Radiographic Results of Expandable Interbody Devices

Introduction: Minimally invasive surgery for transforaminal lumbar interbody fusion (MIS-TLIF) has become a mainstay procedure in the treatment of degenerative conditions of the lumbar spine. Expandable interbody devices have gained popularity in recent times due to several well-cited advantages including greater correction of disc height and lordosis and decreased intraoperative disruption of neurologic structures. However, the clinical benefits offered by these devices compared to traditional static implants remain unclear. This study seeks to investigate differences in the radiographic and clinical outcomes between traditional static versus expandable interbody devices used in MIS-TLIF. Methods: Patients who underwent MIS-TLIF performed by three surgeons from 2014 to 2020 at a single institution high-volume center were retrospectively reviewed. Radiographic measurements were performed on lateral radiographs taken preoperatively, 3-weeks following, and at least 6 months following the date of surgery. Radiographic analysis included anterior and posterior disc height, segmental lordosis, endplate violation, and cage subsidence. Clinical outcomes were evaluated by assessing for the presence of radicular leg pain on the side of the TLIF following surgery at 3 months follow up. Statistical analysis included independent t tests for continuous variables and chi-square analysis for categorical values. Results: Three-hundred and sixty-seven patients who underwent MIS-TLIF for degenerative diagnoses using either a static (229 patients) or expandable (138 patients) cage were included. The mean age was 62.9 ± 11.7 years in the static group and 67.4 ± 11.2 years in the expandable group. The mean body mass index (BMI) was 30.4 ± 6.4 in the static group and 30.73 ± 7.3 in the expandable group. Patients receiving expandable cages had significantly greater anterior disc height (11.5 mm static vs. 13.2 mm expandable, p \u3c 0.001), posterior disc height (7.18 mm static vs 8.19 mm expandable, p \u3c 0.001), and segmental lordosis (6.47 degrees static vs 7.49 degrees expandable, p = 0.001) at most recent follow up. No significant differences in cage subsidence rates were noted between static (19.7%) and expandable (22.9%) devices (OR =0.823, CI 0.513 – 1.321, p = 0.42). Patients who received expandable devices reported greater improvements in leg pain at 3 months follow up (p = 0.012). Discussion: Patients who underwent MIS-TLIF with an expandable device demonstrated greater correction of anterior and posterior disc height, as well as greater and more sustained correction of segmental lordosis compared to static cages. No significant differences were noted in cage subsidence rate between static and expandable cages. Patients who received expandable devices were noted to have greater improvements in radicular leg pain

Is facet joint distraction a cause of postoperative axial neck pain after ACDF surgery?

Introduction: Intervertebral distraction in anterior cervical discectomy and fusion (ACDF) has been postulated to injure the degenerative facet joints posteriorly and increase postoperative pain and disability. This study aims to determine if there is a correlation between the amount of facet distraction and postoperative patient reported outcomes. Methods: A retrospective cohort analysis of patients undergoing ACDF for degenerative pathologies was performed. Each patient received lateral cervical spine x-rays at the immediate postoperative time point and were split into groups based on the amount of facet distraction measured on these films: Group A: \u3c 1.5 mm; Group B: 1.5-2.0 mm; and Group C: \u3e 2.0 mm. Patients reported outcome measures were obtained preoperatively and at 1-year postoperatively. Univariate and multivariate analyses were performed to compare outcomes between groups. Results: A total of 229 patients were included with an average follow-up of 19.8 [19.0, 20.7] months with a mean facet joint distraction of 1.7mm. There were 87 patients in Group A, 76 patients in Group B, and 66 patients in Group C. Patients significantly improved across all outcome measures from baseline to postoperatively (p \u3c 0.05). There was no difference between groups at any time point with respect to outcome scores (p \u3e 0.05). Multiple regression analysis did not identify increasing distraction as a predictor of patient outcomes. Conclusions: There were no significant differences between patient outcomes and the amount of facet distraction after ACDF surgery. Multivariate analysis did not find a correlation between facet distraction and overall HRQOL outcome

Serotonin Reuptake Inhibitor Increases Pseudarthrosis Rates in Anterior Cervical Discectomy and Fusions

STUDY DESIGN: Retrospective cohort. PURPOSE: To determine (1) the effects of serotonin reuptake inhibitors in pseudarthrosis rates after anterior cervical decompression and fusion (ACDF) and (2) to identify patient-reported outcome measures in patients taking serotonin reuptake inhibitors. OVERVIEW OF LITERATURE: Recent literature suggests that selective serotonin reuptake inhibitors (SSRIs) may inhibit fracture healing via downregulation of osteoblast differentiation. Spinal fusion supplementation with osteoblast-rich substances enhances spinal fusion, thus SSRIs may be detrimental. METHODS: Patients with 1-year postoperative dynamic cervical spine radiographs following ACDF were grouped into serotonin reuptake inhibitor prescriptions (SSRI, serotonin-norepinephrine reuptake inhibitor [SNRI], or tricyclic antidepressant [TCA]) and no prescription (atypical antidepressant or no antidepressant). Pseudarthrosis was defined as ≥1 mm interspinous process motion on dynamic radiographs. Logistic regression models were controlled for confounding to analyze pseudarthrosis rates. Alpha was set at p - values of \u3c0.05. RESULTS: Of the 523 patients who meet the inclusion criteria, 137 (26.2%) were prescribed an SSRI, SNRI, or TCA. Patients with these prescriptions were more likely to have pseudarthrosis (p =0.008) but not a revision surgery due to pseudarthrosis (p =0.219). Additionally, these patients had worse 1-year postoperative mental component summary (MCS)-12 (p =0.015) and Neck Disability Index (NDI) (p =0.006). The multivariate logistic regression analysis identified SSRI/SNRI/TCA use (odds ratio [OR], 1.82; 95% confidence interval [CI], 1.11-2.99; p =0.018) and construct length (OR, 1.91; 95% CI, 1.50-2.44; p CONCLUSIONS: Patients taking serotonin reuptake-inhibiting antidepressants are at increased risk of worse postoperative outcome scores, including NDI and MCS-12, likely due to their underlying depression. This may contribute to their greater likelihood of having adjacent segment surgery. Additionally, preoperative use of serotonin reuptake inhibitors in patients undergoing an ACDF is a predictor of radiographic pseudarthrosis but not pseudarthrosis revision