Comparison of No Tap (two-step) and tapping robotic assisted cortical bone trajectory screw insertion.

Workflow for cortical bone trajectory (CBT) screws includes tapping line-to-line or under tapping by 1 mm. We describe a non-tapping, two-step workflow for CBT screw placement, and compare the safety profile and time savings to the Tap (three-step) workflow. Patients undergoing robotic assisted 1-3 level posterior fusion with CBT screws for degenerative conditions were identified and separated into either a No-Tap or Tap workflow. Number of total screws, screw-related complications, estimated blood loss, operative time, robotic time, and return to the operating room were collected and analyzed. There were 91 cases (458 screws) in the No-Tap and 88 cases (466 screws) in the Tap groups, with no difference in demographics, revision status, ASA grade, approach, number of levels fused or diagnosis between cohorts. Total robotic time was lower in the No-Tap (26.7 min) versus the Tap group (30.3 min, p = 0.053). There was no difference in the number of malpositioned screws identified intraoperatively (10 vs 6, p = 0.427), screws converted to freehand (3 vs 3, p = 0.699), or screws abandoned (3 vs 2, p = 1.000). No pedicle/pars fracture or fixation failure was seen in the No-Tap cohort and one in the Tap cohort (p = 1.00). No patients in either cohort were returned to OR for malpositioned screws. This study showed that the No-Tap screw insertion workflow for robot-assisted CBT reduces robotic time without increasing complications.

Intra-Operative Hypotension is an Important Modifiable Risk Factor for Major Complications in Spinal Fusion Surgery.

STUDY DESIGN: Retrospective observational cohort. OBJECTIVES: This study explores the impact of Intraoperative hypotension (IOH)on post-op complications for major thoracolumbar spine fusion procedures. SUMMARY OF BACKGROUND DATA: IOH with mean arterial pressure (MAP) < 65 mmHg is associated with post-op acute kidney injury (AKI) in general surgery. In spinal deformity surgery, IOH is a contributing factor to MEP changes and spinal cord dysfunction with deformity correction. METHODS: 539 thoracolumbar fusion cases, > 6 surgical levels and > 3 hours duration were identified. Anesthetic/surgical data included OR time, fluid volume, blood loss, blood product replacement and use of vasopressors. Arterial-line based MAP data was collected at 1 min intervals. Cummulative duration of MAP < 65 mmHg was recorded. IOH within the first hour of surgery vs. the entire case was determined. Post-op course and complications including SSI, GI complications, pulmonary complications, MI, DVT, PE, AKI and encephalopathy were noted. Cumulative complications were grouped as none, 1-2 complications, or >3 complications. RESULTS: There was a significant association between occurrence of complications and duration of IOH within the first hour of surgery (8.2 vs. 5.6 min, P<0.001) and across the entire procedure (28.1 vs. 19.3 min, P=0.008). This association persisted for individual major complications including SSI, acute respiratory failure, PE, ileus requiring NGT and post-operative cognitive dysfunction. Comparison of patients with 0 vs. 1-2 vs. 3 or more complications demonstrated that patients with 3 or more complications had a longer duration of IOH in the first hour of the surgery and that patients who had no complications received less vasopressor than patients who had 1-2 or 3 or more complications. CONCLUSION: This study identifies duration of IOH during the first hour of surgery as a previously unrecognized modifiable risk associated with major complications for multi-level lumbar fusion surgery.

Staged circumferential lumbar fusions have less intraoperative complications and shorter operative time with no difference in 30-, 90-, and 1-year complications: a propensity-matched cohort analysis of 190 patients.

BACKGROUND CONTEXT: Circumferential lumbar fusions (cLFs) are becoming more common with increasing and more minimally invasive anterior access techniques. Staging allows reassessment of indirect decompression and alignment prior to the posterior approach, and optimization of OR time management. Safety of staging has been well documented in deformity surgery but has yet to be delineated in less extensive, degenerative cLFs. PURPOSE: The purpose of this study is to compare perioperative complications and outcomes between staged versus single-anesthetic circumferential fusions in the lumbar spine. STUDY DESIGN: Propensity-matched comparative observational cohort. PATIENT SAMPLE: Patients who underwent cLFs for lumbar degenerative disease. OUTCOME MEASURES: In-hospital, 30-day, 90-day, and 1-year complications. METHODS: From 123 patients undergoing single-anesthetic and 154 patients undergoing staged cLF, 95 patients in each group were propensity-matched based on age, sex, BMI, ASA score, smoking, revision, and number of levels. We compared perioperative, 30-day, 90-day, and 1-year complications between the two cohorts. RESULTS: Mean days between stages was 1.58. Single-anesthetic cLF had longer total surgery time (304 vs 240 minutes, p<.001) but shorter total PACU total time (133 vs 196 minutes, p<.001). However, there was no difference in total anesthesia time (368 vs 374 minutes, p=.661) and total EBL (357 vs 320cc, p=.313). Intraoperative complications were nine incidental durotomies in the single-anesthetic and one iliac vein injury in the staged group (9% vs 1%, p=.018). There was no difference of in-hospital (38 vs 31, p=.291), 30-day (16 vs 23, p=.281), 90-day (10 vs 15, p=.391), 1-year complications (9 vs 12, p=.644), and overall cumulative 1-year complications (54 vs 56, p=.883) between the two cohorts. CONCLUSIONS: There is a decrease in total surgical time and intraoperative complications during staged compared with single-anesthetic cLF with no difference in in-hospital, 30-day, 90-day, and 1-year complications between approaches.

Clinical and Radiographic Outcomes of Repair of Spondylolitic Spondylolisthesis via Direct Pars Repair.

STUDY DESIGN: A retrospective chart review. OBJECTIVE: The objective of this study is to investigate whether direct pars repair achieves bone healing and symptom relief in patients with spondylolitic spondylolisthesis. SUMMARY OF BACKGROUND DATA: While most cases of spondylolysis can be managed non-operatively, a small percentage of patients require surgical intervention. The outcome of direct pars repair via a standard pedicle-screw with wiring technique is controversial in patients with lumbar spondylolitic spondylolisthesis. METHODS: Medical records of patients who had undergone an open surgical pars repair were retrospectively reviewed. Standard demographic and surgical parameters were collected. All patients underwent a primary repair of the pars with autograft or bone morphogenetic protein and instrumentation using a pedicle-screw with spinous process wiring. At 6-12 months after surgery, patient's pain symptoms and postoperative CT scans were independently reviewed to assess healing; graded as non-union, partial union, or solid union. RESULTS: There were 68 patients identified (33 male and 35 female) with an average age of 18.6 years. Mean estimated blood loss was 139 ml, and mean length of hospital stay was 3.7 days. CT evaluation revealed 35 (52%) solid unions, 21 (31%) partial unions, and 12 (18%) non-unions requiring revisions. Thirty-four (50%) patients had no postop pain, 24 (35%) had mild pain, 10 (15%) had persistent pain. The majority of patients with non-unions on CT had mild or persistent pain. Patients with no or mild pain tended to be younger than those with persistent pain (17.5 years vs 24.6 years, P=0.163). CONCLUSION: This study demonstrated a partial or complete union rate of 82% and a postoperative persistent pain rate of 15%. These figures are comparable to the previous study and this pedicle-screw with wiring technique can be worth trying before interbody fusion for spondylolytic spondylolisthesis to preserve anatomical lumbar motion.

Quantitative Romberg on a Force Plate: Objective Assessment Before and After Surgery for Cervical Spondylotic Myelopathy.

STUDY DESIGN: Longitudinal Observational Cohort. OBJECTIVES: The purpose of this study was to evaluate the utility of Quantitative Romberg measurements as pre- and post-op balance outcome measures. SUMMARY OF BACKGROUND DATA: Cervical Spondylotic Myelopathy (CSM) is characterized by balance deficiencies produced by impaired proprioception. Evaluation is subjective and binary physical exam findings lack the precision to assess postoperative outcome improvement. METHODS: CSM patients were prospectively enrolled to undergo pre- and postoperative Quantitative Romberg tests on a force plate to record center of pressure (COP) motion for 30 seconds with eyes open followed by eyes closed. Revision cases were excluded. Kinematics of COP movement parameters were compared between pre- and postoperative state for each patient. RESULTS: Twenty-seven CSM patients were enrolled and completed both pre/post testing. Mean age was 60.0 years with 13 (48%) males, 9 (33%) smokers. Mean number of surgical levels was 2.48. The minimum mean follow-up was six months. There was a statistically significant improvement in eyes closed after surgery compared to pre-operative for total COP motion (523.44 cm vs. 387.00 cm, P<0.001), average sway speed (17.41 cm/s vs. 13.00 cm/s, P<0.001) and total lateral COP motion (253.44 cm vs. 186.70 cm, P<0.001). There was no statistically significant improvement in mJOA (13.29 vs. 14.29, P=0.28). CONCLUSION: CSM balance findings on Quantitative Romberg testing significantly improves postoperatively in patients with CSM. These findings support this testing as representative of proprioceptive balance deficiencies seen in CSM. Quantitative Romberg may be used as an objective measure of clinical outcome and assist in stratification of surgical interventions, surgery timing and technique.

Cost-Effectiveness of Intraoperative Electromyography to Determine Adequate Screw Position.

STUDY DESIGN: Prospective observational cohort. OBJECTIVES: To examine the cost-effectiveness of IntraOperative ElectroMyeloGraphy (IO-EMG) by evaluating how often an abnormal IO-EMG signal changed the surgeon's surgical plan, or replaced a pedicle screw either intra-operatively or as a second unplanned surgery. METHODS: Patients undergoing instrumented posterolateral lumbar fusion were monitored with intraoperative triggered EMG's. Pedicle screws were placed freehand from L1 to S1 by attending physicians and fellows. Concern for pedicle breach was a screw stimulation<10 mA. RESULTS: There were 145 cases with a total of 725 pedicle screws placed. Mean age was 57.8 ± 14.2 yrs, OR time was 238 ± 95 minutes, EBL was 426.8 ± 354.3cc. Mean number of surgical levels fused was 2.7 ± 1.1. 686 (95%) screws stimulated at >10 mA and 39 (5%) screws stimulated at <10 mA. All 39 screws were removed and pedicles re-examined. Intraoperative screw repositioning was necessary in 8 of 145 cases (6%). No patient required a return to the OR for screw repositioning. As a worst case cost analysis, assuming the 8 patients requiring intraoperative screw positioning would have returned to the OR at a cost of $11,798 per readmission, the per patient cost is $651 which is less than the ION per patient cost of $750. CONCLUSIONS: Only 1% of the 725 lumbar pedicle screws placed in 8 of 145 cases required repositioning. Due to the infrequency of pedicle wall breaches and the cost of ION, the utility of this modality in straightforward lumbar fusions should be critically evaluated.

Predictors of segmental lumbar lordosis following midline posterior (transforaminal) lumbar interbody fusion: Does interbody device type matter?

Background: Controversy exists regarding the ability of posterior (transforaminal) lumbar interbody fusion (PLIF/TLIF) to achieve lordosis. We hypothesized that an interbody device (IBD) designed for positioning in the anterior disc space produces greater lordosis than IBDs designed for straight-in positioning. The purpose of this study is to determine if using either an anterior-position or straight-in position IBD design were associated with successful achievement of postoperative lordosis. Methods: A consecutive series of patients undergoing a undergoing a single-level, posterior open midline (transforaminal) lumbar interbody fusion procedure for degenerative spine conditions during a time period when the two types of interbody devices were being used at surgeon discretion were identified from a multi-surgeon academic training center. Patient demographics and radiographic measures including surgical level lordosis (SLL), anterior disc height, middle disc height, posterior disc height, IBD height, and IBD insertion depth were measured on preop, immediate postop, and one-year postop standing radiographs using PACS. Group comparison and regression analysis were performed using SPSS. Results: Sixty-one patients were included (n=37 anterior, n=34 straight-in). Mean age was 59.8±8.7 years, 32 (52%) were female. There was no difference between IBD type (anterior vs. straight-in) for mean Pre-op SLL (19±7° vs. 20±6°, p=0.7), Post-op SLL (21±5° vs 21±6°, p=0.5), or Change in SLL (2±4° vs. 1±5°, p=0.2). Regression analysis showed that Pre-op SLL was the only variable associated with Change in SLL (Beta = negative 0.48, p=0.000). While the mean Change in SLL could be considered clinically insignificant, there was wide variability: from a loss of 9° to a gain of 13°. Gain of lordosis >5° only occurred when Pre-op SLL was <21°, and loss of lordosis >5° only occurred when Pre-op SLL was >21°. Conclusions: While group averages showed an insignificant change in segmental lordosis following a posterior (transforaminal) interbody fusion regardless of interbody device type, pre-operative lordosis was correlated with a clinically significant change in segmental lordosis. Preoperative hypolordotic discs were more likely to gain significant lordosis, while preoperative hyperlordotic discs were more likely to lose significant lordosis. Surgeon awareness of this tendency can help guide surgical planning and technique.

Postoperative Epidural Hematoma.

Symptomatic postoperative epidural hematomas are rare, with an incidence of 0.10% to 0.69%. Risk factors have varied in the literature, but multiple studies have reported advanced age, preoperative or postoperative coagulopathy, and multilevel laminectomy as risk factors for hematoma. The role of pharmacologic anticoagulation after spine surgery remains unclear, but multiple studies suggest it can be done safely with a low risk of epidural hematoma. Prophylactic suction drains have not been found to lower hematoma incidence. Most symptomatic postoperative epidural hematomas present within the first 24 to 48 hours after surgery but can present later. Diagnosis of a symptomatic hematoma requires correlation of clinical signs and symptoms with a compressive hematoma on MRI. Patients will usually first complain of a marked increase in axial pain, followed by radicular symptoms in the extremities, followed by motor weakness and sphincter dysfunction. An MRI should be obtained emergently, and if it confirms a compressive hematoma, surgical evacuation should be carried out as quickly as possible. The prognosis for neurologic improvement after evacuation depends on the time delay and the degree of neurologic impairment before evacuation.

Etiology and treatment of cervical kyphosis: state of the art review-a narrative review.

OBJECTIVE: To provide state of the art review regarding cervical kyphosis. BACKGROUND: Cervical spine kyphosis has been increasingly common due to the growing elderly population. Clinicians should comprehensively understand its symptoms, biomechanics, etiology, radiographic evaluation, classification, and treatment options and complications of each treatment. Comprehensive review will help clinicians improve the management for patients with cervical kyphosis. METHODS: The available literature relevant to cervical kyphosis was reviewed. PubMed, Medline, OVID, EMBASE, and Cochrane were used to review the literature. CONCLUSIONS: This article summarizes current concepts regarding etiology, evaluation, surgical treatment, complications and outcomes of cervical kyphosis. Major etiologies of cervical kyphosis include degenerative, post-laminectomy, and ankylosing spondylitis. Clinical presentations include neck pain, myelopathy, radiculopathy, and problems with horizontal gaze, swallowing and breathing. Cervical lordosis, C2-7 sagittal vertical axis, chin-brow to vertical angle, and T1 slope should be evaluated from upright lateral 36-inch film. The most widely used classification system includes a deformity descriptor and 5 modifiers. A deformity descriptor provides a basic grouping of the deformity consisting of five types, cervical, cervicothoracic, thoracic, coronal cervical deformity, and cranio-vertebral junction deformity. The 5 modifiers include C2-7 sagittal vertical axis, chin-brow to vertical angle, T1 slope minus cervical lordosis, myelopathy based on modified Japanese Orthopaedic Association score, and SRS-Schwab classification for thoracolumbar deformity. Current treatment options include anterior discectomy and fusion, anterior osteotomy, Smith-Peterson osteotomy, pedicle subtraction osteotomy, or a combination of these based on careful preoperative evaluation.

Changes in Recombinant Human Bone Morphogenetic Protein-2 Use in Posterior Fusion Over the Past Two Decades.

Background In 2011, studies suggested that complications and cancer rates associated with bone morphogenetic protein (BMP) were greater than previously reported. However, later studies reported complication rates similar to prior literature and no increased cancer rate. We evaluated the pattern of clinical utilization of BMP in posteriorly based lumbar fusion by comparing two periods: 2002-2004 and 2017-2019. Methods Patients who received BMP from 2002-2004 (Early) and 2017-2019 (Late) from a single multi-surgeon institution who had a lumbar fusion were identified. One hundred patients from each cohort were randomly selected. Mean total BMP used at each level and the proportion of BMP placed in the interbody space versus posterolateral gutters were evaluated. Results In the transforaminal lumbar intebody fusion (TLIF) cohort, the total BMP dose in the Late group (6.15 mg) was nearly half of that used in the Early group (12.04 mg, p<0.000). The amount of BMP used in the posterolateral gutters remained similar (Early: 4.01 mg vs Late: 3.38 mg, p=0.222). The amount of BMP used in the interbody space was less in the Late group (2.76 mg) compared to the Early group (8.03 mg, p<0.000). In the posterior spinal fusion (PSF) cohort, the total BMP dose remained similar between the Early (11.96 mg) and the Late groups (10.82 mg, p=0.007). Conclusion Change in the use of BMP in TLIF cases was driven by the complications reported in the literature with no change in outcome. A similar impetus was not seen for PSF.

Return to work in patients with lumbar disc herniation undergoing fusion.

BACKGROUND: Lumbar disc herniation (LDH) is a common problem. When surgical treatment is required, the intervention is typically decompression without fusion. Successful return-to-work (RTW) is a standard expectation with these limited procedures. Occasionally, the size or location of the disc herniation suggests the need for fusion, but the inability to RTW is a significant concern in these cases. The purpose of this study is to determine if the addition of lumbar fusion, as compared to decompression alone, will substantially diminish RTW in patients with lumbar disc herniation. METHODS: This is a longitudinal cohort study using prospectively collected data from the Quality and Outcomes Database (QOD). Patients with LDH, eligible to RTW (not retired, a student, or on disability) with complete 12-month follow-up data, were identified. Standard demographic and surgical variables, patient-reported outcomes (PROs), and RTW status at 3 and 12 months were collected. RESULTS: Of the 5062 patients identified, 4560 (90%) had decompression alone and 502 (10%) had a concurrent fusion. Age and gender were similar in the two groups. The fusion group had worse back pain (NRS 6.52 vs. 5.96) and less leg pain (6.31 vs. 7.01) at baseline compared to the no fusion group. Statistically significant improvement in all PROs was seen in both groups. RTW at 3 months post-op was seen in 85% of decompression cases and 66% of cases with supplemental fusion. At 12 months post-op, RTW increased to 93% and 82%, respectively. CONCLUSION: The need for fusion in LDH cases is unusual, seen in only 10% of cases in this series. The addition of fusion decreased the RTW rate from 85 to 66% at 3 months and from 93 to 82% at 12 months post-op. While the difference is significant, the ultimate deterioration in RTW may be less than anticipated. A reasonable RTW rate can still be expected in the rare patient who requires fusion as part of their treatment for LDH.

Drivers of in-hospital opioid consumption in patients undergoing lumbar fusion surgery.

BACKGROUND: With the current opioid crisis, as many as 38% of patients are still on opioids one year after elective spine surgery. Identifying drivers of in-hospital opioid consumption may decrease subsequent opioid dependence. We aimed to identify the drivers of in-hospital opioid consumption in patients undergoing 1-2-level instrumented lumbar fusions. METHODS: This is a retrospective cohort study. Electronic medical record analysts identified consecutive patients undergoing 1-2 level instrumented lumbar fusions for degenerative lumbar conditions from 2016 to 2018 from a single-center hospital administrative database. Oral, intravenous, and transdermal opioid dose administrations were converted to morphine milligram equivalents (MME). Linear regression analysis was used to determine associations between postoperative day (POD) 4 cumulative in-hospital MMEs and the patients' baseline characteristics including body mass index (BMI), race, American Society of Anesthesiologists (ASA) grade, smoking status, marital status, insurance type, zip code, number of fused levels, approach and preoperative opioid use. RESULTS: A total of 1,502 patients were included. The mean cumulative MMEs at POD 4 was 251.5. Linear regression analysis yielded four drivers including younger age, preoperative opioid use, current smokers and more levels fused. There were no associations with surgical approach, zip code, ASA grade, marital status, BMI, race or insurance type. CONCLUSIONS: Use of preoperative opioids and smoking are modifiable risk factors for higher in-hospital opioid consumption and can be targets for intervention prior to surgery in order to decrease in-hospital opioid use.

Economic analysis of 90-day return to the emergency room and readmission after elective lumbar spine surgery: a single-center analysis of 5444 patients.

OBJECTIVE: In the future, payers may not cover unplanned 90-day emergency room (ER) visits or readmissions after elective lumbar spine surgery. Prior studies using large administrative databases lack granularity and/or use a proxy for actual cost. The purpose of this study was to identify risk factors and subsequent costs associated with 90-day ER visits and readmissions after elective lumbar spine surgery. METHODS: A prospective, multisurgeon, single-center electronic medical record was queried for elective lumbar spine fusion surgeries from 2013 to 2017. Predictive models were created for 90-day ER visits and readmissions. RESULTS: Of 5444 patients, 729 (13%) returned to the ER, most often for pain (n = 213, 29%). Predictors of an ER visit were prior ER visit (OR 2.5), underserved zip code (OR 1.4), and number of chronic medical conditions (OR 1.4). In total, 421 (8%) patients were readmitted, most frequently for wound infection (n = 123, 2%), exacerbation of chronic obstructive pulmonary disease (n = 24, 0.4%), and sepsis (n = 23, 0.4%). Predictors for readmission were prior ER visit (OR 1.96), multiple chronic conditions (OR 1.69), obesity (nonobese, OR 0.49), race (African American, OR 1.43), admission status (ER admission, OR 2.29), and elevated hemoglobin A1c (OR 1.80). The mean direct hospital cost for an ER visit was $1971, with 75% of visits costing less than $1890, and the average readmission cost was $7347, with 75% of readmissions costing less than $8820. Over the 5-year study period, the cost to the institution for 90-day return ER visits was $5.1 million. CONCLUSIONS: Risk factors for 90-day ER visit and readmission after elective lumbar spine surgery include medical comorbidities and socioeconomic factors. Proper patient counseling, appropriate postoperative pain management, and optimization of modifiable risk factors prior to surgery are areas to focus future efforts to lower 90-day ER visits and readmissions and reduce healthcare costs.

Health-related quality-of-life improvement with lumbar fusion in patients with lower-extremity arthritis.

OBJECTIVE: Lumbar fusion can lead to significant improvements in patient-reported outcomes (PROs) in patients with degenerative conditions. It is unknown whether the presence of hip or knee arthritis confounds the responses of patients to low-back-specific PROs. This study examined PROs with lumbar fusion in patients with concomitant lower-extremity arthritis. The purpose of the current study was to examine whether patients with significant lower-extremity arthritis who undergo lumbar fusion achieve similar improvements in low-back-specific PROs compared to patients without lower-extremity arthritis. METHODS: Patients were identified from a prospectively enrolled multicenter registry of patients undergoing lumbar fusion surgery for degenerative conditions. Two hundred thirty patients identified with lumbar fusion and who also had concomitant lower-extremity arthritis were propensity matched to 233 patients who did not have lower-extremity arthritis based on age, BMI, sex, smoking status, American Society of Anesthesiologists grade, number of levels fused, and surgical approach. One-year improvement in PROs, numeric rating scales (0-10) for back and leg pain, and the Oswestry Disability Index and EuroQol-5D scores were compared for patients with and without lower-extremity arthritis. RESULTS: Baseline demographics and preoperative outcome measures did not differ between the two propensity-matched groups with 110 cases each. Patients with concomitant lower-extremity arthritis achieved similar improvement in health-related quality-of-life measures to patients without lower-extremity arthritis, with no significant differences between the groups (p > 0.10). CONCLUSIONS: The presence of lower-extremity arthritis does not adversely affect the results of lumbar fusion in properly selected patients. Patients with lower-extremity arthritis who undergo lumbar fusion can achieve meaningful improvement in PROs similar to patients without arthritis.

Drivers for nonhome discharge in a consecutive series of 1502 patients undergoing 1- or 2-level lumbar fusion.

OBJECTIVE: Unexpected nonhome discharge causes additional costs in the current reimbursement models, especially to the payor. Nonhome discharge is also related to longer length of hospital stay and therefore higher healthcare costs to society. With increasing demand for spine surgery, it is important to minimize costs by streamlining discharges and reducing length of hospital stay. Identifying factors associated with nonhome discharge can be useful for early intervention for discharge planning. The authors aimed to identify the drivers of nonhome discharge in patients undergoing 1- or 2-level instrumented lumbar fusion. METHODS: The electronic medical records from a single-center hospital administrative database were analyzed for consecutive patients who underwent 1- to 2-level instrumented lumbar fusion for degenerative lumbar conditions during the period from 2016 to 2018. Discharge disposition was determined as home or nonhome. A logistic regression analysis was used to determine associations between nonhome discharge and age, sex, body mass index (BMI), race, American Society of Anesthesiologists grade, smoking status, marital status, insurance type, residence in an underserved zip code, and operative factors. RESULTS: A total of 1502 patients were included. The majority (81%) were discharged home. Factors associated with a nonhome discharge were older age, higher BMI, living in an underserved zip code, not being married, being on government insurance, and having more levels fused. Patients discharged to a nonhome facility had longer lengths of hospital stay (5.6 vs 3.0 days, p < 0.001) and significantly increased hospital costs ($21,204 vs $17,518, p < 0.001). CONCLUSIONS: Increased age, greater BMI, residence in an underserved zip code, not being married, and government insurance are drivers for discharge to a nonhome facility after a 1- to 2-level instrumented lumbar fusion. Early identification and intervention for these patients, even before admission, may decrease the length of hospital stay and medical costs.

Index episode-of-care propensity-matched comparison of transforaminal lumbar interbody fusion (TLIF) techniques: open traditional TLIF versus midline lumbar interbody fusion (MIDLIF) versus robot-assisted MIDLIF.

OBJECTIVE: Posterior fixation with interbody cage placement can be accomplished via numerous techniques. In an attempt to expedite recovery by limiting muscle dissection, midline lumbar interbody fusion (MIDLIF) has been described. More recently, the authors have developed a robot-assisted MIDLIF (RA-MIDLIF) technique. The purpose of this study was to compare the index episode-of-care (iEOC) parameters between patients undergoing traditional open transforaminal lumbar interbody fusion (tTLIF), MIDLIF, and RA-MIDLIF. METHODS: A retrospective review of a prospective, multisurgeon surgical database was performed. Consecutive patients undergoing 1- or 2-level tTLIF, MIDLIF, or RA-MIDLIF for degenerative lumbar conditions were identified. Patients in each cohort were propensity matched based on age, sex, smoking status, BMI, diagnosis, American Society of Anesthesiologists (ASA) class, and number of levels fused. Index EOC parameters such as length of stay (LOS), estimated blood loss (EBL), operating room (OR) time, and actual, direct hospital costs for the index surgical visit were analyzed. RESULTS: Of 281 and 249 patients undergoing tTLIF and MIDLIF, respectively, 52 cases in each cohort were successfully propensity matched to the authors' first 55 RA-MIDLIF cases. Consistent with propensity matching, there was no significant difference in age, sex, BMI, diagnosis, ASA class, or levels fused. Spondylolisthesis was the most common indication for surgery in all cohorts. The mean total iEOC was similar across all cohorts. Patients undergoing RA-MIDLIF had a shorter average LOS (1.53 days) than those undergoing either MIDLIF (2.71 days) or tTLIF (3.58 days). Both MIDLIF and RA-MIDLIF were associated with lower EBL and less OR time compared with tTLIF. CONCLUSIONS: Despite concerns for additional cost and time while introducing navigation or robotic technology, a propensity-matched comparison of the authors' first 52 RA-MIDLIF surgeries with tTLIF and MIDLIF showed promising results for reducing OR time, EBL, and LOS without increasing cost.

Multi-modal pain control regimen for anterior lumbar fusion drastically reduces in-hospital opioid consumption.

BACKGROUND: The opioid epidemic is at epic proportions currently in the United States. Exposure to opioids for surgery and subsequent postoperative pain management is a known risk factor for opioid dependence. In addition, opioids can have a negative impact on multiple aspects including clinical outcomes, length of hospital stay, and overall cost of care. Thus, the greatest effort to reduce perioperative opioid use is necessary and a multimodal pain control (MMPC) has been gaining popularity. However, its efficacy in spine surgery is not well known. We aimed to evaluate the efficacy of a MMPC protocol in patients undergoing lumbar single-level anterior lumbar interbody fusion (ALIF). METHODS: This is a retrospective comparative study. From a prospective, single-surgeon, surgical database, consecutive patients undergoing single-level ALIF with or without subsequent posterior fusion for degenerative lumbar conditions were identified before and after initiation of the MMPC protocol. The MMPC protocol consisted of a preoperative oral regimen of cyclobenzaprine (10 mg), gabapentin (600 mg), acetaminophen (1 g), and methadone (10 mg). Postoperatively they received a bilateral transverse abdominis plane block with 0.5% Ropivacaine prior to extubation. We compared in-hospital opioid consumption between the MMPC and non-MMPC cohorts as well as baseline demographic, the length of hospital stay, cost, and rate of postoperative ileus. Opioid consumption was calculated and normalized to the morphine milligram equivalents (MMEs). RESULTS: In total, 68 patients in the MMPC cohort and 39 in the non-MMPC cohort were identified. There was no difference in baseline demographics including sex, body mass index, smoking status, or preoperative opioid use between the two groups. Although there was no difference in the MMEs on the day of surgery (58.5 vs. 66.9, P=0.387), cumulative MMEs each day after surgery was significantly lower in the MMPC cohort, with final cumulative MMEs being reduced by 62% (120.2 vs. 314.8, P<0.001). There was no difference in postoperative ileus, length of stay, and hospital costs. CONCLUSIONS: The use of a MMPC protocol in patients undergoing single-level ALIF for degenerative conditions reduced opioid consumption starting on the first day after surgery, resulting in a cumulative reduction of 62%.

Minimally-Invasive midline posterior interbody fusion with cortical bone trajectory screws compares favorably to traditional open transforaminal interbody fusion.

OBJECTIVE: Posterior interbody fusion is commonly performed for degenerative lumbar conditions. A minimally invasive technique of midline exposure limited only to the facets and fixation with laterally directed cortical bone trajectory (CBT) screws was introduced with the intent of decreasing surgical morbidity. The purpose of this study was to determine if posterior interbody fusion with this limited midline exposure will have less blood loss and shorter operative times (i.e., can be considered minimally invasive) compared to traditional open transforaminal interbody fusion. METHODS: A consecutive single-surgeon series of patients who underwent posterior interbody fusion with either a navigated, midline only exposure (MidLIF) or full, traditional open, exposure of the transverse processes with a posterolateral fusion (open TLIF) were identified. Demographic, peri-operative data, patient reported outcomes (PROs), and reoperation/readmission rates were collected and compared. RESULTS: There were 29 cases in the MidLIF and 27 in the open TLIF group. Both groups were similar with respect to surgical indications, age, BMI, gender, ASA grade and operative level. The MidLIF group had significantly lower estimated blood loss (266 vs. 446 cc, p = 0.003), shorter operative time (170 vs. 210 minutes, p = 0.003), and shorter length of hospital stay (2.9 vs. 3.7 days, p = 0.016) compared to the open TLIF group. A sub-analysis of single-level cases showed similar findings with significantly lower estimated blood loss (247 vs. 411 cc, p = 0.10), shorter operative time (159 vs. 199 min, p = 0.003), and shorter length of hospital stay (2.9 vs. 3.7 days, p = 0.023) in the MidLIF group. Patient reported outcomes at 6 weeks, 3 months, 6 months, 12 months and 24 months post-operative favored MidLIF with significantly greater ODI improvements at both 6 weeks and 12 months; and lower ODI and back pain at both 12 months and 24 months. CONCLUSIONS: MidLIF had lower blood loss and shorter operative time compared to the traditional open TLIF technique. These differences compare well to reported values in the literature for tubular minimally-invasive TLIF. Patient reported outcomes from 6 weeks to 24 months post-operative, hospital length of stay, and reoperation/readmission rates all favored MidLIF compared to traditional open TLIF.

Cost-effectiveness of minimally invasive midline lumbar interbody fusion versus traditional open transforaminal lumbar interbody fusion.

OBJECTIVE: The midline transforaminal lumbar interbody fusion (MIDLIF) using cortical screw fixation is a novel, minimally invasive procedure that may offer enhanced recovery over traditional open transforaminal lumbar interbody fusion (TLIF). Little information is available regarding the comparative cost-effectiveness of the MIDLIF over conventional TLIF. The purpose of this study was to compare cost-effectiveness of minimally invasive MIDLIF with open TLIF. METHODS: From a prospective, multisurgeon, surgical database, a consecutive series of patients undergoing 1- or 2-level MIDLIF for degenerative lumbar conditions was identified and propensity matched to patients undergoing TLIF based on age, sex, smoking status, BMI, diagnosis, American Society of Anesthesiologists Physical Status Classification System (ASA) class, and levels fused. Direct costs at 1 year were collected, including costs associated with the index surgical visit as well as costs associated with readmission. Improvement in health-related quality of life was measured using EQ-5D and SF-6D. RESULTS: Of 214 and 181 patients undergoing MIDLIF and TLIF, respectively, 33 cases in each cohort were successfully propensity matched. Consistent with propensity matching, there was no difference in age, sex, BMI, diagnosis, ASA class, smoking status, or levels fused. Spondylolisthesis was the most common indication for surgery in both cohorts. Variable direct costs at 1 year were $2493 lower in the MIDLIF group than in the open TLIF group (mean $15,867 vs $17,612, p = 0.073). There was no difference in implant (p = 0.193) or biologics (p = 0.145) cost, but blood utilization (p = 0.015), operating room supplies (p < 0.001), hospital room and board (p < 0.001), pharmacy (p = 0.010), laboratory (p = 0.004), and physical therapy (p = 0.009) costs were all significantly lower in the MIDLIF group. Additionally, the mean length of stay was decreased for MIDLIF as well (3.21 vs 4.02 days, p = 0.05). The EQ-5D gain at 1 year was 0.156 for MIDLIF and 0.141 for open TLIF (p = 0.821). The SF-6D gain at 1 year was 0.071 for MIDLIF and 0.057 for open TLIF (p = 0.551). CONCLUSIONS: Compared with patients undergoing traditional open TLIF, those undergoing MIDLIF have similar 1-year gains in health-related quality of life, with total direct costs that are $2493 lower. Although the findings were not statistically significant, minimally invasive MIDLIF showed improved cost-effectiveness at 1 year compared with open TLIF.

The Effect of Symptom Duration on Outcomes After Fusion for Degenerative Spondylolisthesis.

STUDY DESIGN: Longitudinal comparative cohort. OBJECTIVES: To determine if the duration of symptoms in patients with degenerative spondylolisthesis affects postoperative outcomes after 1- or 2-level decompression and fusion. METHODS: Patients undergoing primary surgery for grade 1 degenerative spondylolisthesis at a single Quality Outcomes Database (QOD) participating site were identified. Demographic, surgical and patient-reported outcomes (PROs) data, including baseline and 12-month postoperative Oswestry Disability Index (ODI), back pain (BP, 0-10), leg pain (LP, 0-10), and EuroQOL-5D (EQ-5D) scores were collected. Individual medical records were reviewed for data on duration of symptoms prior to surgery. Patients were stratified into 3 cohorts-those with preoperative symptom duration of less than 1 year, 1 to 2 years, or greater than 2 years. RESULTS: Complete data was available in 123 patients. Significant improvement in ODI, BP, and LP scores were observed in all groups. At 12-month follow-up improvement in ODI, BP, or LP was similar among the cohorts; with a trend toward significance with better improvement in LP scores in patients with a symptom duration of less than 1 year to those with symptom duration greater than 2 years (P = .058). CONCLUSIONS: The duration of symptoms up to 2 years prior to surgery may not be a useful predictor of improvement of back pain or disability scores in patients with spondylolisthesis requiring decompression and fusion. Although there was a positive trend for improvement in leg pain for those with a shorter duration of symptoms, this did not reach statistical significance in our study.