The attainment of a patient acceptable symptom state in patients undergoing revision spine fusion.

INTRODUCTION: Revision lumbar fusion is most commonly due to nonunion, adjacent segment disease (ASD), or recurrent stenosis, but it is unclear if diagnosis affects patient outcomes. The primary aim of this study was to assess whether patients achieved the patient acceptable symptom state (PASS) or minimal clinically important difference (MCID) after revision lumbar fusion and assess whether this was influenced by the indication for revision. METHODS: We retrospectively identified all 1-3 level revision lumbar fusions at a single institution. Oswestry Disability Index (ODI) was collected at preoperative, three-month postoperative, and one-year postoperative time points. The MCID was calculated using a distribution-based method at each postoperative time point. PASS was set at the threshold of ≤ 22. RESULTS: We identified 197 patients: 56% with ASD, 28% with recurrent stenosis, and 15% with pseudarthrosis. The MCID for ODI was 10.05 and 10.23 at three months and one year, respectively. In total, 61% of patients with ASD, 52% of patients with nonunion, and 65% of patients with recurrent stenosis achieved our cohort-specific MCID at one year postoperatively with ASD (p = 0.78). At one year postoperatively, 33.8% of ASD patients, 47.8% of nonunion patients, and 37% of patients with recurrent stenosis achieved PASS without any difference between indication (p = 0.47). CONCLUSIONS: The majority of patients undergoing revision spine fusion experience significant postoperative improvements regardless of the indication for revision. However, a large proportion of these patients do not achieve the patient acceptable symptom state. While revision spine surgery may offer substantial benefits, these results underscore the need to manage patient expectations.

An evaluation of fusion status following lumbar fusion surgery utilizing multi-planar computed tomography.

PURPOSE: To report the rate of fusion in a sample of patients undergoing lumbar fusion surgery and assess interrater reliability of computed tomography (CT)-based parameters for the assessment of fusion. METHODS: All adult patients who underwent lumbar fusion surgery from 2017 to 2021 were retrospectively identified. Patient demographics and surgical characteristics were collected through chart review of the electronic medical records. CT scans were reviewed independently by two attending spine surgeons and two spine fellows. Fusion was defined as evidence of bone bridging in any one of (1) posterolateral gutters, (2) facets, or (3) interbody (when applicable) on any CT views. Evidence of screw haloing was indicative of nonunion. Interrater reliability was determined using cohen's kappa. Afterwards, a consensus agreement for each component of fusion was reached between participants. RESULTS: The overall fusion rate among all procedures was 63/69 (91.3%). Overall 22/25 (88.0%) TLIF, 16/19 (84.2%) PLDF, 3/3 (100%) LLIF, and 22/22 (100%) circumferential fusions experienced a successful fusion. Interrater reliability was good for interbody fusion (k = 0.734) and moderate for all other measures (k = 0.561 for posterolateral fusion; k = 0.471 for facet fusion; k = 0.458 for screw haloing). Overall, interrater reliability as to whether a patient had a fusion or nonunion was moderate (k = 0.510). CONCLUSION: There was only moderate interrater reliability across most radiographic measures used in assessing lumbar fusion status. Reliability was highest when evaluating the presence of interbody fusion. The majority of fusions occurred across the facet joints.

Relating preoperative MCS-12 to microdiscectomy outcomes.

PURPOSE: To determine the impact of poor mental health on patient-reported and surgical outcomes after microdiscectomy. METHODS: Patients ≥ 18 years who underwent a single-level lumbar microdiscectomy from 2014 to 2021 at a single academic institution were retrospectively identified. Patient-reported outcomes (PROMs) were collected at preoperative, three-month, and one-year postoperative time points. PROMs included the Oswestry Disability Index (ODI), Visual Analog Scale Back and Leg (VAS Back and VAS Leg, respectively), and the mental and physical component of the short form-12 survey (MCS and PCS). The minimum clinically important differences (MCID) were employed to compare scores for each PROM. Patients were categorized as having worse mental health or better mental health based on a MCS threshold of 50. RESULTS: Of 210 patients identified, 128 (61%) patients had a preoperative MCS score ≤ 50. There was no difference in 90-day surgical readmissions or spine reoperations within one year. At 3- and 12-month time points, both groups demonstrated improvements in all PROMs (p < 0.05). At three months postoperatively, patients with worse mental health had significantly lower PCS (42.1 vs. 46.4, p = 0.004) and higher ODI (20.5 vs. 13.3, p = 0.006) scores. Lower mental health scores were associated with lower 12-month PCS scores (43.3 vs. 48.8, p < 0.001), but greater improvements in 12-month ODI (- 28.36 vs. - 18.55, p = 0.040). CONCLUSION: While worse preoperative mental health was associated with lower baseline and postoperative PROMs, patients in both groups experienced similar improvements in PROMs. Rates of surgical readmissions and reoperations were similar among patients with varying preoperative mental health status.

The severity of preoperative anemia escalates risk of poor short-term outcomes after lumbar spine fusion.

OBJECTIVE: To evaluate how preoperative anemia severity affects 90-day outcomes of spinal fusion surgery. METHODS: A retrospective cohort study was conducted on adult lumbar fusion patients at a tertiary medical center. Patients were classified by World Health Organization anemia severity definitions for comparisons. Multivariate regression models were created to control for confounding variables, for all primary outcomes of transfusion requirements, non-home discharge, readmissions, complications, and length of stay. RESULTS: A total of 2582 patients were included: 2.7% with moderate-severe anemia, 11.0% with mild anemia, and 86.3% without anemia. Moderate-severe patients had the longest hospital stay (5.03 days vs 4.14 and 3.59 days, p < 0.001) and highest risk of transfusion (52.2% vs 13.0% vs 2.69%, p < 0.001), non-home discharge (39.1% vs 27.8% vs 15.4%, p < 0.001), readmission (7.25% vs 5.99% vs 3.36%, p = 0.023), and complications (13.0% vs 9.51% vs 6.20%, p = 0.012). On multivariable logistic regression, both patients with mild and moderate-severe anemia had an increased risk of transfusion (OR: 37.3, p < 0.001; OR: 5.25, p < 0.001, respectively) and non-home discharge (OR: 2.00, p = 0.021; OR: 1.71, p = 0.001, respectively) compared to patients without anemia. Anemia severity was not independently associated with complications or 90-day readmission. On multivariable linear regression, mild anemia (ß: 0.37, p = 0.001) and moderate-severe anemia (ß: 1.07, p < 0.001) were independently associated with length of hospital stay. CONCLUSION: Patients with moderate-severe preoperative anemia are at increased risk for longer length of stay, transfusions, and non-home discharge. Improved optimization of preoperative anemia may significantly reduce healthcare utilization, and surgeons should consider these risks in preoperative planning. LEVEL OF EVIDENCE: III.

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.

Preoperative epidural steroid injections do not increase the risk of postoperative infection in patients undergoing lumbar decompression or fusion: a systematic review and meta-analysis.

PURPOSE: Epidural corticosteroid injections (ESI) are a mainstay of nonoperative treatment for patients with lumbar spine pathology. Recent literature evaluating infection risk following ESI after elective orthopedic surgery has produced conflicting evidence. Our primary objective was to review the literature and provide a larger meta-analysis analyzing the temporal effects of steroid injections on the risk of infection following lumbar spine surgery. METHODS: We conducted a query of the PubMed, Embase, and Scopus databases from inception until April 1, 2022 for studies evaluating the risk of infection in the setting of prior spinal steroid injections in patients undergoing lumbar spine decompression or fusion. Three meta-analyses were conducted, (1) comparing ESI within 30-days of surgery to control, (2) comparing ESI within 30-days to ESI between 1 and 3 months preoperatively, and (3) comparing any history of ESI prior to surgery to control. Tests of proportions were utilized for all comparisons between groups. Study heterogeneity was assessed via forest plots, and publication bias was assessed quantiatively via funnel plots and qualitatively with the Newcastle-Ottawa Scale. RESULTS: Nine total studies were included, five of which demonstrated an association between ESI and postoperative infection, while four found no association. Comparison of weighted means demonstrated no significant difference in infection rates between the 30-days ESI group and control group (2.67% vs. 1.69%, p = 0.144), 30-days ESI group and the > 30-days ESI group (2.34% vs. 1.66%, p = 0.1655), or total ESI group and the control group (1.99% vs. 1.70%, p = 0.544). Heterogeneity was low for all comparisons following sensitivity analyses. CONCLUSION: Current evidence does not implicate preoperative ESI in postoperative infection rates following lumbar fusion or decompression. Operative treatment should not be delayed due to preoperative steroid injections based on current evidence. There remains a paucity of high-quality data in the literature evaluating the impact of preoperative ESI on postoperative infection rates. LEVEL OF EVIDENCE: II.

SPINE20 A global advocacy group promoting evidence-based spine care of value.

PURPOSE: The Global Burden of Diseases (GBD) Studies have estimated that low back pain is one of the costliest ailments worldwide. Subsequent to GBD publications, leadership of the four largest global spine societies agreed to form SPINE20. This article introduces the concept of SPINE20, the recommendations, and the future of this global advocacy group linked to G20 annual summits. METHODS: The founders of SPINE20 advocacy group coordinated with G20 Saudi Arabia to conduct the SPINE20 summit in 2020. The summit was intended to promote evidence-based recommendations to use the most reliable information from high-level research. Eight areas of importance to mitigate spine disorders were identified through a voting process of the participating societies. Twelve recommendations were discussed and vetted. RESULTS: The areas of immediate concern were "Aging spine," "Future of spine care," "Spinal cord injuries," "Children and adolescent spine," "Spine-related disability," "Spine Educational Standards," "Patient safety," and "Burden on economy." Twelve recommendations were created and endorsed by 31/33 spine societies and 2 journals globally during a vetted process through the SPINE20.org website and during the virtual inaugural meeting November 10-11, 2020 held from the G20 platform. CONCLUSIONS: This is the first time that international spine societies have joined to support actions to mitigate the burden of spine disorders across the globe. SPINE20 seeks to change awareness and treatment of spine pain by supporting local projects that implement value-based practices with healthcare policies that are culturally sensitive based on scientific evidence.

Management of Adult Lumbar Spine Problems for General Orthopaedic Surgeons: A Practical Guide.

Low back pain is one of the most common reasons for physician visits, leading to high heath care costs and disability. Patients may present to primary care physicians, pain management physicians, chiropractors, physical therapists, or surgeons with these complaints. A thorough history and physical examination coupled with judicious use of advanced imaging studies will aid in determining the etiology of the pain. As most cases of low back pain are self-limited and will not develop into chronic pain, nonsurgical treatment is the mainstay. First-line treatment includes exercise, superficial heat, massage, acupuncture, or spinal manipulation. Pharmacologic treatment should be reserved for patients unresponsive to nonpharmacologic treatment and may include NSAIDs or muscle relaxants. Surgery is reserved for patients with pain nonresponsive to a full trial of nonsurgical interventions and with imaging studies which are concordant with physical examination findings.

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.

Cervical radiculopathy: epidemiology, etiology, diagnosis, and treatment.

Cervical radiculopathy is a relatively common neurological disorder resulting from nerve root dysfunction, which is often due to mechanical compression; however, inflammatory cytokines released from damaged intervertebral disks can also result in symptoms. Cervical radiculopathy can often be diagnosed with a thorough history and physical examination, but an magnetic resonance imaging or computed tomographic myelogram should be used to confirm the diagnosis. Because of the ubiquity of degenerative changes found on these imaging modalities, the patient's symptoms must correlate with pathology for a successful diagnosis. In the absence of myelopathy or significant muscle weakness all patients should be treated conservatively for at least 6 weeks. Conservative treatments consist of immobilization, anti-inflammatory medications, physical therapy, cervical traction, and epidural steroid injections. Cervical radiculopathy typically is self-limiting with 75%-90% of patients achieving symptomatic improvement with nonoperative care. For patients who are persistently symptomatic despite conservative treatment, or those who have a significant functional deficit surgical treatment is appropriate. Surgical options include anterior cervical decompression and fusion, cervical disk arthroplasty, and posterior foraminotomy. Patient selection is critical to optimize outcome.

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.

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.

A new perspective on intervertebral disc calcification-from bench to bedside.

Disc degeneration primarily contributes to chronic low back and neck pain. Consequently, there is an urgent need to understand the spectrum of disc degeneration phenotypes such as fibrosis, ectopic calcification, herniation, or mixed phenotypes. Amongst these phenotypes, disc calcification is the least studied. Ectopic calcification, by definition, is the pathological mineralization of soft tissues, widely studied in the context of conditions that afflict vasculature, skin, and cartilage. Clinically, disc calcification is associated with poor surgical outcomes and back pain refractory to conservative treatment. It is frequently seen as a consequence of disc aging and progressive degeneration but exhibits unique molecular and morphological characteristics: hypertrophic chondrocyte-like cell differentiation; TNAP, ENPP1, and ANK upregulation; cell death; altered Pi and PPi homeostasis; and local inflammation. Recent studies in mouse models have provided a better understanding of the mechanisms underlying this phenotype. It is essential to recognize that the presentation and nature of mineralization differ between AF, NP, and EP compartments. Moreover, the combination of anatomic location, genetics, and environmental stressors, such as aging or trauma, govern the predisposition to calcification. Lastly, the systemic regulation of calcium and Pi metabolism is less important than the local activity of PPi modulated by the ANK-ENPP1 axis, along with disc cell death and differentiation status. While there is limited understanding of this phenotype, understanding the molecular pathways governing local intervertebral disc calcification may lead to developing disease-modifying drugs and better clinical management of degeneration-related pathologies.

Implementation of a Private Payer Bundled Payment Model While Maintaining High-Value Lumbar Spinal Fusion.

STUDY DESIGN: Retrospective single-institution cohort. OBJECTIVE: To evaluate the implementation of a commercial bundled payment model in patients undergoing lumbar spinal fusion. SUMMARY OF BACKGROUND DATA: BPCI-A caused significant losses for many physician practices, prompting private payers to establish their own bundled payment models. The feasibility of these private bundles has yet to be evaluated in spine fusion. METHODS: Patients undergoing lumbar fusion from October to December 2018 in BPCI-A before our institution's departure were included for BPCI-A analysis. Private bundle data was collected from 2018 to 2020. Analysis of the transition was conducted among Medicare-aged beneficiaries. Private bundles were grouped by calendar year (Y1, Y2, Y3). Stepwise multivariate linear regression was performed to measure independent predictors of net deficit. RESULTS: The net surplus was the lowest in Y1 ($2,395, P =0.03) but did not differ between our final year in BPCI-A and subsequent years in private bundles (all, P >0.05). AIR and SNF patient discharges decreased significantly in all private bundle years compared with BPCI. Readmissions fell from 10.7% (N=37) in BPCI-A to 4.4% (N=6) in Y2 and 4.5% (N=3) Y3 of private bundles ( P <0.001). Being in Y2 or Y3 was independently associated with a net surplus in comparison to the Y1 (ß: $11,728, P =0.001; ß: $11,643, P =0.002). Postoperatively, length of stay in days (ß: $-2,982, P <0.001), any readmission (ß: -$18,825, P =0.001), and discharge to AIR (ß: $-61,256, P <0.001) or SNF (ß: $-10,497, P =0.058) were all associated with a net deficit. CONCLUSIONS: Nongovernmental bundled payment models can be successfully implemented in lumbar spinal fusion patients. Constant price adjustment is necessary so bundled payments remain financially beneficial to both parties and systems overcome early losses. Private insurers who have more competition than the government may be more willing to provide mutually beneficial situations where cost is reduced for payers and health systems. LEVEL OF EVIDENCE: 3.

Subfascial Lumbar Spine Drain Output Does Not Affect Outcomes After Incidental Durotomies in Elective Spine Surgery.

OBJECTIVE: Postoperative drains have long been regarded as a preventive measure to mitigate the risks of complications such as neurological impairment by reducing fluid accumulation following spine surgery. Our study aims to contribute to the existing body of knowledge by examining the effects of postoperative drain output on the 90-day postoperative outcomes for patients who experienced an incidental durotomy after lumbar decompression procedures, with or without fusion. METHODS: All patients aged ≥18 years with an incidental durotomy from spinal decompression with or without fusion surgery between 2017 and 2021 were retrospectively identified. The patient demographics, surgical characteristics, method of dural tear repair (DuraSeal, suture, and/or DuraGen), surgical outcomes, and drain data were collected via medical record review. Patients were grouped by readmission status and final 8-hour drain output. Those with a final 8-hour drain output of ≥40 mL were included in the high drain output (HDO) group and those with <40 mL were in the low drain output (LDO) group. RESULTS: There were no statistically significant differences in preoperative patient demographics, surgical characteristics, method of dural tear repair, length of stay (HDO, 4.02 ± 1.90 days; vs. LDO, 4.26 ± 2.10 days; P = 0.269), hospital readmissions (HDO, 10.6%; vs. LDO, 7.96%; P = 0.744), or occurrence of reoperation during readmission (HDO, 6.06%; vs. LDO, 2.65%; P = 0.5944) between the 2 groups. CONCLUSIONS: For patients undergoing primary lumbar decompression with or without fusion and experiencing an incidental durotomy, no significant association was found between the drain output and 90-day patient outcomes. Adequate fascial closure and the absence of symptoms may be satisfactory criteria for standard patient discharge regardless of drain output.

A Longitudinal Evaluation of Coronavirus Disease 2019 and Its Effects on Spinal Decompressions With or Without Fusion.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: The objectives were to (1) compare the safety of spine surgery before and after the emergence of coronavirus disease 2019 (COVID-19) and (2) determine whether patients with a history of COVID-19 were at increased risk of adverse events. SUMMARY AND BACKGROUND DATA: The COVID-19 pandemic had a tremendous impact on several health care services. In spine surgery, elective cases were canceled and patients received delayed care due to the uncertainty of disease transmission and surgical outcomes. As new coronavirus variants arise, health care systems require guidance on how to provide optimal patient care to all those in need of our services. PATIENTS AND METHODS: A retrospective review of patients undergoing spine surgery between January 1, 2019 and June 30, 2021 was performed. Patients were split into pre-COVID or post-COVID cohorts based on local government guidelines. Inpatient complications, 90-day readmission, and 90-day mortality were compared between groups. Secondary analysis included multiple logistic regression to determine independent predictors of each outcome. RESULTS: A total of 2976 patients were included for analysis with 1701 patients designated as pre-COVID and 1275 as post-COVID. The pre-COVID cohort had fewer patients undergoing revision surgery (16.8% vs 21.9%, P < 0.001) and a lower home discharge rate (84.5% vs 88.2%, P = 0.008). Inpatient complication (9.9% vs 9.2%, P = 0.562), inpatient mortality (0.1% vs 0.2%, P = 0.193), 90-day readmission (3.4% vs 3.2%, P = 0.828), and 90-day mortality rates (0.8% vs 0.8%, P = 0.902) were similar between groups. Patients with positive COVID-19 tests before surgery had similar complication rates (7.7% vs 6.1%, P = 1.000) as those without a positive test documented. CONCLUSIONS: After the emergence of COVID-19, patients undergoing spine surgery had a greater number of medical comorbidities, but similar rates of inpatient complications, readmission, and mortality. Prior COVID-19 infection was not associated with an increased risk of postsurgical complications or mortality. LEVEL OF EVIDENCE: Level III.

Circulating microRNAs May Be Predictive of Degenerative Cervical Myelopathy.

STUDY DESIGN: Basic Science. OBJECTIVE: The objective of this study was to identify a unique serum profile of circulating miRNAs and inflammatory markers in patients with degenerative cervical myelopathy (DCM) compared to healthy controls (HC). SUMMARY OF BACKGROUND DATA: Currently, DCM is diagnosed with a combination of history, physical examination, and close correlation to advanced imaging. To date, no serum marker has been identified to be diagnostic of this condition. METHODS: Whole venous blood was collected from patients with DCM as well as healthy age- and sex-matched controls. miRNA was extracted from venous blood and a screening analysis was initially conducted to identify miRNA dysregulation in DCM patients. RT-qPCR was used to analyze the expression of 2 specific miRNAs based on screening analysis and literature review. Bioinformatics analysis was used to identify gene networks and potential targets of the miRNA. In addition, the serum inflammatory profile of DCM and HC groups was differentiated using a pro-inflammatory panel. RESULTS: Thirty-six patients were enrolled in the DCM group (36.1% male, 61.5±9.5 y) while 35 patients were enrolled in the HC group (31.4% male, 57.5±8.9 y). Of the 15 total miRNAs differentially expressed between DCM and HC groups, two were selected for further analysis: miR-223-3p (upregulated) and miR-451a (downregulated). Functional gene network analysis revealed the highest-ranking gene network was involved in neurological disease, while the most overexpressed miRNA in this network (miR-233-3p) was noted to have over 100 targets including CDKN1B and the insulin receptor. Serum cytokine analysis showed significant upregulation of several pro-inflammatory cytokines in the DCM cohort compared to the HC group. CONCLUSION: DCM patients demonstrated a set of unique circulating miRNAs in addition to a different serum inflammatory profile compared to HC. These miRNAs may potentially serve as targets for future therapeutic intervention or diagnostic/prognostic testing.

Immediate vs. delayed venous thromboembolism prophylaxis following spine surgery: increased rate of unplanned reoperation for postoperative hematoma with immediate prophylaxis.

BACKGROUND CONTEXT: There is significant variability in postoperative chemoprophylaxis protocols amongst spine providers due to perceived risks and benefits, but limited data on the topic. At our institution, both orthopaedic spine and neurosurgery departments utilize unfractionated subcutaneous heparin in identical dosages and frequency, with the only difference being time to initiation postoperatively. PURPOSE: To evaluate the rate of symptomatic venous thromboembolism (VTEs) and unplanned reoperation for hematoma based on timing of chemoprophylaxis initiation. STUDY DESIGN/SETTING: Single institution retrospective cohort study. PATIENT SAMPLE: Patients undergoing elective spine surgery, excluding patients undergoing surgery in the setting of trauma, malignancy, or infection OUTCOME MEASURES: Outcome measures included the diagnosis of a venous thromboembolism within 90 days of surgery and unplanned reoperation for a hematoma METHODS: Patients undergoing elective spine surgery from 2017 to 2021 were grouped based on chemoprophylaxis protocol. In the "immediate" group, patients received subcutaneous heparin 5000 units every 8 hours starting immediately after surgery, and in the "delayed" group, patients received chemoprophylaxis starting postoperative day (POD)-2 for any decompressions and/or fusions involving a spinal cord level (i.e., L2 and above) and POD-1 for those involving only levels below the spinal cord (i.e., L3 to pelvis). A cox proportional hazards model was created to assess independent predictors of venous thromboembolic events, while a logistic regression was utilized for unplanned reoperations for hematoma. RESULTS: Of 8,704 patients, a total of 98 (1.13%) VTE events occurred, of which 43 (0.49%) were pulmonary embolism. Fifty-four patients (0.62%) had unplanned reoperations for postoperative hematomas. On cox proportional hazards model analysis, immediate chemoprophylaxis was not protective of a venous thromboembolism (Hazard Ratio: 1.18, p=.436), but, it was a significant independent predictor for unplanned reoperation for hematoma on multivariable logistic regression modeling (Odds Ratio: 3.29, p<.001). CONCLUSIONS: Both chemoprophylaxis protocols in our study resulted in low rates of VTE and postoperative hematoma. However, our findings suggest that the delayed chemoprophylaxis protocol may mitigate postoperative hematoma formation without increasing the risk for a thrombotic event.

Which North American spine society disc herniation morphology descriptors are most associated with improvements in clinical outcomes after microdiscectomy?

Background: The North American Spine Society (NASS) assembled the first ever comprehensive naming system for describing lumbar disc disease, including lumbar disc herniation. The objectives of this study were (1) to determine which NASS descriptors are most predictive of independent patient-reported outcomes after microdiscectomy and (2) to identify the inter-rater reliability of each NASS descriptor. Methods: Adult patients (≥18 years) who underwent a lumbar microdiscectomy from 2014-2021 were retrospectively identified. Patient-reported outcome measures (PROMs) were collected at preoperative, 3-month, and 1-year postoperative time points. Lumbar disc herniations were evaluated and classified on preoperative MRI using the NASS lumbar disc nomenclature specific to disc herniation. Results: About 213 microdiscectomy patients were included in the final analysis. Herniation descriptors exhibiting the greatest reliability included sequestration status (κ=0.83), axial disc herniation area (κ=0.83), and laterality (κ=0.83). The descriptor with the lowest inter-rater reliability was direction of migration (κ=0.53). At 3 months, a sequestered herniation was associated with lower odds of achieving the minimal clinically important difference (MCID) for ODI (p=.004) and MCS (p=.032). At 12 months, a similar trend was observed for Oswestry Disability Index (ODI) MCID achievement (p=.001). At 3 months, a herniation with larger axial area was a predictor of MCID achievement in ODI (p=.004) and the mental component summary (MCS) (p=.009). Neither association persisted at 12 months; however, larger axial disc herniation area was able to predict MCID achievement in the Visual Analogue Scale (VAS) leg (p=.031) at 12 months. Conclusions: The utility of the NASS nomenclature system in predicting postoperative outcomes after microdiscectomy has yet to be studied. We showed that sequestration status and disc area are both reliable and able to predict the odds of achieving MCID in certain clinical outcomes at 3 months and 12 months after surgery. Hence, preoperative imaging analysis of lumbar disc herniations may be useful in accurately setting patient expectations.