to harness computing power and enable the surgeon to improve outcomes. Virtual reality (VR) and augmented reality (AR) represent the pinnacle of emerging technology, not only to deliver higher quality education through simulated care, but also to provide valuable intraoperative information to assist in more efficient and more precise surgeries.

Objective: To describe how the disruptive technologies of VR and AR interface in spine surgery and education.

Methods: We review the relevance of VR and AR technologies in spine care, and describe the feasibility and limitations of the technologies.

Results: We discuss potential future applications, and provide a case study demonstrating the feasibility of a VR program for neurosurgical spine education.

Conclusion: Initial experiences with VR and AR technologies demonstrate their applicability and ease of implementation. However, further prospective studies through multi-institutional and industry-academic partnerships are necessary to solidify the future of VR and AR in spine surgery education and clinical practice.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ons/opab114DOI Listing
June 2021

Commentary: Present and Future Spinal Robotic and Enabling Technologies.

Oper Neurosurg (Hagerstown) 2021 06;21(Suppl 1):S57-S58

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ons/opaa405DOI Listing
June 2021

Prevention of Perioperative Abdominal Migraine in a Patient Undergoing Spinal Fusion: A Case Report.

A A Pract 2021 Jun 10;15(6):e01484. Epub 2021 Jun 10.

Department of Neurosurgery, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, Arizona.

Abdominal migraine is a variant of migraine headaches characterized by episodic attacks of severe abdominal pain with migrainous features, including anorexia, nausea, vomiting, and pallor. It is more commonly diagnosed in children rather than adults. We describe a 74-year-old patient with progressively worsening back pain, severe neurogenic claudication, and a history of opioid-triggered abdominal migraine. As a precautionary measure, a perioperative opioid-sparing treatment plan was devised to prevent abdominal migraine while the patient underwent elective lumbar fusion surgery. Opioid-sparing treatment plans may enable similar patients to undergo surgery without experiencing perioperative abdominal migraines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1213/XAA.0000000000001484DOI Listing
June 2021

Safety of lateral access to the concave side for adult spinal deformity.

J Neurosurg Spine 2021 May 14:1-5. Epub 2021 May 14.

1Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona; and.

Objective: Minimally invasive surgery (MIS) techniques, particularly lateral lumbar interbody fusion (LLIF), have become increasingly popular for adult spinal deformity (ASD) correction. Much discussion has been had regarding theoretical and clinical advantages to addressing coronal curvature from the convex versus concave side of the curve. In this study, the authors aimed to broadly evaluate the clinical outcomes of addressing ASD with circumferential MIS (cMIS) techniques while accessing the lumbar coronal curvature from the concave side.

Methods: A multi-institution, retrospective chart and radiographic review was performed for all ASD patients with at least a 10° curvature, as defined by the Scoliosis Research Society, who underwent cMIS correction. The data collected included convex versus concave access to the coronal curve, durable or sensory femoral nerve injury lasting longer than 6 weeks, vascular injury, visceral injury, and any additional major complication, with at least a 2-year follow-up. Neither health-related quality-of-life metrics nor spinopelvic parameters were included within the scope of this study.

Results: A total of 152 patients with ASD treated with cMIS correction via lateral access were identified and analyzed. Of these, 126 (82.9%) were approached from the concave side and 26 (17.1%) were approached from the convex side. In the concave group, 1 (0.8%) motor and 4 (3.2%) sensory deficit cases remained at 6 weeks after the operation. No vascular, visceral, or catastrophic intraoperative injuries were encountered in the concave group. Of the 26 patients in the convex group, 2 (7.7%) experienced motor deficits lasting longer than 6 weeks and 5 (19.2%) had lower-extremity sensory deficits.

Conclusions: It has been reported that lateral access to the convex side is associated with similar clinical and radiographic outcomes with fewer complications when compared with access to the concave side. Advantages to approaching the lumbar spine from the concave side include using one incision to access multiple levels, breaking the operative table to assist with curvature correction, easier access to the L4-5 disc space, the ability to release the contracted side, and, often, avoidance of the need to access or traverse the thoracic cavity. This study illustrates the largest reported cohort of concave access for cMIS scoliosis correction; few postoperative sensory and motor deficits were found.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.10.SPINE191270DOI Listing
May 2021

Single-Position Prone Lateral Interbody Fusion Improves Segmental Lordosis in Lumbar Spondylolisthesis.

World Neurosurg 2021 Jul 6;151:e786-e792. Epub 2021 May 6.

Department of Neurosurgery, Barrow Neurological Institute, Phoenix, Arizona, USA. Electronic address:

Objective: Single-position surgery in prone position is a novel technique for lateral interbody fusion with pedicle screw fixation. We performed a radiographic comparison of patients treated for spondylolisthesis using the prone lateral (PL) transpsoas approach versus the traditional dual position (DP) approach (lateral decubitus then prone).

Methods: Thirty consecutive patients with spondylolisthesis were treated using the PL approach (n = 15) versus the dual position approach (n = 15). Radiographic factors in the groups were retrospectively compared.

Results: The groups were similar for age, sex, body mass index, and implant size, but there were more 15° (vs. 10°) cages inserted in the dual position group. Radiographically the groups had similar baseline spinopelvic parameters, lumbar lordosis (LL), segmental lordosis, anterolisthesis, and disc height (P > 0.05). Postoperatively the PL group demonstrated a larger improvement in segmental lordosis (5.1° vs. 2.5°, P = 0.02), but not overall LL (6.3° vs. 3.1°, P = 0.14). Both groups had similar improvements in pelvic tilt, disc height, and spondylolisthesis reduction (P > 0.05). The mean relative distance of the implant from the posterior edge of the vertebral body was greater in the PL group (26% vs. 17%, P < 0.001) indicating a tendency for more anterior cage placement. However, there was no significant correlation between the relative cage position and the increase in segmental lordosis (P = 0.35), so this result alone did not explain the relative increase in lordosis seen.

Conclusions: This is the first study to our knowledge to demonstrate an improvement in segmental lordosis for patients with single-level spondylolisthesis using the PL approach.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2021.04.128DOI Listing
July 2021

Predictors of indirect neural decompression in minimally invasive transpsoas lateral lumbar interbody fusion.

J Neurosurg Spine 2021 Apr 30:1-11. Epub 2021 Apr 30.

Departments of1Neurosurgery and.

Objective: An advantage of lateral lumbar interbody fusion (LLIF) surgery is the indirect decompression of the neural elements that occurs because of the resulting disc height restoration, spinal realignment, and ligamentotaxis. The degree to which indirect decompression occurs varies; no method exists for effectively predicting which patients will respond. In this study, the authors identify preoperative predictive factors of indirect decompression of the central canal.

Methods: The authors performed a retrospective evaluation of prospectively collected consecutive patients at a single institution who were treated with LLIF without direct decompression. Preoperative and postoperative MRI was used to grade central canal stenosis, and 3D volumetric reconstructions were used to measure changes in the central canal area (CCA). Multivariate regression was used to identify predictive variables correlated with radiographic increases in the CCA and clinically successful improvement in visual analog scale (VAS) leg pain scores.

Results: One hundred seven levels were treated in 73 patients (mean age 68 years). The CCA increased 54% from a mean of 0.96 cm2 to a mean of 1.49 cm2 (p < 0.001). Increases in anterior disc height (74%), posterior disc height (81%), right (25%) and left (22%) foraminal heights, and right (12%) and left (15%) foraminal widths, and reduction of spondylolisthesis (67%) (all p < 0.001) were noted. Multivariate evaluation of predictive variables identified that preoperative spondylolisthesis (p < 0.001), reduced posterior disc height (p = 0.004), and lower body mass index (p = 0.042) were independently associated with radiographic increase in the CCA. Thirty-two patients were treated at a single level and had moderate or severe central stenosis preoperatively. Significant improvements in Oswestry Disability Index and VAS back and leg pain scores were seen in these patients (all p < 0.05). Twenty-five (78%) patients achieved the minimum clinically important difference in VAS leg pain scores, with only 2 (6%) patients requiring direct decompression postoperatively due to persistent symptoms and stenosis. Only increased anterior disc height was predictive of clinical failure to achieve the minimum clinically important difference.

Conclusions: LLIF successfully achieves indirect decompression of the CCA, even in patients with substantial central stenosis. Low body mass index, preoperative spondylolisthesis, and disc height collapse appear to be most predictive of successful indirect decompression. Patients with preserved disc height but severe preoperative stenosis are at higher risk of failure to improve clinically.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.8.SPINE20676DOI Listing
April 2021

Subaxial Cervical Pedicle Screw Placement With Direct Visualization of Pedicle Borders: 2-Dimensional Operative Video.

Oper Neurosurg (Hagerstown) 2021 Jun;21(1):E54

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.

Pedicle screws provide superior fixation of the subaxial cervical spine to other techniques. However, a high degree of accuracy is required for safe placement given the proximity of pedicles to critical neurovascular structures. A variety of techniques are described to maximize accuracy, including freehand, fluoroscopy-guided, and neuronavigation-based methods.  We present a technique for the placement of pedicle screws in the subaxial cervical spine using direct visualization of the pedicle in a patient who required an occipito-cervical fusion construct in the setting of a C2 chordoma. A laminotomy or laminectomy is performed laterally to allow for visualization of the medial, superior, and inferior walls of the pedicle. The entry point for screw placement is determined based on pedicle anatomy and is typically 1 to 2 mm lateral to the midpoint of the lateral mass, just below the base of the superior articulating process. Screw trajectory is determined by visualizing the pedicle borders and is aimed at the junction of the medial pedicle wall, with the posterior vertebral body down the pedicle axis. Tactile feedback (loss of resistance) is used to assess for a breach while drilling. The cannulation is then tapped, and the screw is placed in a standard fashion.  Direct visualization of pedicle anatomy can be a useful adjunct to guide the safe placement of subaxial pedicle screws when superior fixation is required or when normal anatomy is distorted. The technique may be combined with fluoroscopic or navigation-based techniques to provide real-time anatomic guidance during screw placement. The patient provided informed, written consent for this procedure before surgery. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ons/opab086DOI Listing
June 2021

Perioperative and swallowing outcomes in patients undergoing 4- and 5-level anterior cervical discectomy and fusion.

J Neurosurg Spine 2021 Apr 2:1-8. Epub 2021 Apr 2.

Objective: Anterior cervical discectomy and fusion (ACDF) is a common and robust procedure performed on the cervical spine. Literature on ACDF for 4 or more segments is sparse. Increasing the number of operative levels increases surgical complexity, tissue retraction, and risks of complications, particularly dysphagia. The overall risks of these complications and rates of dysphagia are not well studied for surgery on 4 or more segments. In this study, the authors evaluated their institution's perioperative experience with 4- and 5-level ACDFs.

Methods: The authors retrospectively reviewed patients who underwent 4- or 5-level ACDF at their institution over a 6-year period (May 2013-May 2019). Patient demographics, perioperative complications, readmission rates, and swallowing outcomes were recorded. Outcomes were analyzed with a multivariate linear regression.

Results: A total of 174 patients were included (167 had 4-level and 7 had 5-level ACDFs). The average age was 60.6 years, and 54.0% of patients (n = 94) were men. A corpectomy was performed in 12.6% of patients (n = 22). After surgery, 56.9% of patients (n = 99) experienced dysphagia. The percentage of patients with dysphagia decreased to 22.8% (37/162) at 30 days, 12.9% (17/132) at 90 days, and 6.3% (5/79) and 2.8% (1/36) at 1 and 2 years, respectively. Dysphagia was more likely at 90 days postoperatively in patients with gastroesophageal reflux (OR 4.4 [95% CI 1.5-12.8], p = 0.008), and the mean (± SD) lordosis change was greater in patients with dysphagia than those without at 90 days (19.8° ± 13.3° vs 9.1° ± 10.2°, p = 0.003). Dysphagia occurrence did not differ with operative implants, including graft and interbody type. The mean length of time to solid food intake was 2.4 ± 2.1 days. Patients treated with dexamethasone were more likely to achieve solid food intake prior to discharge (OR 4.0 [95% CI 1.5-10.6], p = 0.004). Postsurgery, 5.2% of patients (n = 9) required a feeding tube due to severe approach-related dysphagia. Other perioperative complication rates were uniformly low. Overall, 8.6% of patients (n = 15) returned to the emergency department within 30 days and 2.9% (n = 5) required readmission, whereas 1.1% (n = 2) required unplanned return to surgery within 30 days.

Conclusions: This is the largest series of patients undergoing 4- and 5-level ACDFs reported to date. This procedure was performed safely with minimal intraoperative complications. More than half of the patients experienced in-hospital dysphagia, which increased their overall length of stay, but dysphagia decreased over time.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.10.SPINE201307DOI Listing
April 2021

The minimally invasive interbody selection algorithm for spinal deformity.

J Neurosurg Spine 2021 Mar 12:1-8. Epub 2021 Mar 12.

13Department of Neurological Surgery, Weill Cornell Medical College, New York, New York.

Objective: Minimally invasive surgery (MIS) for spinal deformity uses interbody techniques for correction, indirect decompression, and arthrodesis. Selection criteria for choosing a particular interbody approach are lacking. The authors created the minimally invasive interbody selection algorithm (MIISA) to provide a framework for rational decision-making in MIS for deformity.

Methods: A retrospective data set of circumferential MIS (cMIS) for adult spinal deformity (ASD) collected over a 5-year period was analyzed by level in the lumbar spine to identify surgeon preferences and evaluate segmental lordosis outcomes. These data were used to inform a Delphi session of minimally invasive deformity surgeons from which the algorithm was created. The algorithm leads to 1 of 4 interbody approaches: anterior lumbar interbody fusion (ALIF), anterior column release (ACR), lateral lumbar interbody fusion (LLIF), and transforaminal lumbar interbody fusion (TLIF). Preoperative and 2-year postoperative radiographic parameters and clinical outcomes were compared.

Results: Eleven surgeons completed 100 cMISs for ASD with 338 interbody devices, with a minimum 2-year follow-up. The type of interbody approach used at each level from L1 to S1 was recorded. The MIISA was then created with substantial agreement. The surgeons generally preferred LLIF for L1-2 (91.7%), L2-3 (85.2%), and L3-4 (80.7%). ACR was most commonly performed at L3-4 (8.4%) and L2-3 (6.2%). At L4-5, LLIF (69.5%), TLIF (15.9%), and ALIF (9.8%) were most commonly utilized. TLIF and ALIF were the most selected approaches at L5-S1 (61.4% and 38.6%, respectively). Segmental lordosis at each level varied based on the approach, with greater increases reported using ALIF, especially at L4-5 (9.2°) and L5-S1 (5.3°). A substantial increase in lordosis was achieved with ACR at L2-3 (10.9°) and L3-4 (10.4°). Lateral interbody arthrodesis without the use of an ACR did not generally result in significant lordosis restoration. There were statistically significant improvements in lumbar lordosis (LL), pelvic incidence-LL mismatch, coronal Cobb angle, and Oswestry Disability Index at the 2-year follow-up.

Conclusions: The use of the MIISA provides consistent guidance for surgeons who plan to perform MIS for deformity. For L1-4, the surgeons preferred lateral approaches to TLIF and reserved ACR for patients who needed the greatest increase in segmental lordosis. For L4-5, the surgeons' order of preference was LLIF, TLIF, and ALIF, but TLIF failed to demonstrate any significant lordosis restoration. At L5-S1, the surgical team typically preferred an ALIF when segmental lordosis was desired and preferred a TLIF if preoperative segmental lordosis was adequate.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.9.SPINE20230DOI Listing
March 2021

Coronal balance with circumferential minimally invasive spinal deformity surgery for the treatment of degenerative scoliosis: are we leaning in the right direction?

J Neurosurg Spine 2021 Mar 12:1-9. Epub 2021 Mar 12.

Objective: Coronal malalignment (CM) in adult spinal deformity is associated with poor outcomes and remains underappreciated in the literature. Recent attempts at classifying CM indicate that some coronal shifts may be more difficult to treat than others. To date, outcomes for circumferential minimally invasive surgery (cMIS) of the spine in the context of these new CM classifications are unreported.

Methods: A retrospective evaluation of patients with degenerative scoliosis (Cobb angle > 20°) consecutively treated with cMIS at a single institution was performed. Preoperative and 1-year postoperative standing radiographs were used to make the comparisons. Clinical outcome measures were compared. Patients were subgrouped according to the preoperative distance between their C7 plumb line and central sacral vertical line (C7-CSVL) as either coronally aligned (type A, C7-CSVL < 3 cm); shifted ≥ 3 cm toward the concavity (type B); or shifted ≥ 3 cm toward the convexity (type C) of the main lumbar curve.

Results: Forty-two patients were included (mean age 67.7 years). Twenty-six patients (62%) were classified as type A, 5 patients (12%) as type B, and 11 patients (26%) as type C. An average of 4.9 segments were treated. No type A patients developed postoperative CM. All type B patients had CM correction. Six of the 11 type C patients had CM after surgery. Overall, there was an improvement in the C7-CSVL (from 2.4 to 1.8 cm, p = 0.04). Among subgroups, only type B patients improved (from 4.5 to 0.8 cm, p = 0.002); no difference was seen for type A patients (from 1.2 to 1.4 cm, p = 0.32) or type C patients (from 4.3 to 3.1 cm, p = 0.11). Comparing type C patients with postoperative CM versus those without postoperative CM, patients with CM had worse visual analog scale back scores at 1 year (5 vs 1, p = 0.01). Moreover, they had higher postoperative L4 tilt angles (11° vs 5°, p = 0.01), indicating inadequate correction of the lumbosacral fractional curve.

Conclusions: cMIS improved coronal alignment, curve magnitudes, and clinical outcomes among patients with degenerative scoliosis. It did not result in CM in type A patients and was successful at improving the C7-CSVL in type B patients. Type C patients remain the most difficult to treat coronally, with worse visual analog scale back pain scores in those with postoperative CM. Regional coronal restoration of the lumbosacral fracture curve should be the focus of correction in cMIS for these patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.8.SPINE201147DOI Listing
March 2021

Robotics in Spine Surgery: A Technical Overview and Review of Key Concepts.

Front Surg 2021 23;8:578674. Epub 2021 Feb 23.

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, United States.

The use of robotic systems to aid in surgical procedures has greatly increased over the past decade. Fields such as general surgery, urology, and gynecology have widely adopted robotic surgery as part of everyday practice. The use of robotic systems in the field of spine surgery has recently begun to be explored. Surgical procedures involving the spine often require fixation via pedicle screw placement, which is a task that may be augmented by the use of robotic technology. There is little margin for error with pedicle screw placement, because screw malposition may lead to serious complications, such as neurologic or vascular injury. Robotic systems must provide a degree of accuracy comparable to that of already-established methods of screw placement, including free-hand, fluoroscopically assisted, and computed tomography-assisted screw placement. In the past several years, reports have cataloged early results that show the robotic systems are associated with equivalent accuracy and decreased radiation exposure compared with other methods of screw placement. However, the literature is still lacking with regard to long-term outcomes with these systems. This report provides a technical overview of robotics in spine surgery based on experience at a single institution using the ExcelsiusGPS (Globus Medical; Audobon, PA, USA) robotic system for pedicle screw fixation. The current state of the field with regard to salient issues in robotics and future directions for robotics in spinal surgery are also discussed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fsurg.2021.578674DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7940754PMC
February 2021

Adverse Effects of Perioperative Blood Transfusion in Spine Surgery.

World Neurosurg 2021 05 2;149:73-79. Epub 2021 Feb 2.

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA. Electronic address:

Background: Perioperative blood transfusion is often necessary during spine surgery because of blood loss from the surgical field during and after surgery. However, blood transfusions are associated with a small but significant risk of causing several adverse events including hemolytic transfusion reactions and transfusion-associated circulatory overload. Moreover, many prior publications have noted increased rates of perioperative morbidity and worsened outcomes in spine surgery patients who received blood transfusions. We performed a systematic review of the literature to better characterize the effects of blood transfusion on spine surgery outcomes.

Methods: The PubMed/MEDLINE database was queried using the composite key word "transfus∗ AND 'spine surgery.'" A title and abstract review were performed to identify articles for final inclusion.

Results: A title and abstract review of the resulting 372 English-language articles yielded 13 relevant publications, which were subsequently incorporated into this systematic review. All included studies were retrospective, nonrandomized analyses.

Conclusions: Overall, prior literature indicates a relationship between perioperative blood transfusion and worsened outcomes after spine surgery. However, the available data represent level IV evidence at best. In the future, prospective, randomized, controlled studies may help define the effects of perioperative blood transfusion on spine surgery outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2021.01.093DOI Listing
May 2021

When Indirect Decompression Fails: A Review of 220 Consecutive Direct Lateral Interbody Fusions and Unplanned Secondary Decompression.

Spine (Phila Pa 1976) 2021 Feb 3. Epub 2021 Feb 3.

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.

Study Design: A consecutive series of patients who underwent minimally invasive spinal surgery by a single surgeon at a high-volume academic medical center were studied.

Objective: The objective of this study was to identify the prevalence, radiographic features, and clinical characteristics of patients who require unplanned secondary decompressive laminectomy or foraminotomy after lateral lumbar interbody fusion (LLIF).

Summary Of Background Data: LLIF indirectly decompresses the spinal canal, lateral recess, and neural foramen when properly performed. However, indirect decompression relies on endplate integrity, reasonable bone quality, and sufficient contralateral release so that ligament distraction can occur. Some patients have insufficient decompression, resulting in persistent axial low back pain or radiculopathy.

Methods: Patients undergoing LLIF for radiculopathy or refractory low back pain were enrolled in this prospective registry. Preoperative and postoperative imaging, clinical presentation, and operative reports were reviewed from this registry.

Results: During the registry, 122 patients were enrolled (220 lumbar levels treated), with nearly even representation between men (64/122, 52.5%) and women (58/122, 47.5%). Overall, right-sided lumbar spinal approaches (74/122, 60.7%) were more common. Ultimately, 4.1% (5/122) of patients required unplanned direct decompressive laminectomy or foraminotomy because of refractory radiculopathy and persistent radiographic evidence of compression at the index LLIF level. All patients for whom indirect decompression failed were men that underwent stand-alone LLIF and had radiculopathy contralateral to the side of the LLIF approach. Most patients (59.8%, 73/122) had evidence of graft subsidence (grade 0 or 1) or osteoporosis.

Conclusions: We report a 4.1% rate of return to the operating room for failed indirect decompression following after LLIF for refractory radiculopathy. Graft subsidence and osteoporosis were common in these patients. All 5 patients who required secondary decompressive laminectomy or foraminotomy underwent stand-alone primary LLIF, and the persistent radiculopathy was consistently contralateral to the initial side of the LLIF approach.Level of Evidence: 4.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/BRS.0000000000003976DOI Listing
February 2021

Single-Position Surgery: Prone Lateral Lumbar Interbody Fusion: 2-Dimensional Operative Video.

Oper Neurosurg (Hagerstown) 2021 Apr;20(5):E369

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.

Lateral lumbar interbody fusion (LLIF) is a widely used technique for anterior fusion. However, posterior decompression or instrumentation often requires repositioning the patient, which increases operative time. This video describes the prone LLIF as a modification of the standard surgical technique. The prone LLIF facilitates simultaneous decompression and fusion, which avoids the need for repositioning the patient, increasing operative efficiency. Positioning, fluoroscopic considerations, and operative nuances involved in performing the LLIF in the prone position are described, and an illustrative case is presented. The patient provided informed consent for the procedure and videography. LLIF in the prone position can decrease operative time and increase operative efficiency. The prone position is a viable alternative to the conventional lateral decubitus position. Video used with permission from Barrow Neurological Institute, Phoenix, Arizona.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ons/opaa478DOI Listing
April 2021

Lateral Interbody Fusion at L4/5: Management of the Transitional Psoas.

World Neurosurg 2021 04 29;148:e192-e196. Epub 2020 Dec 29.

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA. Electronic address:

Objective: Managing retraction of the lumbar plexus is critical to safely perform lateral lumbar interbody fusion (LLIF) via the transpsoas approach. Occasionally, a transitional psoas is encountered at L4/5 and has been postulated to be a contraindication to transpsoas LLIF. A case series of patients with transitional psoas who underwent L4/5 LLIFs is presented.

Methods: This retrospective review assessed 79 consecutive patients who underwent L4/5 LLIF during a 24-month period. Preoperative imaging was reviewed, and patients were classified into 2 groups: normal psoas or transitional psoas. Intraoperative features and outcomes were compared between groups.

Results: Seventy-nine patients underwent L4/5 LLIFs, of whom 23 had transitional psoas anatomy and 56 had normal psoas anatomy. Among patients with transitional psoas, the center of the psoas was a mean (range) of 11.2 (5.2-26.6) mm in front of the center of the vertebral body compared with 2.0 (0-4) mm in the normal psoas group. The mean (range) retraction time was similar between groups (10.8 [6.7-14.9] minutes in the transitional psoas group vs. 11.0 [7.8-15.0] minutes in the normal psoas group). No permanent motor injuries occurred in either group, and no differences in length of stay or preoperative or postoperative Oswestry Disability Index scores were found between the groups. The protocol for L4/5 LLIF in patients with transitional psoas anatomy is described.

Conclusions: Transitional psoas anatomy is frequently encountered in surgical candidates for L4/5 LLIF. Through careful identification of the lumbar plexus and judicious retraction, the transpsoas LLIF can safely be performed in these patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2020.12.105DOI Listing
April 2021

Prone Lateral Lumbar Interbody Fusion: Case Report and Technical Note.

World Neurosurg 2020 12 4;144:170-177. Epub 2020 Sep 4.

Department of Neurosurgery, Allen Memorial Hospital, UnityPoint Clinic, Waterloo, Iowa, USA.

Objective: The transpsoas lateral lumbar interbody fusion (LLIF) is a commonly used technique to manage various spinal conditions. LLIF is often performed in combination with posterior lumbar instrumentation, which requires patient repositioning or staging of the procedure. Here we present a step-by-step detailed description of a prone LLIF using an intraoperative laser level to guide orthogonal insertion of instrumentation.

Methods: A 57-year-old man with history of L4-S1 instrumentation, who developed symptomatic adjacent L3L/4 level stenosis and sagittal plane imbalance. The single position prone lateral lumbar interbody fusion with posterior fixation was chosen in order to minimize operative room time and optimize lumbar lordosis (LL) correction.

Results: The patient was positioned prone on a Jackson table. This position allowed for improved LL correction. A self-leveling laser line ensured ideal orthogonal use of instrumentation. The patient had improvement of symptoms immediately postoperatively and was discharged home on postoperative day 2 without complications.

Conclusions: The single position prone LLIF with posterior fixation offers a shorter operative room time by eliminating necessity to reposition the patient between stages of operation. The prone position of the patient optimizes LL correction. Further experience with this approach will allow for refining of the technique to overcome its limitations and facilitate its utilization.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2020.08.172DOI Listing
December 2020

Mini-open lateral retropleural/retroperitoneal approaches for thoracic and thoracolumbar junction anterior column pathologies.

Neurosurg Focus 2020 09;49(3):E13

1Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia.

Objective: Advancements in less invasive lateral retropleural/retroperitoneal approaches aim to address the limitation of posterolateral approaches and avoid complications associated with anterior open thoracotomy or thoracoabdominal approaches.

Methods: Consecutive patients treated with a mini-open lateral approach for thoracic or thoracolumbar anterior column pathologies were analyzed in a retrospective case series including clinical and radiographic outcomes. Special attention is given to operative techniques and surgical nuances.

Results: Eleven patients underwent a mini-open lateral retropleural or combined retropleural/retroperitoneal approach for thoracic or thoracolumbar junction lesions. Surgical indications included chronic fracture/deformity (n = 5), acute fracture (n = 2), neoplasm (n = 2), and osteomyelitis (n = 2). The mean length of postoperative hospital stay was 7.2 days (range 2-19 days). All patients ultimately had successful decompression and reconstruction with a mean follow-up of 16.7 months (range 6-29 months). Axial back pain assessed by the visual analog scale improved from a mean score of 8.2 to 2.2. Complications included 1 patient with deep venous thrombosis and pulmonary embolism and 1 with pneumonia. One patient developed increased leg weakness, which subsequently improved. One patient undergoing corpectomy with only lateral plate fixation developed cage subsidence requiring posterior stabilization.

Conclusions: Mini-open lateral retropleural and retroperitoneal corpectomies can safely achieve anterior column reconstruction and spinal deformity correction for various thoracic and thoracolumbar vertebral pathologies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.6.FOCUS20360DOI Listing
September 2020

Single-position prone lateral approach: cadaveric feasibility study and early clinical experience.

Neurosurg Focus 2020 09;49(3):E15

1Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona; and.

Objective: Lateral lumbar interbody fusion (LLIF) is a useful minimally invasive technique for achieving anterior interbody fusion and preserving or restoring lumbar lordosis. However, achieving circumferential fusion via posterior instrumentation after an LLIF can be challenging, requiring either repositioning the patient or placing pedicle screws in the lateral position. Here, the authors explore an alternative single-position approach: LLIF in the prone lateral (PL) position.

Methods: A cadaveric feasibility study was performed using 2 human cadaveric specimens. A retrospective 2-center early clinical series was performed for patients who had undergone a minimally invasive lateral procedure in the prone position between August 2019 and March 2020. Case duration, retractor time, electrophysiological thresholds, implant size, screw accuracy, and complications were recorded. Early postoperative radiographic outcomes were reported.

Results: A PL LLIF was successfully performed in 2 cadavers without causing injury to a vessel or the bowel. No intraoperative subsidence was observed. In the clinical series, 12 patients underwent attempted PL surgery, although 1 case was converted to standard lateral positioning. Thus, 11 patients successfully underwent PL LLIF (89%) across 14 levels: L2-3 (2 of 14 [14%]), L3-4 (6 of 14 [43%]), and L4-5 (6 of 14 [43%]). For the 11 PL patients, the mean (± SD) age was 61 ± 16 years, mean BMI was 25.8 ± 4.8, and mean retractor time per level was 15 ± 6 minutes with the longest retractor time at L2-3 and the shortest at L4-5. No intraoperative subsidence was noted on routine postoperative imaging.

Conclusions: Performing single-position lateral transpsoas interbody fusion with the patient prone is anatomically feasible, and in an early clinical experience, it appeared safe and reproducible. Prone positioning for a lateral approach presents an exciting opportunity for streamlining surgical access to the lumbar spine and facilitating more efficient surgical solutions with potential clinical and economic advantages.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.6.FOCUS20359DOI Listing
September 2020

State of the art advances in minimally invasive surgery for adult spinal deformity.

Spine Deform 2020 12 6;8(6):1143-1158. Epub 2020 Aug 6.

Department of Neurological Surgery, University of California, San Francisco, CA, USA.

Adult spinal deformity (ASD) can be associated with substantial suffering due to pain and disability. Surgical intervention for achieving neural decompression and restoring physiological spinal alignment has shown to result in significant improvement in pain and disability through patient-reported outcomes. Traditional open approaches involving posterior osteotomy techniques and instrumentation are effective based on clinical outcomes but associated with high complication rates, even in the hands of the most experienced surgeons. Minimally invasive techniques may offer benefit while decreasing associated morbidity. Minimally invasive surgery (MIS) for ASD has evolved over the past 20 years, driven by improved understanding of open procedures along with novel technique development and technologic advancements. Early efforts were hindered due to suboptimal outcomes resulting from high pseudarthrosis, inadequate correction, and fixation failure rates. To address this, multi-center collaborative groups have been established to study large numbers of ASD patients which have been vital to understanding optimal patient selection and individualized management strategies. Different MIS decision-making algorithms have been described to better define appropriate candidates and interbody selection approaches in ASD. The purpose of this state of the review is to describe the evolution of MIS surgery for adult deformity with emphasis on landmark papers, and to discuss specific MIS technology for ASD, including percutaneous pedicle screw instrumentation, hyperlordotic grafts, three-dimensional navigation, and robotics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s43390-020-00180-8DOI Listing
December 2020

Multistage Hybrid Approach to Management of Significant Sagittal Malalignment: 2-Dimensional Operative Video.

Oper Neurosurg (Hagerstown) 2020 Jul 17. Epub 2020 Jul 17.

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.

Minimally invasive surgery (MIS) approaches for the correction of adult spinal deformity have gained popularity in the past decade. MIS approaches can result in decreased hospitalization times and decreased morbidity. However, compared to open techniques, MIS approaches are challenging in the setting of fixed sagittal deformity and strategic surgical staging. Combined MIS and miniopen techniques are described as "hybrid" techniques. We report on the surgical approach for a fixed sagittal deformity using both MIS and miniopen techniques, specifically a miniopen pedicle subtraction osteotomy (PSO) and an anterior column release (ACR). The patient gave written informed consent for surgical treatment; institutional review board approval was not required. The patient first underwent the placement of percutaneous modular pedicle screws from T12 to the pelvis as well as a mini-PSO across the previously fused L5 vertebral body, with the placement of a temporary rod. The following day, the patient underwent lateral transpsoas interbody fusion and ACR at L2/3; a percutaneous rod was then passed from T12 to the pelvis for segmental fixation. The patient recovered well and was discharged home without complication 6 d after the initial day of surgery. The combined use of surgical staging and traditional open techniques in a selective, minimalistic fashion and adherence to minimally invasive principles provide for a powerful set of surgical techniques that capitalize on less invasive approaches to deformity management. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ons/opaa211DOI Listing
July 2020

Factors affecting approach selection for minimally invasive versus open surgery in the treatment of adult spinal deformity: analysis of a prospective, nonrandomized multicenter study.

J Neurosurg Spine 2020 Jun 19:1-6. Epub 2020 Jun 19.

5Department of Orthopaedic Surgery, Scripps Clinic, La Jolla, California.

Objective: Surgical decision-making and planning is a key factor in optimizing outcomes in adult spinal deformity (ASD). Minimally invasive spinal (MIS) strategies for ASD have been increasingly used as an option to decrease postoperative morbidity. This study analyzes factors involved in the selection of either a traditional open approach or a minimally invasive approach to treat ASD in a prospective, nonrandomized multicenter trial. All centers had at least 5 years of experience in minimally invasive techniques for ASD.

Methods: The study enrolled 268 patients, of whom 120 underwent open surgery and 148 underwent MIS surgery. Inclusion criteria included age ≥ 18 years, and at least one of the following criteria: coronal curve (CC) ≥ 20°, sagittal vertical axis (SVA) > 5 cm, pelvic tilt (PT) > 25°, or thoracic kyphosis (TK) > 60°. Surgical approach selection was made at the discretion of the operating surgeon. Preoperative significant differences were included in a multivariate logistic regression analysis to determine odds ratios (ORs) for approach selection.

Results: Significant preoperative differences (p < 0.05) between open and MIS groups were noted for age (61.9 vs 66.7 years), numerical rating scale (NRS) back pain score (7.8 vs 7), CC (36° vs 26.1°), PT (26.4° vs 23°), T1 pelvic angle (TPA; 25.8° vs 21.7°), and pelvic incidence-lumbar lordosis (PI-LL; 19.6° vs 14.9°). No significant differences in BMI (29 vs 28.5 kg/m2), NRS leg pain score (5.2 vs 5.7), Oswestry Disability Index (48.4 vs 47.2), Scoliosis Research Society 22-item questionnaire score (2.7 vs 2.8), PI (58.3° vs 57.1°), LL (38.9° vs 42.3°), or SVA (73.8 mm vs 60.3 mm) were found. Multivariate analysis found that age (OR 1.05, p = 0.002), VAS back pain score (OR 1.21, p = 0.016), CC (OR 1.03, p < 0.001), decompression (OR 4.35, p < 0.001), and TPA (OR 1.09, p = 0.023) were significant factors in approach selection.

Conclusions: Increasing age was the primary driver for selecting MIS surgery. Conversely, increasingly severe deformities and the need for open decompression were the main factors influencing the selection of traditional open surgery. As experience with MIS surgery continues to accumulate, future longitudinal evaluation will reveal if more experience, use of specialized treatment algorithms, refinement of techniques, and technology will expand surgeon adoption of MIS techniques for adult spinal deformity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.4.SPINE20169DOI Listing
June 2020

Neuroanesthesia Guidelines for Optimizing Transcranial Motor Evoked Potential Neuromonitoring During Deformity and Complex Spinal Surgery: A Delphi Consensus Study.

Spine (Phila Pa 1976) 2020 Jul;45(13):911-920

Valley Anesthesiology Consultants, Phoenix, AZ.

Study Design: Expert opinion-modified Delphi study.

Objective: We used a modified Delphi approach to obtain consensus among leading spinal deformity surgeons and their neuroanesthesiology teams regarding optimal practices for obtaining reliable motor evoked potential (MEP) signals.

Summary Of Background Data: Intraoperative neurophysiological monitoring of transcranial MEPs provides the best method for assessing spinal cord integrity during complex spinal surgeries. MEPs are affected by pharmacological and physiological parameters. It is the responsibility of the spine surgeon and neuroanesthesia team to understand how they can best maintain high-quality MEP signals throughout surgery. Nevertheless, varying approaches to neuroanesthesia are seen in clinical practice.

Methods: We identified 19 international expert spinal deformity treatment teams. A modified Delphi process with two rounds of surveying was performed. Greater than 50% agreement on the final statements was considered "agreement"; >75% agreement was considered "consensus."

Results: Anesthesia regimens and protocols were obtained from the expert centers. There was a large amount of variability among centers. Two rounds of consensus surveying were performed, and all centers participated in both rounds of surveying. Consensus was obtained for 12 of 15 statements, and majority agreement was obtained for two of the remaining statements. Total intravenous anesthesia was identified as the preferred method of maintenance, with few centers allowing for low mean alveolar concentration of inhaled anesthetic. Most centers advocated for <150 μg/kg/min of propofol with titration to the lowest dose that maintains appropriate anesthesia depth based on awareness monitoring. Use of adjuvant intravenous anesthetics, including ketamine, low-dose dexmedetomidine, and lidocaine, may help to reduce propofol requirements without negatively effecting MEP signals.

Conclusion: Spine surgeons and neuroanesthesia teams should be familiar with methods for optimizing MEPs during deformity and complex spinal cases. Although variability in practices exists, there is consensus among international spinal deformity treatment centers regarding best practices.

Level Of Evidence: 5.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/BRS.0000000000003433DOI Listing
July 2020

Postural Stability and Dynamic Balance in Adult Spinal Deformity: Prospective Pilot Study.

World Neurosurg 2020 09 12;141:e783-e791. Epub 2020 Jun 12.

Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona. Electronic address:

Objective: We sought to evaluate dynamic balance and postural stability in patients with adult spinal deformity (ASD) compared with published age-matched normative data.

Methods: Eleven patients with ASD were prospectively enrolled. Postural stability was tested using static and dynamic posturography; patients stood on a movable platform with an integrated force plate and performed standardized sensory organization testing (SOT), evaluating the influence of sensory processing on postural stability under 6 conditions, and motor control testing, assessing reflexive postural reactions to an external perturbation. Patient performance was compared with that of published age-matched controls. Quality of life metrics included scores on the Scoliosis Research Society-22 questionnaire, SF-36, and Morse Fall Scale. Correlations between postural stability and radiographic measurements were performed.

Results: ASD patients demonstrated significantly lower SOT scores (P ≤ 0.03) in 5 of 6 conditions tested and greater latency of limb movement during backward translation (P = 0.04) compared with controls. Lower SOT scores were associated with a history of falls. ASD patients who self-reported falling in the previous 6 months, when compared with nonfallers, demonstrated significantly lower SOT scores (P = 0.04) and significantly lower Scoliosis Research Society-22 self-image subscores (P = 0.003). Thoracic kyphosis and mediolateral sway (predictor of falls) were positively correlated in the eyes-open and eyes-closed conditions (P ≤ 0.04).

Conclusions: ASD patients demonstrated impaired postural stability, diminished sensory integration, and delayed response to external perturbations compared with normal control data. Postural stability and quality of life metrics correlated with self-reported falls. These findings suggest that ASD patients have abnormal postural stability and may be at elevated risk of falls.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.wneu.2020.06.010DOI Listing
September 2020

Minimally Invasive Anterior Longitudinal Ligament Release for Anterior Column Realignment.

Global Spine J 2020 Apr 28;10(2 Suppl):101S-110S. Epub 2020 May 28.

Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA.

Study Design: Review of the literature.

Objectives: Anterior column realignment (ACR) is a powerful but relatively new minimally invasive technique for deformity correction. The purpose of this study is to provide a literature review of the ACR surgical technique, reported outcomes, and future directions.

Methods: A review of the literature was performed regarding the ACR technique. A review of patients at our single center who underwent ACR was performed, with illustrative cases selected to demonstrate basic and nuanced aspects of the technique.

Results: Clinical and cadaveric studies report increases in segmental lordosis in the lumbar spine by 73%, approximately 10° to 33°, depending on the degree of posterior osteotomy and lordosis of the hyperlordosis interbody spacer. These corrections have been found to be associated with a similar risk profile compared with traditional surgical options, including a 30% to 43% risk of proximal junctional kyphosis in early studies.

Conclusions: ACR represents a powerful technique in the minimally invasive spinal surgeon's toolbox for treatment of complex adult spinal deformity. The technique is capable of significant sagittal plane correction; however, future research is necessary to ascertain the safety profile and long-term durability of ACR.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/2192568219880178DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7263342PMC
April 2020

Letter to the Editor. Indirect decompression via lateral interbody fusion for patients with severe degenerative lumbar spinal stenosis.

J Neurosurg Spine 2020 May 29:1-2. Epub 2020 May 29.

4Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3171/2020.4.SPINE20481DOI Listing
May 2020

Range of Motion Testing of a Novel 3D-Printed Synthetic Spine Model.

Global Spine J 2020 Jun 23;10(4):419-424. Epub 2019 Jun 23.

Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA.

Study Design: Biomechanical model study.

Objective: The Barrow Biomimetic Spine (BBS) project is a resident-driven effort to manufacture a synthetic spine model with high biomechanical fidelity to human tissue. The purpose of this study was to investigate the performance of the current generation of BBS models on biomechanical testing of range of motion (ROM) and axial compression and to compare the performance of these models to historical cadaveric data acquired using the same testing protocol.

Methods: Six synthetic spine models comprising L3-5 segments were manufactured with variable soft-tissue densities and print orientations. Models underwent torque loading to a maximum of 7.5 N m. Torques were applied to the models in flexion-extension, lateral bending, axial rotation, and axial compression. Results were compared with historic cadaveric control data.

Results: Each model demonstrated steadily decreasing ROM on flexion-extension testing with increasing density of the intervertebral discs and surrounding ligamentous structures. Vertically printed models demonstrated markedly less ROM than equivalent models printed horizontally at both L3-4 (5.0° vs 14.0°) and L4-5 (3.9° vs 15.2°). Models D and E demonstrated ROM values that bracketed the cadaveric controls at equivalent torque loads (7.5 N m).

Conclusions: This study identified relevant variables that affect synthetic spine model ROM and compressibility, confirmed that the models perform predictably with changes in these print variables, and identified a set of model parameters that result in a synthetic model with overall ROM that approximates that of a cadaveric model. Future studies can be undertaken to refine model performance and determine intermodel variability.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/2192568219858981DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7222693PMC
June 2020
-->