The impact of cage positioning on lumbar lordosis and disc space restoration following minimally invasive lateral lumbar interbody fusion.

OBJECTIVE: The objective of this study was to evaluate patient and surgical factors that predict increased overall lumbar lordosis (LL) and segmental lordosis correction following a minimally invasive lateral lumbar interbody fusion (LLIF) procedure. METHODS: A retrospective review was conducted of all patients who underwent one- or two-level LLIF. Preoperative, initial postoperative, and 6-month postoperative measurements of LL, segmental lordosis, anterior disc height, and posterior disc height were collected from standing lateral radiographs for each patient. Cage placement was measured utilizing the center point ratio (CPR) on immediate postoperative radiographs. Spearman correlations were used to assess associations between cage lordosis and radiographic parameters. Multivariate linear regression was performed to assess independent predictors of outcomes. RESULTS: A total of 106 levels in 78 unique patients were included. Most procedures involved fusion of one level (n = 50, 64.1%), most commonly L3-4 (46.2%). Despite no differences in baseline segmental lordosis, patients with anteriorly or centrally placed cages experienced the greatest segmental lordosis correction immediately (mean anterior 4.81° and central 4.46° vs posterior 2.47°, p = 0.0315) and at 6 months postoperatively, and patients with anteriorly placed cages had greater overall lordosis correction postoperatively (mean 6.30°, p = 0.0338). At the 6-month follow-up, patients with anteriorly placed cages experienced the greatest increase in anterior disc height (mean anterior 6.24 mm vs posterior 3.69 mm, p = 0.0122). Cages placed more posteriorly increased the change in posterior disc height postoperatively (mean posterior 4.91 mm vs anterior 1.80 mm, p = 0.0001) and at 6 months (mean posterior 4.18 mm vs anterior 2.06 mm, p = 0.0255). There were no correlations between cage lordotic angle and outcomes. On multivariate regression, anterior cage placement predicted greater 6-month improvement in segmental lordosis, while posterior placement predicted greater 6-month improvement in posterior disc height. Percutaneous screw placement, cage lordotic angle, and cage height did not independently predict any radiographic outcomes. CONCLUSIONS: LLIF procedures reliably improve LL and increase intervertebral disc space. Anterior cage placement improves the lordosis angle greater than posterior placement, which better corrects sagittal alignment, but there is still a significant improvement in lordosis even with a posteriorly placed cage. Posterior cage placement provides greater restoration in posterior disc space height, maximizing indirect decompression, but even the anteriorly placed cages provided indirect decompression. Cage parameters including cage height, lordosis angle, and material do not impact radiographic improvement.

Does Medicaid Insurance Confer Adequate Access to Adult Orthopaedic Care in the Era of the Patient Protection and Affordable Care Act?

BACKGROUND: A current appraisal of access to orthopaedic care for the adult patient receiving Medicaid is important, since Medicaid expansion was written into law by the Patient Protection and Affordable Care Act (PPACA). QUESTIONS/PURPOSES: (1) Do orthopaedic practices provide varying access to orthopaedic care for simulated patients with Medicaid insurance versus private insurance in a blinded survey? (2) What are the surveyed state-by-state Medicaid acceptance rates for adult orthopaedic practices in the current era of Medicaid expansion set forth by the PPACA? (3) Do surveyed rates of access to orthopaedic care in the adult patient population vary across practice setting (private vs academic) or vary with different Medicaid physician reimbursement rates? (4) Are there differences in the surveyed Medicaid acceptance rates for adult orthopaedic practices in states that have expanded Medicaid coverage versus states that have foregone expansion? METHODS: Simulated Patient Survey: We performed a telephone survey study of orthopaedic offices in four states with Medicaid expansion. In the survey, the caller assumed a fictitious identity as a 38-year-old male who experienced an ankle fracture 1 day before calling, and attempted to secure an appointment within 2 weeks. During initial contact, the fictitious patient reported Medicaid insurance status. One month later, the fictitious patient contacted the same orthopaedic practice and reported private insurance coverage status. National Orthopaedic Survey: Private and academic orthopaedic practices operating in each state in the United States were called and asked to complete a survey assessing their practice model of Medicaid insurance acceptance. State reimbursement rates for three different Current Procedural Terminology (CPT®) codes were collected from state Medicaid agencies. Results Simulated Patient Survey: Offices were less likely to accept Medicaid than commercial insurance (30 of 64 [47%] versus 62 of 64 [97%]; odds ratio [OR], 0.0145; 95% CI, 0.00088-0.23639; p < 0.001), and patients with Medicaid were less likely to be offered an appointment within 2 weeks (23 of 64 [36%] versus 59 of 64 [89%]; OR, 0.0154; 95% CI, 0.00094- 0.251; p < 0.001). The Medicaid acceptance rates observed across states sampled in the simulated patient survey were 67% (Pennsylvania), 21% (New Jersey), 58% (Delaware), and 50% (Maryland) (p = 0.04). National Orthopaedic Survey: Adult patients with Medicaid insurance had limited access to care in 109 of 342 (32%) orthopaedic practices: 37% of private and 13% of academic practices (p < 0.001). Practices that accepted Medicaid received higher reimbursement for each CPT® code relative to those that did not and acceptance of Medicaid became increasingly more likely as reimbursement rates increased (99243: OR, 1.03, 95% CI, 1.02-1.04 per dollar, p < 0.001; 99213: OR, 1.05; 95% CI, 1.03-1.07 per dollar, p < 0.001; 28876: OR, 1.01, 95% CI, 1.00-1.01 per dollar, p < 0.001). For a given reimbursement rate, private practices were less likely to take an adult patient with Medicaid relative to an academic practice (99243: OR, 0.11, 95% CI, 0.04-0.33, p < 0.001; 99213: OR, 0.11, 95% CI, 0.04-0.32, p < 0.001; 27786: OR, 0.12, 95% CI, 0.04-0.35, p < 0.001). No difference was observed when comparing Medicaid acceptance rates for all practice types between states that have expanded their Medicaid program versus those that have not (OR, 1.02; 95% CI 0.62-1.70; p = 0.934). CONCLUSIONS: In this two-part survey study, we found that a simulated patient with commercial insurance was more likely to have their insurance accepted and to gain timely access to orthopaedic care than a patient with Medicaid. Academic practice setting and increased Medicaid reimbursement rates were associated with increased access to care for the patient with Medicaid. Inequality in access to orthopaedic care based on health insurance status likely exists for the adult patient with Medicaid. Furthermore, Medicaid expansion has likely realized minimal gains in access to care for the adult orthopaedic patient. Further research is needed in delineating the patient-payer selection criteria used by orthopaedic practices to aid policymakers in reforming the Medicaid program and comprehensibly addressing this access to care disparity. LEVEL OF EVIDENCE: Level II, prognostic study.

Avoiding and Managing Intraoperative Complications During Cervical Spine Surgery.

The incidence of intraoperative complications during cervical spine surgery is low; however, if they do occur, intraoperative complications have the potential to cause considerable morbidity and mortality. Spine surgeons should be familiar with methods to minimize intraoperative complications. If they do occur, surgeons must be prepared to immediately treat each potential complication to reduce any associated morbidity.

Radiographic variables that may predict clinical outcomes in cervical disk replacement surgery.

STUDY DESIGN: Retrospective analysis of prospectively collected data. OBJECTIVE: To determine which, if any, radiographic parameters are predictive of clinical outcome after cervical disk replacement (CDR) surgery. SUMMARY OF BACKGROUND DATA: It is unclear whether radiographic parameters are predictive of outcome after CDR. METHODS: An analysis of the radiographic parameters and clinical outcomes of the CDR cohort of the Discover artificial cervical disk IDE trial was performed. Clinical outcome measures included Neck Disability Index (NDI), visual analog pain scale (neck, arm, and shoulder), and SF-36 physical component summary score scores, collected preoperatively and at regularly scheduled postoperative time periods. Patients with at least 1-year follow-up were included. The change in outcomes from baseline was determined at each follow-up interval. The following minimal clinically important difference (MCID) thresholds were applied: -7.5 for NDI, -25 for visual analog pain scale, and +4.1 for physical component summary score. Fifty-six radiographic variables were analyzed to identify factors that may be associated with a poor clinical outcome, defined as failure to achieve the MCID in NDI. RESULTS: A total of 243 patients underwent CDR at 304 levels (182 one level, 61 two level). One hundred seventy-one patients (89 female, 82 male; mean age, 44.2 y; range, 28-67 y) had at least 1-year follow-up. A preoperative disk height of <3.5 mm was associated with a 3.4 times greater risk of not achieving a MCID in NDI (P=0.018). Increasing the functional spinal unit angle by >3 degrees was associated with a 3.5 times greater risk of not achieving a MCID in NDI (P=0.016). There were 21/171 patients (25 levels) who did not achieve the NDI MCID threshold. All of these patients had at least1, and 16/21 of these patients had more than 1 abnormal radiographic finding. Seventy percent of treatment levels had severe or bridging heterotopic ossification at 3-years follow-up, the incidence of which increased linearly with time. CONCLUSIONS: Several radiographic variables are predictive of clinical outcomes, including decreased preoperative disk space height and excessive postoperative segmental lordosis.

Disc space preparation in transforaminal lumbar interbody fusion: a comparison of minimally invasive and open approaches.

BACKGROUND: Minimally invasive surgical (MIS) approaches to transforaminal lumbar interbody fusion (TLIF) have been developed as an alternative to the open approach. However, concerns remain regarding the adequacy of disc space preparation that can be achieved through a minimally invasive approach to TLIF. QUESTIONS/PURPOSES: The purpose of this cadaver study is to compare the adequacy of disc space preparation through MIS and open approaches to TLIF. Specifically we sought to compare the two approaches with respect to (1) the time required to perform a discectomy and the number of endplate violations; (2) the percentage of disc removed; and (3) the anatomic location where residual disc would remain after discectomy. METHODS: Forty lumbar levels (ie, L1-2 to L5-S1 in eight fresh cadaver specimens) were randomly assigned to open and MIS groups. Both surgeons were fellowship-trained spine surgeons proficient in the assigned approach used. Time required for discectomy, endplate violations, and percentage of disc removed by volume and mass were recorded for each level. A digital imaging software program (ImageJ; US National Institutes of Health, Bethesda, MD, USA) was used to measure the percent disc removed by area for the total disc and for each quadrant of the endplate. RESULTS: The open approach was associated with a shorter discectomy time (9 versus 12 minutes, p = 0.01) and fewer endplate violations (one versus three, p = 0.04) when compared with an MIS approach, percent disc removed by volume (80% versus 77%, p = 0.41), percent disc removed by mass (77% versus 75%, p = 0.55), and percent total disc removed by area (73% versus 71%, p = 0.63) between the open and MIS approaches, respectively. The posterior contralateral quadrant was associated with the lowest percent of disc removed compared with the other three quadrants in both open and MIS groups (50% and 60%, respectively). CONCLUSIONS: When performed by a surgeon experienced with MIS TLIF, MIS and open approaches are similar in regard to the adequacy of disc space preparation. The least amount of disc by percentage is removed from the posterior contralateral quadrant regardless of the approach; surgeons should pay particular attention to this anatomic location during the discectomy portion of the procedure to minimize the likelihood of pseudarthrosis.

Minimally invasive versus open posterior lumbar interbody fusion: a systematic review.

BACKGROUND: Although conventional open posterior lumbar interbody fusion (open PLIF) is efficacious in management of lumbar spinal instability, concerns exist regarding lengthy hospital stays, blood loss, and postoperative complications. Minimally invasive posterior lumbar interbody fusion (MIS PLIF) may be able to address these concerns, but the research on this topic has not been systematically reviewed. QUESTIONS/PURPOSES: We performed a systematic review to determine whether MIS PLIF or open PLIF results in (1) better perioperative parameters, including blood loss, operative times, and length of hospital stay; (2) improved patient-reported outcome scores; and (3) improved disc distraction and (4) frequency of reoperation and complications when compared with open PLIF procedures. METHODS: A literature search of the MEDLINE database identified seven studies that met our inclusion criteria. A total of seven articles were included; quality was assessed using the Methodological Index for Non-Randomised Studies (MINORS) scale. Descriptive statistics were used to describe the included articles. RESULTS: In most studies, MIS PLIF was associated with decreased blood loss and shorter hospital stay but longer operative times. MIS PLIF resulted in better patient-related outcomes when compared with open PLIF in two studies in the short term, but most of the studies in this review found no short-term differences, and there was no difference at long-term followup in any studies. There was no significant difference in disc distraction. Both techniques appeared to have similar complication rates and reoperation rates. CONCLUSIONS: Based on the available evidence, which we restricted to prospective and retrospective studies with control groups, but did not include any well-designed randomized trials, MIS PLIF might lead to better perioperative parameters, but there was little evidence for improved patient-reported outcomes in the MIS groups. Randomized controlled trials are needed to compare these two surgical techniques.

Cervical laminectomy width and spinal cord drift are risk factors for postoperative C5 palsy.

BACKGROUND: Cervical laminectomy and fusion (CLF) is a treatment option for multilevel cervical spondylotic myelopathy. Postoperative C5 nerve palsy is a possible complication of CLF. It has been suggested that C5 nerve palsy may be due to posterior drift of the spinal cord related to a wide laminectomy trough. PURPOSE: To test the hypothesis that excessive spinal cord drift into a wide laminectomy trough is associated with C5 palsy. STUDY DESIGN: Retrospective case-control study. PATIENT SAMPLE: Seventeen patients with C5 palsy, 8 patients as control group. OUTCOME MEASURES: Spinal cord positional measurements on magnetic resonance imaging (MRI). METHODS: All patients who underwent elective CLF for cervical spondylotic myelopathy or ossified posterior longitudinal ligament using posterior instrumentation between 2004 and 2008 were included. Patients who underwent CLF for trauma, infection, or tumors were excluded. Clinical and radiographic outcomes were assessed by chart review (minimum of 1 y follow-up). Patients who developed a new postoperative C5 nerve palsy underwent repeat MRI. The control group also underwent CLF, did not develop a neurological deficit, and received a postoperative MRI for evaluation of possible infection. MRI measurements included the width of the laminectomy trough, the distance from the posterior vertebral body or disk to the anterior spinal cord, the width of the spinal cord herniated into the laminectomy defect, and C2-7 sagittal alignment. Preoperative radiographic measurements included preoperative vertebral body diameter, spinal canal diameter, and sagittal vertical offset. RESULTS: There were seventeen patients with C5 nerve root palsy and 8 patients without C5 nerve root palsy. There were no baseline differences in fusion levels, instrumentation used, patient age, or sex. MRI measurements revealed an increase in mean postoperative cord drift in patients with C5 palsy at C3 (4.2 vs. 2.2 mm, P=0.002), C4 (4.6 vs. 2.8 mm, P=0.056), C5 (5.1 vs. 2.4 mm, P=0.011), and C6 (5.2 vs. 2.4 mm, P=0.003). There was a significant increase in C5 laminectomy trough width among patients with postoperative C5 palsy (17.9 vs. 15.2 mm, P=0.032), but there was no difference in sagittal alignment. CONCLUSIONS: A wider laminectomy at C5 was associated with an increased risk of postoperative C5 palsy. Increased preoperative spinal canal diameter is also associated with increased risk of C5 palsy. In addition, patients who experienced C5 nerve palsy had a significantly greater posterior spinal cord drift. Strategies to reduce postoperative laminectomy trough width and spinal cord drift may reduce the risk of postoperative C5 palsy.

Does Operative Level Impact Dysphagia Severity After Anterior Cervical Discectomy and Fusion?: A Multicenter Prospective Analysis.

STUDY DESIGN: Prospective multicenter cohort study. OBJECTIVE: To explore the association between operative level and postoperative dysphagia after anterior cervical discectomy and fusion (ACDF). BACKGROUND: Dysphagia is common after ACDF and has several risk factors, including soft tissue edema. The degree of prevertebral soft tissue edema varies based on the operative cervical level. However, the operative level has not been evaluated as a source of postoperative dysphagia. PATIENTS AND METHODS: Adult patients undergoing elective ACDF were prospectively enrolled at 3 academic centers. Dysphagia was assessed using the Bazaz Questionnaire, Dysphagia Short Questionnaire, and Eating Assessment Tool-10 (EAT-10) preoperatively and at 2, 6, 12, and 24 weeks postoperatively. Patients were grouped based on the inclusion of specific surgical levels in the fusion construct. Multivariable regression analyses were performed to evaluate the independent effects of the number of surgical levels and the inclusion of each particular level on dysphagia symptoms. RESULTS: A total of 130 patients were included. Overall, 24 (18.5%) patients had persistent postoperative dysphagia at 24 weeks and these patients were older, female, and less likely to drink alcohol. There was no difference in operative duration or dexamethasone administration. Patients with persistent dysphagia were significantly more likely to have C4-C5 included in the fusion construct (62.5% vs . 34.9%, P = 0.024) but there were no differences based on the inclusion of other levels. On multivariable regression, the inclusion of C3-C4 or C6-C7 was associated with more severe EAT-10 (ß: 9.56, P = 0.016 and ß: 8.15, P = 0.040) and Dysphagia Short Questionnaire (ß: 4.44, P = 0.023 and (ß: 4.27, P = 0.030) at 6 weeks. At 12 weeks, C3-C4 fusion was also independently associated with more severe dysphagia (EAT-10 ß: 4.74, P = 0.024). CONCLUSION: The location of prevertebral soft tissue swelling may impact the duration and severity of patient-reported dysphagia outcomes at up to 24 weeks postoperatively. In particular, the inclusion of C3-C4 and C4-C5 into the fusion may be associated with dysphagia severity.

Significance of Facet Fluid Index in Anterior Cervical Degenerative Spondylolisthesis.

STUDY DESIGN: Retrospective cohort study. PURPOSE: To correlate cervical facet fluid characteristics to radiographic spondylolisthesis, determine if facet fluid is associated with instability in cervical degenerative spondylolisthesis, and examine whether vertebral levels with certain facet fluid characteristics and spondylolisthesis are more likely to be operated on. OVERVIEW OF LITERATURE: The relationship between facet fluid and lumbar spondylolisthesis is well-documented; however, there is a paucity of literature investigating facet fluid in degenerative cervical spondylolisthesis. METHODS: Patients diagnosed with cervical degenerative spondylolisthesis were identified from a hospital's medical records. Demographic and surgical characteristics were collected through a structured query language search and manual chart review. Radiographic measurements were made on preoperative MRIs for all vertebral levels diagnosed with spondylolisthesis and adjacent undiagnosed levels between C3 and C6. The facet fluid index was calculated by dividing the facet fluid measurement by the width of the facet. Bivariate analysis was conducted to compare facet characteristics based on radiographic spondylolisthesis and spondylolisthesis stability. RESULTS: We included 154 patients, for whom 149 levels were classified as having spondylolisthesis and 206 levels did not. The average facet fluid index was significantly higher in patients with spondylolisthesis (0.26±0.07 vs. 0.23±0.08, p <0.001). In addition, both fluid width and facet width were significantly larger in patients with spondylolisthesis (p <0.001 each). Cervical levels in the fusion construct demonstrated a greater facet fluid index and were more likely to have unstable spondylolisthesis than stable spondylolisthesis (p <0.001 each). CONCLUSIONS: Facet fluid index is associated with cervical spondylolisthesis and an increased facet size and fluid width are associated with unstable spondylolisthesis. While cervical spondylolisthesis continues to be an inconclusive finding, vertebral levels with spondylolisthesis, especially the unstable ones, were more likely to be included in the fusion procedure than those without spondylolisthesis.

Defining the value of spine care.

The increased cost and frequency of spine-related procedures, expanding indications, and regional variation in care has led to a shift toward delivery of value-based spine care. In this model, payers show preference for interventions and treatments with proven value and incentivize providers who use such interventions and demonstrate value in their practices. Thus, spine care providers must understand how to determine the value of interventions and treatments. Determining value (ie, cost and quality of care, measured over time) can be challenging in the setting of spine care. Data collection and reporting are complicated by variation in diagnostic coding and surgical techniques. Typically, outcomes in spine care are based on subjective patient-reported measures that are influenced by concomitant orthopaedic, medical, and psychological disease. Health utility is a preferable measure of quality that can be converted into quality-adjusted life years and used in cost-effectiveness analysis. Although no standard currently exists, estimates of cost should include both direct and indirect costs of care over an adequate time horizon.

Does Facet Distraction Affect Patient Outcomes After ACDF?

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of this study is to determine if there is a correlation between the amount of facet distraction and postoperative patient-reported outcomes after ACDF. METHODS: A retrospective cohort analysis of patients undergoing 1 to 3 level ACDF for degenerative pathologies at a single academic center was performed. Each patient received upright, lateral cervical spine x-rays at the immediate postoperative time point from which interfacet distance (facet distraction) was measured. Patient-reported outcome measures including NDI, PCS-12, MCS-12, VAS Neck, and VAS Arm pain scores were obtained preoperatively and at short-term (<3 months) and long-term (>1 year) follow-up. Receiver operating curves were generated to evaluate the possibility of a critical interfacet distraction distance. Univariate and multivariate analysis were performed to compare outcomes between groups based on the degree of facet distraction. RESULTS: A total of 229 patients met the inclusion criteria. Receiver operating curves failed to yield a critical interfacet distraction distance associated with worse post-operative outcomes. Patients were instead grouped based on facet distraction distance below and above the third quartile (0.8mm-2.0 mm, 2.0mm-3.7 mm), with 173 and 56 patients in each respective group. Univariate analysis did not detect any statistically significant differences in outcome measures, recovery ratio, or % MCID achievement at short- and long-term follow-up between groups. Multivariate analysis also failed to demonstrate any significant differences between the facet distraction groups. CONCLUSION: Increased interfacet distance did not correlate with increased neck pain or disability after an ACDF.

Evaluating Dysphagia Duration and Severity After ACDF in Patients With Underlying Dysphagia - A Prospective, Multicenter Study.

STUDY DESIGN: Prospective Cohort Study. OBJECTIVES: The purpose of this study was to prospectively evaluate the impact of preoperative dysphagia on the postoperative incidence and severity of dysphagia in patients undergoing ACDF at multiple institutions. METHODS: After IRB approval, patients over 18 years of age who underwent an elective ACDF for degenerative conditions were prospectively enrolled at two academic centers from 2018 to 2021. Preoperative dysphagia was self-reported by patients through a pre-operative questionnaire on a binary basis. Patients completed dysphagia surveys (Bazaz, Dysphagia Short Questionnaire, 10-item Eating Assessment Tool) to assess dysphagia severity during their preoperative visit, and these dysphagia surveys were repeated immediately postoperatively, at two weeks and again at six, 12, and 24 weeks postoperatively. Patients were stratified into three subgroups based on dysphagia status preoperatively and immediately postoperatively and compared using ANOVA tests or Kruskal-Wallis tests for continuous variables and Pearson chi-square analysis or Fisher's Exact test for categorical variables. RESULTS: A total of 168 patients (23 with preoperative dysphagia, 145 without preoperative dysphagia) met study criteria and were enrolled in the study. Patients with preoperative dysphagia had less frequent alcohol consumption (23.8% vs 53.7%, P = .0210), and higher rates of dysphagia at 2-weeks (77.8% vs 38.7%, P = .004) and 24-weeks (43.8% vs 14.8%, P = .010) postoperatively. These patients also had higher severity scores for dysphagia on the Bazaz (P = .001), DSQ (P = .012), EAT10 (P = .022) questionnaires at the 2-week follow-up period, higher DSQ scores (P = .036) at the 6-week follow-up period, higher EAT-10 scores (P = .009) at the 12-week follow-up period, and higher Bazaz (P = .001), DSQ (P = .002), and EAT-10 (P = .005) scores at the 24-week follow-up period. There were no differences in demographic, medical history, surgical variables, rates of ENT consultation, length of stay, or other in-hospital events between groups. CONCLUSIONS: Patients undergoing ACDF who had preoperative dysphagia have prolonged postoperative dysphagia and greater dysphagia severity. Surgeons should be aware of the risk of prolonged dysphagia severity that may persist past 24 weeks after surgery when discussing clinical decisions with patients.

Evaluating the Effect of Gastroesophageal Reflux Disease on Postoperative Dysphagia Following Anterior Cervical Spine Surgery-A Prospective, Multicenter Study.

STUDY DESIGN: Prospective cohort study. OBJECTIVES: The purpose of this study was to prospectively evaluate the impact of a preoperative diagnosis of gastroesophageal reflux disease on the incidence and severity of postoperative dysphagia in a multicenter population. METHODS: After Institutional Review Board approval, written informed consent was obtained from all participating patients. Patients over 18 years of age who underwent an elective anterior cervical discectomy and fusion for a degenerative condition were prospectively enrolled at two academic centers from the years 2018 to 2020. Patients were separated into two groups: those with and without a preoperative diagnosis of GERD. Continuous variables were assessed using either an independent t-test or Mann Whitney U-test for parametric and non-parametric data. All categorical variables were compared using a chi-square test. RESULTS: A total of 116 patients met study criteria and were subsequently enrolled. Overall rates of postoperative dysphagia increased to 47.3% (n = 53) at 2-weeks but eventually decreased towards the preoperative prevalence of 25.0% at the 24-week mark. Patients with preoperative diagnosis of GERD had lower dysphagia severity scores on a continuous variable analysis in both the DSQ and EAT-10 surveys at 2-week follow-up in addition to the Bazaz survey at 24-week follow-up. Our follow up at 24-weeks was 85.7%. CONCLUSIONS: Our study shows that having a preoperative diagnosis of GERD has no significant effect on the incidence of dysphagia following ACDF. Nevertheless, having a preoperative diagnosis of GERD does seem to provide some protective effect on the severity of dysphagia that this patient population develops at multiple intervals over a 24-week postoperative period.

Do Patient Outcomes Predict Loss to Long-Term Follow-Up After Spine Surgery?

OBJECTIVE: To determine if spine surgery patients with greater improvement in patient-reported outcomes measures (PROMs) at early postoperative follow-up are more likely to be lost to follow-up at the 1-year and 2-year postoperative visits. METHODS: All patients older than 18 years who underwent primary or revision decompression or fusion surgery for degenerative spinal conditions at an academic institution were retrospectively identified. Univariate analysis compared patient demographics, surgical factors, and changes in short-term and long-term postoperative PROMs (Neck Disability Index, Oswestry Disability Index, visual analog scale [VAS] neck, VAS arm, VAS back, VAS leg, and Short-Form 12 Physical and Mental Component Scores) across groups with and without 1 year and 2 years follow-up. Logistic regression isolated predictors of loss to follow-up. RESULTS: A total of 1412 patients were included. Younger patient age, primary surgery, and single surgical approach independently predicted loss at 1 year follow-up. Female sex predicted loss at 2 years follow-up, whereas multilevel fusion surgery predicted attendance at 2 years clinical follow-up. In patients lost at 1 year follow-up compared with those who attended, preoperative to 3-month Mental Component Score and VAS neck pain improvement was significantly greater. When comparing patients based on 2 years follow-up status, VAS back pain improvement at 1 year postoperatively was significantly greater in patients lost to 2 years follow-up. All other changes in PROMs did not differ significantly by 1 or 2 years follow-up attendance. CONCLUSIONS: Overall patient outcomes were not found to affect loss to long-term follow-up after spine surgery. The general lack of association between postoperative follow-up status and clinical outcome may limit bias introduced in retrospective PROM studies.

Clinical Outcomes of Robotic Versus Freehand Pedicle Screw Placement After One-to Three-Level Lumbar Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The purpose of this study is to compare patient-reported outcome measures (PROMs) for patients undergoing one-to three-level lumbar fusion using robotically assisted vs freehand pedicle screw placement. METHODS: Patients who underwent either robotically assisted or freehand pedicle screw placement for one-to three-level lumbar fusion surgery from January 1, 2014 to August 31, 2020 at a single academic institution were identified. Propensity score matching was performed based on demographic variables. Clinical and surgical outcomes were compared between groups. Recovery Ratios (RR) and the proportion of patients achieving the minimally clinically important difference (%MCID) were calculated for Oswestry Disability Index, PCS-12, MCS-12, VAS Back, and VAS Leg at 1 year. Surgical outcomes included complication and revision rates. RESULTS: A total of 262 patients were included in the study (85 robotic and 177 freehand). No significant differences were found in ΔPROM scores, RR, or MCID between patients who underwent robotically assisted vs freehand screw placement. The rates of revision (1.70% freehand vs 1.18% robotic, P = 1.000) and complications (.57% freehand vs 1.18% robotic, P = .546) were not found to be statically different between the 2 groups. Controlling for demographic factors, procedure type (robotic vs freehand) did not emerge as a significant predictor of ΔPROM scores on multivariate linear regression analysis. CONCLUSIONS: Robotically assisted pedicle screw placement did not result in significantly improved clinical or surgical outcomes compared to conventional freehand screw placement for patients undergoing one-to three-level lumbar fusion.

Facet Distraction and Dysphagia: A Prospective Evaluation of This Common Postoperative Issue Following Anterior Cervical Spine Surgery.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: Our primary study was to investigate whether the degree of postoperative facet and disk space distraction following anterior cervical discectomy and fusion (ACDF) affects the rate of postoperative dysphagia. SUMMARY OF BACKGROUND DATA: Although ACDF is safe and well tolerated, postoperative dysphagia remains a common complication. Intervertebral disk space distraction is necessary in ACDF to visualize the operative field, prepare the endplates for fusion, and facilitate graft insertion. However, the degree of distraction tolerated, before onset of dysphagia, is not well characterized ACDF. MATERIALS AND METHODS: A prospective cohort study was conducted of 70 patients who underwent ACDF between June 2018 and January 2019. Two independent reviewers measured all preoperative and postoperative radiographs measured for interfacet distraction distance and intervertebral distraction distance, with intrareviewer reproducibility measurements after one month. For multilevel surgery, the level with the greatest distraction was measured. Primary outcomes were numerical dysphagia (0-10), Eating Assessment Tool 10, and Dysphagia Symptom Questionnaire score collected at initial visit and two, six, 12, and 24 weeks postoperatively. RESULTS: A total of 70 patients were prospectively enrolled, 59 of whom had adequate radiographs. An average of 1.71 (SD: 0.70) levels were included in the ACDF construct. Preoperatively, 13.4% of patients reported symptoms of dysphagia, which subsequently increased in the postoperative period at through 12 weeks postoperatively, before returning to baseline at 24 weeks. Intrareviewer and interreviewer reliability analysis demonstrated strong agreement. There was no relationship between interfacet distraction distance/intervertebral distraction distance and dysphagia prevalence, numerical rating, Eating Assessment Tool 10, or Dysphagia Symptom Questionnaire. CONCLUSIONS: Patients who had an ACDF have an increased risk of dysphagia in the short term, however, this resolved without intervention by six months. Our data suggests increased facet and intervertebral disk distraction does not influence postoperative dysphagia rates. LEVEL OF EVIDENCE: 3.

Impact of Prolonged Operative Duration on Postoperative Symptomatic Venous Thromboembolic Events After Thoracolumbar Spine Surgery.

OBJECTIVE: To determine the effect of operative duration on the rate of postoperative symptomatic venous thromboembolic (VTE) events in patients undergoing thoracolumbar spine fusion. METHODS: We identified all thoracolumbar spine fusion patients between 2012 and 2021. Operative duration was defined as time from skin incision to skin closure. A 1:1 propensity match was conducted incorporating patient and surgical characteristics. Logistic regression was performed to assess predictors of postoperative symptomatic VTE events. A receiver operating characteristic curve was created to determine a cutoff time for increased likelihood of VTE. RESULTS: We identified 101 patients with VTE and 1108 patients without VTE. Seventy-five patients with VTE were matched to 75 patients without VTE. Operative duration (339 vs. 262 minutes, P = 0.010) and length of stay (5.00 vs. 3.54 days, P = 0.008) were significantly longer in patients with a VTE event. Operative duration was an independent predictor of VTE on multivariate regression (odds ratio: 1.003, 95% confidence interval: 1.001-1.01, P = 0.021). For each additional hour of operative duration, the risk of VTE increased by 18%. A cutoff time of 218 minutes was identified (area under the curve [95% confidence interval] = 0.622 [0.533-0.712]) as an optimal predictor of increased risk for a VTE event. CONCLUSIONS: Operative duration significantly predicted symptomatic VTE, especially after surgical time cutoff of 218 minutes. Each additional hour of operative duration was found to increase VTE risk by 18%. We also identify the impact of VTE on 90-day readmission rates, suggesting significantly higher costs and opportunity for hospital acquired conditions, in line with prior literature.

Effect of Clinical and Radiographic Degenerative Spondylolisthesis Classification on Patient-reported Outcomes and Spinopelvic Parameters for Patients With Single-level L4-L5 Degenerative Spondylolisthesis After Lumbar Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To determine whether preoperative clinical and radiographic degenerative spondylolisthesis (CARDS) classification is associated with differences in patient-reported outcomes and spinopelvic parameters after posterior decompression and fusion for L4-L5 degenerative spondylolisthesis (DS). SUMMARY: The CARDS classification for lumbar DS, an alternative to the Meyerding system, considers additional radiographic findings such as disc space collapse and segmental kyphosis and stratifies DS into 4 radiographically distinct classes. Although CARDS has been shown to be a reliable and reproducible method for classifying DS, very few studies have assessed whether the CARDS types represent distinct clinical entities. PATIENTS AND METHODS: A retrospective cohort analysis was conducted on patients with L4-L5 DS who underwent posterior lumbar decompression and fusion. Changes in spinopelvic alignment and patient-reported outcomes measures, including recovery ratios and percentage of patients achieving the minimal clinically important difference, were compared among patients in each CARDS classification 1-year postoperatively using analysis of variance or Kruskal-Wallis H with Dunn post hoc analysis. Multiple linear regression determined whether CARDS groups significantly predicted patient-reported outcomes measures, lumbar lordosis (LL), and pelvic incidence-lumbar lordosis mismatch (PI-LL) while controlling for demographic and surgical characteristics. RESULTS: Preoperative type B spondylolisthesis predicted decreased improvement in "physical component and mental component score of the short form-12" compared with type A spondylolisthesis (ß-coefficient = -5.96, P = 0.031) at 1 year. Significant differences were found between CARDS groups with regards to ΔLL (A: -1.63 degrees vs B: -1.17 degrees vs C: 2.88 degrees vs D: 3.19 degrees, P = 0.010) and ΔPI-LL (A: 1.02 degrees vs B: 2.09 degrees vs C: -2.59 degrees vs D: -3.70 degrees, P = 0.012). Preoperative type C spondylolisthesis was found to predict increased LL (ß-coefficient = 4.46, P = 0.0054) and decreased PI-LL (ß-coefficient = -3.49, P = 0.025) at 1 year compared with type A spondylolisthesis. CONCLUSIONS: Clinical and radiographic outcomes differed significantly by preoperative CARDS classification type for patients undergoing posterior decompression and fusion for L4-L5 DS. LEVEL OF EVIDENCE: Level III.

Comparison of Postoperative Opioid Use After Anterior Cervical Diskectomy and Fusion or Posterior Cervical Fusion.

INTRODUCTION: Posterior cervical fusion (PCF) and anterior cervical diskectomy and fusion (ACDF) are two main surgical management options for the treatment of cervical spondylotic myelopathy. Although ACDF is less invasive than PCF which should theoretically reduce postoperative pain, it is still unknown whether this leads to reduced opioid use. Our objective was to evaluate whether PCF increases postoperative opioid use compared with ACDF. METHODS: We retrospectively identified all patients undergoing 2-level to 4-level ACDF or PCF at a single center from 2017 to 2021. Our state's prescription drug-monitoring program was queried for filled opioid prescriptions using milligrams morphine equivalents (MMEs) up to 1 year postoperatively. In-hospital opioid use was collected from the electronic medical record. Bivariate statistics compared ACDF and PCF cohorts. Multivariate linear regression was done to assess independent predictors of in-hospital opioid use and short-term (0 to 30 days), subacute (30 to 90 days), and long-term (3 to 12 months) opioid prescriptions. RESULTS: We included 211 ACDF patients and 91 PCF patients. Patients undergoing PCF used more opioids during admission (126.7 vs. 51.0 MME, P < 0.001) and refilled more MMEs in the short-term (118.2 vs. 86.1, P = 0.001) but not subacute (33.6 vs. 19.7, P = 0.174) or long-term (85.6 vs. 47.8, P = 0.310) period. A similar percent of patients in both groups refilled at least one prescription after 90 days (39.6% vs. 33.2%, P = 0.287). PCF (ß = 56.7, P = 0.001) and 30-day preoperative MMEs (ß = 0.28, P = 0.041) were associated with greater in-hospital opioid requirements. PCF (ß = 26.7, P = 0.039), C5 nerve root irritation (ß = 51.4, P = 0.019), and a history of depression (ß = 40.9, P < 0.001) were independently associated with 30-day postoperative MMEs. CONCLUSIONS: PCF is initially more painful than ACDF but does not lead to persistent opioid use. Surgeons should optimize multimodal analgesia protocols to reduce long-term narcotic usage rather than change the surgical approach.Level of Evidence:III.

Comparing Posterior Lumbar Decompression and Fusion and Transforaminal Lumbar Interbody Fusion in Lumbar Degenerative Spondylolisthesis as Assessed by the CARDS Classification System.

OBJECTIVE: In a retrospective cohort study, we compared the outcomes among clinical and radiographic degenerative spondylolisthesis (CARDS) subtypes for patients undergoing posterior lumbar decompression and fusion (PLDF) or transforaminal lumbar interbody fusion (TLIF) and evaluated the CARDS system as a tool to guide clinical decisions regarding the treatment of degenerative spondylolisthesis (DS). METHODS: Patients undergoing PLDF or TLIF for DS from 2010 to 2020 were identified. The patients were grouped by the preoperative CARDS classification. Multivariate analysis was used to determine the effects of the treatment approach on the 1-year patient-reported outcome measures (PROMs) and 90-day surgical outcomes. RESULTS: A total of 1056 patients were included: 148 patients with type A DS, 323 with type B, 525 with type C, and 60 with type D. Patients with CARDS types A and C who underwent PLDF experienced a longer length of stay and were less likely to be discharged home. No differences were found in the incidence of revisions, complications, or readmissions between the surgical approaches. Patients with CARDS type A undergoing PLDF were less likely to achieve a minimal clinically important difference for back pain (36.8% vs. 76.7%; P = 0.013). No other significant differences were found in the PROMs among the CARDS subtypes. TLIF independently predicted for better leg pain improvement using the visual analog scale at 1 year of follow-up (ß = -2.92; P = 0.017) for patients with CARDS type A. Multivariable analysis demonstrated no significant differences in PROMs by surgical approach among the other CARDS subtypes. CONCLUSIONS: Patients with disc space collapse and endplate apposition (CARDS type A) appear to benefit from TLIF. However, patients with lumbar spondylolisthesis without disc space collapse or kyphotic angulation (CARDS types B and C) showed no benefit from additional interbody placement.