Lumbar plexus safe working zones with lateral lumbar interbody fusion: a systematic review and meta-analysis.

PURPOSE: Significant risk of injury to the lumbar plexus and its departing motor and sensory nerves exists with lateral lumbar interbody fusion (LLIF). Several cadaveric and imaging studies have investigated the lumbar plexus position with respect to the vertebral body anteroposterior plane. To date, no systematic review and meta-analysis of the lumbar plexus safe working zones for LLIF has been performed. METHODS: This systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Relevant studies reporting on the position of the lumbar plexus with relation to the vertebral body in the anteroposterior plane were identified from a PubMed database query. Quantitative analysis was performed using Welch's t test. RESULTS: Eighteen studies were included, encompassing 1005 subjects and 2472 intervertebral levels. Eleven studies used supine magnetic resonance imaging (MRI) with in vivo subjects. Seven studies used cadavers, five of which performed dissection in the left lateral decubitus position. A significant correlation (p < 0.001) existed between anterior lumbar plexus displacement and evaluation with in vivo MRI at all levels between L1-L5 compared with cadaveric measurement. Supine position was also associated with significant (p < 0.001) anterior shift of the lumbar plexus at all levels between L1-L5. CONCLUSIONS: This is the first comprehensive systematic review and meta-analysis of the lumbar neural components and safe working zones for LLIF. Our analysis suggests that the lumbar plexus is significantly displaced ventrally with the supine compared to lateral decubitus position, and that MRI may overestimate ventral encroachment of lumbar plexus.

The odontoid-CSVL distance in a global population of asymptomatic volunteers: normative values and implications for spinal coronal alignment.

PURPOSE: In a population of asymptomatic volunteers across 5 countries, we sought to: (a) establish normative values of the Odontoid-Central Sacral Vertical Line (OD-CSVL) across patient factors, and (b) assess correlations of OD-CSVL with other radiographic parameters. METHODS: A prospective, cross-sectional study of asymptomatic adult volunteers, ages 18-80 years, were enrolled across 5 countries (France, Japan, Singapore, Tunisia, United States) forming the Multi-Ethnic Alignment Normative Study (MEANS) cohort. Included volunteers had no known spinal disorder(s), no significant neck/back pain (VAS ≤ 2; ODI ≤ 20), and no significant scoliosis (Cobb ≤ 20°). Radiographic measurements included commonly used coronal alignment parameters (mm) and angles (°). OD-CSVL was defined as the difference between the odontoid plumb line (line from the tip of the odontoid vertically down) and the CSVL (vertical line from the center of the sacrum). Chi-square, student's t tests, Kruskal-Wallis, Wilcoxon rank-sum, linear regression, and Pearson's correlation were used with significance at p < 0.05. RESULTS: 467 volunteers were included with normative OD-CSVL values by age decade, gender, BMI, and country. Mean ± SD OD-CSVL was 8.3 mm ± 6.5 mm and 31 (6.6%) volunteers were almost perfectly aligned (OD-CSVL < 1 mm). A linear relationship was seen between OD-CSVL with both age (p < 0.001) and BMI (p = 0.015). Significant variation was seen between OD-CSVL and 5 different ethnicities (p = 0.004). OD-CSVL correlated best with other coronal radiographic parameters, C7-CSVL (r = 0.743, p < 0.001), OD-knee (r = 0.230, p < 0.001), CAM-knee (r = 0.612, p < 0.001), and regional TL cobb angle (r = 0.4214, p = 0.005). CONCLUSION: Among asymptomatic volunteers, increased OD-CSVL was significantly associated with increased age, increased BMI, and ethnicity, but not gender. OD-CSVL correlated strongest with C7-CSVL, TL cobb angle, OD-knee, and CAM-knee. OD-CSVL. These results support further study of OD-CSVL in symptomatic adult spine deformity patients.

Anterior cervical discectomy and fusion with a dynamic translational plating versus a rigid carbon fiber reinforced PEEK plating system - a comparison study of radiographic parameters.

PURPOSE: In this study the authors compare the radiographic findings of patients undergoing 1-3 level ACDF a rigid CFRP plate and a translational titanium plate system with a focus on radiographic alignment. MATERIAL AND METHODS: A retrospective review 70 consecutive patients undergoing a 1 to 3 level ACDF for cervical spondylosis was conducted. 2 groups depending on the cervical plating system were created including 38 patients in group 1 (dynamic plate) and 32 in group 2 (rigid CFRP plate). Plain neutral radiographs preoperatively, immediately after surgery and at most recent follow-up were used to assess parameters on sagittal alignment, fusion height, adjacent segment ossification (ASO), fusion rate and implant failure. RESULTS: There were no significant differences between groups preoperatively. Both groups had a more than 12 months follow-up (p = 0.327). Improvement of C2-7 lordosis was seen in both groups but only in group 1 it reached statistical significance at final follow-up. Significant improvement in sagittal segmental alignment was noted in both groups following surgery. A significant sagittal correction of 5.5 ± 9.1 degrees (p = 0.002) was maintained through follow-up only in group 2. No significantly different was seen for segmental fusion rates and loss of fusion height. There were no instances of implant failure within both groups. Worsening of ASO was 20% for both groups. CONCLUSION: ACDF allows for correction and maintenance of cervical alignment. Rigid rigid plate appears more effective at maintaining segmental lordotic correction. The fusion rate and implant failure was not different for both groups.

Atypical Teratoid/Rhabdoid Tumor of the Conus Medullaris.

INTRODUCTION: Atypical teratoid/rhabdoid tumor (AT/RT) is a rare tumor of the central nervous system, especially when involving the spinal column or spinal cord. CASE PRESENTATION: We present a case of a 5-year-old girl with progressive bilateral lower extremity pain found to have a discrete nodular lesion of the conus with mild heterogeneous enhancement. Surgical decompression and resection demonstrated a pathologic tumor consistent with AT/RT with loss of INI1 protein on immunohistochemistry. DISCUSSION AND CONCLUSION: AT/RT lesions of the conus medullaris are exceedingly rare and associated with extensive disease. We report a rare case of AT/RT with selective involvement of the conus medullaris, as well as describe the surgical, radiographic, and pathologic findings of this tumor.

Minimally invasive options for surgical management of adjacent segment disease of the lumbar spine.

BACKGROUND: The incidence of adjacent segment disease (ASD) after lumbar spine surgery is a condition that has become increasingly common as the rate of lumbar spine surgery continues to rise. Minimally invasive techniques continue to be refined and offer an opportunity to treat ASD with minimal tissue disruption, lower blood loss, a shorter hospital stay, and decreased morbidity. The aim of this report is to describe the various minimally invasive options for ASD with a comprehensive review of the existing literature. MATERIALS AND METHODS: A retrospective chart review of patients undergoing minimally invasive spine surgery (MIS) for ASD of the lumbar spine was conducted. Four basic techniques and their modifications were identified to address ASD. Illustrative cases, surgical techniques, and post-surgical outcomes are described. RESULTS: Four MIS techniques were identified as common surgical methods to correct ASD. (1) Non-instrumented discectomy, foraminotomy, or decompression, (2) anterior lumbar interbody fusion (ALIF), (3) transforaminal lumbar interbody fusion (TLIF), and (4) lateral lumbar interbody fusion (LLIF) were found to be MIS techniques that address ASD. ALIF and LLIF provide indirect decompression of the neural foramina, while TLIF provides direct decompression. The addition and removal of screws and rods can be combined with any of these techniques. CONCLUSIONS: MIS techniques provide decompression of the neural elements, stabilization, and, potentially, fusion for patients with ASD. These illustrated cases and the review of MIS surgical techniques can provide a comprehensive framework for addressing ASD.

Cervical arthroplasty: what does the labeling say?

OBJECTIVE The aim of this paper was to comprehensively review each of the Food and Drug Administration (FDA)-approved labels of 7 total cervical disc replacements, assess the exact methodology in which the trial was conducted, and provide a broad comparison of these devices to allow each surgeon to determine which disc best suits his or her specific treatment goals based on the specific labels and not the studies published. METHODS The FDA-approved labels for each of the 7 artificial discs were obtained from the official FDA website. These labels were meticulously compared with regard to the statistical analysis performed, the safety and efficacy data, and the randomized controlled trial that each artificial disc was involved in to obtain the FDA approval for the product or device. Both single-level and 2-level approvals were examined, and primary and secondary end points were assessed. RESULTS In the single-level group, 4 of the 7 artificial discs-Prestige LP, Prestige ST, Bryan, and Secure-C-showed superiority in overall success. Prestige ST showed superiority in 3 of 4 outcome measures (neurological success, revision surgery, and overall success), while the other aforementioned discs showed superiority in 2 or fewer measures (Prestige LP, neurological and overall success; Bryan, Neck Disability Index [NDI] and overall success; Secure-C, revision surgery and overall success; Pro-Disc C, revision surgery). The PCM and Mobi-C discs demonstrated noninferiority across all outcome measures. In the 2-level group, Prestige LP and Mobi-C demonstrated superiority in 3 outcome measures (NDI, secondary surgery, and overall success) but not neurological success. CONCLUSIONS This paper provides a comprehensive analysis of 7 currently approved and distributed artificial discs in the United States. It compares specific outcome measures of these devices against those following the standard of care, which is anterior cervical discectomy and fusion. This information will provide surgeons the opportunity to easily answer patients' questions and remain knowledgeable when discussing devices with manufacturers.

The Importance of Pelvic Obliquity in Assessing Spinal Coronal Alignment: Normative Values, Demographic, and Radiographic Correlations.

STUDY DESIGN: Prospective, cross-sectional study. OBJECTIVE: In a geographically diverse population of asymptomatic volunteers, we sought to report the incidence of pelvic obliquity (PO), establish normative values of PO across patient factors, and assess the correlation of PO with radiographic parameters. SUMMARY OF BACKGROUND DATA: PO is defined as the misalignment of the pelvis and can be assessed through several anatomic landmarks. Significant PO, whether caused by leg-length discrepancy or not, can lead to coronal malalignment which causes severe pain and disability. Significant emphasis has been placed on achieving appropriate sagittal alignment in recent decades; however, a greater understanding of coronal alignment is needed, and PO is a crucial aspect of evaluating the coronal plane in adult spinal deformity patients. METHODS: Asymptomatic adult volunteers, ages 18-80 years, enrolled patients from 5 countries (France, Japan, Singapore, Tunisia, and the United States) in the "multiethnic alignment normative study" cohort (IRB 201812144). The included volunteers had no known spinal disorder(s), no significant neck or back pain (Visual Analog Scale: ≤2; Oswestry Disability Index: ≤20), and no abnormal alignment (Cobb ≤20°). PO was measured in the frontal plane as the distance between the highest points of each acetabulum, calculated along the vertical axis in millimeters (mm). The incidence of PO was defined as PO ≥10 mm. Kruskal-Wallis, Wilcoxon rank-sum, Pearson correlation, and linear regression were used. RESULTS: A total of 467 patients were included, and PO values by age, sex, body mass index, and country were provided. The overall incidence of PO ≥10 mm was 4.3%, and a nonsignificant trend toward increased PO with age was seen ( P = 0.077). No significant differences were seen in PO between sex, ethnicity, or body mass index groups. No significant correlation existed between PO and other commonly used coronal radiographic measurements. CONCLUSION: PO ≥10 mm occurred in 4.3% of asymptomatic volunteers. Despite the importance of recognizing PO in preventing coronal malalignment, PO did not seem to be associated with other radiographic and demographic information, which underscores the importance of intentionally assessing for any PO before surgery. These results in an asymptomatic population provide a foundation for studying PO in patients with spinal pathology.

Postoperative coronal malalignment after adult spinal deformity surgery: incidence, risk factors, and impact on 2-year outcomes.

PURPOSE: To evaluate the incidence, risk factors, and patient-reported outcomes (PROs) of adult spinal deformity (ASD) patients with postoperative coronal malalignment. METHODS: A single-institution, retrospective cohort study of ASD patients undergoing ≥ 6 level fusions from 2015 to 2019 was undertaken. The primary outcome was postoperative coronal malalignment, defined as C7-coronal vertical axis (CVA) > 3 cm. Secondary outcomes included: complications, readmissions, reoperations, and 2-year PROs. RESULTS: A total of 243 ASD patients undergoing spinal surgery had preoperative and immediate postoperative measurements, and 174 patients (72%) had 2-year follow-up. Mean age was 49.3 ± 18.3yrs and mean instrumented levels was 13.5 ± 3.9. Mean preoperative CVA was 2.9 ± 2.7 cm, and 90 (37%) had preoperative coronal malalignment. Postoperative coronal malalignment occurred in 43 (18%) patients. Significant risk factors for postoperative coronal malalignment were: preoperative CVA (OR 1.21, p = 0.001), preoperative SVA (OR 1.05, p = 0.046), pelvic obliquity (OR 1.21; p = 0.008), Qiu B vs. A (OR 4.17; p = 0.003), Qiu C vs. A (OR 7.39; p < 0.001), lumbosacral fractional (LSF) curve (OR 2.31; p = 0.021), max Cobb angle concavity opposite the CVA (OR 2.10; p = 0.033), and operative time (OR 1.16; p = 0.045). Postoperative coronal malalignment patients were more likely to sustain a major complication (31% vs. 14%; p = 0.01), yet no differences were seen in readmissions (p = 0.72) or reoperations (p = 0.98). No significant differences were seen in 2-year PROs (p > 0.05). CONCLUSIONS: Postoperative coronal malalignment occurred in 18% of ASD patients and was most associated with preoperative CVA/SVA, pelvic obliquity, Qiu B/C curves, LSF curve concavity to the same side as the CVA, and maximum Cobb angle concavity opposite side of the CVA. Postoperative coronal malalignment was significantly associated with increased complications but not readmission, reoperation, or 2-year PROs.

Do Grip Strength Dynamometer Readings Improve After Cervical Spine Surgery?

STUDY DESIGN: Retrospective, cohort study. OBJECTIVES: Hand function can be difficult to objectively assess perioperatively. In patients undergoing cervical spine surgery by a single-surgeon, we sought to: (1) use a hand dynamometer to report pre/postoperative grip strength, (2) distinguish grip strength changes in patients with radiculopathy-only vs myelopathy, and (3) assess predictors of grip strength improvement. METHODS: Demographic and operative data were collected for patients who underwent surgery 2015-2018. Hand dynamometer readings were pre/postoperatively at three follow-up time periods (0-3 m, 3-6 m, 6-12 m). RESULTS: 262 patients (mean age of 59 ± 14 years; 37% female) underwent the following operations: ACDF (80%), corpectomy (25%), laminoplasty (19%), and posterior cervical fusion (7%), with 81 (31%) patients undergoing multiple operations in a single anesthetic setting. Radiculopathy-only was seen in 128 (49%) patients, and myelopathy was seen 134 (51%) patients. 110 (42%) had improved grip strength by ≥10-lbs, including 69/128 (54%) in the radiculopathy-only group, and 41/134 (31%) in the myelopathy group. Those most likely to improve grip strength were patients undergoing ACDF (OR 2.53, P = .005). Patients less likely to improve grip strength were older (OR = .97, P = .003) and underwent laminoplasty (OR = .44, 95% CI .23, .85, P = .014). Patients undergoing surgery at the C2/3-C5/6 levels and C6/7-T1/2 levels both experienced improvement during the 0-3-month time range (C2-5: P = .035, C6-T2: P = .015), but only lower cervical patients experienced improvement in the 3-6-month interval (P = .030). CONCLUSIONS: Grip strength significantly improved in 42% of patients. Patients with radiculopathy were more likely to improve than those with myelopathy. Patients undergoing surgery from the C2/3-C5/6 levels and the C6/7-T1/2 levels both significantly improved grip strength at 3-month postoperatively.

Do Adult Spinal Deformity Patients Undergoing Surgery Continue to Improve From 1-Year to 2-Years Postoperative?

OBJECTIVE: Evaluate clinical improvement as measured by patient-reported outcomes (PROs) during the 1 to 2-year interval. STUDY DESIGN: Retrospective Cohort. METHODS: A single-institution registry of ASD patients undergoing surgery was queried for patients with ≥6 level fusions. Demographics and radiographic variables were collected. PROs collected were the ODI and SRS-22r scores at: preoperative, 1-year and 2-years. Outcome measures of clinical improvement during the 1-2 year time interval were: 1) group medians, 2) percent minimum clinically important difference (MCID), and 3) percent minimal symptom scale (MSS)(ODI < 20 or SRS-pain + function >8). Wilcoxon rank-sum tests, chi-squared tests, Kruskal-Wallis tests, and logistic regression were performed. RESULTS: 157 patients undergoing ASD surgery with minimum of 1-year follow-up were included. Mean age was 53.2 and mean instrumented levels was 13.1. Preoperative alignment was: Neutral Alignment (NA) 49%, Coronal Malalignment (CM) 17%, Sagittal Malalignment (SM 17%), and Combined Coronal/Sagittal Malalignment (CCSM) 18%. Preoperative to 1-year, and preoperative to 2-years, all ODI/SRS-22r significantly improved (P < .001). In all patients, the only significant improvement in PROs between 1-and 2-year postoperative were those reaching ODI MCID (69% 1-year vs. 84% 2-years; P < .001). Subgroup analysis: ≥55 years had an improved median ODI (18 vs. 8; P = .047) and an improved percent achieving ODI MCID (73% vs. 84%, P = .048). CCSM patients experienced significant improvement in SRS-appearance score (75% vs. 100%; P = .050), along with those with severe preoperative SM >7.5 cm (73% vs. 100%; P = .032). CONCLUSIONS: Most ASD patients experience the majority of PRO improvement by 1-year postoperative. However, subsets of patients that may continue to improve up to 2-years postoperative include patients ≥55 years, combined coronal/sagittal malalignment, and those with severe sagittal malalignment ≥7.5 cm.

The Lumbosacral Fractional Curve vs Maximum Coronal Cobb Angle in Adult Spinal Deformity Patients with Coronal Malalignment: Which Matters More?

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: In patients undergoing adult spinal deformity (ASD) surgery we sought to: 1) report preoperative and postoperative lumbosacral fractional (LSF) curve and maximum coronal Cobb angles and 2) determine their impact on radiographic, clinical, and patient-reported outcomes (PROs). METHODS: A single-institution cohort study was undertaken. The LSF curve was the cobb angle between the sacrum and most tilted lower lumbar vertebra. Coronal/sagittal vertical axis (CVA/SVA) were collected. Patients were compared between 4 groups: 1) Neutral Alignment (NA); 2) coronal malalignment only (CM); 3) Sagittal malalignment only (SM); and 4) Combined-Coronal-Sagittal-Malalignment (CCSM). Outcomes including postoperative CM, postoperative coronal vertical axis, complications, readmissions, reoperation, and PROs. RESULTS: A total of 243 patients underwent ASD surgery with mean total instrumented levels of 13.5. Mean LSF curve was 12.1±9.9°(0.2-62.3) and mean max Cobb angle was 43.0±26.5° (0.0-134.3). The largest mean LSF curves were seen in patients with CM (14.6°) and CCSM (13.1°) compared to NA (12.1°) and SM (9.5°) (p=0.100). A higher LSF curve was seen in patients with fusion to the sacrum and instrumentation to the pelvis (p=0.009), and a higher LSF curve was associated with more TLIFs (p=0.031). Postoperatively, more TLIFs were associated with greater amount of LSF curve correction (p<0.001). Comparing the LSF and the max Cob angle among Qiu types, the highest mean max Cobb angle was in Qiu Type B patients (p=0.025), whereas the highest mean LSF curve was in Qiu Type C patients (p=0.037). Moreover, 82.7% of patients had a LSF curve opposite the max Cobb angle. The LSF curve was larger than the max Cobb angle in 22/243 (9.1%) patients, and most of these 22 patients were Qiu Type A (59.1%). Regarding correction, the max Cobb angle achieved more correction than the LSF curve, judged by the percent improved from preop (54.5% Cobb vs. 46.5% LSF, p=0.025) in patients with max cobb>20° and LSF curve >5°. The LSF curve underwent greater correction in Qiu Type C patients (9.2°) compared to Type A (5.7°) and Type B (5.1°) (p=0.023); however, the max Cobb angle was similarly corrected among Qiu Types: Type A 21.8°, Type B 24.6°, and Type C 25.4° (p=0.602). Minimal differences were seen comparing the preop/postop/change in LSF curve and max Cobb angle regarding postop CM, postop CVA, complications, readmissions, reoperation, and PROs. CONCLUSIONS: The LSF curve was highest in patients with CM, CCSM, and Qiu Type C curves. Most patients had a LSF curve opposite the max Cobb angle. The max Cobb angle was more often corrected than the LSF curve. The LSF curve underwent greater correction among Qiu Type C patients, whereas the max Cobb angle was similarly corrected among all Qiu Types. No clear trend was seen regarding postoperative complications and PROs between the LSF curve and max Cobb angle.

Recurrent IgG4-Related Meningeal Disease of the Cervicothoracic Spine: A Case Report and Review of the Literature.

Background: IgG4-related disease is a rare, recently recognized chronic inflammatory disease. IgG4-related hypertrophic pachymeningitis (IgG4-RHP) of the central nervous system predominantly involves the cranial meninges. Spinal involvement remains rare. Objective: We report a case of recurrent cervicothoracic IgG4-RHP and review the surgical literature. Methods and Materials: A 35-year-old woman presented with a 6-month history of neck and right shoulder pain, progressive right triceps weakness and paresthesias in the right C8 and T1 dermatomes. MRI demonstrated a T2 hypointense epidural soft tissue mass extending from C6-T1. The patient underwent C6-T1 laminoforaminotomy and partial resection with near complete symptom resolution. Histopathology was consistent with diagnosis of IgG4-RHP. Eighteen months postoperatively, she experienced symptom recurrence necessitating re-operation and adjuvant postoperative prednisone with complete resolution at 40-months' follow-up. Results and Conclusions: Of the now nineteen confirmed cases of IgG4-RHP, fifteen underwent surgery. A majority achieved partial resection. Three surgical patients did not receive adjuvant therapy with symptomatic recurrence between 2 and 18 months.

Preoperative Transvenous Liquid Embolization for a Symptomatic Lumbar Spinal Epidural Varix Mimicking Radiculopathy.

Background: Symptomatic spinal epidural veins (SEV) are a rare cause of neurologic dysfunction. Treatment is centered upon addressing the underlying venous pathology to relieve mechanical compression of the neurologic structures. However, open surgical ligation is often associated with considerable blood loss. Objective: We discuss a unique case of a large symptomatic epidural venous varix and potential treatment strategy. Methods and Materials: A 15-year-old female presented with a 1-year history of left L5 radicular pain and weakness. Lumbar MRI demonstrated a central L5/S1 herniated disc and a large extradural anomalous SEV compressing the exiting left L5 nerve root at the L5/S1 neuroformina. The SEV was treated using a transvenous liquid embolic agent providing symptomatic relief. At 16-months follow-up, she reported recurrent symptoms. She ultimately underwent a left L5/S1 MIS decompression without complication. Conclusion: Transvenous liquid embolization of large symptomatic SEV may provide temporary neurologic relief and decrease morbidity associated with open surgical treatment options.

Lumbar discectomies in elite rowers: presentation, operative treatment, and return to play.

OBJECTIVE: In a cohort of elite rowers requiring lumbar spine surgery, we report information regarding: (1) presentation, (2) operative treatment, and (3) return to play (RTP). METHODS: All competitive rowers undergoing spine surgery at a single academic institution from 2015 to 2020 were analyzed. Three rowers underwent spine surgery during the allotted time period. Demographic, clinical, operative, and RTP data was recorded. Each athlete's self-reported level of effort/performance was assessed before and after surgery. First RTP was defined as the time of initial return to rowing activities, and full RTP was defined as the time of unrestricted return to rowing activities. Descriptive statistics were performed. RESULTS: The three collegiate rowers ranged from 20- to 21-year-old, each with L5/S1 disc herniations. Preoperative pain levels ranged from 8 to 10, and inciting injury events included back squats, front squats, and rowing during the 'finish' stage. Each athlete underwent a minimally invasive, unilateral L5/S1 decompression, partial medial facetectomy, and partial discectomy with microscopic-assistance. First RTP ranged from 4-6 months, with full RTP at 6-8 months. Pain dissipated to the 0-1 range at full RTP. Final effort/performance improved from 10-60% mid-injury to 90-100% at full RTP. Each athlete's 2000m row time showed a decline mid-injury and an improvement to at or within 10 s of their pre-injury time. CONCLUSIONS: Drawing from three collegiate rowers who underwent lumbar decompression surgery, each athlete successfully returned to rowing, with initial RTP in the 4-6 months range and full RTP in the 6-8 months range. Performance levels rebounded to near or better than pre-injury performance. The results of this small case series warrant replication in larger, multi-institutional samples.

Evaluation of coronal alignment from the skull using the novel orbital-coronal vertical axis line.

OBJECTIVE: When treating patients with adult spinal deformity (ASD), radiographic measurements evaluating coronal alignment above C7 are lacking. The current objectives were to: 1) describe the new orbital-coronal vertical axis (ORB-CVA) line that evaluates coronal alignment from cranium to sacrum, 2) assess correlation with other radiographic variables, 3) evaluate correlations with patient-reported outcomes (PROs), and 4) compare the ORB-CVA with the standard C7-CVA. METHODS: A retrospective cohort study of patients with ASD from a single institution was undertaken. Traditional C7-CVA measurements were obtained. The ORB-CVA was defined as the distance between the central sacral vertical line and the vertical line from the midpoint between the medial orbital walls. The ORB-CVA was correlated using traditional coronal measurements, including C7-CVA, maximum coronal Cobb angle, pelvic obliquity, leg length discrepancy (LLD), and coronal malalignment (CM), defined as a C7-CVA > 3 cm. Clinical improvement was analyzed as: 1) group means, 2) minimal clinically important difference (MCID), and 3) minimal symptom scale (MSS) (Oswestry Disability Index < 20 or Scoliosis Research Society-22r Instrument [SRS-22r] pain + function domains > 8). RESULTS: A total of 243 patients underwent ASD surgery, and 175 had a 2-year follow-up. Of the 243 patients, 90 (37%) had preoperative CM. The mean (range) ORB-CVA at each time point was as follows: preoperatively, 2.9 ± 3.1 cm (-14.2 to 25.6 cm); 1 year postoperatively, 2.0 ± 1.6 cm (-12.4 to 6.7 cm); and 2 years postoperatively, 1.8 ± 1.7 cm (-6.0 to 11.1 cm) (p < 0.001 from preoperatively to 1 and 2 years). Preoperative ORB-CVA correlated best with C7-CVA (r = 0.842, p < 0.001), maximum coronal Cobb angle (r = 0.166, p = 0.010), pelvic obliquity (r = 0.293, p < 0.001), and LLD (r = 0.158, p = 0.006). Postoperatively, the ORB-CVA correlated only with C7-CVA (r = 0.629, p < 0.001) and LLD (r = 0.153, p = 0.017). Overall, 155 patients (63.8%) had an ORB-CVA that was ≥ 5 mm different from C7-CVA. The ORB-CVA correlated as well and sometimes better than C7-CVA with SRS-22r subdomains. After multivariate logistic regression, a greater ORB-CVA was associated with increased odds of complication, whereas C7-CVA was not associated with any of the three clinical outcomes (complication, readmission, reoperation). A larger difference between the ORB-CVA and C7-CVA was significantly associated with readmission and reoperation after univariate and multivariate logistic regression analyses. A threshold of ≥ 1.5-cm difference between the preoperative ORB-CVA and C7-CVA was found to be predictive of poorer outcomes. CONCLUSIONS: The ORB-CVA correlated well with known coronal measurements and PROs. ORB-CVA was independently associated with increased odds of complication, whereas C7-CVA was not associated with any outcomes. A ≥ 1.5-cm difference between the preoperative ORB-CVA and C7-CVA was found to be predictive of poorer outcomes.

Understanding the role of pelvic obliquity and leg length discrepancy in adult spinal deformity patients with coronal malalignment: unlocking the black box.

OBJECTIVE: This study had 3 objectives: 1) to describe pelvic obliquity (PO) and leg-length discrepancy (LLD) and their relationship with coronal malalignment (CM); 2) to report rates of isolated PO and PO secondary to LLD; and 3) to assess the importance of preoperative PO and LLD in postoperative complications, readmission, reoperation, and patient-reported outcomes. METHODS: Patients undergoing surgery (≥ 6-level fusions) for adult spinal deformity at a single institution were reviewed. Variables evaluated were as follows: 1) PO, angle between the horizontal plane and a line touching bilateral iliac crests; and 2) LLD, distance from the head to the tibial plafond. Coronal vertical axis (CVA) and sagittal vertical axis measurements were collected, both from C7. The cutoff for CM was CVA > 3 cm. The Oswestry Disability Index (ODI) was collected preoperatively and at 2 years. RESULTS: Of 242 patients undergoing surgery for adult spinal deformity, 90 (37.0%) had preoperative CM. Patients with preoperative CM had a higher PO (2.8° ± 3.2° vs 2.0° ± 1.7°, p = 0.013), a higher percentage of patients with PO > 3° (35.6% vs 23.5%, p = 0.044), and higher a percentage of patients with LLD > 1 cm (21.1% vs 9.8%, p = 0.014). Whereas preoperative PO was significantly positively correlated with CVA (r = 0.26, p < 0.001) and maximum Cobb angle (r = 0.30, p < 0.001), preoperative LLD was only significantly correlated with CVA (r = 0.14, p = 0.035). A total of 12.2% of patients with CM had significant PO and LLD, defined as follows: PO ≥ 3°; LLD ≥ 1 cm. Postoperatively, preoperative PO was significantly associated with both postoperative CM (OR 1.22, 95% CI 1.05-1.40, p = 0.008) and postoperative CVA (ß = 0.14, 95% CI 0.06-0.22, p < 0.001). A higher preoperative PO was independently associated with postoperative complications after multivariate logistic regression (OR 1.24, 95% CI 1.05-1.45, p = 0.010); however, 2-year ODI scores were not. Preoperative LLD had no significant relationship with postoperative CM, CVA, ODI, or complications. CONCLUSIONS: A PO ≥ 3° or LLD ≥ 1 cm was seen in 44.1% of patients with preoperative CM and in 23.5% of patients with normal coronal alignment. Preoperative PO was significantly associated with preoperative CVA and maximum Cobb angle, whereas preoperative LLD was only associated with preoperative CVA. The direction of PO and LLD showed no consistent pattern with CVA. Preoperative PO was independently associated with complications but not with 2-year ODI scores.

Clinicians' User Experience of Telemedicine in Neurosurgery During COVID-19.

BACKGROUND: Restricted access to hospitals due to the 2019 novel coronavirus disease (COVID-19) pandemic has significantly altered practice patterns for elective neurosurgical care. Particularly, telemedicine has become the primary modality of patient visits for nonemergent conditions. This study aimed to characterize user experiences of neurosurgeons and advanced practice providers focusing on perceived utility and barriers of telemedicine in management of elective neurosurgical patients during COVID-19. METHODS: An online survey was sent to clinicians involved in neurosurgical care using telemedicine with questions focusing on frequency of utilization, duration of patient encounters, benefits of telemedicine, and barriers to current forms of remote patient visits. Survey responses were stratified by clinical position (neurosurgeon vs. advanced practice provider) and subspecialty focus (cranial vs. spinal neurosurgery). RESULTS: The survey was completed by 14 of 17 eligible clinicians. Respondents included 10 neurosurgeons and 4 APPs with 57% specializing in cranial neurosurgery and 43% specializing in spinal neurosurgery. During the COVID-19 period, 78% of respondents used teleconference/video conference visits multiple times in a week, and 86% planned to continue using telemedicine after the pandemic. The most common barrier for telemedicine was the inability to perform a neurological examination, while the most common perceived benefit was increased convenience for patients. CONCLUSIONS: During the COVID-19 period, telemedicine was heavily relied on to ensure the continuation of perioperative care for patients with elective neurosurgical pathologies. While clinicians identified numerous barriers for current telemedicine platforms, the use of telemedicine will likely continue, as it has provided unique benefits for patients, clinicians, and hospitals.

Be Prepared: Preoperative Coronal Malalignment Often Leads to More Extensive Surgery Than Sagittal Malalignment During Adult Spinal Deformity Surgery.

OBJECTIVE: To evaluate the effect of coronal alignment on: (1) surgical invasiveness and operative complexity and (2) postoperative complications. METHODS: A retrospective, cohort study of adult spinal deformity patients was conducted. Alignment groups were: (1) neutral alignment (NA): coronal vertical axis (CVA) ≤ 3 cm and sagittal vertical axis (SVA) ≤ 5 cm; (2) coronal malalignment (CM) only: CVA > 3 cm; (3) Sagittal malalignment (SM) only: SVA > 5 cm; and (4) coronal and sagittal malalignment (CCSM): CVA > 3 cm and SVA > 5 cm. RESULTS: Of 243 patients, alignment groups were: NA 115 (47.3%), CM 48 (19.8%), SM 38 (15.6%), and CCSM 42 (17.3%). Total instrumented levels (TILs) were highest in CM (14.5 ± 3.7) and CCSM groups (14 ± 4.0) (p < 0.001). More 3-column osteotomies (3COs) were performed in SM (21.1%) and CCSM (28.9%) groups than CM (10.4%) (p = 0.003). CM patients had more levels instrumented (p = 0.029), posterior column osteotomies (PCOs) (p < 0.001), and TLIFs (p = 0.002) than SM patients. CCSM patients had more TLIFs (p = 0.012) and higher estimated blood loss (EBL) (p = 0.003) than SM patients. CVA displayed a stronger relationship with TIL (p = 0.002), EBL (p < 0.001), and operative time (p < 0.001) than SVA, which had only one significant association with EBL (p = 0.010). Both SM/CCSM patients had higher readmissions (p = 0.003) and reoperations (p < 0.001) than CM patients. CONCLUSION: Amount of preoperative CM was a better predictor of surgical invasiveness than the amount of SM, despite 3COs more commonly performed in SM patients. CM patients had more instrumented levels, PCOs, and TLIFs than SM patients.

Transforaminal lumbar interbody fusion using a novel minimally invasive expandable interbody cage: patient-reported outcomes and radiographic parameters.

OBJECTIVE: The goal of this study was to evaluate the clinical and radiographic outcomes of a novel multidirectional in situ expandable minimally invasive surgery (MIS) transforaminal lumbar interbody fusion (TLIF) cage. METHODS: A retrospective analysis of 69 consecutive patients undergoing a 1- or 2-level MIS TLIF using an expandable cage was performed over a 2-year period. Standard MIS techniques with pedicle screw fixation were used in all cases. Upright lateral dynamic flexion/extension radiographs were reviewed prior to and at 1 year after surgery. Clinical metrics included numeric rating scale for back and leg pain, Oswestry Disability Index, and the SF-12 and VR-12 physical and mental health surveys. Radiographic parameters included anterior and posterior disc height, neuroforaminal height, spondylolisthesis, segmental lordosis, lumbar lordosis, and fusion rate. RESULTS: A total of 69 patients representing 75 operative levels met study inclusion criteria. The mean patient age at surgery was 63.4 ± 1.2 years, with a female predominance of 51%. The average radiographic and clinical follow-ups were 372 and 368 days, respectively. A total of 63 patients (91%) underwent 1-level surgery and 6 patients (9%) underwent 2-level surgery. Significant reductions of numeric rating scale scores for back and leg pain were observed-from 6.1 ± 0.7 to 2.5 ± 0.3 (p < 0.0001) and 4.9 ± 0.6 to 1.9 ± 0.2 (p < 0.0001), respectively. A similar reduction in Oswestry Disability Index from 38.0 ± 4.6 to 20.0 ± 2.3 (p < 0.0001) was noted. Likewise, SF-12 and VR-12 scores all showed statistically significant improvement from baseline (p < 0.001). The mean anterior and posterior disc heights improved from 8.7 ± 1.0 mm to 13.4 ± 1.5 mm (p = 0.0001) and 6.5 ± 0.8 mm to 9.6 ± 1.1 mm (p = 0.0001), respectively. Neuroforaminal height improved from 17.6 ± 2.0 mm to 21.9 ± 2.5 mm (p = 0.0001). When present, spondylolisthesis was, on average, reduced from 4.3 ± 0.5 mm to 1.9 ± 0.2 mm (p = 0.0001). Lumbar lordosis improved from 47.8° ± 5.5° to 58.5° ± 6.8° (p = 0.2687), and no significant change in segmental lordosis was observed. The overall rate of radiographic fusion was 93.3% at 1 year. No perioperative complications requiring operative revision were encountered. CONCLUSIONS: In this series of MIS TLIFs, use of this novel interbody cage was shown to be safe and effective. Significant improvements in pain and disability were observed. Effective and durable restoration of disc height and neuroforaminal height and reduction of spondylolisthesis were obtained, with concurrent gains in lumbar lordosis. Taken together, this device offers excellent clinical and radiographic outcomes via an MIS approach.