Construct length analysis of type B and C cervical and thoracolumbar fractures.

Objectives: The purpose of this study is to identify if construct length affects the rate of surgical complications and instrumentation revision following surgical fixation of subaxial and thoracolumbar Type B and C fractures. This study evaluates the effect of ankylosing spondylitis/diffuse idiopathic skeletal hyperostosis (AS/DISH) within this population on outcomes. Methods: Retrospective review of 91 cervical and 89 thoracolumbar Type B and C fractures. Groups were divided by construct length for analysis: short-segment (constructs spanning two or less segments adjacent to the fracture) and long-segment (constructs spanning more than two segments adjacent to the vertebral fracture). Results: For cervical fractures, construct length did not impact surgical complications (P = 0.641), surgical hardware revision (P = 0.167), or kyphotic change (P = 0.994). For thoracolumbar fractures, construct length did not impact surgical complications (P = 0.508), surgical hardware revision (P = 0.224), and kyphotic change (P = 0.278). Cervical Type B fractures were nonsignificantly more likely to have worsened kyphosis (P = 0.058) than Type C fractures. Assessing all regions of the spine, a diagnosis of AS/DISH was associated with an increase in kyphosis (P = 0.030) and a diagnosis of osteoporosis was associated with surgical hardware failure (P = 0.006). Conclusion: Patients with short-segment instrumentation have similar surgical outcomes and changes in kyphosis compared to those with long-segment instrumentation. A diagnosis of AS/DISH or osteoporosis was associated with worse surgical outcomes.

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.

The impact of robotic assistance for lumbar fusion surgery on 90-day surgical outcomes and 1-year revisions.

Objectives: To evaluate the (1) 90-day surgical outcomes and (2) 1-year revision rate of robotic versus nonrobotic lumbar fusion surgery. Methods: Patients >18 years of age who underwent primary lumbar fusion surgery at our institution were identified and propensity-matched in a 1:1 fashion based on robotic assistance during surgery. Patient demographics, surgical characteristics, and surgical outcomes, including 90-day surgical complications and 1-year revisions, were collected. Multivariable regression analysis was performed. Significance was set to P < 0.05. Results: Four hundred and fifteen patients were identified as having robotic lumbar fusion and were matched to a control group. Bivariant analysis revealed no significant difference in total 90-day surgical complications (P = 0.193) or 1-year revisions (P = 0.178). The operative duration was longer in robotic surgery (287 + 123 vs. 205 + 88.3, P ≤ 0.001). Multivariable analysis revealed that robotic fusion was not a significant predictor of 90-day surgical complications (odds ratio [OR] = 0.76 [0.32-1.67], P = 0.499) or 1-year revisions (OR = 0.58 [0.28-1.18], P = 0.142). Other variables identified as the positive predictors of 1-year revisions included levels fused (OR = 1.26 [1.08-1.48], P = 0.004) and current smokers (OR = 3.51 [1.46-8.15], P = 0.004). Conclusion: Our study suggests that robotic-assisted and nonrobotic-assisted lumbar fusions are associated with a similar risk of 90-day surgical complications and 1-year revision rates; however, robotic surgery does increase time under anesthesia.

PA and NP burnout in orthopedic surgery.

OBJECTIVE: To quantify the burnout rate among physician associates/assistants (PAs) and NPs in a large orthopedic surgery practice affiliated with an academic institution. METHODS: The Maslach Burnout Inventory (MBI) and original research questions were given to all PAs and NPs in orthopedics at the facility. Burnout was defined as a high level of emotional exhaustion or depersonalization on the MBI subscale. RESULTS: Of the 129 PAs and NPs in orthopedics at our institution, 91 (70.5%) completed all survey items. Nearly 42% of respondents were burned out, as defined by high depersonalization or emotional exhaustion. PAs and NPs who met the burnout criteria were significantly older than those who did not (41.8 ± 10 versus 36.5 ± 7.71 years, P = .007) and spent longer in practice (12.4 ± 6.66 versus 9.35 ± 6.41 years, P = .01). CONCLUSIONS: The prevalence of burnout is high among PAs and NPs in orthopedics who practice in an academic setting.

The Inhibitory Effect of NSAIDs and Opioids on Spinal Fusion: An Animal Model.

STUDY DESIGN: Translational research. OBJECTIVE: To evaluate the relative effects of NSAIDs, opioids, and a combination of the two on spinal fusion inhibition in a rodent model. SUMMARY OF BACKGROUND DATA: Nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids are common postoperative analgesic agents. Since NSAIDs inhibit the cyclooxygenase (COX) pathway, they are seldom prescribed following spinal fusion. Opioids may be given instead, but recent evidence suggests opioids also adversely affect spinal fusion quality and success. METHODS: Eighty male Sprague-Dawley rats underwent L4-5 posterior lumbar fusion and were given one of the following analgesia regimens: saline, morphine (6 mg/kg), ketorolac (4 mg/kg), or morphine (3 mg/kg) and ketorolac (2 mg/kg). Serum samples were drawn to evaluate systemic pro-osteoblastic cytokines and vascular endothelial growth factor-A (VEGF-A) levels, which were measured through enzyme-linked immunosorbent assays (ELISA). After six weeks, the rats were sacrificed, and the operated spinal segments underwent manual palpation, microCT, and histologic analysis. RESULTS: Manual palpation scores were significantly diminished in the opioid, NSAID, and multimodal groups when compared with control ( P <0.001). MicroCT fusion scores ( P <0.001) and fusion rates (control: 75% vs . NSAID: 35% vs . opioid: 0% vs . combination: 15%, P <0.001) were significantly diminished in the treatment groups. The bone volume (BV) to tissue volume (TV) ratio (BV/TV) ( P <0.001) and bone mineral density (BMD) ( P <0.001) were all lower in the treatment groups, with the opioid and combined groups having the lowest BMD. Although statistically insignificant ( P <0.09), the concentration of VEGF-A was greater in the control group compared with opioids, NSAIDs, and the combined group. CONCLUSION: Opioids and NSAIDs, both independently and combined, inhibited spinal fusion and caused inferior bony callus. Administration of opioids resulted in the lowest rate of spinal fusion. We propose this may be due to the inhibition of VEGF-A, which limits angiogenesis to the burgeoning fusion mass.

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.

Cellular Bone Matrix in Spine Surgery - Are They Worth the Risk: A Systematic Review.

STUDY DESIGN: Systematic Review. OBJECTIVE: To review the literature for complications and outcomes after the implantation of cellular bone matrix (CBM) during spine fusion. METHODS: The PubMed database was queried from inception to January 31, 2023 for any articles that discussed the role of and identified a specific CBM in spinal fusion procedures. Adverse events, reoperations, methods, and fusion rates were collected from all studies and reported. RESULTS: Six hundred articles were identified, of which 19 were included that reported outcomes of 7 different CBM products. Seven studies evaluated lumbar fusion, 11 evaluated cervical fusion, and 1 study reported adverse events of a single CBM product. Only 4 studies were comparative studies while others were limited to case series. Fusion rates ranged from 68% to 98.7% in the lumbar spine and 87% to 100% in the cervical spine, although criteria for radiographic fusion was variable. While 7 studies reported no adverse events, there was no strict consensus on what constituted a complication. One study reported catastrophic disseminated tuberculosis from donor contaminated CBM. The authors of 14 studies had conflicts of interest with either the manufacturer or distributor for their analyzed CBM. CONCLUSIONS: Current evidence regarding the use of cellular bone matrix as an osteobiologic during spine surgery is weak and limited to low-grade non-comparative studies subject to industry funding. While reported fusion rates are high, the risk of severe complications should not be overlooked. Further large clinical trials are required to elucidate whether the CBMs offer any benefits that outweigh the risks.

Does physical therapy impact clinical outcomes after lumbar decompression surgery?

Objectives: The objectives of our study were to (1) determine if physical therapy (PT) impacts patient-reported outcomes (PROMs) after lumbar decompression surgery and (2) determine if PT impacts postsurgical readmissions or reoperations after lumbar decompression surgery. Methods: Patients >18 years of age who underwent primary one- or two-level lumbar decompression at our institution were identified. Patient demographics, surgical characteristics, surgical outcomes (all-cause 90 days readmissions and 90 days surgical readmissions), and patient-reported outcomes (PROMs) were compared between the groups. Multivariate linear regression was utilized to determine the individual predictors of 90 days readmissions and PROMs at the 1-year postoperative point. Alpha was set at P < 0.05. Results: Of the 1003 patients included, 421 attended PT postoperatively. On univariate analysis, PT attendance did not significantly impact 90-day surgical reoperations (P = 0.225). Although bivariate analysis suggests that attendance of PT is associated with worse improvement in physical function (P = 0.041), increased preoperative Visual Analogue Scale leg pain (0 = 0.004), and disability (P = 0.006), as measured by the Oswestry Disability Index, our multivariate analysis, which accounts for confounding variables found there was no difference in PROM improvement and PT was not an independent predictor of 90-day all-cause readmissions (P = 0.06). Instead, Charlson Comorbidity Index (P = 0.025) and discharge to a skilled nursing facility (P = 0.013) independently predicted greater 90-day all-cause readmissions. Conclusions: Postoperative lumbar decompression PT attendance does not significantly affect clinical improvement, as measured by PROMs or surgical outcomes including all-cause 90 days readmissions and 90-day surgical readmissions.

Radiographic and Patient-Reported Outcomes: Anteriorly Placed Transforaminal Lumbar Interbody Fusion Cage vs. Anterior Lumbar Interbody Fusion with Posterior Instrumentation.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: To compare outcomes in anteriorly placed transforaminal lumbar interbody fusions (TLIFs) and anterior lumbar interbody fusions (ALIFs). SUMMARY OF BACKGROUND DATA: TLIF and ALIF are surgical techniques that have become more prevalent in recent years. Although studies have compared the two, none have considered TLIFs with anteriorly placed cages, which may serve as a better comparison to ALIFs. MATERIALS AND METHODS: Patients undergoing TLIF or ALIF with posterior instrumentation from 2010-2020 at a tertiary care institution were retrospectively identified. TLIF cage position was assessed and those with anterior placement were included. Electronic medical records were reviewed to identify patient characteristics and patient-reported outcomes. Radiographic outcomes included posterior disc height (DH), lumbar lordosis (LL), sacral slope (SS), pelvic incidence (PI) and pelvic tilt (PT). Statistical analysis was performed to compare the two groups. RESULTS: Of the 351 patients, 108 had ALIF with posterior instrumentation and 207 had a TLIF. Preoperatively, TLIF patients had less LL (53.7° vs. 60.6°, P<0.001), SS (38.3° vs. 43.7°, P<0.001), and PI (60.1° vs. 66.1°, P<0.001), all of which remained significant at one-year and long-term follow-up (P<0.001). The TLIF group had less ∆DH (1.51° vs. 5.43°, P<0.001), ∆LL (1.8° vs. 2.97°, P=0.038), and ∆SL (0.18° vs. 4.40°, P<0.001) at one year postoperatively. At two to three years, ∆DH (P<0.001) and ∆SL (P=0.001) remained significant, but ∆LL (P=0.695) did not. Patients in the TLIF group had higher VAS-Back scores one year postoperatively (3.68 vs. 2.16, P=0.008) and experienced less improvement in ODI (-17.1 vs. -28.6, P=0.012) and VAS-Back (-2.67 vs. -4.50, P=0.008) compared to ALIF patients. CONCLUSIONS: Our findings suggest that ALIF with posterior instrumentation performed superiorly in radiographic outcomes and PROMs compared to anteriorly placed TLIFs. Anteriorly placed TLIF cages may not achieve the same results as those of ALIF cages.

Assessment of a Private Payer Bundled Payment Model for Lumbar Decompression Surgery.

INTRODUCTION: Although bundled payment models are well-established in Medicare-aged individuals, private insurers are now developing bundled payment plans. The role of these plans in spine surgery has not been evaluated. Our objective was to analyze the performance of a private insurance bundled payment program for lumbar decompression and microdiskectomy. METHODS: A retrospective review was conducted of all lumbar decompressions in a private payer bundled payment model at a single institution from October 2018 to December 2020. 120-day episode of care cost data were collected and reported as net profit or loss regarding set target prices. A stepwise multivariable linear regression model was developed to measure the effect of patient and surgical factors on net surplus or deficit. RESULTS: Overall, 151 of 468 (32.2%) resulted in a deficit. Older patients (58.6 vs. 50.9 years, P < 0.001) with diabetes (25.2% vs. 13.9%, P = 0.004), hypertension (38.4% vs. 28.4%, P = 0.038), heart disease (13.9% vs. 7.57%, P = 0.030), and hyperlipidemia (51.7% vs. 35.6%, P = 0.001) were more likely to experience a loss. Surgically, decompression of more levels (1.91 vs. 1.19, P < 0.001), posterior lumbar decompression (86.8% vs. 56.5%, P < 0.001), and performing surgery at a tertiary hospital (84.8% vs. 70.3%, P < 0.001) were more likely to result in loss. All readmissions resulted in a loss (4.64% vs. 0.0%, P < 0.001). On multivariable regression, microdiskectomy (ß: $2,398, P = 0.012) and surgery in a specialty hospital (ß: $1,729, P = 0.096) or ambulatory surgery center (ß: $3,534, P = 0.055) were associated with cost savings. Increasing number of levels, longer length of stay, active smoking, and history of cancer, dementia, or congestive heart failure were all associated with degree of deficit. CONCLUSIONS: Preoperatively optimizing comorbidities and using risk stratification to identify those patients who may safely undergo surgery at a facility other than an inpatient hospital may help increase cost savings in a bundled payment model of working-age and Medicare-age individuals.

The impact of demineralized bone matrix characteristics on pseudarthrosis and surgical outcomes after posterolateral lumbar decompression and fusion.

Objectives: The objectives of our study were to compare the fusion rates and surgical outcomes of lumbar fusion surgery based on the (1) type of demineralized bone matrix (DBM) carrier allograft, (2) the presence/absence of a carrier, and (3) the presence of bone fibers in DBM. Methods: Patients >18 years of age who underwent single-level posterolateral decompression and fusion (PLDF) between L3 and L5 between 2014 and 2021 were retrospectively identified. We assessed bone grafts based on carrier type (no carrier, sodium hyaluronate carrier, and glycerol carrier) and the presence of bone fibers. Fusion status was determined based on a radiographic assessment of bony bridging, screw loosening, or change in segmental lordosis >5°. Analyses were performed to assess fusion rates and surgical outcomes. Results: Fifty-four patients were given DBM with a hyaluronate carrier, 75 had a glycerol carrier, and 94 patients were given DBM without a carrier. DBM carrier type, bone fibers, and carrier presence had no impact on 90-day readmission rates (P = 0.195, P = 0.099, and P = 1.000, respectively) or surgical readmissions (P = 0.562, P = 0.248, and P = 0.640, respectively). Multivariable logistic regression analysis found that type of carrier, presence of fibers (odds ratio [OR] = 1.106 [0.524-2.456], P = 0.797), and presence of a carrier (OR = 0.701 [0.370-1.327], P = 0.274) were also not significantly associated with successful fusion likelihood. Conclusion: Our study found no significant differences between DBM containing glycerol, sodium hyaluronate, or no carrier regarding fusion rates or surgical outcomes after single-level PLDF. Bone particulates versus bone fibers also had no significant differences regarding the likelihood of bony fusion.

The Impact of Physical Therapy After Lumbar Fusion Surgery.

STUDY DESIGN: Retrospective Cohort. OBJECTIVE: To determine if outcomes varied between patients based on physical therapy (PT) attendance after lumbar fusion surgery. SUMMARY OF BACKGROUND DATA: The literature has been mixed regarding the efficacy of postoperative PT to improve disability and back pain, as measured by patient-reported outcome measures. Given the prevalence of PT referrals and lack of high-quality evidence, there is a need for additional studies investigating the efficacy of PT after lumbar fusion surgery to aid in developing robust clinical guidelines. METHODS: We retrospectively identified patients receiving lumbar fusion surgery by current procedural terminology codes and separated them into 2 groups based on whether PT was prescribed. Electronic medical records were reviewed for patient and surgical characteristics, PT utilization, and surgical outcomes. Patient-reported outcome measures (PROMs) were identified and compared preoperatively, at 90 days postoperatively and one year postoperatively. RESULTS: The two groups had similar patient characteristics and comorbidities and demonstrated no significant differences between readmission, complication, and revision rates after surgery. Patients that attended PT had significantly more fused levels (1.41 ± 0.64 vs. 1.32 ± 0.54, P =0.027), longer operative durations (234 ± 96.4 vs. 215 ± 86.1 min, P =0.012), and longer postoperative hospital stays (3.35 ± 1.68 vs. 3.00 ± 1.49 days, P =0.004). All groups improved similarly by Oswestry Disability Index, short form-12 physical and mental health subsets, and back and leg pain by Visual Analog Scale at 90-day and 1-year follow-up. CONCLUSION: Our data suggest that physical therapy does not significantly impact PROMs after lumbar fusion surgery. Given the lack of data suggesting clear benefit of PT after lumbar fusion, surgeons should consider more strict criteria when recommending physical therapy to their patients after lumbar fusion surgery. LEVEL OF EVIDENCE: Level-Ⅲ.

The Implication of Preoperative Central Stenosis on Patient-Reported Outcomes After Lumbar Decompression Surgery.

OBJECTIVE: To assess the impact of central stenosis severity on patient-reported outcomes after lumbar decompression. METHODS: Patient diagnosis, demographics, and surgical characteristics were collected via query search and manual chart review of electronic medical records. The inclusion criteria were posterior lumbar decompressions from 2014-2020, with accessible magnetic resonance imaging reports. As previously validated by Lee et al., central stenosis was determined on magnetic resonance imaging and graded as none, mild, moderate, or severe. Patients were dichotomized into 2 groups to improve statistical power for comparisons: none or mild central stenosis and moderate or severe central stenosis. Patient-reported outcome measures (PROMs) were compared between cohorts at 1 year postoperatively. Statistical significance was set at P < 0.05. RESULTS: On bivariate analysis, no significant differences were noted between cohorts with regard to preoperative, 1-year postoperative, and delta PROMs. In addition, no significant difference in the number of patients attaining minimal clinically important difference (MCID) for each PROM was noted between cohorts. With the exception of mental score of the Short Form-12 survey, all intragroup preoperative to postoperative PROMs indicated significant improvement (all P < 0.05) after lumbar decompression surgery. Multivariate regression identified moderate or severe central canal stenosis as a significant independent predictor of improvement in visual analog scale back (estimate = -1.464, P = 0.045). CONCLUSIONS: We demonstrate that patients with moderate or severe central spinal stenosis may have more improvement in back pain than those with mild or no central stenosis after lumbar spine decompression surgery.

Procedures employing interbody devices and multi-level fusion require target price adjustment to build a sustainable lumbar fusion bundled payment model.

BACKGROUND CONTEXT: Bundled payment models require risk adjustment to ensure appropriate targets are set. While this may be standardized for many services, spine fusions demonstrate significant variability in approach, invasiveness, and use of implants, that may require further risk adjustment. PURPOSE: To evaluate variability in costs of spinal fusion episodes in a private insurer bundle payment program and identify whether current procedural terminology (CPT) code modifications are necessary for sustainable implementation. STUDY DESIGN/SETTING: Retrospective single-institution cohort study. PATIENT SAMPLE: A total of 542 lumbar fusion episodes in a private insurer bundled payment program from October 2018 to December 2020. OUTCOME MEASURES: A total of 120-day episode of care net surplus/deficit, 90-day readmissions, discharge disposition, and length of hospital stay. METHODS: A review was conducted of all lumbar fusions in a single institution's payer database. Surgical characteristics (approach [posterior lumbar decompression and fusion (PLDF), transforaminal lumbar interbody fusion (TLIF), and circumferential fusion], levels fused, and primary vs revision) were collected from manual chart review. Episode of care cost data were collected as net surplus or deficit with respect to target prices. A multivariate linear regression model was constructed to measure the independent effects of primary versus revision, levels fused, and approach on the net cost savings. RESULTS: Most procedures were PLDFs (N=312, 57.6%), single-level (N=416, 76.8%) and primary fusions (N=477, 88.0%). Overall, 197 (36.3%) resulted in a deficit, and were more likely to be three levels (7.11% vs 2.03%, p=.005), revisions (18.8% vs 8.12%, p<.001), and TLIF (47.7% vs 35.1%, p<.001) or circumferential fusions (p<.001). One-level PLDFs resulted in the greatest cost savings per episode ($6,883). Across both PLDFs and TLIFs, 3-level procedures resulted in significant deficit of -$23,040 and -$18,887, respectively. For circumferential fusions, 1-level fusions resulted in deficit of -$17,169 per case which rose to -$64,485 and -$49,222 for 2- and 3-level fusions. All 2- and 3-level circumferential spinal fusions resulted in a deficit. On multivariable regression, TLIF and circumferential fusions were independently associated with a deficit of -$7,378 (p=.004) and -$42,185 (p<.001), respectively. Three-level fusions were independently associated with an additional -$26,003 deficit compared to single-level fusions (p<.001). CONCLUSIONS: Interbody fusions, especially circumferential fusions, and multi-level procedures are not adequately risk adjusted by current bundled payment models. Health systems may not be able to financially support these alternative payment models with improved procedure-specific risk adjustment.

Patient-specific Risk Factors Increase Episode of Care Costs After Lumbar Decompression.

STUDY DESIGN: Retrospective cohort analysis. OBJECTIVE: To determine, which patient-specific risk factors increase total episode of care (EOC) costs in a population of Centers for Medicare and Medicaid Services beneficiaries undergoing lumbar decompression. SUMMARY OF BACKGROUND DATA: Lumbar decompression is an effective option for the treatment of central canal stenosis or radiculopathy in patients unresponsive to nonoperative management. Given that elderly Americans are more likely to have one or more chronic medical conditions, there is a need to determine, which, if any, patient-specific risk factors increase health care costs after lumbar decompression. METHODS: Care episodes limited to lumbar decompression surgeries were retrospectively reviewed on a Centers for Medicare and Medicaid Service reimbursement database at our academic institution between 2014 and 2019. The 90-day total EOC reimbursement payments were collected. Patient electronic medical records were then matched to the selected care episodes for the collection of patient demographics, medical comorbidities, surgical characteristics, and clinical outcomes. A stepwise multivariate linear regression model was developed to predict patient-specific risk factors that increased total EOC costs after lumbar decompression. Significance was set at P <0.05. RESULTS: A total of 226 patients were included for analysis. Risk factors associated with increased total EOC cost included increased age (per year) (ß = $324.70, P < 0.001), comorbid depression (ß = $4368.30, P = 0.037), revision procedures (ß = $6538.43, P =0.012), increased hospital length of stay (per day) (ß = $2995.43, P < 0.001), discharge to an inpatient rehabilitation facility (ß = $14,417.42, P = 0.001), incidence of a complication (ß = $8178.07, P < 0.001), and readmission (ß = $18,734.24, P < 0.001) within 90 days. CONCLUSIONS: Increased age, comorbid depression, revision decompression procedures, increased hospital length of stay, discharge to an inpatient rehabilitation facility, and incidence of a complication and readmission within 90 days were all associated with increased total episodes of care costs.

Cellular Bone Matrix Leading to Disseminated Tuberculosis After Spinal Fusion: A Report of 2 Cases.

CASE: Although implanted tuberculosis (TB) is rare, a single lot of cellular bone matrix was found to be infected with TB, leading to devastating outcomes. We present 2 cases referred to our institution because of instrumentation failure caused by TB inoculation of cellular bone matrix. CONCLUSION: Irrespective of spinal region of implanted TB infection, excision of infected bone, extensive irrigation and debridement, and instrumented stabilization are of primary importance to ensure TB eradication and adequate stabilization.

Varenicline mitigates the increased risk of pseudarthrosis associated with nicotine.

BACKGROUND CONTEXT: High serum nicotine levels increase the risk of nonunion after spinal fusion. Varenicline, a pharmaceutical adjunct for smoking cessation, is a partial agonist designed to displace and outcompete nicotine at its receptor binding site, thereby limiting downstream activation. Given its mechanism, varenicline may have therapeutic benefits in mitigating nonunion for active smokers undergoing spinal fusion. PURPOSE: To compare fusion rate and fusion mass characteristics between cohorts receiving nicotine, varenicline, or concurrent nicotine and varenicline after lumbar fusion. STUDY DESIGN: Rodent noninstrumented spinal fusion model. METHODS: Sixty eight-week-old male Sprague-Dawley rats weighing approximately 300 grams underwent L4-5 posterolateral fusion (PLF) surgery. Four experimental groups (control: C, nicotine: N, varenicline: V, and combined: NV [nicotine and varenicline]) were included for analysis. Treatment groups received nicotine, varenicline, or a combination of nicotine and varenicline delivered through subcutaneous osmotic pumps beginning two weeks before surgery until the time of sacrifice at age 14 weeks. Manual palpation testing, microCT imaging, bone histomorphometry, and biomechanical testing were performed on harvested spinal fusion segments. RESULTS: Control (p=0.016) and combined (p=0.032) groups, when compared directly to the nicotine group, demonstrated significantly greater manual palpation scores. The fusion rate in the control (93.3%) and combined (93.3%) groups were significantly greater than that of the nicotine group (33.3%) (p=0.007, both). Biomechanical testing demonstrated greater Young's modulus of the fusion segment in the control (17.1 MPa) and combined groups (34.5 MPa) compared to the nicotine group (8.07 MPa) (p<0.001, both). MicroCT analysis demonstrated greater bone volume fraction (C:0.35 vs N:0.26 vs NV:0.33) (p<0.001, all) and bone mineral density (C:335 vs N:262 vs NV:328 mg Ha/cm3) (p<0.001, all) in the control and combined groups compared to the nicotine group. Histomorphometry demonstrated a greater mineral apposition rate in the combined group compared to the nicotine group (0.34 vs 0.24 µm/day, p=0.025). CONCLUSION: In a rodent spinal fusion model, varenicline mitigates the adverse effects of high nicotine serum levels on the rate and quality of spinal fusion. CLINICAL SIGNIFICANCE: These findings have the potential to significantly impact clinical practice guidelines and the use of pharmacotherapy for active nicotine users undergoing fusion surgery.

Predictors of Academic Productivity Among Spine Surgeons.

INTRODUCTION: The relationship between research productivity in training and future productivity as an attending spine surgeon is not well-established in the literature nor has the effect of geographic location of training institutions on future academic success been investigated. The aim of our study was to (1) summarize characteristics of academically productive spine surgeons, (2) assess predictors of long-term academic productivity, and (3) establish the effect of geographic location on long-term academic productivity. METHODS: A query was conducted of the 2021 to 2022 North American Spine Society Spine Fellowship Directory of all orthopaedic and neurosurgical spine fellowship selection committee members for each institution participating in the spine fellowship match. The attending publication rate and h- index were determined. A multivariate linear regression model was developed. P value was set to <0.05. RESULTS: We identified 310 orthopaedic and neurosurgical spine surgeons, representing 76 fellowship programs. Multivariate linear regression analysis identified that the publications during residency ( P < 0.001) and during fellowship ( P < 0.001) were significant predictors of an increased publication rate as an attending surgeon. By contrast, the preresidency publication rate ( P = 0.729) was not significantly predictive of the attending publication rate. Multivariate analysis of h- index found that residency publication rate had a positive correlation ( P = 0.031) compared with preresidency ( P = 0.579) or fellowship ( P = 0.257) rates. Attendings who had attended residency in the Northeast and currently practicing in the Northeast had a higher publication rate ( P < 0.001 and P = 0.004, respectively). DISCUSSION: A higher number of publications in residency and fellowship were markedly predictive of an increased publication rate as an attending spine surgeon. By contrast, preresidency publications may not be indicative of future academic productivity as an attending. Location may also contribute to attending publication rate and favor those who undergo residency training and ultimately practice in the Northeast.

Is disc height loss at 1 year predictive of pseudarthrosis and patient-reported outcome measures following anterior cervical discectomy and fusion with structural allograft?

OBJECTIVE: The authors sought to determine if postoperative disc height loss is associated with pseudarthrosis following anterior cervical discectomy and fusion (ACDF). They also sought to determine if the amount of postoperative disc height loss is predictive of need for revision for pseudarthrosis, as well as the impact of postoperative disc height loss on patient-reported outcome measures (PROMs) following surgery. METHODS: The authors retrospectively identified patients aged > 18 years who underwent primary one- to three-level ACDF with allograft at a single institution with 1-year postoperative lateral and flexion-extension cervical spine radiographs. Logistic regression models and receiver operating characteristic curves were used for analysis. Alpha was set at p < 0.05. RESULTS: Anterior or posterior disc height loss ≥ 2 mm was found in 52.5% of patients. Patients with a loss ≥ 2 mm were more likely to develop pseudarthrosis (p = 0.021) but not to undergo revision surgery due to pseudarthrosis (p = 0.459). Multivariable analysis identified male sex (OR 1.66, p = 0.013), the number of levels fused (OR 2.09, p < 0.001), and fusion at C6-7 (OR 1.52, p = 0.043) as predictors of disc height loss. The analysis also revealed that levels at the top (OR 0.383, 95% CI 0.170-0.854, p = 0.020) and middle (OR 0.174, 95% CI 0.053-0.548, p = 0.003) of fusion constructs were significant independent predictors of lower pseudarthrosis rates while disc height loss was not. Patients with disc height loss had significantly less improvement in scores for the Neck Disability Index (p = 0.002), visual analog scale (VAS) for arm pain (p = 0.018), and VAS for neck pain (p = 0.011) at 1 year following surgery. CONCLUSIONS: This study is, to the authors' knowledge, the largest study to date to assess the impact of postoperative disc height loss after ACDF. Disc height loss following ACDF was not predictive of revision surgery for pseudarthrosis or overall pseudarthrosis rates. However, pseudarthrosis was less likely to occur at the top and middle of fusion constructs. Loss in disc height postoperatively was significantly associated with less improvement in PROMs.

MRSA Prophylaxis in Spine Surgery Decreases Postoperative Infections.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To compare infection rates before and after the implementation of a quality improvement protocol focused on methicillin-resistant Staphylococcus aureus (MRSA) screening and decolonization in patients undergoing lumbar fusion and/or decompression. SUMMARY OF BACKGROUND DATA: Prior studies have demonstrated MRSA infections comprise a sizable portion of SSIs. Additional studies are required to improve our understanding of the risks and benefits of MRSA decolonization with vancomycin prophylaxis. METHODS: A retrospective cohort analysis was conducted on patients who underwent spinal fusion or laminectomy before (2008-2011) and after (2013-2016) the implementation of an MRSA screening and treatment protocol. Odds ratios for MRSA, methicillin-sensitive Staphylococcus aureus (MSSA), and Vancomycin-resistant Enterococcus (VRE) infection before and after screening was calculated. Multivariate analysis assessed demographic characteristics as potential independent predictors of infection. RESULTS: A total of 8425 lumbar fusion and 2558 lumbar decompression cases met inclusion criteria resulting in a total cohort of 10,983 patients. There was a significant decrease in the overall rate of infections ( P <0.001), MRSA infections ( P <0.001), and MSSA infections ( P <0.001) after protocol implementation. Although VRE infections after protocol implementation were not significantly different ( P =0.066), VRE rates as a percentage of all postoperative infections were substantially increased (0 vs. 3.36%, P =0.007). On multivariate analysis, significant predictors of the infection included younger age (OR=0.94[0.92-0.95]), shorter length of procedure (OR=1.00[0.99-1.00]), spinal fusion (OR=18.56[8.22-53.28]), higher ASA class (OR=5.49[4.08-7.44]), male sex (OR=1.61[1.18-2.20]), and history of diabetes (OR=1.58[1.08-2.29]). CONCLUSION: The implemented quality improvement protocol demonstrated that preoperative prophylactically treating MRSA colonized patients decreased the rate of overall infections, MSSA infections, and MRSA infections. In addition, younger age, male sex, diabetic status, greater ASA scores, and spinal fusions were risk factors for postoperative infection.