Put Down the Tin: Chewing Tobacco Use Is Associated With Worse Outcomes After Primary Lumbar Fusion.

STUDY DESIGN: Retrospective study. OBJECTIVE: This study evaluated the impact of chewing tobacco on both medical and spine-related complication rates after spinal lumbar fusions in comparison to both a control cohort and a smoking cohort. SUMMARY OF BACKGROUND DATA: Smoking is a prevalent modifiable risk factor that has been demonstrated to be associated with increased complications after lumbar fusion. Although smoking rates have decreased in the United States, chewing tobacco use has not similarly reduced. Despite chewing tobacco delivering up to 4 times the dose of smoking, the impact of chewing tobacco is incompletely understood. METHODS: A retrospective cohort study was conducted using the PearlDiver database. Patients who underwent lumbar spine fusion and used chewing tobacco were matched with a control cohort and a smoking cohort. Medical complications within 90 days after primary lumbar fusion were evaluated, including deep venous thrombosis, acute kidney injury, pulmonary embolism, transfusion, acute myocardial infarction, and inpatient readmission. Spine-related complications were evaluated at 2 years postoperatively, including pseudoarthrosis, incision and drainage (I&D), instrument failure, revision, and infection. RESULTS: After primary lumbar fusion, the chewing tobacco cohort demonstrated significantly higher rates of pseudoarthrosis [odds ratio (OR): 1.41], revision (OR: 1.57), and any spine-related complication (OR: 1.32) compared with controls. The smoking cohort demonstrated significantly higher rates of pseudoarthrosis (OR: 1.88), I&D (OR: 1.27), instrument failure (OR: 1.39), revision (OR: 1.54), infection (OR: 1.34), and any spine-related complication (OR: 1.77) compared with controls. The chewing tobacco cohort demonstrated significantly lower rates of pseudoarthrosis (OR: 0.84), I&D (OR: 0.49), infection (OR: 0.70), and any spine-related complication (OR: 0.81) compared with the smoking cohort. CONCLUSIONS: This study demonstrated that chewing tobacco is associated with higher rates of both spine-related and medical complications after primary lumbar fusion. However, chewing tobacco use is associated with less risk of complications compared with smoking. LEVEL OF EVIDENCE: Level III.

Trends in Surgical Approach for Single-Level Lumbar Fusion Over the Past Decade.

STUDY DESIGN: Retrospective Comparative Study. OBJECTIVE: The purpose of this study was to characterize trends in surgical approach for single-level lumbar fusion over the past decade. SUMMARY OF BACKGROUND DATA: The number of elective lumbar fusion cases performed is increasing annually. Several different surgical approaches exist for lumbar spinal fusion including novel anterior approaches developed in recent years. With ongoing innovation, trends in the utilization of common surgical approaches in recent years are unclear. MATERIALS AND METHODS: A retrospective cohort study was conducted using the PearlDiver database (Fort Wayne, IN). Patients undergoing single-level lumbar fusion between 2010 and 2019 were identified using Current Procedural Technology codes and divided into 4 mutually exclusive cohorts based on surgical approach: (1) anterior-only, (2) anterior approach with posterior instrumentation, (3) posterolateral, and (4) posterior-only interbody. Trend analyses of surgical approach utilization over the last decade were performed with the Cochran-Armitage test to evaluate the 2-tailed null hypothesis that utilization of each surgical approach for single-level lumbar fusion remained constant. RESULTS: A total of 53,234 patients met inclusion criteria and were stratified into 4 cohorts: anterior-only (n=5104), anterior with posterior instrumentation (n=23,515), posterolateral (n=5525), and posterior-only interbody (n=19,090). Trend analysis revealed the utilization of a posterior-only interbody approach significantly decreased from 36.7% to 29.2% ( P <0.001), whereas the utilization of a combined anterior and posterior approach significantly increased from 45.8% to 50.4% ( P <0.001). The utilization of an anterior-only approach also significantly increased from 7.9% to 10.5% ( P <0.001). CONCLUSIONS: Utilization of anterior-only and anterior with posterior instrumentation approaches for single-level lumbar fusion have been significantly increasing over the past decade while use of posterior-only interbody approach trended significantly downward. These data may be particularly useful for trainees and spine surgeons as new techniques and technology become available. LEVEL OF EVIDENCE: Level III-retrospective cohort study.

Anterior lumbar spinal fusion surgery associated with lower risk of stroke, pneumonia, and infection compared to posterior lumbar spinal fusion surgery.

Background: Prior studies, comparing anterior and posterior approaches to lumbar fusion surgery, found similar fusion rates and clinical outcomes, but are limited by sample size. Further evaluation of the postoperative complications of each approach is necessary. Methods: The MSpine database by PearlDiver was queried using ICD-9, ICD-10, and CPT codes to identify patients who had undergone single-level anterior or posterior lumbar interbody fusion surgery. Readmission rates, ileus, lower extremity DVT, infection, pneumonia, and stroke were used to compare post-operative complications of an anterior vs. posterior approach. Results: 112,023 patients were included in this study, with 38,529 (34.4%) in the anterior group (ALIF/LLIF) and 73,494 (65.6%) in the posterior group (PLIF/TLIF). At both 30 and 90-days postoperative, patients undergoing an anterior approach to lumbar interbody fusion had a higher odds ratio of lower extremity DVT (30-day OR: 1.19, 90-day OR: 1.16; P<0.05) and ileus complication (30-day OR: 1.87, P= <.05; 90-day OR: 1.81, P<.05). At both 30 and 90-days postoperative, patients undergoing a posterior approach had a higher odds ratio of stroke (30-day: OR: 0.79, 90-day OR: 0.87; P<0.05), transfusion (30-day OR: 0.66, 90-day OR: 0.69; P<.05), infection (30-day OR: 0.88, 90-day OR: 0.91; P <.05), and pneumonia (30-day OR: 0.85, 90-day OR: 0.90; P<.05). There was no statistically significant difference in myocardial infarction or pulmonary embolism between both approaches at 30 and 90-days postoperative. Conclusions: Anterior and posterior approaches for lumbar interbody fusion were associated with differences in postoperative complications at 30 and 90-days. The complication profiles associated with each approach can inform surgeon treatment decisions based on patient profiles.

Trends of single-level anterior cervical discectomy and fusion documentation after the 2015 Centers for Medicare & Medicaid Services coding audit.

OBJECTIVE: With the use of anterior cervical discectomy and fusion (ACDF) expected to rise by 13.3% from 2020 to 2040, the increased usage of interbody cages with integral anterior fixation prompted a Centers for Medicare & Medicaid Services (CMS) review, which resulted in coding changes affecting anterior instrumentation documentation. CMS determined that Current Procedural Terminology (CPT) code 22845 should not be used to report integrated instrumentation (plate) with an interbody device, and if additional anterior instrumentation (e.g., plates and screws) is placed with an integrated interbody device, then a 59 modifier should be used. There is sparse literature examining the trends of ACDF without and with additional anterior instrumentation after the 2015 CMS audit. Therefore, this study aimed to evaluate the trends of single-level subaxial ACDF utilization from 2011 to 2019 to determine whether the 2015 CMS audit influenced the documented usage of additional anterior instrumentation. METHODS: A retrospective cohort study was performed using the commercially available database PearlDiver. Patient records were queried from 2011 to 2019 for single-level subaxial ACDF without (CPT code 22551) and with (CPT codes 22551 + 22845) instrumentation. Cochran-Armitage trend analyses were performed to evaluate the hypothesis that ACDF with additional anterior instrumentation decreased over the given time period. RESULTS: Between 2011 and 2019, the total number of single-level ACDFs decreased from 6202 to 4402. From 2011 to 2015, an average of 6240 patients per year underwent single-level subaxial ACDF; of those, 950 patients (15.2%) had ACDF without instrumentation and 5290 patients (84.8%) had ACDF with instrumentation. In 2016, the total number of single-level subaxial ACDFs decreased to 5525, with 1006 patients (18.2%) receiving no instrumentation and 4519 patients (81.8%) receiving instrumentation. From 2017 to 2019, an average of 4283 patients per year underwent a single-level subaxial ACDF; of these, 1280 (29.9%) had no instrumentation and 3003 (70.1%) had instrumentation (all p < 0.0001). CONCLUSIONS: From 2015 to 2019, single-level ACDF without instrumentation significantly increased by 91.5% and ACDF with anterior instrumentation significantly decreased by 18.1%. The 2015 CMS audit of interbody cages and anterior instrumentation coding (CPT code 22845) may account for the decreased documentation of anterior instrumentation in the 9-year period. Understanding CMS auditing could help surgeons perceive changes in practice patterns that may lead to a more thorough evaluation of patient outcomes, cost, and overall value.

Lumbar spine surgery reduces postoperative opioid use in the veteran population.

Background: The United States has been facing a worsening opioid epidemic over the past two decades. The veteran population represents a large and vulnerable group with a higher burden of mental health comorbidities. The purpose of this study was to analyze the impact of lumbar spine surgery on postoperative opioid usage in the United States veteran population. Methods: A retrospective cohort study was conducted using the Veterans Affairs Informatics and Computing Infrastructure database. Patients who underwent lumbar spine surgery were stratified into three groups by their preoperative opioid claims within 365 days of surgery. Postoperative cumulative morphine milligram equivalents (MME) were tracked for each group and the paired Wilcoxon signed rank test was used to compare cumulative preoperative MME (days -365-0) to cumulative postoperative MME (days 91-455). Results: At one year, 30.6% of patients in the high preoperative opioid group and 73.1% of patients in the low preoperative opioid group were no longer using opioids. In the opioid naive cohort, 10.0% of patients were still using opioids at one year. Among all patients, median cumulative postoperative MME was significantly less than median cumulative preoperative MME (P<0.001). High preoperative opioid usage of more than 3 claims was most significantly associated with continued postoperative opioid usage (odds ratio 12.55, P<0.001). From 2010 to 2020 the proportion of patients with preoperative opioid claims decreased (58.8% to 34.8%). Conclusions: In the veteran population, lumbar spine surgery was effective in getting 50% of patients who were on opioids preoperatively to discontinue opioids postoperatively. Even minimal exposure to opioids preoperatively resulted in a 2.69-time increase in risk of being on opioids at one year versus opioid naive patients. This study affirms that despite being a high-risk population, the veteran population has a similar response to lumbar spine surgery as the general population in regards to opioid dependence.

Anterior Lumbar Interbody Fusion With Cement Augmentation Without Posterior Fixation to Treat Isthmic Spondylolisthesis in an Osteopenic Patient-A Surgical Technique.

BACKGROUND: Anterior lumbar interbody fusion (ALIF) has been well established as an effective surgical intervention for chronic back pain due to osteoporotic vertebral collapse. Historically, ALIF has consisted of an anterior approach to disc height restoration with a subsequent posterior pedicle screw fixation. Although the applications of cement augmentation with posterior fixation have been previously reported, treatment of patients with both isthmic spondylolisthesis and decreased bone mineral density using a stand-alone ALIF is controversial because of concerns for decreased fusion rates and increased subsidence risk, respectively. We report a case of stand-alone ALIF used to treat a low-grade isthmic spondylolisthesis in the setting of idiopathic thoraco-lumbar scoliosis in a patient with secondary degenerative changes and discuss the benefits of this surgical technique in a patient with several comorbidities. METHODS: An osteopenic 66-year-old woman with multiple medical comorbidities and 2 years of left radicular leg pain was found to have a Myerding grade I isthmic spondylolisthesis in the setting of idiopathic thoraco-lumbar scoliosis with secondary changes. The patient underwent an L5-S1 stand-alone ALIF with anterior cement augmentation without posterior pedicle screw fixation. RESULTS: The patient experienced immediate relief of radicular leg pain postoperatively and had an uneventful course. At 2 years follow-up, she remained symptom free, and radiographs showed excellent fusion and maintenance of intervertebral disc height. CONCLUSIONS: The use of stand-alone ALIF with anterior cement augmentation of the vertebral bodies is a surgical technique that could produce excellent improvement in patients with low-grade isthmic spondylolisthesis in the setting of osteopenia. The use of the all-anterior approach in similar patients with multiple medical comorbidities can also be a useful technique, as it decreases associated morbidity of surgery and complication risks associated with prolonged operative times.

The P-mJOA: A Patient-derived, Self-reported Outcome Instrument for Evaluating Cervical Myelopathy: Comparison with the mJOA.

STUDY DESIGN: Prospective Cohort Study. OBJECTIVE: The objective of this study is to evaluate and validate a patient-derived version of the modified Japanese Orthopaedic Association (the "P-mJOA") that a patient can complete along with other patient-derived outcome measures. SUMMARY OF BACKGROUND DATA: The modified Japanese Orthopaedic Association (mJOA) is a validated instrument widely used in the assessment of cervical myelopathy; however, it is not a patient-derived outcome. If available and reliable, a patient-derived version of the mJOA (P-mJOA) could facilitate research because the data would be immediately available upon patient completion and also remove any potential physician bias. Currently, there is no patient-derived myelopathy survey with the widespread acceptance of the mJOA. METHODS: The P-mJOA was created by very slightly modifying the verbiage of the mJOA to make it possible for a patient to complete the instrument while maintaining the questionnaire's core structure. A total of 100 consecutive consenting patients with cervical myelopathy were enrolled. After the patient completed the P-mJOA, the mJOA was scored by a physician blinded to the P-mJOA result. RESULTS: The P-mJOA and the mJOA had identical mean scores of 14.7 (mean difference±SD: 0.0±1.5; P=0.89). Several measures of reliability demonstrated agreement between the 2 surveys, including strong agreement with the intraclass correlation coefficient and Spearman ρ (both 0.83) and moderate to substantial agreement with weighted κ values (0.55 to 0.66). In addition, 67% of patients preferred to fill out the P-mJOA themselves, suggesting low patient burden. CONCLUSIONS: The P-mJOA provided identical mean scores to the mJOA in assessing myelopathy with moderate to strong agreement. Comprised of the same 4 questions as the mJOA but slightly reworded for patient comprehension, the P-mJOA also demonstrated low patient burden in completing the survey. We believe the P-mJOA is a promising tool in cervical myelopathy research with the benefits of a patient-derived outcome measure and low patient burden. LEVEL OF EVIDENCE: Level II.

Complications, Readmissions, and Reoperations in Posterior Cervical Fusion.

STUDY DESIGN: Retrospective cohort study of the American College of Surgeons National Surgical Quality Improvement Program database from 2011 to 2012. OBJECTIVE: Minimizing the morbidity of posterior cervical fusion can be improved with identification of patient risk factors. SUMMARY OF BACKGROUND DATA: Posterior cervical fusion is an effective technique for treating a variety of pathology. Stability and neurological improvement have been well documented. The increasing frequency of these procedures necessitates further investigation into the factors that may negatively impact perioperative care. METHODS: The American College of Surgeons National Surgical Quality Improvement Program was queried for all patients undergoing posterior cervical fusion in 2011 and 2012. Preoperative and intraoperative variables were investigated for correlation to complications, readmissions, prolonged intubation, reintubation, and reoperation. A frailty-based score was used to assess preoperative risk. Regression models for prediction were performed. RESULTS: The study identified 5627 patients of posterior cervical fusion in 2011 and 2012. Of these, 2029 patients (36.1%) had any of our identified complications. Transfusion was the most common in 1482 (26.3%) patients. Excluding transfusion, the complication rate was 9.8%. Prolonged intubation greater than 48 hours occurred in 83 (1.5%) patients. Reintubation occurred in 72 (1.3%) patients. Readmission occurred in 398 (7.8%) patients. Reoperation was necessary in 273 (4.9%) patients with postoperative infection being the most common reason. The frailty-based score was shown to be predictive of any of the above events (P < 0.0001). The majority of patients (54.9%) in the group that had complications was found to have a frailty score of 1 or higher. CONCLUSION: The predictors for any event included female sex, increased surgical time, combined anterior-posterior procedures, preoperative inpatient status, diabetes, smoking, American Society of Anesthesiologists class 3 or higher, and increasing age. The frailty-based score is a viable option to predict morbidity in posterior cervical fusion.Level of Evidence: 3.

Biomechanical analysis of an expandable lateral cage and a static transforaminal lumbar interbody fusion cage with posterior instrumentation in an in vitro spondylolisthesis model.

OBJECTIVE: Insufficient biomechanical data exist from comparisons of the stability of expandable lateral cages with that of static transforaminal lumbar interbody fusion (TLIF) cages. The purpose of this biomechanical study was to compare the relative rigidity of L4-5 expandable lateral interbody constructs with or without additive pedicle screw fixation with that of L4-5 static TLIF cages in a novel cadaveric spondylolisthesis model. METHODS: Eight human cadaver spines were used in this study. A spondylolisthesis model was created at the L4-5 level by creating 2 injuries. First, in each cadaver, a nucleotomy from 2 channels through the anterior side was created. Second, the cartilage of the facet joint was burred down to create a gap of 4 mm. Light-emitting-diode tracking markers were placed at L-3, L-4, L-5, and S-1. Specimens were tested in the following scenarios: intact model, bilateral pedicle screws, expandable lateral 18-mm-wide cage (alone, with unilateral pedicle screws [UPSs], and with bilateral pedicle screws [BPSs]), expandable lateral 22-mm-wide cage (alone, with UPSs, and with BPSs), and TLIF (alone, with UPSs, and with BPSs). Four of the spines were tested with the expandable lateral cages (18-mm cage followed by the 22-mm cage), and 4 of the spines were tested with the TLIF construct. All these constructs were tested in flexion-extension, axial rotation, and lateral bending. RESULTS: The TLIF-alone construct was significantly less stable than the 18- and 22-mm-wide lateral lumbar interbody fusion (LLIF) constructs and the TLIF constructs with either UPSs or BPSs. The LLIF constructs alone were significantly less stable than the TLIF construct with BPSs. However, there was no significant difference between the 18-mm LLIF construct with UPSs and the TLIF construct with BPSs in any of the loading modes. CONCLUSIONS: Expandable lateral cages with UPSs provide stability equivalent to that of a TLIF construct with BPSs in a degenerative spondylolisthesis model.

The unusual presentation of a vascular injury after lumbar microdiscectomy: case report.

Vascular injury during lumbar spine surgery is a relatively rare complication but can have devastating outcomes. The injury may not be apparent during surgery and can present acutely or late in various manners, and some injuries can be asymptomatic. This report discusses the unusual case of a 35-year-old woman who underwent a right L4-5 microdiscectomy for disc herniation and 4 days postoperatively presented with a pulmonary embolus. A subsequent CT scan revealed a pseudoaneurysm and arteriovenous fistula of the right common iliac vein and artery, which gave rise to the embolus. The patient received a right iliac artery stent, and at 4 months after surgery she continues to be symptom free. This report describes the atypical presentation of vascular injury after lumbar microdiscectomy and stresses the importance of cautiously using the pituitary rongeur when removing deeper disc fragments.

In vitro cytotoxic effects of benzalkonium chloride in corticosteroid injection suspension.

BACKGROUND: Some deleterious effects on cartilage and even severe arthropathy have been reported after intra-articular corticosteroid injections. The objective of the present in vitro study was to determine if an injectable corticosteroid suspension is toxic to articular chondrocytes and synovial cells. METHODS: Human and bovine articular chondrocytes, bovine synovial cells, mouse C3H10T1/2 cells, and human osteosarcoma MG-63 cells were treated for thirty minutes in monolayer or suspension culture with an injectable corticosteroid suspension or its chemical components, including betamethasone sodium phosphate, betamethasone acetate, and benzalkonium chloride (as preservative). Cell viability was determined by means of microscopy or flow cytometry analysis. RESULTS: In monolayer culture, the betamethasone corticosteroids per se did not cause cell death, whereas benzalkonium chloride caused death of articular chondrocytes. In suspension culture, betamethasone sodium phosphate at dosages of as high as 6 mg/mL did not cause significant death of human or bovine articular chondrocytes (p > 0.05). In contrast, benzalkonium chloride caused a death rate of 10.6% in human articular chondrocytes at a dosage of 10 microg/mL (p < 0.01), 21.0% at a dosage of 13.3 microg/mL (p < 0.01), and 99.3% and 99.4% at dosages of 20 and 200 microg/mL, respectively (p < 0.001 for both). Similarly, benzalkonium chloride caused death of bovine articular chondrocytes, bovine synovial cells, C3H10T1/2 cells, and MG-63 cells in a dose-dependent manner. When treated with a combination of betamethasone sodium phosphate and 200 microg/mL benzalkonium chloride, >99% of human or bovine articular chondrocytes were dead (p < 0.001). CONCLUSIONS: The injectable corticosteroid suspension caused death in in vitro culture of human and bovine articular chondrocytes as well as bovine synovial cells because of its preservative benzalkonium chloride. The betamethasone corticosteroids per se did not cause significant chondrocyte death under the conditions tested.