Study Design: A prospective study. Objectives: We present a largest study until date performed over a period of 10 years assessing the perioperative complications. The primary aim of this study was to review the incidence of perioperative complications of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) in single-level lumbar degenerative diseases. Methods: A prospective study performed over a period of 10 years involving 560 patients who underwent single-level lumbar MI-TLIF. Perioperative clinical and radiological parameters, postoperative complications, and satisfactory outcomes in the form of Wang’s criteria were evaluated. All patients were scrutinized into 5 different categories based on the descriptive classification for perioperative complications suggested by the authors. Results: The mean age was 61.8 ± 12.7 years and male to female ratio was 0.8:1. The overall incidence of the perioperative complication was 25.5%. In all, 19.64% patients developed single complication, 4.64% patients were with 2 complications, and 1.25% patients developed 3 complications from the described categories. A total of 16.78% patients developed early (<6 months postsurgery) and 8.75% patients developed late (>6 months postsurgery) complications. Conclusion: This study showed 25.5% incidence of perioperative complications in MI-TLIF for degenerative lumbar disease over a period of 10 years with a higher incidence rate during the initial 3 years of practice. The described classification for perioperative complications is helpful to record, to evaluate and to understand the etiology based on its duration of occurrence in the perioperative period. MI-TLIF is an effective procedure with substantial clinical benefits in the form of excellent to good clinical-radiological outcomes.

The purpose of this study was to compare the clinical-radiological outcome and incidence of perioperative complications of MIS-TLIF at lower lumbar levels for elderly (Age >65 years) and younger patients (Age<65 years). Methods: A retrospective cohort study performed from 2011 to 2017. A total 138 patients who underwent MIS-TLIF were divided into two groups based on age (group A>65 years and group B<65 years). Perioperative clinical (co-morbidities, surgical time, blood loss, hospital stay, fusion level, VAS, ODI), radiological parameters (fusion, cage subsidence, implant failure), postoperative complications and satisfactory outcomes in the form of Wang's criteria were evaluated in both the groups. A statistical analysis between two matched groups was done with logistic regression analysis, chisquare and student t-test. Results: There was no statistical difference in blood loss, surgical time, mobilization and hospital stay between two groups however elderly patients took longer time to become pain free (p=0.001). Both groups showed significant improvement in ODI, VAS and Wang's outcome score however, no statistically significant difference noted in outcome between two groups at final follow up. General complications not affecting outcome were common in elderly group but no statistically significant difference noted among neurological events between both groups. Conclusion: MISS-TLIF surgery in elderly can produce successful clinical outcome and satisfaction after surgery in judiciously selected patients with proper preoperative risk assessment and optimization of medical co-morbidities. Elder age does not prove deterrent to outcome and should not be a contraindication to perform MISS-TLIF in lumbar degenerative diseases.

Study Design: This study was a radiographic observational study for C1–C2 anthropometry. Purpose: The purpose of the study was to understand the anatomic relationship of C1–C2 in view of transarticular screw (TAS) fixation, to overcome the difficulties related with TAS placement, and to minimize the technique-related complications. Materials and Methods: It was an anthropometric observational study with retrospectively obtained anatomical data of randomly selected 116 patients from a single center. The anatomical measurements such as pars width, pars height, screw trajectory, and length were evaluated on the axial, sagittal, and three-dimensional reconstructed cervical CT scan using the radiant DICOM viewer software by the two fellowship trained spine surgeons which were blind to the study group details. The intra- and interobserver reliability with regard to the measured parameters was statistically analyzed. Results: The mean age of male and female was 28 and 29 years. The average BMI was calculated to be 23.5 and 25 for males and females, respectively. The mean right pars width in males was 5.78 ± 0.93 (range: 3.1–6.5 mm), while in female, it was 5.84 ± 0.95 (range: 3.1–6.5). The mean left pars width in males was 5.95 ± 1.13 (range: 3.8–8.1 mm), while in females, it was 5.70 ± 1.18 (range: 3.7–8.1 mm). Right side mean pars height in males was 5.90 ± 1.2 (range: 3.7–9.4 mm), and in females, it was 6.11 ± 1.04 (range: 3.8–9.3 mm). Left-sided mean pars height in males was 6.0 ± 1.1 (range: 3.2–9.4 mm) as compared to females, in which it was 5.77 ± 1.23 (range: 4.1–9.3 mm). The mean lateral angulation angle in males was 9.99° ± 1.70° (8.1°–15°), while in females, it was 10.15° ± 1.73° (8.1°–15°). The mean sagittal angulation in males was 26.33° ± 3.32° (21.0°–32.80°), while in females, it was 27.18 ± 3.05 (21.0°–32.10°). The average screw length in males was 41.74 ± 5.63 (34–54.8 mm), whereas in females, it was 41.35 ± 4.77 (34–54.8 mm). Conclusion: This study provides a morphometric database which is characteristic of the C1–C2 vertebrae in the normal Indian population with regard to the anatomic feasibility of the TAS fixation for various C1–C2 pathologies. The C2 pars width and height measured in the current study can guide the selection of TAS screws in the Indian population. This study could serve in providing the baseline anatomic parameters assessed in the healthy individuals to design and develop customized screws and related implant assembly which might provide wider clinical applicability.

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Objective: To evaluate the learning curve associated with minimally invasive surgery (MIS) in posterior C1-C2 trans-articular (TAS) screw fixation based on surgical and clinical parameters. Also, to report the challenges faced and measures to overcome them. Methods: 84 patients who underwent C1-C2 MIS-TAS between 2009-2014 were included in the study and were divided into four quartiles (q) (21 patients each) based on the date of their surgery with each consecutive group serving as a control for prior. Pre-and post-operative clinical and perioperative parameters, technical issues and complications were evaluated. Results: The mean age of the patients was 36.26±5.78 years (20-78 years) with male to female ratio of 48:36. A statistically significant difference was observed between the mean operative time and mean blood loss between second and third quartile. Inadvertent vertebral artery injury occurred in 3 cases without any post-operative sequelae. There were 6 instances of guide wire migration (q1=4, q2=2). At 2 instances (q1=2) there was guide wire breakage. Total 9 times (q1=5, q2=2, q3=1, q4=1) dorsal burst into C2 pars occurred. VAS, ODI and mJOA scores showed a significant improvement from their pre-operative values in the entire study population without any significant difference between the quartiles. Conclusion: C1-C2 MIS-TAS is a very safe and effective means of treating reducible atlanto-axial instability. Pre-operative planning, detailed radiological evaluation, practice on cadavers/bone-saw models and by following the mentioned recommendations the learning curve of C1-C2 MIS-TAS can be reduced.