Atlantoaxial instability (AAI) is surgically a complex entity due to its proximity to vital neurovascular structures. C1-C2 fusion has been an established standard in its treatment for a considerable time now. Here, we have outlined the most common techniques for C2 screw fixation in practice at present such as C2 pedicle, C2 pars, C2 translaminar, C2 subfacetal, C2-C3 transfacetal, and C2 inferior facet screw. We have discussed in detail the technical as well as biomechanical aspects of each technique of C2 screw fixation in AAI and explored the intricacies of each technique.

Background: Steadily increasing expenditure in the United States health-care system has led to a shift toward a value-based model that focuses on quality of care and cost-effectiveness. Operations involving the spine rank among some of the most common and expensive procedures performed in operating rooms nationwide. Patient-reported outcomes measures (PROMs) are a useful tool for reporting levels of outcome and analyzing patient recovery but are both under-utilized and nonstandardized in spine surgery. Methods: We conducted a systematic review of the literature using the PubMed database, focusing on the most commonly utilized PROMs for spine disease as well as spinal deformity. The benefits and drawbacks of these PROMs were then summarized and compared. Results: Spine-specific PROMs were based on the class of disease. The most frequently utilized PROMs were the Neck Disability Index and the modified Japanese Orthopaedic Association scale; the Oswestry Disability Index and the Roland-Morris Disability Questionnaire; and the Scoliosis Research Society 22-item questionnaire (SRS-22) for cervicothoracic spine disease, lumbar spine disease, and spinal deformity, respectively. Conclusion: We found limited, though effective, use of PROMs targeting specific classes of disease within spine surgery. Therefore, we advocate for increased use of PROMs in spine surgery, in both the research and clinical settings. PROM usage can help physicians assess subjective outcomes in standard ways that can be compared across patients and institutions, more uniquely tailor treatment to individual patients, and engage patients in their own medical care.

The aim of this meta-analysis was to analyze the results of one-stage all-posterior spinal fusion for severe adolescent idiopathic scoliosis (AIS). A systematic search of articles about one-stage posterior spinal fusion for severe AIS was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Data about population, pre-and postoperative radiographical data, surgical procedure details, and complications were extracted. Meta-analyses were performed when possible. Fourteen studies (640 patients) were included. The mean Cobb angle of the major curve varied from 80.0 ± 7.3 to 110.8 ± 12.1. The meta analysis showed a comprehensive coronal correction rate of the major curve of 58.6%, a comprehensive operative time of 274.5 min, and a comprehensive estimated intraoperative blood loss of 866.5 mL (95% confidence interval: 659.3–1073.6, I² ≈ 0%). A total of 48 complications (5.4%) were reported. Overall, the meta-analysis showed a major complication rate of 4%. In seven cases, revision surgery was needed. Posterior-only approach is effective enough to correct severe curves and can spare the patient possible adverse events due to anterior approach. However, when choosing this approach for severe AIS, screw density needs to be high and posterior column osteotomies may need to be planned to mobilize the spine and maximize correction.

Objective: Lumbar spinal degenerative disease (LSDD), unresponsive to conservative therapy, is commonly treated by surgical decompression and interbody fusion. Since facet joint incompetence has been suggested as responsible for the entire phenomenon of spinal degeneration, facet stabilization can be considered as an alternative technique to treat symptomatic spinal degenerative disease. The purpose of this study was to systematically review the literature for studies utilizing lumbar facet joint fixation techniques for LSDD to assess their safety and efficacy. Methods: A systematic literature review was performed following the preferred reporting items for systematic reviews and meta-analyses statement, with no limits in terms of date of publication. Demographic data, inclusion criteria, clinical and radiological outcome, frequency of adverse events (AEs), and follow-up time were evaluated. Results: A total of 19 studies were included with a total of 1577 patients. The techniques used for facet arthrodesis were Goel intra-articular spacers in 21 patients (5.3%), Facet Wedge in 198 patients (15.8%), facet screws fixation techniques in 1062 patients (52.6%), and facet joints arthroplasty in 296 patients (26.3%). Clinical outcomes were assessed through the evaluation of pain relief and improvement in functional outcome. Radiological outcomes were assessed by the evaluation of proper positioning of instrumentation, solid bony fusion rate, and preservation of disk height. AE's mainly observed were pseudoarthrosis, reoperation, instrumentation displacement/malpositioning/migration, neurological impairment, deep vein thrombosis, and infections. The mean follow-up time ranged from 6 months to 11.7 years. Conclusion: Our data demonstrate that facet joint arthrodesis appears to be effective in managing LSDD. These findings, however, are limited by the small sample size of patients. Accordingly, larger series are needed before formal recommendations can be made.

Background: Traumatic vertebral artery dissections (tVADs) occur in up to 20% of patients with head trauma, yet data on their presentation and associated sequelae are limited. Aims and Objectives: To characterize the tVAD population and identify factors associated with clinical outcomes. Materials and Methods: We retrospectively analyzed all cases of tVAD at our institution from January 2004 to December 2018 with respect to mechanism of injury, clinical presentation, anatomic factors, associated pathologies, and relevant outcomes. Results: Of the 123 patients with tVAD, the most common presenting symptoms were neck pain (n=76, 67.3%), headache (57.5%), and visual changes (29.6%). 101 cases (82.1%) were unilateral, and 22 cases (17.9%) were bilateral. V2 was the most involved anatomic segment (83 cases, 70.3). 30 cases (25.4%) led to stroke, and 39 cases (31.7%) had a concomitant cervical fracture. The anatomic segment and number of segments involved, and baseline clinical and demographic characteristics were not associated with risk of stroke. Patients with associated fractures were older (50.3 years v. 36.4 years, p=0.0233), had a higher comorbid disease burden (CCI 1 vs. CCI 1, p<0.0007), were more likely to smoke (OR 3.0 [1.2178, 7.4028], p=0.0202), be male (OR 7.125 [3.0181, 16.8236], p<0.0001), and have mRS≥3 at discharge (OR 3.0545 [1.0937, 8.5752], p=0.0449). On multivariable regression, only fracture independently predicted mRS≥3 at discharge (OR 5.6898 [1.5067, 21.4876], p=0.010). Conclusion: tVADs may be associated with stroke and/or cervical fracture. Presenting symptoms predict stroke, but baseline demographic and clinical characteristics do not. Comorbid cervical fractures, not stroke, drive negative outcomes

Study Design: The study design used was a retrospective cohort. Objective: The objective of this study is to determine if intraoperative improvements in sagittal alignment on the operating table persisted on postoperative standing radiographs. Summary of Background Data: Cervical sagittal alignment may be correlated to postoperative outcomes. Since anterior cervical discectomy and fusions (ACDFs) can restore some cervical lordosis through intervertebral grafts/cages, it is important to understand if intraoperative radiographic measurements correlate with persistent postoperative radiographic changes. Materials and Methods: Patients undergoing elective primary ACDF were screened for the presence of lateral cervical radiographs preoperatively, intraoperatively, and postoperatively. Patients were excluded if their first postoperative radiograph was more than 3 months following the procedure or if cervical lordosis was not able to be measured at each time point. Paired t-tests were utilized to compare differences in measurements between time points. Statistical significance was set at P < 0.05. Results: Of 46 included patients, 26 (56.5%) were female, and the mean age was 55.2 ± 11.6 years. C0-C2 lordosis significantly increased from the preoperative to intraoperative time point (delta [Δ] = 4.49, P = 0.029) and significantly decreased from the intraoperative to postoperative time period (Δ = −6.57, P < 0.001), but this resulted in no significant preoperative to postoperative change (Δ = −2.08, P = 0.096). C2 slope decreased from the preoperative to the intraoperative time point (Δ = −3.84, P = 0.043) and significantly increased from the intraoperative to the postoperative time point (Δ = 3.68, P = 0.047), which also resulted in no net change in alignment between the preoperative and postoperative periods (Δ = −0.16, P = 0.848). There was no significant difference in the C2-C7 SVA from the preoperative to intraoperative (Δ = 0.85, P = 0.724) or intraoperative to postoperative periods (Δ = 2.04, P = 0.401); however, the C2-C7 SVA significantly increased from the preoperative to postoperative period (Δ = 2.88, P = 0.006). Conclusions: Intraoperative positioning predominantly affects the mobile upper cervical spine, particularly C0-C2 lordosis and C2 slope, but these changes do not persist postoperatively.

Background: Limited literature is available to define the impact of the longus colli muscle, a deep flexor of the spine, on cervical spine stability despite its close proximity to the vertebrae. Aims and Objectives: The purpose of this study was to determine if longus colli cross-sectional area (CSA) is associated with the severity preoperative cervical degenerative spondylolisthesis. Materials and Methods: Patients undergoing elective anterior cervical discectomy and fusion (ACDF) for cervical spondylolisthesis between 2010-2021 were retrospectively identified. Longus colli cross-sectional areas (CSA) were measured from preoperative MRI images at the C5 level. Preoperative spondylolisthesis measurements were recorded with cervical radiographs. Patients were grouped by quartiles respectively according to longus colli CSAs. Statistical tests compared patient demographics, surgical characteristics, and surgical outcomes between groups. Multiple linear regression analysis was utilized to assess if longus colli CSA predicted cervical spondylolisthesis. Results: A total of 157 patients met inclusion criteria. Group 1 (first quartile) was the oldest (60.4 ± 12.0 years, P = 0.024) and was predominantly female (59.0%, P = 0.001). Group 1 also had the highest maximum spondylolisthesis (0.19 mm, P = 0.031) and highest proportion of grade 2 spondylolisthesis (23.1%, P = 0.003). On regression analysis, lowest quartile of longus colli CSA was an independent predictor of larger measured maximum spondylolisthesis (β: 0.04, P = 0.012). Conclusion: Smaller longus colli CSA is independently associated with a higher grade and degree of preoperative cervical spondylolisthesis, but this finding does not result in adverse postsurgical outcomes.

Context: Despite the growing evidence demonstrating its effectiveness, lumbar disc arthroplasty (LDA) rates have not increased significantly in recent years. A likely contributing factor is uncertainties related to reimbursement and insurers' denial of coverage due to fear of late complications, reoperations, and unknown secondary costs. However, no prior study has compared the physician reimbursement rates of lumbar fusion and LDA. Aim: The aim of this study was to compare the relative value units (RVUs) per min as well as 30-day readmission, reoperation, and morbidity rates between anterior lumbar interbody fusion (ALIF) and LDA. Settings and Design: This was a retrospective cohort study. Subjects and Methods: The current study utilizes data obtained from the National Surgical Quality Improvement Program database. Patients who underwent ALIF or LDA between 2011 and 2019 were included in the study. Statistical Analysis Used: Propensity score matching analysis was performed according to demographic characteristics and comorbidities. Matched groups were compared through Fisher's exact test and independent t-test for categorical and continuous variables, respectively. Results: Five hundred and two patients who underwent ALIF were matched with 591 patients who underwent LDA. Mean RVUs per min was significantly higher for ALIF compared to LDA. ALIF was associated with a significantly higher 30-day morbidity rate compared to LDA, while readmission and reoperation rates were statistically similar. ALIF was also associated with higher frequencies of deep venous thrombosis (DVT) and blood transfusions. Conclusions: ALIF is associated with significantly higher RVUs per min compared to LDA. ALIF is also associated with higher rates of 30-day morbidity, DVT, and blood transfusions, while readmission and reoperation rates were statistically similar.

Objective: The purpose of our study was to identify adult trauma patients with an acute C1 burst fracture, evaluate for concomitant transverse atlantal ligament (TAL) injury, and apply the modified Gehweiler and AO spine classification systems to determine the utility of these classification systems in accurately defining C1 trauma. Materials and Methods: Adult trauma patients with an acute C1 fracture were identified retrospectively using Nuance mPower software. The C1 fracture was described based on whether the fracture involved the anterior arch, posterior arch, lateral mass, medial tubercle, and/or transverse process. If follow-up cervical magnetic resonance imaging (MRI) was performed, the presence and location of an associated TAL injury was recorded. The anatomic location of the C1 burst fracture and TAL injury, if present, were compared with the descriptive classification systems outlined by Gehweiler/Dickman (modified) and the AO Spine society. Any additional osseous trauma of the skull base and C1-C2 was also recorded along with relevant clinical history and management. Results: Thirty-nine patients were identified with an acute C1 burst fracture on cervical computed tomography (CT) with seventy-seven percent of patients undergoing follow-up cervical MRI. Observed fracture patterns were divided into five distinct types based on CT findings and further subdivided based on the integrity of the transverse altantal ligament on MRI. TAL tears were observed exclusively in type 3 fractures (anterior and posterior arch fractures) and type 4 fractures (anterior arch, posterior arch, and lateral mass fractures). The modified Gehweiler classification system failed to accurately describe the anatomic location of the C1 fracture in forty-four percent of patients, whereas the AO spine was too broad and failed to accurately describe fracture location in our cohort. Conclusions: The Gehweiler and AO spine classifications demonstrated significant shortcomings in the accurate description of patients with C1 trauma. Whereas the Gehweiler system did not accurately describe the anatomic location of the various C1 fractures, the AO spine system was too broad and failed to radiologically classify fracture location. Moreover, there was a high number of patients with AO spine type B injuries without atlantoaxial translation that nevertheless required C1-C2 fusion for atlantoaxial instability. We suggest the need for an updated classification system that takes into account both the CT (fracture location) and MRI (TAL integrity) appearance of C1 trauma. An updated classification strategy will offer a radiologic standardization of C1 trauma that will aid in future research studies and help optimize patient management.

Background: Craniovertebral junction (CVJ) anomalies involve mosaic interaction of multifaceted neurovascular and bony elements. Most of them present late in the course of illness usually as acute presentations following trivial trauma. Knowing subclinical autonomic dysfunction in such anomalies when managed medically can not only indicate progression but also provide en route to early intervention for better outcomes, especially in relatively asymptomatic patients. Materials and Methods: We conducted a 6-year longitudinal prospective study including 40 consecutive patients of CVJ anomalies with clinical, radiological, and heart rate variability (HRV) parameters and found their correlation in preoperative and follow-up period. Results: Twenty-eight patients were male and the rest were female. The mean age was 32 years with the least age being 8 years and maximum age being 75 years old. Mean Nurick's grade and Barthel's index were 1.8 and 83.75, respectively. 38% had severe-to-moderate compression. The mean follow-up was 17.4 months. Both sympathetic and parasympathetic oscillator HRV indices were significantly affected in the preoperative period (P ≤ 0.001) with no association with Nurick's grade or degree of compression although there was association with grade of Barthel's index. Poincare plots showed “fan,” “complex,” or “torpedo” patterns in 36 patients. Forty patients had both preoperative and follow-up clinical grade whereas 22 patients HRV tests in the above periods. None of the HRV indices showed significant improvement at follow-up. Nonetheless both sympathetic and parasympathetic did improve at follow-up with sympathetic tone registering better scores. Poincare plots showed improvement toward “comet” patterns in all patients. Conclusion: HRV indices not only help in prognosticating but may also help in predicting outcomes.

Objective: Loss of lumbar lordosis (LL) in degenerative deformity activates spinal compensatory mechanisms to maintain neutral C7 sagittal vertical axis (C7SVA), such as an increase in pelvic tilt (PT) and decreased thoracic kyphosis (TK). We study the extent to which PT increase and TK reduction contribute to the compensation of pelvic incidence (PI)-LL mismatch. Methods: A cohort of 43 adult patients with adult degenerative thoracolumbar deformity were included in this retrospective study. Radiographic spinopelvic measurements were obtained before and after corrective surgery. Pearson correlations were calculated. Results: Preoperative PI-LL mismatch significantly correlated with an increase in PT and a decrease in TK in the whole cohort r = +0.66 (95% confidence interval [CI] 0.44–0.8) and r = −0.67 (95% CI − 0.81–−0.47), respectively, at a relative rate of 0.37 (standard deviation [SD]: 0.07) and − 0.57 (SD: 0.09), respectively. In patients with low PI, only TK showed a significant correlation with PI-LL mismatch, r = −0.56 (95% CI − 0.8 to − 0.16), at a rate of − 0.57 (SD: 0.19). The high PI subgroup showed a significant correlation with PT, TK, and C7SVA, r = 0.62 (95% CI 0.26–0.82), r = −0.8 (95% CI − 0.9–−0.58), and r = 0.71 (95% CI 0.41–0.87) at rates of 0.48 (SD: 0.11), −0.72 (SD: 0.12), and 0.62 (SD: 1.27). Conclusions: Decreased TK represented a more consistent compensatory mechanism in patients with high and low PI when compared to an increase in PT. PI-LL mismatch induced more pronounced changes in TK than did PT in both subgroups. Patients with high PI relied more on increases in PT and a relative decrease in TK to compensate for PI-LL mismatch than patients with low PI.