Multilevel ossification of the posterior longitudinal ligament causing cervical myelopathy: An observational series of North American patients.

Background: Few studies regarding ossification of the posterior longitudinal ligament (OPLL) outside of Asia currently exist in the literature. A set of patients with multilevel cervical OPLL causing symptomatic myelopathy or radiculopathy from a North American sample is analyzed. Objective: The objective of this study was to describe the demographics, radiographic findings, and surgical outcomes of a cohort of North American patients with degenerative spondylosis presenting for operative management of multilevel (>3 segments) cervical OPLL. Materials and Methods: Forty-three patients diagnosed with multilevel cervical OPLL and degenerative spondylosis presenting with symptomatic cervical myelopathy or radiculopathy were surgically treated over a 9-year period at a single tertiary care academic medical center. Radiographic measurements were performed on preoperative computed tomography and magnetic resonance imaging images of the cervical spine. Clinical outcomes included pre- and postoperative Nurick scores, 90-day readmission, complication, and revision surgery rates. Results: The mean age was 66.1 ± 10.9 years with a mean latest follow-up time of 32.7 ± 16.4 months. Most patients had previous diagnoses of obesity (70.7%) and hypertension (55.8%). At least one-quarter of patients were diagnosed with type 2 diabetes (34.9%), hyperlipidemia (41.9%), cardiovascular disease (25.6%), or chronic kidney disease (25.3%). The most common OPLL subtype was segmental (39.5%) and spanned a mean of 3.54 ± 1.48 segments. Myelopathic symptoms were present in 88.4% of patients. All patients experienced significant neurologic improvement at 3-week and latest follow-up (P < 0.001 for both). Conclusions: Obesity, diabetes, and other metabolic derangements in patients with existing cervical spondylosis may be risk factors for a particularly aggressive form of multilevel OPLL. Various operative approaches may be employed to achieve adequate neurologic recovery. Further workup for OPLL in patients with these risk factors may prove beneficial to ensure appropriate operative management.

Static versus Expandable Interbody Fusion Devices: A Comparison of 1-Year Clinical and Radiographic Outcomes in Minimally Invasive Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective cohort study. PURPOSE: To compare the radiographic and clinical outcomes of static versus expandable interbody cages in transforaminal lumbar interbody fusion using minimally invasive surgery (MIS-TLIF). OVERVIEW OF LITERATURE: Expandable interbody cages may potentially improve radiographic and clinical outcomes following MIS-TLIF compared to static pages, but at a potentially higher cost and increased rates of subsidence. METHODS: A retrospective chart review of 1- and 2-level MIS-TLIFs performed from 2014 to 2020 was reviewed. Radiographic measurements were obtained preoperatively, 6 weeks postoperatively, and at final follow-up. Patient-reported outcome measures (PROMs) including the Oswestry Disability Index, Visual Analog Scale (VAS) back, and VAS leg were evaluated. Multivariate linear regression analysis determined the effect of cage type on the change in PROMs, controlling for demographic characteristics. Alpha was set at 0.05. RESULTS: A total of 221 patients underwent MIS-TLIF including 136 static and 85 expandable cages. Expandable cages had significantly greater anterior (static: 11.41 mm vs. expandable: 13.11 mm, p <0.001) and posterior disk heights (static: 7.22 mm vs. expandable: 8.11 mm, p <0.001) at 1-year follow-up. Expandable cages offered similar improvements in segmental lordosis at 6 weeks (static: 1.69° vs. expandable: 2.81°, p =0.243), but segmental lordosis was better maintained with expandable cages leading to significant differences at 1-year follow-up (static: 0.86° vs. expandable: 2.45°, p =0.001). No significant differences were noted in total complication (static: 12.5% vs. expandable: 16.5%, p =0.191) or cage subsidence rates (static: 19.7% vs. expandable: 22.4%, p =0.502) groups at 1-year follow-up. CONCLUSIONS: Expandable devices provide greater improvements in radiographic measurements including anterior disk height, posterior disk height, and segmental lordosis, but this did not lead to significant improvements in PROMs, complication rates, subsidence rates, or subsidence distance.

Patient Outcomes Following Short-segment Lumbar Fusion Are Not Affected by PI-LL Mismatch.

STUDY DESIGN: This is a retrospective cohort study. OBJECTIVE: The objective of this study was to further elucidate the relationship between pelvic incidence-lumbar lordosis (PI-LL) mismatch and surgical outcomes in patients undergoing short segment lumbar fusions for degenerative lumbar disease. SUMMARY OF BACKGROUND DATA: There are few studies examining the relationship between spinopelvic parameters and patient reported outcome measurements (PROMs) in short segment lumbar degenerative disease. MATERIALS AND METHODS: A retrospective review was conducted at single academic institution. Patients undergoing 1- or 2-level lumbar fusion were retrospectively identified and separated into 2 groups based on postoperative PI-LL mismatch ≤10 degrees (NM) or PI-LL mismatch >10 degrees (M). Outcomes including the Physical Component Score (PCS)-12, Mental Component Score (MCS)-12, Oswestry Disability Index (ODI), Visual Analog Scale (VAS) back and leg scores were analyzed. Absolute PROM scores, the recovery ratio and the percentage of patients achieving minimum clinically important difference between groups were compared and a multiple linear regression analysis was performed. RESULTS: A total of 306 patients were included, with 59 patients in the NM group and 247 patients in the M group. Patients in the M group started with a higher degree of PI-LL mismatch compared with the NM group (22.2 vs. 7.6 degrees, P<0.001) and this difference increased postoperatively (24.7 vs. 2.5 degrees, P<0.001). There were no differences between the 2 groups in terms of baseline, postoperative, or Δ outcome scores (P>0.05). In addition, having a PI-LL mismatch was not found to be an independent predictor of any PROM on multivariate analysis (P>0.05). CONCLUSION: The findings in this study show that even though patients in the M group had a higher degree of mismatch preoperatively and postoperatively, there was no difference in PROMs. LEVEL OF EVIDENCE: Level III.

Transpsoas Lumbar Interbody Fusion Without Psoas Stimulated Electromyography.

STUDY DESIGN: This is a retrospective case review. OBJECTIVE: The objective of this study was to present an anatomic approach to transpsoas interbody fusion without psoas stimulated electromyography (sEMG) and to evaluate the rate of neurological and approach-related complications. BACKGROUND: The transpsoas approaches have become commonly utilized for lumbar interbody fusion and may have certain advantages compared with other methods of interbody stabilization. Traditionally, transpsoas approaches have been performed utilizing sEMG as it has been purported to reduce the risk of injury to the lumbar plexus; however, an anatomic approach to transpsoas surgery is also possible as cadaveric studies have demonstrated the anatomy of the psoas muscle and lumbar plexus. METHODS: Patients who underwent transpsoas interbody fusion using an anatomic approach without psoas sEMG between 2005 and 2018 were enrolled in this study. The preoperative and postoperative medical records for this cohort were carefully reviewed to identify any new or persistent radicular symptoms, neurological deficits or approach-related complications. RESULTS: A total of 133 patients (48 males, 85 females) underwent transpsoas interbody fusion at 222 levels in this cohort-which had a mean age of 63 (61, 65) years and body mass index of 28.8 (27.8, 29.9). New neurological complications were seen in 5 patients (3.8%) and 5 patients (3.8%) were found to have new postoperative radicular pain, up to 3 months postoperatively. The total number of perioperative, approach-related complications was 7 (5.3%) for the entire cohort. CONCLUSION: An anatomic transpsoas approach to the interbody space without psoas sEMG demonstrated a rate of neurological and approach-related complications that was comparable or superior to the rate of complications reported using the traditional transpsoas approach with sEMG.

Processing and Handling Cost of Single-use Versus Traditional Instrumentation for 1 Level Lumbar Fusions.

STUDY DESIGN: A single center, observational prospective clinical study. OBJECTIVE: The aim of this study was to compare the instrumentation-related cost and efficiency of single-use instrumentation versus traditional reusable instrument trays. SUMMARY OF BACKGROUND DATA: Single-use instrumentation provides the opportunity to reduce costs associated with cleaning and sterilizing instrumentation after surgery. Although previous studies have shown single-use instrumentation is effective in other orthopedic specialties, it is unclear if single-use instrumentation could provide economic advantages in spine surgery. MATERIALS AND METHODS: A total of 40 (20 reusable instrumentation and 20 single-use instrumentation) lumbar decompression (1-3 level) and fusion (1 level) spine surgeries were collected. Instrument handling, opening, setup, re-stocking, cleaning, sterilization, inspection, packaging, and storage were recorded by direct observation for both reusable and single-use instrumentation. The rate of infection was noted for each group. RESULTS: Mean time of handling instruments by the scrub nurse was 11.6 (±3.9) minutes for reusable instrumentation and 2.1 (±0.5) minutes for single-use instrumentation. Mean cost of handling reusable instruments was estimated to be $8.52 (±$2.96) per case, and the average cost to reprocess a single tray by Sterilization Processing Department (SPD) was $58. Thus, the median cost for sterilizing 2 reusable trays per case was $116, resulting in an average total Costresuable of $124.52 (±$2.96). Mean cost of handling single-use instrumentation was estimated to be $1.57 ($0.38) per case. CONCLUSION: Single-use instrumentation provided greater cost savings and reduced time from the opening of instrumentation to use in surgery when compared with reusable instrumentation.

Are Patient Outcomes Affected by the Presence of a Fellow or Resident in Lumbar Decompression Surgery?

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of this study was to determine whether the presence of a fellow or resident (F/R) compared to a physician assistant (PA) affected surgical variables or short-term patient outcomes. SUMMARY OF BACKGROUND DATA: Although orthopedic spine fellows and residents must participate in minimum number of decompression surgeries to gain competency, the impact of trainee presence on patient outcomes has not been assessed. METHODS: One hundred and seventy-one patients that underwent a one- to three-level lumbar spine decompression procedure at a high-volume academic center were retrospectively identified. Operative reports from all cases were examined and patients were placed into one of two groups based on whether the first assist was a F/R or a PA. Univariate analysis was used to compare differences in total surgery duration, 30-day and 90-day readmissions, infection and revision rates, patient-reported outcome measures (Short Form-12 Physical Component Score and Mental Component Score, Oswestry Disability Index, Visual Analog Scale [VAS] Back, VAS Leg) between groups. Multiple linear regression was used to assess change in each patient reported outcome and multiple binary logistic regression was used to determine significant predictors of revision, infection, and 30- or 90-day readmission. RESULTS: Seventy-eight patients were included in the F/R group compared to 93 patients in the PA group. There were no differences between groups for total surgery time, 30-day or 90-day readmissions, infection, or revision rates. Using univariate analysis, there were no differences between the two groups pre- or postoperatively (P > 0.05). Using multivariate analysis, presence of a surgical trainee did not significantly influence any patient reported outcome and did not affect infection, revision, or 30- and 90-day readmission rates. CONCLUSION: This is one of the first studies to show that the presence of an orthopedic spine fellow or resident does not affect patient short-term outcomes in lumbar decompression surgery. LEVEL OF EVIDENCE: 3.

Depression Identified on the Mental Component Score of the Short Form-12 Affects Health Related Quality of Life After Lumbar Decompression Surgery.

STUDY DESIGN: This was a retrospective comparative study. OBJECTIVE: The goal of this study was to further elucidate the relationship between preoperative depression and patient-reported outcome measurements (PROMs) following lumbar decompression surgery. SUMMARY OF BACKGROUND DATA: The impact of preoperative depression on PROMs after lumbar decompression surgery is not well established. METHODS: Patients undergoing lumbar decompression between 1 and 3 levels were retrospectively identified. Patients were split into 2 groups using a preoperative Mental Component Score (MCS)-12 threshold score of 45.6 or 35.0 to identify those with and without depressive symptoms. In addition, patients were also split based on a pre-existing diagnosis of depression in the medical chart. Absolute PROM scores, the recovery ratio and the percent of patients achieving minimum clinically important difference between groups were compared, and a multiple linear regression analysis was performed. RESULTS: A total of 184 patients were included, with 125 (67.9%) in the MCS-12 >45.6 group and 59 (32.1%) in the MCS-12 ≤45.6 group. The MCS-12 ≤45.6 and MCS<35.0 group had worse baseline Oswestry Disability Index (ODI) (P<0.001 for both) and Visual Analogue Scale Leg (P=0.018 and 0.024, respectively) scores. The MCS ≤45.6 group had greater disability postoperatively in terms of SF-12 Physical Component Score (PCS-12) (39.1 vs. 43.1, P=0.015) and ODI (26.6 vs. 17.8, P=0.006). Using regression analysis, having a baseline MCS-12 scores ≤45.6 before surgical intervention was a significant predictor of worse improvement in terms of PCS-12 [ß=-4.548 (-7.567 to -1.530), P=0.003] and ODI [ß=8.234 (1.433, 15.035), P=0.010] scores than the MCS-12 >45.6 group. CONCLUSION: Although all patients showed improved in all PROMs after surgery, those with MCS-12 ≤45.6 showed less improvement in PCS-12 and ODI scores.

Development of a Telemedicine Neurological Examination for Spine Surgery: A Pilot Trial.

STUDY DESIGN: This was a prospective cohort study. OBJECTIVE: The objective of this study was to design and test a novel spine neurological examination adapted for telemedicine. SUMMARY OF BACKGROUND DATA: Telemedicine is a rapidly evolving technology associated with numerous potential benefits for health care, especially in the modern era of value-based care. To date, no studies have assessed whether. METHODS: Twenty-one healthy controls and 20 patients with cervical or lumbar spinal disease (D) were prospectively enrolled. Each patient underwent a telemedicine neurological examination as well as a traditional in-person neurological examination administered by a fellowship trained spine surgeon and a physiatrist. Both the telemedicine and in-person tests consisted of motor, sensory, and special test components. Scores were compared via univariate analysis and secondary qualitative outcomes, including responses from a satisfaction survey, were obtained upon completion of the trial. RESULTS: Of the 20 patients in the D group, 9 patients had cervical disease and 11 patients had lumbar disease. Comparing healthy control with the D group, there were no significant differences with respect to all motor scores, most sensory scores, and all special tests. There was a high rate of satisfaction among the cohort with 92.7% of participants feeling "very satisfied" with the overall experience. CONCLUSIONS: This study presents the development of a viable neurological spine examination adapted for telemedicine. The findings in this study suggest that patients have comparable motor, sensory, and special test scores with telemedicine as with a traditional in-person examination administered by an experienced clinician, as well as reporting a high rate of satisfaction among participants. To our knowledge, this is the first telemedicine neurological examination for spine surgery. Further studies are warranted to validate these findings.

Risk Factors for Prolonged Opioid Use and Effects of Opioid Tolerance on Clinical Outcomes After Anterior Cervical Discectomy and Fusion Surgery.

STUDY DESIGN: Retrospective study. OBJECTIVE: The aim of this study was to determine risk factors for prolonged opioid use and to investigate whether opioid-tolerance affects patient-reported outcomes following anterior cervical discectomy and fusion (ACDF) surgery. SUMMARY OF BACKGROUND DATA: There is a lack of consensus on risk factors that can affect continued opioid use after cervical spine surgery and the influence of opioid use on patient-reported outcomes. METHODS: Ninety-two patients who underwent ACDF for degenerative cervical pathologies were retrospectively identified and their opioid usage before surgery was investigated using a state-sponsored prescription drug monitoring registry. Opioid-naïve and opioid tolerant groups were defined using criteria most consistent with the Federal Drug Administration (FDA) definition. Patient-reported outcomes were then collected, including the Short Form-12 (SF-12) Physical Component (PCS-12) and Mental Component (MCS-12), the Neck Disability Index (NDI), the Visual Analogue Scale Neck (VAS neck) and the Visual Analogue Scale Arm (VAS Arm) pain scores. Logistic regression was used to determine predictors for prolonged opioid use following ACDF. Univariate and multivariate analyses were conducted to compare change in outcomes over time between the two groups. RESULTS: Logistic regression analysis demonstrated that opioid tolerance was a significant predictor for prolonged opioid use after ACDF (odds ratio [OR]: 18.2 [1.46, 226.4], P = 0.02). Duration of usage was also found to be a significant predictor for continued opioid use after surgery (OR: 1.10 [1.0, 1.03], P = 0.03). No other risk factors were found to be significant predictors. Both groups overall experienced improvements in patient-reported outcomes after surgery. Multiple linear regression analysis, controlling for patient demographics, demonstrated that opioid-tolerant user status positively affected change in outcomes over time for NDI (ß = -13.7 [-21.8,-5.55], P = 0.002) and PCS-12 (ß = 6.99 [2.59, 11.4], P = 0.003) but no other outcomes measured. CONCLUSION: Opioid tolerance was found to be a significant predictor for prolonged opioid use after ACDF. Additionally, opioid-naïve and opioid-tolerant users experienced overall improvements across PROMs following ACDF. Opioid-tolerance was associated with NDI and PCS-12 improvements over time compared to opioid-naïve users. LEVEL OF EVIDENCE: 4.

Preoperative Mental Health Component Scoring Is Related to Patient Reported Outcomes Following Lumbar Fusion.

STUDY DESIGN: Retrospective cohort review. OBJECTIVE: The objective of this study was to identify depression using the Mental Component Score (MCS-12) of the Short Form-12 (SF-12) survey and to correlate with patient outcomes. SUMMARY OF BACKGROUND DATA: The impact of preexisting depressive symptoms on health-care related quality of life (HRQOL) outcomes following lumbar spine fusion is not well understood. METHODS: Patients undergoing lumbar fusion between one to three levels at a single center, academic hospital were retrospectively identified. Patients under the age of 18 years and those undergoing surgery for infection, trauma, tumor, or revision, and less than 1-year follow-up were excluded. Patients with depressive symptoms were identified using an existing clinical diagnosis or a score of MCS-12 less than or equal to 45.6 on the preoperative SF-12 survey. Absolute HRQOL scores, the recovery ratio (RR) and the percent of patients achieving minimum clinically important difference (MCID) between groups were compared, and a multiple linear regression analysis was performed. RESULTS: A total of 391 patients were included in the total cohort, with 123 (31.5%) patients reporting symptoms of depression based on MCS-12 and 268 (68.5%) without these symptoms. The low MCS-12 group was found to have significantly worse preoperative Oswestry disability index (ODI), visual analogue scale back pain (VAS Back) and visual analogue scale leg pain (VAS Leg) scores, and postoperative SF-12 physical component score (PCS-12), ODI, VAS Back, and VAS Leg pain scores (P < 0.05) than the non-depressed group. Finally, multiple linear regression analysis revealed preoperative depression to be a significant predictor of worse outcomes after lumbar fusion. CONCLUSION: Patients with depressive symptoms, identified with an MCS-12 cutoff below 45.6, were found to have significantly greater disability in a variety of HRQOL domains at baseline and postoperative measurement, and demonstrated less improvement in all outcome domains included in the analysis compared with patients without depression. However, while the improvement was less, even the low MCS-12 cohort demonstrated statistically significant improvement in all HRQOL outcome measures after surgery. LEVEL OF EVIDENCE: 3.

Circulating miR-155-5p as a Novel Biomarker of Lumbar Degenerative Disc Disease.

MINI: Circulating microRNAs provide an insight into current disease states. Comparing patients with degenerative disc disease to healthy controls, patients with disc disease were found to have significantly downregulated levels of miR-155-5p. This marker was found to be an accurate diagnostic predictor for the presence of degeneration (P = 0.006). STUDY DESIGN: Case-control study measuring differential gene expression of circulating microRNA (miRNA) in patients with degenerative disc disease (DDD). OBJECTIVE: To identify miRNA dysregulation in serum samples of patients with DDD compared to healthy controls (HC). SUMMARY OF BACKGROUND DATA: Early DDD can be a difficult diagnosis to make clinically, with lack of positive and specific findings on physical exam or advanced imaging. miRNAs are a class of molecules that act as gene regulators and have been shown to be dysregulated in local degenerative disc tissue. However, to date no studies have identified dysregulation of serum miRNA in patients with DDD. METHODS: Whole blood samples were obtained from 69 patients with DDD and 16 HC. Patient-reported outcomes were collected preoperatively and degree of DDD was classified using Pfirrmann grade on preoperative imaging. Differential gene expression analysis using a screening assay for several hundred miRNAs and further characterization for five specific miRNAs (miR-16-5p, miR-21-5p, miR-142-3p, miR-146a-5p, and miR-155-5p) was performed. In addition, a pro-inflammatory cytokine multiplex assay and bioinformatics analysis were done. RESULTS: The initial screening assay showed 13 miRNA molecules that were significantly dysregulated in DDD patients, with miR-155-5p showing significant downregulation (p = 0.027) and direct interactions with the pro-inflammatory cytokine IL-1ß, and the tumor suppressor genes p53 and BRAF. Analyzing the whole cohort, miR-155 showed an almost four-fold downregulation in DDD patients (-3.94-fold, P < 0.001) and was the sole miRNA that accurately predicted the presence of disc degeneration (P = 0.006). Downregulation of miR-155 also correlated with increased leg pain (P = 0.018), DDD (P = 0.006), and higher Pfirrmann grade (P = 0.039). On cytokine analysis, TNF-α (0.025) and IL-6 (P < 0.001) were significantly higher in DDD patients. CONCLUSION: Serum miR-155-5p is significantly downregulated in patients with DDD and may be a diagnostic marker for degenerative spinal disease. LEVEL OF EVIDENCE: N/A.

Case-control study measuring differential gene expression of circulating microRNA (miRNA) in patients with degenerative disc disease (DDD). To identify miRNA dysregulation in serum samples of patients with DDD compared to healthy controls (HC). Early DDD can be a difficult diagnosis to make clinically, with lack of positive and specific findings on physical exam or advanced imaging. miRNAs are a class of molecules that act as gene regulators and have been shown to be dysregulated in local degenerative disc tissue. However, to date no studies have identified dysregulation of serum miRNA in patients with DDD. Whole blood samples were obtained from 69 patients with DDD and 16 HC. Patient-reported outcomes were collected preoperatively and degree of DDD was classified using Pfirrmann grade on preoperative imaging. Differential gene expression analysis using a screening assay for several hundred miRNAs and further characterization for five specific miRNAs (miR-16-5p, miR-21-5p, miR-142-3p, miR-146a-5p, and miR-155-5p) was performed. In addition, a pro-inflammatory cytokine multiplex assay and bioinformatics analysis were done. The initial screening assay showed 13 miRNA molecules that were significantly dysregulated in DDD patients, with miR-155-5p showing significant downregulation (p = 0.027) and direct interactions with the pro-inflammatory cytokine IL-1ß, and the tumor suppressor genes p53 and BRAF. Analyzing the whole cohort, miR-155 showed an almost four-fold downregulation in DDD patients (−3.94-fold, P < 0.001) and was the sole miRNA that accurately predicted the presence of disc degeneration (P = 0.006). Downregulation of miR-155 also correlated with increased leg pain (P = 0.018), DDD (P = 0.006), and higher Pfirrmann grade (P = 0.039). On cytokine analysis, TNF-α (0.025) and IL-6 (P < 0.001) were significantly higher in DDD patients. Serum miR-155-5p is significantly downregulated in patients with DDD and may be a diagnostic marker for degenerative spinal disease. Level of Evidence: N/A.

How Does Body Mass Index Influence Outcomes in Patients After Lumbar Fusion?

STUDY DESIGN: Retrospective study. OBJECTIVE: The purpose of the present study is to determine how body mass index (BMI) affects patient-reported outcome measurements (PROMs) after lumbar fusions. SUMMARY OF BACKGROUND DATA: Although greater preoperative BMI is known to increase the rates of adverse events after surgery, there is a paucity of literature assessing the influence of BMI on PROMs after lumbar fusion. METHODS: Patients undergoing lumbar fusion surgery between 1 and 3 levels were retrospectively identified. PROMs analyzed were the Short Form-12 Physical Component Score, Mental Component Score, Oswestry Disability Index (ODI), and Visual Analog Scale Back and Leg pain scores. Patients were divided into groups based on preoperative BMI: class 1, BMI <25.0; class 2, BMI 25.0 to 29.9; class 3, BMI 30.0 to 34.9; and class 4, BMI ≥35.0. Absolute PROM scores, the recovery ratio, and the percentage of patients achieving minimum clinically important difference between groups were compared. RESULTS: A total of 54 (14.8%) patients in class 1, 140 (38.2%) in class 2, 109 (29.8%) in class 3, and 63 (17.2%) in class 4 were included. All patients improved after surgery across all outcome measures (P < 0.001) except for class 4 patients, who did not improve in terms of Short Form-12 Mental Component Score scores after surgery (P = 0.276). Preoperative Short Form-12 Physical Component Score (P = 0.002) and Oswestry Disability Index (P < 0.0001) scores were significantly different between BMI groups-with class 4 having worse disability than class 1 and 2. BMI was not a significant predictor for any outcome domain. Overall 30- and 90-day readmission rates were similar between groups, with a higher revision rate in the class 4 group (P = 0.036), due to a higher incidence of postoperative surgical site infections (P = 0.014). CONCLUSION: All patients undergoing short-segment lumbar fusion for degenerative disease improved to a similar degree with respect to PROMs. Those in the highest class of obesity (BMI ≥35.0) were, however, at a greater risk for postoperative surgical site infection. LEVEL OF EVIDENCE: 3.

Comparison of Short-term Outcomes After Lumbar Fusion Between an Orthopedic Specialty Hospital and Tertiary Referral Center.

STUDY DESIGN: A retrospective review of all elective single-level lumbar fusions performed at a single orthopedic specialty hospital (OSH) and tertiary referral center (TRC). OBJECTIVE: This study compared the perioperative outcomes for lumbar fusion procedures performed at an OSH and TRC. SUMMARY OF BACKGROUND DATA: The role of an OSH for lumbar fusion procedures has not been defined. METHODS: A large institutional database was searched for single-level lumbar fusions performed between 2013 and 2016. Comparisons were made between procedures performed at the OSH and TRC in terms of operative time, total operating room (OR) time, length of stay (LOS), inpatient rehabilitation utilization, postoperative 90-day readmission, reoperation, and mortality rates. RESULTS: A total of 101 patients at the OSH and 481 at the TRC were included. There was no difference in gender, age, age adjusted Charlson comorbidity Index (AACCI), body mass index, mean number of concomitant levels decompressed, and use of interbody fusion between OSH and TRC patients. The mean operative time (149.5 vs. 179.7 minutes, P < 0.001), total OR time (195.1 vs. 247.9 minutes, P < 0.001), and postoperative LOS (2.61 vs. 3.73 days, P < 0.001) were significantly shorter at the OSH. More patients required postoperative inpatient rehabilitation at the TRC (7.1% vs. 2%, P < 0.001). There was no difference in 90-day readmission or reoperation rates. There was one mortality at the TRC and two patients required transfer from the OSH to the TRC due to medical complications. Regression analysis demonstrated that procedures performed at the TRC (P < 0.001), total OR time (P = 0.004), AACCI (P < 0.001), current smokers (P = 0.048), and number of decompressed levels (P = 0.032) were independent predictors of LOS. CONCLUSION: Lumbar fusion procedures may be safely performed at both the OSH and TRC. OSH utilization may demonstrate safe reduction in operative time, total OR time, and postoperative LOS in the appropriately selected patients. LEVEL OF EVIDENCE: 3.

The Total Cost to the Health Care System in Medicare and Medicaid Patients for the Treatment of Cervical Myelopathy.

INTRODUCTION: Cervical myelopathy is a common indication for spine surgery. Modern medicine demands high quality, cost-effective treatment. Most cost analyses fail to account for complication costs from nonoperative treatment. The purpose is to compare the total health care costs for operative versus nonoperative treatment of cervical myelopathy. METHODS: The Center for Medicare and Medicaid Services Carrier File from 2005 to 2012 was reviewed using the PearlDiver database, representing a 5% sampling of Medicare billings which diagnosed patients with cervical myelopathy by International Classification of Diseases 9 code. Patients were separated into operative and nonoperative cohorts, and the total health care expenditures per patient normalized to 2012 dollars were collected. RESULTS: A total of 3209 patients were included, and 1755 (55.87%) underwent surgery. A 6-year cost analysis performed on 309 patients over the age of 65 from 2006 undergoing surgery resulted in a nonsignificant increase in total health care expenditures ($166,192 vs. $153,556; P=0.45). Operative treatment had a net decrease in total health care costs following the first year of surgery. CONCLUSIONS: There is no significant difference in the total health care expenditures for operative versus nonoperative treatment of cervical myelopathy after 3 years. It is critical to understand that nonoperative treatment of this progressive disease leads to a substantial increase in total health care expenditures with increased risk of falls, injury, and further morbidity.

Longer Preoperative Duration of Symptoms Negatively Affects Health-related Quality of Life After Surgery for Cervical Radiculopathy.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: Determine the effect of duration of symptoms (DOS) on health-related quality of life (HRQOL) outcomes for patients with cervical radiculopathy. SUMMARY OF BACKGROUND DATA: The effect of DOS has not been extensively evaluated for cervical radiculopathy. METHODS: A retrospective analysis of patients who underwent an anterior cervical decompression and fusion for radiculopathy was performed. Patients were grouped based on DOS of less than 6 months, 6 months to 2 years, and more than 2 years and HRQOL outcomes were evaluated. RESULTS: A total of 216 patients were included with a mean follow-up of 16.0 months. There were 86, 61, and 69 patients with symptoms for less than 6 months, 6 months to 2 years, and more than 2 years, respectively. No difference in the absolute postoperative score of the patient reported outcomes was identified between the cohorts. However, in the multivariate analysis, radiculopathy for more than 2 years predicted lower postoperative Short Form-12 Physical Component Score (P = 0.037) and Short Form-12 Mental Component Score (P = 0.029), and higher postoperative Neck Disability Index (P = 0.003), neck pain (P = 0.001), and arm pain (P = 0.004) than radiculopathy for less than 6 months. Furthermore, the recovery ratios for patients with symptoms for less than 6 months demonstrated a greater improvement in NDI, neck pain, and arm pain than for 6 months to 2 years (P = 0.041; 0.005; 0.044) and more than 2 years (P = 0.016; 0.014; 0.002), respectively. CONCLUSION: Patients benefit from spine surgery for cervical radiculopathy at all time points, and the absolute postoperative score for the patient reported outcomes did not vary based on the duration of symptoms; however, the regression analysis clearly identified symptoms for more than 2 years as a predictor of worse outcomes, and the recovery ratio was statistically significantly improved in patients who underwent surgery within 6 months of the onset of symptoms. LEVEL OF EVIDENCE: 3.

Comparing Health-Related Quality of Life Outcomes in Patients Undergoing Either Primary or Revision Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: A retrospective review of prospectively collected data. OBJECTIVE: Compare health-related quality of life (HRQOL) outcome metrics in patients undergoing primary and revision anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: ACDF is associated with significant improvements in HRQOL outcome metrics. However, 2.9% of patients per year will develop symptomatic adjacent segment disease and there is a paucity of literature on HRQOL outcomes after revision ACDF. METHODS: Patients were identified who underwent either a primary or revision ACDF, and who had both preoperative and a minimum of 1-year postoperative HRQOL outcome data. Pre- and postoperative Short Form 12 Physical Component Score (SF12 PCS), Short Form 12 Mental Component Score (SF12 MCS) Visual Analog Scale for neck pain (VAS-Neck), VAS-Arm, and Neck Disability Index (NDI) scores were compared. RESULTS: A total of 360 patients (299 primary, 61 revision) were identified. Significant improvement in SF12 PCS, NDI, VAS-Neck, and VAS-Arm was seen in both groups; however, only a significant improvement in SF12 MCS was seen in the primary group. When comparing the results of a primary versus a revision surgery, the SF12 PCS score was the only outcome with a significantly different net improvement in the primary group (7.23 ±â€Š9.72) compared to the revision group (2.9 ±â€Š11.07; P = 0.006) despite similar baseline SF12 PCS scores. The improvement in each of the other reported HRQOL outcomes did not significantly vary between surgical groups. CONCLUSION: A revision ACDF for cervical radiculopathy or myelopathy leads to a significant improvement in the HRQOL outcome, and with the exception of the SF12 PCS, these results are similar to those of patients undergoing a primary ACDF. LEVEL OF EVIDENCE: 2.

Reliability and Clinical Utility of the CARDS Classification for Degenerative Spondylolisthesis.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The objective of this study is to determine the reliability and clinical utility of the of the proposed CARDS classification for degenerative spondylolisthesis. BACKGROUND: The Clinical and Radiographic Degenerative Spondylolisthesis (CARDS) classification system was recently proposed as an alternative to the Meyerding system for classifying degenerative spondylolisthesis (DS). Unlike Meyerding, CARDS considers other relevant radiographic findings such as disk space collapse and segmental kyphosis to stratify DS into 4 radiographically discreet types. Currently, no studies have been conducted to assess the clinical utility of the CARDS system. METHODS: A total of 78 consecutive surgical patients with L4-L5 DS were rated as CARDS types A through D and Fleiss' κ for interobserver agreement was calculated. Then, demographics as well as preoperative and postoperative outcome scores (ODI, SF-12 mental and physical, VAS) were collected. The Kruskal-Wallis test was used to detect significant differences amongst CARDS types. An unpaired t test was used to compare individual CARDS types with all other subtypes combined. RESULTS: Grading showed: 4 type A, 19 type B, 45 type C, and 8 type D (k=0.63). There was a statistically significant difference in preoperative back pain (P=0.046) between groups. CARDS type D had the highest mean back pain scores (8.8) of all subtypes which was significantly higher than mean back pain for all other subtypes combined (P=0.016). CARDS D showed the largest degree of improvement in all outcome measures. There was a trend towards an increased improvement in ODI (P=0.074) and SF-12 MCS (P=0.095) in the CARDS D subtype relative to the rest of the cohort. CONCLUSIONS: The CARDS classification system represents a reliable method for classifying cases of DS. Our results indicate that kyphotic segmental alignment (CARDS D) may be a less common, yet clinically distinct subset of DS characterized by worse preoperative back pain. CARDS type D cases may also show a greater degree of improvement in multiple outcome measures following surgical intervention.

Intervertebral Disc Cells Produce Interleukins Found in Patients with Back Pain.

OBJECTIVE: To examine the link between cytokines in intervertebral disc (IVD) tissues and axial back pain. DESIGN: In vitro study with human IVD cells cultured from cadaveric donors and annulus fibrosus (AF) tissues from patients. RESULTS: Cultured nucleus pulposus (NP) and AF cells were stimulated with interleukin (IL)-1ß. IL-8 and IL-7 gene expression was analyzed using real-time polymerase chain reaction. IL-8 protein was quantified by enzyme-linked immunosorbent assay. After IL-1ß stimulation, IL-8 gene expression increased 26,541 fold in NP cells and 22,429 fold in AF cells, whereas protein released by the NP and AF cells increased 2,389- and 1,784-fold, respectively. IL-7 gene expression increased 3.3-fold in NP cells (P < 0.05).Cytokine profiles in AF tissues collected from patients undergoing surgery for back pain (painful group) or scoliosis (controls) were compared by cytokine array. IL-8 protein in the AF tissues from patients with back pain was 1.81-fold of that in controls. IL-7 and IL-10 in AF tissues from the painful group were 6.87 and 4.63 times greater than the corresponding values in controls, respectively (P < 0.05). CONCLUSION: Inflammatory mediators found in AF tissues from patients with discogenic back pain are likely produced by IVD cells and may play a key role in back pain.

Complications of Flat Bed Rest After Incidental Durotomy.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To determine whether bed rest is a risk factor for specific medical complications. SUMMARY OF BACKGROUND DATA: Flat bed rest after incidental durotomy is commonly used to reduce the risk of CSF leakage and associated complications. METHODS: Retrospective case series of consecutive patients after lumbar laminectomy were identified. Medical records were reviewed for duration of bed rest and complications (pulmonary, wound, neurological, gastrointestinal, and urinary) in the chart notes, repair methods, subfascial drain placement, consultant notes, imaging reports, and discharge summaries. Patients were compared with duration of bed rest >24 hours versus duration of bed rest ≤24 hours. The incidence of complications was compared between groups using the Fisher exact test. RESULTS: There were a total of 42 patients with incidental durotomy. There were 18 patients in the bed rest ≤24 hours group and 24 patients in the bed rest >24 hours group. Comparing the bed rest ≤24 hours to bed rest >24 hours patients, there was no statistically significant difference in the incidence of postdurotomy-related neurological complications, wound complications, and need for revision surgery. There was a statistically significant decrease in the incidence of total medical complications in the ≤24-hour group (0% vs. 50%, P=0.0003). CONCLUSION: There was an increased incidence of medical complications in the bed rest group >24 hours. Flat bed rest after modern dural repair method may not be a necessity in all cases and may be associated with a higher incidence of medical complications.

Conservative vs. Surgical Management of Post-Traumatic Epidural Hematoma: A Case and Review of Literature.

BACKGROUND: Trauma is the leading cause of death in people younger than 45 years and head injury is the main cause of trauma mortality. Although epidural hematomas are relatively uncommon (less than 1% of all patients with head injuries and fewer than 10% of those who are comatose), they should always be considered in evaluation of a serious head injury. Patients with epidural hematomas who meet surgical criteria and receive prompt surgical intervention can have an excellent prognosis, presumably owing to limited underlying primary brain damage from the traumatic event. The decision to perform a surgery in a patient with a traumatic extraaxial hematoma is dependent on several factors (neurological status, size of hematoma, age of patients, CT findings) but also may depend on the judgement of the treating neurosurgeon. CASE REPORT: A 30-year old man arrived at our Emergency Department after a traumatic brain injury. General examination revealed severe headache, no motor or sensory disturbances, and no clinical signs of intracranial hypertension. A CT scan documented a significant left fronto-parietal epidural hematoma, which was considered suitable for surgical evacuation. The patient refused surgery. Following CT scan revealed a minimal increase in the size of the hematoma and of midline shift. The neurologic examination maintained stable and the patient continued to refuse the surgical treatment. Next follow up CT scans demonstrated a progressive resorption of hematoma. CONCLUSIONS: We report an unusual case of a remarkable epidural hematoma managed conservatively with a favorable clinical outcome. This case report is intended to rather add to the growing knowledge regarding the best management for this serious and acute pathology.