Static vs. Expandable PEEK Interbody Cages: A Comparison of One-Year Clinical and Radiographic Outcomes for One-Level TLIF

Introduction: Degenerative spine disease is a disabling condition affecting many worldwide. Transoforaminal lumbar interbody fusion (TLIF) procedures help stabilize the spine, while improving back and/or leg pain. With the introduction of new implant designs and modifications, focus has shifted to optimizing spinopelvic alignment, fusion rates, and more. This study aims to explore the effect of static versus expandable polyetheretherketone (PEEK) cages on patient-reported outcomes (PROMs) and radiographic outcomes (subsidence, disk height, and alignment parameters). Materials/Methods: A retrospective cohort study was conducted using a database of patients in a single, high volume academic center. Patient outcomes were obtained from charts and radiographic outcomes were measured using standing, lateral radiographs. Data were analyzed using mean sample t-tests or categorical chi-squared tests, and multiple linear regression where appropriate. Results: Our results showed improved Oswestry Disability Index (ODI) scores perioperatively in the expandable cage group compared to the static cage group at the three-month and one-year time periods. In addition, there were a significantly greater proportion of patients that reached minimal clinically important difference (MCID) in the expandable group compared to the static cage group. There were no significant changes in subsidence or alignment parameters between the two groups at the one-year time period. Conclusion: Overall, our results show that TLIF patients treated with expandable PEEK cages had significantly greater improvement in one-year outcomes compared to patients with static cages. Expandable cages confer the advantage of more precise insertion into the intervertebral disk space, while providing a way to tailor the cage height for better distraction and spinal alignment. Further prospective studies are warranted to get a better idea of the impact of interbody design on clinical/radiographic outcomes

A Case of Intradural Extramedullary Spinal Tuberculosis Diagnosed 8 Years After Treatment of the Primary Infection

Tuberculosis (TB), the disease caused by Mycobacterium tuberculosis, is the second leading killer worldwide from a single infectious agent. Spinal TB is associated with pulmonary disease and may originate from (1) hematogenous spread outside the central nervous system (CNS), (2) sites located within the cranium (meningitis), or (3) secondary extension from vertebral bodies or discs (Pott’s disease).1 Other presentations of tuberculosis include tuberculous arachnoiditis, nonosseous spinal tuberculoma, and spinal meningitis. Of these conditions, spinal tuberculoma can be intradural, extradural, intramedullary, or extramedullary. Intradural extramedullary tuberculosis is the most rare type and is only observed in 1 out of 50,000 cases of tuberculosis.2,3 To date, there has only been one documented intradural extramedullary tuberculoma in a non-HIV-infected patient in North America.4 Intradural spinal tuberculomas often present simultaneously or are preceded by tuberculous meningitis (TBM).5,6 We treated an otherwise healthy 68-yearold male that developed progressive lower extremity pain and weakness from an intradural spinal tuberculoma. While spinal tuberculomas have been previously described, no prior author has reported a tuberculoma several years after successful eradication of the pulmonary infection. In this case report, we present the case, pertinent imaging, operative findings, histopathology, and a review of the literature

Traumatic thoracic ASIA A examinations and potential for clinical trials

Study Design: Retrospective review of prospective database Objectives: To define the variability of neurologic examination and recovery after non-penetrating complete thoracic spinal cord injuries (ASIA A). Background Data: Neurologic examinations after SCI can be difficult and inconsistent. Unlike cervical SCI patients, alterations in thoracic (below T1) complete SCI (ASIA A – based on the ASIA Impairment Scale [AIS]) patients’ exams are based only on sensory testing, thus changes in the neurological level (NL) are determined only by sensory changes. Methods: A retrospective review of the placebo control patients in a multicenter prospective database utilized for the pharmacologic trial of Sygen. Patients were included if they had a complete thoracic SCI on initial evaluation, with completed ASIA examinations at follow-up weeks 4, 8, 16, 26 and 52. Specifically, pin prick (PP) and light touch (LT) were assessed and the absolute change was calculated as the number of spinal levels at a given observation time. Results 3165 patients were initially screened for the Sygen clinical trial, of which 57 were the control placebo patients used in this analysis. Alterations from the baseline exam (PP and LT) were fairly consistent and the median change/recovery in neurologic examination was one spinal level. Across all observations post-baseline, the average change for PP was 1.48 +/- 0.13 (mean +/- SE), and for LT, 1.40 +/-0.13. There were equal proportions of directional changes (none, improved, lost). Conclusions: Changes in a thoracic complete (ASIA A) SCI patient ASIA examination as measured through sensory modalities (PP/LT) are fairly uncommon. The overall examination had only 1-2 level variability across patients, indicating minimal change in the sensory exam over the follow-up period. Stability in the ASIA examination as measured through sensory modalities has thus been demonstrated over time, making it an excellent tool to monitor changes in neurologic function

Static v. Expandable TLIF Cage Outcomes

Static cages were introduced in the 1990s as a solution to degenerative spondylolisthesis, recurrent disc herniation and spinal stenosis. As this procedure was popularized, a new class of expandable Transforaminal Lumbar Interbody Fusion devices was introduced to further improve outcomes that will be studied in this project. It will be explored how expandable cages compare to static cages in TLIF procedures in patient-reported outcomes, complications and restoration of appropriate lumbar lordosis. We conducted a retrospective cohort review comparing those who received expandable and static cages. Eligible patients received TLIF procedure at the Rothman Institute, were ≥18 years of age and had radiographic follow-up at 3 months and 1 year postoperatively. Outcomes were measured in lumbar lordosis via calculating angles via radiographic images preoperatively and 3 month and 1 year postoperatively as well as pre- and post-operative SF-12 surveys. At this time, data acquisition is ongoing and no preliminary data has been generated. However, we anticipate better patient reported outcomes and greater and sustained restoration of Lumbar Lordosis in patients who received expandable cages. Data collection is scheduled to be completed shortly. Once completed, this will be a study of greater magnitude and will address the shortage of investigations into the surgical outcomes of static and expandable cages and clarify the theorized benefits of expandable cages. Recent emphasis has been placed on restoring appropriate lumbar lordosis in fusion surgeries and this project was designed to investigate lordosis at different time posts as compared to patient-reported outcomes

Clinical Outcomes After Four-Level Anterior Cervical Discectomy and Fusion.

Study Design: Retrospective cohort study. Objectives: Anterior cervical discectomy and fusion (ACDF) demonstrates reliable improvement in neurologic symptoms associated with anterior compression of the cervical spine. There is a paucity of data on outcomes following 4-level ACDFs. The purpose of this study was to evaluate clinical outcomes for patients undergoing 4-level ACDF. Methods: All 4-level ACDFs with at least 1-year clinical follow-up were identified. Clinical outcomes, including fusion rates, neurologic outcomes, and reoperation rates were determined. Results: Retrospective review of our institutional database revealed 25 patients who underwent 4-level ACDF with at least 1-year clinical follow-up. Average age was 57.5 years (range 38.2-75.0 years); 14 (56%) were male, and average body mass index was 30.2 kg/m Conclusions: Review of our institution\u27s experience demonstrated a low rate of revision cervical surgery for any reason of 8% at mean 19 months follow-up, and neurological examinations consistently improved, despite a high rate of radiographic nonunion (31%)

Neurologic improvement after thoracic, thoracolumbar, and lumbar spinal cord (conus medullaris) injuries

Study Design. Retrospective. Objective. With approximately 10,000 new spinal cord injury (SCI) patients in the United States each year, predicting public health outcomes is an important public health concern. Combining all regions of the spine in SCI trials may be misleading if the lumbar and sacral regions (conus) have a neurologic improvement at different rates than the thoracic or thoracolumbar spinal cord. Summary of Background Data. Over a 10-year period between January 1995 to 2005, 1746 consecutive spinal injured patients were seen, evaluated, and treated through a level 1 trauma referral center. A retrospective analysis was performed on 150 patients meeting the criteria of T4 to S5 injury, excluding gunshot wounds. One-year follow-up data were available on 95 of these patients. Methods. Contingency table analyses (chi-squared statistics) and multivariate logistic regression. Variables of interest included level of injury, initial American Spinal Injury Association (ASIA), age, race, and etiology. Results. A total of 92.9% of lumbar (conus) patients neurologically improved one ASIA level or more compared with 22.4% of thoracic or thoracolumbar spinal cord-injured patients. Only 7.7% of ASIA A patients showed neurologic improvement, compared with 95.2% of ASIA D patients; ASIA B patients demonstrated a 66.7% improvement rate, whereas ASIA C had a 84.6% improvement rate. When the two effects were considered jointly in a multivariate analysis, ASIA A and thoracic/thoracolumbar patients had only a 4.1% rate of improvement, compared with 96% for lumbar (conus) and incomplete patients (ASIA B-D) and 66.7% to 72.2% for the rest of the patients. All of these relationships were significant to P \u3c 0.001 (chi-square test). There was no link to age or gender, and race and etiology were secondary to region and severity of injury. Conclusion. Thoracic (T4-T9) SCIs have the least potential for neurologic improvement. Thoracolumbar (T10-T12) and lumbar (conus) spinal cord have a greater neurologic improvement rate, which might be related to a greater proportion of lower motor neurons. Thus, defining the exact region of injury and potential for neurologic improvement should be considered in future clinical trial design. Combining all anatomic regions of the spine in SCI trials may be misleading if different regions have neurologic improvement at different rates. Over a ten-year period, 95 complete thoracic/thoracolumbar SCI patients had only a 4.1% rate of neurologic improvement, compared with 96.0% for incomplete lumbar (conus) patients and 66.7% to 72.2% for all others

Effectiveness of Surgery for Lumbar Stenosis and Degenerative Spondylolisthesis in the Octogenarian Population: Analysis of the Spine Patient Outcomes Research Trial (SPORT) Data.

BACKGROUND: The purpose of this study was to determine whether surgery is an effective option for the treatment of stenosis of the lumbar spine and degenerative spondylolisthesis in the octogenarian population. METHODS: An as-treated analysis of patients with lumbar stenosis and degenerative spondylolisthesis enrolled in the Spine Patient Outcomes Research Trial (SPORT) was performed. Patients who were at least eighty years of age (n = 105) were compared with those younger than eighty years (n = 1130). Baseline patient and clinical characteristics were noted, and the difference in improvement from baseline between operative and nonoperative treatment was determined for each group at each follow-up time period up to four years. RESULTS: There were no significant baseline differences in the primary or secondary patient-reported clinical outcome measures between the two patient age groups. Patients at least eighty years of age had higher prevalences of multilevel stenosis, severe stenosis, and asymmetric motor weakness. Patients at least eighty years of age also had higher prevalences of hypertension, heart disease, osteoporosis, and joint problems at baseline, but they had a lower body mass index and lower prevalences of depression and smoking. Fifty-eight of the 105 patients at least eighty years of age and 749 of the 1130 younger patients underwent operative management. There were no differences in the rates of intraoperative or postoperative complications, reoperation, or postoperative mortality between the older and younger groups. Averaged over a four-year follow-up period, operatively treated patients at least eighty years of age had significantly greater improvement in all primary and secondary outcome measures compared with nonoperatively treated patients. The treatment effects in patients at least eighty years of age were similar to those in younger patients for all primary and secondary measures except the SF-36 (Short Form-36) bodily pain domain and the percentage who self-rated their progress as a major improvement, in both of which the treatment effect was significantly smaller. CONCLUSIONS: Operative treatment of lumbar stenosis and degenerative spondylolisthesis offered a significant benefit over nonoperative treatment in patients at least eighty years of age (p \u3c 0.05). There were no significant increases in the complication and mortality rates following surgery in this patient population compared with younger patients (p \u3e 0.05). LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence

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