OBJECTIVE Prior studies investigating the use of minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) for treatment of degenerative lumbar conditions and concomitant sagittal deformity have not stratified patients by preoperative pelvic incidence (PI)–lumbar lordosis (LL) mismatch, which is the earliest parameter to deteriorate in mild sagittal deformity. Thus, the aim of the present study was to determine the impact of preoperative PI-LL mismatch on clinical outcomes and sagittal balance restoration among patients undergoing MI-TLIF for degenerative spondylolisthesis (DS). METHODS Consecutive adult patients undergoing primary 1-level MI-TLIF between April 2017 and April 2022 for DS with ≥ 6 months radiographic follow-up were included. Patient-reported outcome measures (PROMs) included the Oswestry Disability Index, visual analog scale (VAS), 12-Item Short-Form Health Survey (SF-12), and Patient-Reported Outcomes Measurement Information System at preoperative, early postoperative (< 6 months), and late postoperative (≥ 6 months) time points. The minimal clinically important difference (MCID) for PROMs was also evaluated. Radiographic parameters included PI, LL, pelvic tilt (PT), and sagittal vertical axis (SVA). Patients were categorized into balanced and unbalanced groups based on preoperative PI-LL mismatch according to age-adjusted alignment goals. Changes in radiographic parameters and PROMs were evaluated. RESULTS Eighty patients were included (L4–5 82.5%, grade I spondylolisthesis 82.5%, unbalanced 58.8%). Mean clinical and radiographic follow-up were 17.0 and 8.3 months, respectively. The average preoperative PI-LL was 18.8° in the unbalanced group and −3.3° in the balanced group. Patients with preoperative PI-LL mismatch had significantly worse preoperative PT (26.2° vs 16.4°, p < 0.001) and SVA (53.2 vs 9.0 mm, p = 0.001) compared with balanced patients. Patients with preoperative PI-LL mismatch also showed significantly worse PI-LL (16.0° vs 0.54°, p < 0.001), PT (25.9° vs 18.7°, p < 0.001), and SVA (49.4 vs 22.8 mm, p = 0.013) at long-term follow-up. No significant radiographic improvement was observed among unbalanced patients. All patients demonstrated significant improvements in all PROMs (p < 0.05) except for SF-12 mental component score. Achievement of MCID for VAS back score was significantly greater among patients with preoperative PI-LL mismatch (85.7% vs 65.5%, p = 0.045). CONCLUSIONS Although 1-level MI-TLIF did not restore sagittal alignment in patients with preoperative PI-LL mismatch, patients presenting with DS can expect significant improvement in PROMs following 1-level MI-TLIF regardless of preoperative alignment or extent of correction. Thus, attaining good clinical outcomes in patients with mild sagittal imbalance may not require addressing imbalance directly.

Background: Postoperative sagittal alignment has been shown to be associated with patient-reported outcome measures (PROMs) following open lumbar decompression procedures, although it is unknown whether preoperative sagittal imbalance affects clinical outcomes of minimally invasive surgical (MIS) decompression only surgery. Purpose: We sought to evaluate the impact of preoperative pelvic incidence-lumbar lordosis (PI-LL) imbalance on PROMs after MIS laminectomy for the treatment of neurogenic claudication symptoms. Methods: We conducted a retrospective cohort study of adult patients undergoing MIS laminectomy for degenerative lumbar spinal stenosis between April 2017 and April 2021 at a single institution. Of the 52 patients included (mean follow-up, 17 months) radiographs were taken prior to surgery and assessed for sagittal alignment parameters. Patients were grouped based on the preoperative PI-LL (balanced vs unbalanced). Changes in PROMs were compared between unbalanced PI-LL and balanced PI-LL groups. Minimal clinically important difference (MCID) for Oswestry Disability Index (ODI) was also assessed. Results: Of the 52 patients, 17 (32.7%) had unbalanced age-adjusted preoperative PI-LL. There was no significant difference found in PROMs between unbalanced and balanced PI-LL groups preoperatively or at final follow-up. Compared with those with unbalanced PI-LL, patients with balanced PI-LL were shown to have no added benefit in achieving MCID for ODI at long-term follow-up and no added benefit in the time to achieving MCID. Conclusion: These retrospective findings suggest that patients with unbalanced preoperative PI-LL may experience significant benefit in long-term clinical outcomes following MIS laminectomy, similarly to those with balanced PI-LL at baseline. The findings also suggest that the presence of sagittal imbalance preoperatively may not appreciably influence the long-term clinical outcomes following MIS laminectomy. Prospective study involving a larger population is warranted.

BACKGROUND CONTEXT:Published rates for disc reherniation following primary discectomy are around 6%, but the ultimate reoperation outcomes in patients after receiving revision discectomy are not well understood. Additionally, any disparity in the outcomes of subsequent revision discectomy (SRD) versus subsequent lumbar fusion (SLF) following primary/revision discectomy remains poorly studied.PURPOSE:To determine the 8-year SRD/SLF rates and time until SRD/SLF after primary/revision discectomy respectively.STUDY DESIGN:Retrospective cohort study.PATIENT SAMPLE:Patients undergoing primary or revision discectomy, with records in the PearlDiver Patient Records Database from the years 2010 to 2019.OUTCOME MEASURES:Subsequent surgery type and time to subsequent surgery.METHODS:Patients were grouped into primary or revision discectomy cohorts based off of the nature of "index" procedure (primary or revision discectomy) using ICD9/10 and CPT procedure codes from 2010 to 19 insurance data sets in the PearlDiver Patient Records Database. Preoperative demographic data was collected. Outcome measures such as subsequent surgery type (fusion or discectomy) and time to subsequent surgery were collected prospectively in PearlDiver Mariner database. Statistical analysis was performed using BellWeather statistical software. A Kaplan-Meier survival analysis of time to SLF/SRD was performed on each cohort, and log-rank test was used to compare the rates of SLF/SRD between cohorts.RESULTS:A total of 20,147 patients were identified (17,849 primary discectomy, 2,298 revision discectomy). The 8-year rates of SRD (6.1% in revision cohort, 4.8% in primary cohort, p<.01) and SLF (10.4% in revision cohort, 6.2% in primary cohort, p<.01) were higher after revision versus primary discectomy. Time to SLF was shorter after revision versus primary discectomy (709 vs. 886 days, p<.01). After both primary and revision discectomy, the 8-year rate of SLF (10.4% in revision cohort, 6.2% in primary cohort, p<.01) is greater than SRD (6.1% in revision cohort, 4.8% in primary cohort, p<.01).CONCLUSIONS:Compared to primary discectomy, revision discectomy has higher rates of SLF (10.4% vs. 6.2%), and faster time to SLF (2.4 vs. 1.9 years) at 8-year follow up.

BACKGROUND CONTEXTMinimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is a common operative approach to address degenerative lumbar stenosis and spondylolisthesis which has failed nonoperative care. Compared to open TLIF, MI-TLIF relies to a greater extent on indirect decompression resulting in a heightened awareness of spondylolisthesis reduction among MI surgeons. To what extent intraoperative reduction is achieved as well as the rate and clinical impact of loss or reduction and slip recurrence remain unknown.PURPOSETo determine the rate and clinical impact of slip recurrence after MI-TLIF with expandable cage technologySTUDY DESIGN/SETTINGRetrospective Cohort StudyPATIENT SAMPLEPatients undergoing MI-TLIF for degenerative spondylolisthesis using an articulating, expandable cageOUTCOME MEASURESPatient-reported outcome measures (PROMs), including the Oswestry Disability Index (ODI), visual analog scale (VAS) for back/leg pain, Short Form-12 (SF-12), and PROMIS Physical Function (PF)METHODSPatients undergoing MI-TLIF for degenerative spondylolisthesis using articulating, expandable cages from 2017 to 2019 were retrospectively studied. Lateral radiographs were reviewed and evaluated for the presence or absence of spondylolisthesis preoperatively, intraoperatively, and at follow-up times including 2 weeks, 6 weeks, 12 weeks, 6 months, and 1 year postoperatively. Spondylolisthesis was measured from the posterior inferior corner of the cephalad vertebra to the posterior superior corner of the caudal vertebra, with any measurement >1 mm classified as spondylolisthesis, and Meyerding grade was noted. Intraoperative reduction was measured, and loss of reduction was defined as >1 mm increase in spondylolisthesis comparing follow-up imaging to intraoperative films. PROMs were recorded at the preoperative and follow-up time points. Fusion was assessed at 1 year postoperatively via CT.RESULTSA total of 63 patients and 70 levels were included, with mean age 59.8 years (SD,13.8). 19 levels (27.1%) had complete reduction intraoperatively, 40 (57.1%) had partial reduction, and 11 (15.7%) had no reduction. Of the 30 levels with loss of reduction (50.8%), 20 (66.7%) occurred by 2 weeks postoperatively and 28 (93.3%) occurred by 12 weeks postoperatively. At 6 months, there were significant differences between those who had loss of reduction and those who did not in VAS back pain (3.0 vs. 0.9, p = .017) and SF-12 PCS (41.5 vs. 50.0, p = .035), but no differences were found between the groups for any instruments at any other time points. The overall fusion rate was 82.1% (32/39) at 1 year postoperatively. There was no significant difference in fusion rate between the loss of reduction (16/20) and no loss of reduction (20/23) groups. Patients with loss of reduction had no difference in reoperation rate (1/28) compared to those without loss of reduction (2/24).CONCLUSIONSWhile a majority of patients demonstrated reduction intraoperatively, 51% had loss of reduction, most commonly in the acute postoperative period. There were few differences in PROMs between patients who had loss of reduction and those who did not, suggesting that radiographic loss of reduction after MI-TLIF in the setting of degenerative spondylolisthesis may not be clinically meaningful.

This is a critical analysis of a study by Hoernschemeyer et al, "Anterior Vertebral Body Tethering for Adolescent Scoliosis with Growth Remaining: A Retrospective Review of 2 to 5-Year Postoperative Results" (J Bone Joint Surg Am, 2020;102[13]:1169-1176), that assessed the clinical and radiographic outcomes of vertebral body tethering (VBT) in the treatment of adolescent scoliosis. The authors demonstrated successful treatment in 74% of patients, based on radiographic outcomes and avoidance of subsequent posterior spinal fusion. Nearly a quarter of patients required revision surgery. Almost half suffered a broken tether, although the effects of such complications are not fully understood. The study provided valuable information for determining which patients are reasonable candidates for VBT and emphasizes several questions surrounding this novel technology that remain unanswered. This analysis discusses the study's strengths and weaknesses, suggests potential directions of future research, and examines the potential indications for VBT.

STUDY DESIGN:Retrospective cohort comparison study. OBJECTIVE:The aim was to compare perioperative complications and 30-day readmission between ambulatory and inpatient posterior cervical foraminotomy (PCF) in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. SUMMARY OF BACKGROUND DATA:Single-level PCF for cervical radiculopathy is increasingly being performed as an ambulatory procedure. Despite this increase, there is a lack of published literature documenting the safety of ambulatory PCF. MATERIALS AND METHODS:Patients who underwent PCF (through laminotomy or laminectomy) were identified in the 2005-2018 NSQIP database. Ambulatory procedures were defined as cases that had hospital length of stay=0 days. Inpatient procedures were defined as cases that had length of stay=1-4 days. Patient characteristics, comorbidities, and procedural variables (laminotomy or laminectomy performed) were compared between the 2 cohorts. Propensity score matched comparisons were then performed for postoperative complications and 30-day readmissions between the 2 groups. RESULTS:In total, 795 ambulatory and 1789 inpatient single-level PCF cases were identified. After matching, there were 795 ambulatory and 795 inpatient cases. Statistical analysis after propensity score matching revealed no significant difference in individual complications including 30-day readmission, thromboembolic events, wound complications, and reoperation, or aggregated complications between ambulatory versus matched inpatient procedures. Overall 30-day readmissions after ambulatory single-level PCF were noted for 2.46% of the study population, and the most common reasons were surgical site infections (46%) and pain control (15%). CONCLUSIONS:The perioperative outcomes assessed in this study support the conclusion that single-level PCF for cervical radiculopathy can be performed for correctly selected patients in the ambulatory setting without increased rates of 30-day perioperative complications or readmissions compared with inpatient procedures. LEVEL OF EVIDENCE:Level III.

Purpose To determine the association of preoperative opioid prescriptions with reoperations and postoperative opioid prescriptions after adult spina deformity (ASD) surgery. Summary of background data With the current opioid crisis, patients undergoing surgery for ASD are at particular risk for opioid-related complications due to significant preoperative disability and surgical morbidity. No previous studies consider preoperative opioids in this population. Methods A retrospective cohort study of patients undergoing posterior spinal fusion (7 or more levels) for ASD was performed. All patients had at least 3 years of postoperative follow-up 3 years postoperatively. Prescriptions for 4 different opioid medications (hydromorphone, oxycodone, hydrocodone, and tramadol) were identified within 3 months preoperatively and up to 3 years postoperatively. Multivariate regression was utilized to determine the association of preoperative use with reoperations and with postoperative opioid use, controlling for both patient and surgery-related confounding factors. Results A total of 743 patients were identified and 59.6% (443) had opioid prescriptions within 3 months preoperatively. Postoperative opioid prescriptions were identified in 66.9% of patients at 12 months postoperatively, and in 54.8% at 36 months postoperatively. The 3-year reoperation rate was 11.0% in patients without preoperative prescriptions, 16.0% in patients with preoperative any opioid prescriptions (P = 0.07), and 34.8% in patients with preoperative hydromorphone prescriptions (P < 0.01). In multivariate analysis, preoperative opioid prescriptions were associated with increased reoperations (odds ratio [OR]: 1.62, P = 0.04), and chronic postoperative opioid use (OR: 4.40, P < 0.01). Preoperative hydromorphone prescriptions had the strongest association with both reoperations (OR: 4.96; P < 0.01) and chronic use (OR: 5.19: P = 0.03). Conclusion In the ASD population, preoperative opioids are associated with both reoperations and chronic opioid use, with hydromorphone having the strongest association. Further investigation of the benefits of preoperative weaning programs is warranted.

Study Design. A retrospective cohort comparison study. Objective. To compare perioperative outcomes, radiographic parameters, and patient-reported outcome measures (PROMs) between minimally invasive unilateral laminotomy with bilateral decompression (MIS-ULBD) versus MIS transforaminal lumbar interbody fusion (MIS-TLIF) for treatment of low-grade lumbar degenerative spondylolisthesis. Summary of Background Data. While lumbar degenerative spondylolisthesis is a common condition, optimal surgical treatment remains controversial. Newer MIS techniques, which preserve bone, paraspinal musculature, and posterior midline stabilizers, are thought to reduce the risk of iatrogenic instability and may obviate the need for fusion. However, few comparative studies of MIS techniques for low-grade lumbar degenerative spondylolisthesis currently exist. Materials and Methods. Consecutive patients with low-grade (Meyerding grade I or II) lumbar degenerative spondylolisthesis treated with single-level MIS-ULBD or MIS-TLIF were identified retrospectively from a prospectively collected spine surgery registry from April 2017 to November 2021. Perioperative outcomes, radiographic data, and PROMs were assessed. Results. A total of 188 patients underwent either MIS-ULBD or MIS-TLIF (79 MIS-ULBD and 109 MIS-TLIF). Patients who underwent MIS-ULBD tended to be older, had higher Charlson Comorbidity Index, lower mean percentage back pain, higher percentage of L4/L5 pathology, shorter operative time, lower estimated blood loss, and lower postoperative pain (P<0.05). In both groups, there were statistically significant improvements at one year for five of the six PROMs studied: Oswestry Disability Index (ODI), visual analog scale (VAS)-back pain, VAS-leg pain, Short Form 12 Physical Component Score (SF12-PCS), and Patient-Reported Outcomes Measurement Information System (PROMIS) (P<0.05). On multivariate analysis controlling for confounders, there were no associations between procedure type and achieving minimal clinically important difference at one year in any of the PROMs studied. Conclusions. The current study suggests that both MIS-ULBD and MIS-TLIF result in significant improvements in pain and physical function for patients with low-grade lumbar degenerative spondylolisthesis. Level of Evidences: 3

OBJECTIVE:The objective of this study was to initially validate a recent morphological classification of cervical spine deformity pathology.METHODS:The records of 10 patients for each of the 3 classification subgroups (flat neck, focal deformity, and cervicothoracic), as well as for 8 patients with coronal deformity only, were extracted from a prospective multicenter database of patients with cervical deformity (CD). A panel of 15 physicians of various training and professional levels (i.e., residents, fellows, and surgeons) categorized each patient into one of the 4 groups. The Fleiss kappa coefficient was utilized to evaluate intra- and interrater reliability. Accuracy, defined as properly selecting the main driver of deformity, was reported overall, by morphotype, and by reviewer experience.RESULTS:The overall classification demonstrated a moderate to substantial agreement (round 1: interrater Fleiss kappa = 0.563, 95% CI 0.559-0.568; round 2: interrater Fleiss kappa = 0.612, 95% CI 0.606-0.619). Stratification by level of training demonstrated similar mean interrater coefficients (residents 0.547, fellows 0.600, surgeons 0.524). The mean intrarater score was 0.686 (range 0.531-0.823). A substantial agreement between rounds 1 and 2 was demonstrated in 81.8% of the raters, with a kappa score > 0.61. Stratification by level of training demonstrated similar mean intrarater coefficients (residents 0.715, fellows 0.640, surgeons 0.682). Of 570 possible questions, reviewers provided 419 correct answers (73.5%). When considering the true answer as being selected by at least one of the two main drivers of deformity, the overall accuracy increased to 86.0%.CONCLUSIONS:This initial validation of a CD morphological classification system reiterates the importance of dynamic plain radiographs for the evaluation of patients with CD. The overall reliability of this CD morphological classification has been demonstrated. The overall accuracy of the classification system was not impacted by rater experience, demonstrating its simplicity.

The objective was to evaluate medical comorbidities and surgical variables as independent risk factors for increased health care costs in Medicare patients undergoing lumbar fusion. Care episodes limited to lumbar fusions were retrospectively reviewed on the Centers of Medicare and Medicaid Innovation (CMMI) Bundled Payment for Care Improvement (BPCI) reimbursement database at a single academic institution. Total episode of care cost was also collected. A multivariable linear regression model was developed to identify independent risk factors for increased total episode of care cost, and logistic models for surgical complications and readmission. A total of 500 Medicare patients were included. Risk factors associated with increased total episode of care cost included transforaminal interbody fusion (TLIF) and anterior lumbar interbody fusion (ALIF) (β = $5,399, P < 0.001) and ALIF+PLF (AP) fusions (β = $24,488, P < 0.001), levels fused (β = $3,989, P < 0.001), congestive heart failure (β = $6,161, P = 0.022), hypertension with end-organ damage (β = $10,138, P < 0.001), liver disease (β = $16,682, P < 0.001), inpatient complications (β = $4,548, P = 0.001), 90-day complications (β = $10,012, P = 0.001), and 90-day readmissions (β = $15,677, P < 0.001). The most common surgical complication was postoperative anemia, which was associated with significantly increased costs (β = $18,478, P < 0.001). Female sex (OR = 2.27, P = 0.001), AP fusion (OR = 2.59, P = 0.002), levels fused (OR = 1.45, P = 0.005), cerebrovascular disease (OR = 4.19, P = 0.003), cardiac arrhythmias (OR = 2.32, P = 0.002), and fluid electrolyte disorders (OR = 4.24, P = 0.002) were independent predictors of surgical complications. Body mass index (OR = 1.07, P = 0.029) and AP fusions (OR = 2.87, P = 0.049) were independent predictors of surgical readmission. Among medical comorbidities, congestive heart failure, hypertension with end-organ damage, and liver disease were independently associated with a significant increase in total episode of care cost. Interbody devices were associated with increased admission cost.

Study Design: Retrospective case series. Objective: To report contemporary rates of complications and subsequent surgery after spinal surgery in patients with skeletal dysplasia. Methods: A case series of 25 consecutive patients who underwent spinal surgery between 2007 and 2017 were identified from a single institution’s skeletal dysplasia registry. Patient demographics, medical history, surgical indication, complications, and subsequent surgeries (revisions, extension to adjacent levels, or for pathology at a non-contiguous level) were collected. Charlson comorbidity indices were calculated as a composite measure of overall health. Results: Achondroplasia was the most common skeletal dysplasia (76%) followed by spondyloepiphyseal dysplasia (20%); 1 patient had diastrophic dysplasia (4%). Average patient age was 53.2 ± 14.7 years and most patients were in excellent cardiovascular health (88% Charlson Comorbidity Index 0-4). Mean follow up after the index procedure was 57.4 ± 39.2 months (range). Indications for surgery were mostly for neurologic symptoms. The most commonly performed surgery was a multilevel thoracolumbar decompression without fusion (57%). Complications included durotomy (36%), neurologic complication (12%), and infection requiring irrigation and debridement (8%). Nine patients (36%) underwent a subsequent surgery. Three patients (12%) underwent a procedure at a non-contiguous anatomic zone, 3 (12%) underwent a revision of the previous surgery, and another 3 (12%) required extension of their previous decompression or fusion. Conclusions: Surgical complication rates remain high after spine surgery in patients with skeletal dysplasia, likely attributable to inherent characteristics of the disease. Patients should be counseled on their risk for complication and subsequent surgery.

Study Design: Retrospective cohort study. Objective: The objective of this study is to determine how often patients with degenerative cervical myelopathy (DCM) and initially treated with cervical steroid injections (CSI) and to determine whether these injections provide any benefit in delaying ultimate surgical treatment. Methods: All patients with a new diagnosis of DCM, without previous cervical spine surgery or steroid injections, were identified in PearlDiver, a large insurance database. Steroid injection and surgery timing was identified using Current Procedural Terminology (CPT) codes. Multivariate logistic regression identified associations with surgical treatment. Results: A total of 686 patients with DCM were identified. Pre-surgical cervical spine steroid injections were utilized in 244 patients (35.6%). All patients underwent eventual surgical treatment. Median time from initial DCM diagnosis to surgery was 75.5 days (mean 351.6 days; standard deviation 544.9 days). Cervical steroid injections were associated with higher odds of surgery within 1 year (compared to patients without injections, OR = 1.44, P < .001) and at each examined time point through 5 years (OR = 2.01, P < .001). In multivariate analysis comparing injection types, none of the 3 injection types were associated with decreased odds of surgery within 1 month of diagnosis. Conclusions: While cervical steroid injections continue to be commonly performed in patients with DCM, there is an overall increased odds of surgery after any type of cervical injection. Therefore injections should not be used to prevent surgical management of DCM.

Background: the demographics, mechanisms of injury, and concurrent injuries associated with cervical, thoracic and lumbar spinal fracture and/or spinal cord injury remain poorly characterized. Methods: Patients aged 18 and older with spinal injury between 2011 and 2015 in the National Trauma Data Bank (NTDB) were identified. Patient demographics, comorbidity burden, mechanism of injury, and associated injuries were analyzed. Results: in total, 520,183 patients with acute spinal injury were identified including 216,522 cervical, 191,218 thoracic, and 220,294 lumbar. The age distributions were trimodal with peaks in incidence at around 2155 and a lesser peak around 85 years of age. The number of comorbidities increased while injury severity decreased with advancing patient age. Motor vehicle accidents (MVAs) were the most common mechanism of injury. Associated bony and internal organ injuries were common and occurred in 63% of cervical spine injury patients, 79% of thoracic spine injury patients, and 71% of lumbar spine injury patients. In all three sub-populations, there was a predominance of injuries in the local area of the primary injury. For cervical, these were rib injuries (28%), thoracic spine injuries (22%), skull fractures (20%), intracranial injuries (26%) and lung injuries (21%). For thoracic, these were rib injuries (47%), lumbar spine injuries (26%), cervical spine injuries (25%), lung injuries (35%) and intracranial injuries (24%). For lumbar, these were rib injuries (38%), thoracic spine injuries (22%), pelvic fractures (20%), lung injuries (26%) and intracranial injuries (19%). Multivariate regression analysis demonstrated that increased injury severity was strongly correlated with increased mortality, with lesser contributions from increased age and comorbidity burden. Conclusions: the current study revealed spinal fractures and/or cord injuries had high incidences of associated injuries that had a predominance of local distribution. These findings, in combination with the mortality analysis, demonstrate the importance of local targeted evaluations for associated injuries.

Study Design. A retrospective cohort study. Objective. The aim of this study was to identify an association between preoperative opioid use and reoperations rates. Summary of Background Data. Chronic opioid use is a public health crisis in the United States and has been linked to worse outcomes after lumbar spine surgery. However, no studies have identified an association between preoperative opioid use and reoperations rates. Methods. A retrospective cohort study was conducted using patients from one private insurance database who underwent primary lumbar decompression/discectomy (LDD) or posterior/transforaminal lumbar interbody fusion (PLIF/TLIF). Preoperative use of five specific opioid medications (tramadol, hydromorphone, oxycodone, hydromorphone, and extended-release oxycodone) was categorized as acute (within 3 months), subacute (acute use and use between 3 and 6 months), or chronic (subacute use and use before 6 months). Multivariate regression, controlling for multilevel surgery, age, sex, and Charlson Comorbidity Index, was used to determine the association of each medication on reoperations within 5 years. Results. A total of 11,551 patients undergoing LDD and 3291 patients undergoing PLIF/TLIF without previous lumbar spine surgery were identified. In the LDD group, opioid-naive patients had a 5-year reoperation rate of 2.8%, compared with 25.0% and 8.0 with chronic preoperative use of hydromorphone and oxycodone, respectively. In multivariate analysis, any preoperative use of oxycodone was associated with increased reoperations (odds ratios [OR] = 1.4, 2.0, and 2.3, for acute, subacute, and chronic use; P < 0.01). Chronic use of hydromorphone was also associated with increased reoperations (OR = 7.5, P < 0.01). In the PLIF/TLIF group, opioid-naive patients had a 5-year reoperation rate of 11.3%, compared with 66.7% and 16.8% with chronic preoperative use of hydromorphone and oxycodone, respectively. In multivariate analysis, any preoperative use of hydromorphone was associated with increased reoperations (OR = 2.9, 4.0, and 14.0, for acute, subacute, and chronic use; P < 0.05). Conclusion. Preoperative use of the higher-potency opioid medications is associated with increased reoperations after LDD and PLIF/TLIF in a dose-dependent manner. Surgeons should use this data for preoperative opioid cessation counseling and individualized risk stratification.

STUDY DESIGN:Retrospective cohort study. OBJECTIVE:To (1) define utilization trends for navigated instrumented posterior lumbar fusion (PLF), (2) compare reasons and rates of revision at 30-day, 60-day, 90-day, and 1-year follow-up, and (3) compare 90-day perioperative complications between navigated versus conventional instrumented PLF. METHODS:Patients who underwent navigated or conventional instrumented PLF were identified from the Humana insurance database using the PearlDiver Patient Records between 2007-2017. Usage of navigation was characterized. Patient demographics and operative characteristics (number of levels fused, interbody usage) were compared between the 2 treatment groups. Propensity score matching was done and comparisons were made for revision rates at different follow-up periods (categorized by reasons) and other 90-day perioperative complications. RESULTS:This study included 1,648 navigated and 23 429 conventional instrumented PLF. Navigated cases increased over the years studied to approximately 10% in 2017. Statistical analysis after propensity score matching revealed significantly lower rates of hardware-related revision at 90-day follow-up in the navigated cohort (0.49% versus 1.15%, P = .033). At 1-year follow-up, the navigated cohort continued to have significantly lower rates of hardware-related revision (1.70% versus 2.73%, P = .044) as well as all cause revision (2.67% versus 4.00%, P = .032). There were no statistical differences between the 2 cohorts in any of the 90-day perioperative complications studied, such as cellulitis and blood transfusion (P > .05 for all). CONCLUSIONS:These findings suggest that navigation is associated with reductions in hardware-related revisions after instrumented PLF. However, these results should be interpreted cautiously in the setting of potential confounding by other unmeasured variables.

BACKGROUND CONTEXT Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is commonly used to treat lumbar spinal stenosis with degenerative disc disease. Expandable cage technology has been increasingly adopted and has demonstrated successful results, offering a larger footprint and intraoperative height adjustment, enabling more precise dialing in of sagittal alignment and disc height. While many advances have been made, endplate violation and postoperative cage subsidence can still be seen. PURPOSE To determine the rate and clinical implications of subsidence after expandable cage use in MI-TLIF. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE Patients undergoing MI-TLIF for degenerative disc disease using articulating, expandable cages. OUTCOME MEASURES Patient-reported outcome measures (PROMs), including the Oswestry Disability Index (ODI), visual analog scale (VAS) for back/leg pain, Short Form-12 (SF-12), and PROMIS physical function (PF). METHODS Patients undergoing MI-TLIF for degenerative disc disease using articulating, expandable cages from 2017-2019 were retrospectively studied. AP and lateral radiographs were reviewed and evaluated for the presence or absence of subsidence intraoperatively and at follow-up times including 2 weeks, 6 weeks, 12 weeks, 6 months and 1 year postoperatively. Each of the four corners of the implant was evaluated, and subsidence was determined to have occurred if there was endplate violation ≥3mm at any corner. Patient-reported outcome measures, including the ODI, VAS for back/leg pain, SF-12 and PROMIS PF were recorded at the preoperative and follow-up time points. Fusion was assessed 1-year postoperatively via CT. RESULTS A total of 87 patients were included, with mean age 58.3 years (SD,13.4). Of 87 total patients, 13 (14.9%) demonstrated subsidence, with the majority (84.6%) of cases occurring within the first 12 weeks. Patients who had subsidence were older (67.2 vs 56.7 yrs; p=0.009), had lower bone quality (p=0.049), and were more likely to have 2-level surgery compared to those without (p=0.032). On multiple regression analysis, age was the only variable which retained significance when comparing the subsidence and no subsidence groups (p=0.04). There were significant differences in subsidence rate with greater implant height (p=0.013) and smaller width (p=0.026). With the exception of SF-12 PCS at 1-year postoperative, there were no significant differences in any patient-reported outcomes between the 2 groups. The overall fusion rate was 90.5% (57/63 levels) at 1-year postoperative, with no significant difference in fusion rate between the subsidence and no subsidence groups. CONCLUSIONS The rate of subsidence after MI-TLIF was 14.9%, with the majority of cases occurring within the first 12 weeks postoperatively. Patients who had subsidence were older with lower bone quality, had cages with greater height and smaller width, and were more likely to have 2-level surgery. With the exception of SF-12 PCS at 1 year, there were no significant differences in any of the PROMs between the groups. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is commonly used to treat lumbar spinal stenosis with degenerative disc disease. Expandable cage technology has been increasingly adopted and has demonstrated successful results, offering a larger footprint and intraoperative height adjustment, enabling more precise dialing in of sagittal alignment and disc height. While many advances have been made, endplate violation and postoperative cage subsidence can still be seen. To determine the rate and clinical implications of subsidence after expandable cage use in MI-TLIF. Retrospective cohort study. Patients undergoing MI-TLIF for degenerative disc disease using articulating, expandable cages. Patient-reported outcome measures (PROMs), including the Oswestry Disability Index (ODI), visual analog scale (VAS) for back/leg pain, Short Form-12 (SF-12), and PROMIS physical function (PF). Patients undergoing MI-TLIF for degenerative disc disease using articulating, expandable cages from 2017-2019 were retrospectively studied. AP and lateral radiographs were reviewed and evaluated for the presence or absence of subsidence intraoperatively and at follow-up times including 2 weeks, 6 weeks, 12 weeks, 6 months and 1 year postoperatively. Each of the four corners of the implant was evaluated, and subsidence was determined to have occurred if there was endplate violation ≥3mm at any corner. Patient-reported outcome measures, including the ODI, VAS for back/leg pain, SF-12 and PROMIS PF were recorded at the preoperative and follow-up time points. Fusion was assessed 1-year postoperatively via CT. A total of 87 patients were included, with mean age 58.3 years (SD,13.4). Of 87 total patients, 13 (14.9%) demonstrated subsidence, with the majority (84.6%) of cases occurring within the first 12 weeks. Patients who had subsidence were older (67.2 vs 56.7 yrs; p=0.009), had lower bone quality (p=0.049), and were more likely to have 2-level surgery compared to those without (p=0.032). On multiple regression analysis, age was the only variable which retained significance when comparing the subsidence and no subsidence groups (p=0.04). There were significant differences in subsidence rate with greater implant height (p=0.013) and smaller width (p=0.026). With the exception of SF-12 PCS at 1-year postoperative, there were no significant differences in any patient-reported outcomes between the 2 groups. The overall fusion rate was 90.5% (57/63 levels) at 1-year postoperative, with no significant difference in fusion rate between the subsidence and no subsidence groups. The rate of subsidence after MI-TLIF was 14.9%, with the majority of cases occurring within the first 12 weeks postoperatively. Patients who had subsidence were older with lower bone quality, had cages with greater height and smaller width, and were more likely to have 2-level surgery. With the exception of SF-12 PCS at 1 year, there were no significant differences in any of the PROMs between the groups.

Study Design: Systematic review. Objective: Indirect decompression via lateral lumbar interbody fusion (LLIF) can ameliorate central and foraminal lumbar stenosis. In severe central stenosis, additional posterior direct decompression is utilized. The aim of this review is to synthesize existing literature on these 2 techniques and identify significant differences in outcomes between isolated indirect decompression via LLIF and combined indirect decompression supplemented with direct posterior decompression. Methods: A database search algorithm was utilized to query MEDLINE, COCHRANE, and EMBASE to identify literature reporting adult decompression study groups that involved an oblique or lateral fusion approach through September 2020. Improvement in outcomes measures and complication rates were pooled and tested for significance. Results: A total of 110 publications were assessed with 15 studies meeting inclusion criteria, including 557 patients and 1008 levels. Mean age was 63.1 years with BMI of 27.5 kg/m2. For the combined indirect and direct decompression cohort, lumbar lordosis (LL) increased 133.9%, from 22.8o to 48.7o, while the indirect decompression cohort LL increased 8.9%, from 41.9o to 45.5o. Difference in LL improvement between cohorts was insignificant (P > .05). Oswestry Disability Index (ODI) decreased from 36.5 to 19.4 in the combined indirect and direct decompression cohort, and from 44.4 to 23.1 in the indirect decompression cohort. ODI reduction was insignificant (P = .053). Conclusions: Prior studies of both indirect decompression as well as combined indirect and direct decompression of lumbar spine stenosis are limited by small samples, heterogeneous populations, and lack of direct comparisons. Both procedures result in improved function and pain postoperatively with direct decompression restoring more lordosis in patients with worse preoperative alignment.

BACKGROUND CONTEXT Single-level posterior cervical foraminotomy (PCF) for cervical radiculopathy is increasingly performed as an ambulatory procedure. Despite this increase, there is a lack of published literature documenting the safety of ambulatory PCF. PURPOSE To evaluate for potential differences in 30-day perioperative complications between ambulatory and inpatient single-level PCF. STUDY DESIGN/SETTING Retrospective cohort comparison study. PATIENT SAMPLE Patients who underwent single-level PCF for cervical radiculopathy from the 2005-2018 National Surgical Quality Improvement Program (NSQIP) registry. OUTCOME MEASURES Perioperative complications within 30 days and readmission within 30 days. METHODS Patients who underwent single-level PCF for cervical radiculopathy were identified using ICD and CPT codes from the 2005-2018 NSQIP registry, which contains multi-institutional prospectively collected data for the purpose of clinical research. Ambulatory status was defined as discharge home on same day as surgery was performed (length of stay of 0 days). To account for potential selection bias due to nonrandom assignment of patients between the ambulatory and inpatient cohorts, 1:1 matching utilizing a propensity score (a single score calculated from available patient demographic data to match patients between different treatment groups) was performed. Each ambulatory case was matched with one inpatient case by age, gender, body mass index, functional status, ASA, diabetes mellitus type, and hypertension. Rates of 30-day perioperative aggregated and individual complications, such as readmission, thromboembolic events, wound complications, and reoperation between the matched cohorts were then compared using chi-squared and Fisher's exact tests with Bonferroni correction. In addition, reasons for 30-day readmission after ambulatory single-level PCF were characterized. RESULTS In total, 795 ambulatory and 1,789 inpatient single-level PCF cases were identified. After matching, there were 795 ambulatory and 795 inpatient cases. Statistical analysis after propensity score matching revealed no significant difference in individual complications including 30-day readmission, thromboembolic events, wound complications, and reoperation, or aggregated complications between ambulatory vs matched inpatient procedures (p>0.004). The most common reasons for 30-day readmission after ambulatory single-level PCF include surgical site infections (46%) and pain control (15%). CONCLUSIONS The perioperative outcomes assessed in the current study support the conclusion that single-level PCF for cervical radiculopathy can be performed in the ambulatory setting without increased rates of 30-day perioperative complications or readmissions compared to inpatient procedures. However, careful patient selection should be exercised in order to determine appropriate ambulatory candidates. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. Single-level posterior cervical foraminotomy (PCF) for cervical radiculopathy is increasingly performed as an ambulatory procedure. Despite this increase, there is a lack of published literature documenting the safety of ambulatory PCF. To evaluate for potential differences in 30-day perioperative complications between ambulatory and inpatient single-level PCF. Retrospective cohort comparison study. Patients who underwent single-level PCF for cervical radiculopathy from the 2005-2018 National Surgical Quality Improvement Program (NSQIP) registry. Perioperative complications within 30 days and readmission within 30 days. Patients who underwent single-level PCF for cervical radiculopathy were identified using ICD and CPT codes from the 2005-2018 NSQIP registry, which contains multi-institutional prospectively collected data for the purpose of clinical research. Ambulatory status was defined as discharge home on same day as surgery was performed (length of stay of 0 days). To account for potential selection bias due to nonrandom assignment of patients between the ambulatory and inpatient cohorts, 1:1 matching utilizing a propensity score (a single score calculated from available patient demographic data to match patients between different treatment groups) was performed. Each ambulatory case was matched with one inpatient case by age, gender, body mass index, functional status, ASA, diabetes mellitus type, and hypertension. Rates of 30-day perioperative aggregated and individual complications, such as readmission, thromboembolic events, wound complications, and reoperation between the matched cohorts were then compared using chi-squared and Fisher's exact tests with Bonferroni correction. In addition, reasons for 30-day readmission after ambulatory single-level PCF were characterized. In total, 795 ambulatory and 1,789 inpatient single-level PCF cases were identified. After matching, there were 795 ambulatory and 795 inpatient cases. Statistical analysis after propensity score matching revealed no significant difference in individual complications including 30-day readmission, thromboembolic events, wound complications, and reoperation, or aggregated complications between ambulatory vs matched inpatient procedures (p>0.004). The most common reasons for 30-day readmission after ambulatory single-level PCF include surgical site infections (46%) and pain control (15%). The perioperative outcomes assessed in the current study support the conclusion that single-level PCF for cervical radiculopathy can be performed in the ambulatory setting without increased rates of 30-day perioperative complications or readmissions compared to inpatient procedures. However, careful patient selection should be exercised in order to determine appropriate ambulatory candidates.

The published article contained four sentences with incorrect reference citations. Here, those sentences and the reference list are corrected.

STUDY DESIGN:Retrospective cohort study. OBJECTIVE:The aim of this study was to determine that rates of preoperative opioid use in patients undergoing single-level anterior discectomy and fusion (ACDF) without myelopathy and determine the association with reoperations over 5 years. SUMMARY OF BACKGROUND DATA:Preoperative opioid use before cervical spine surgery has been linked to worse postoperative outcomes. However, no studies have determined the association of duration and type of opioid used with reoperations after ACDF. METHODS:Patients undergoing single-level ACDF without myelopathy between 2007 and 2016 with at least 5-year follow-up were identified in one private insurance administrative database. Preoperative opiate use was divided into acute (within 3 months), subacute (acute use and use between 3 and 6 months), and chronic (subacute use and use before 6 months) and by the opiate medication prescribed (tramadol, oxycodone, and hydrocodone). Postoperative rates of additional cervical spine surgery were determined at 5 years and multivariate logistic regression was used to determine the association of preoperative opiates with additional surgery. RESULTS:Of 445 patients undergoing single-level ACDF without myelopathy, 66.3% were taking opioid medications before surgery. The most commonly used preoperative opioid was hydrocodone (50.3% acute use, 24.7% chronic use). Opioid-naïve patients had a 5-year reoperation rate of 4.7%, compared to 25.0%, 15.5%, and 23.3% with chronic preoperative use of tramadol, hydrocodone, and oxycodone. In multivariate analysis, controlling for age, sex, and Charlson Comorbidity Index, chronic use of hydrocodone (odds ratio [OR] = 2.08, P = 0.05), oxycodone (OR = 4.46, P < 0.01), and tramadol (OR = 4.01, P = 0.01) were all associated with increased reoperations. However, acute use of hydrocodone, oxycodone, and tramadol was not associated with reoperations (P > 0.05). CONCLUSION:Both subacute and chronic use of common lower-dose opioid medications is associated with increased reoperations after single-level ACDF in nonmyelopathic patients. This information is critical when counseling patients preoperatively and developing preoperative opioid cessation programs.Level of Evidence: 3.