Faculty Bibliography

BACKGROUND CONTEXT/UNASSIGNED:Oblique lumbar interbody fusion (OLIF) and extreme lateral interbody fusion (XLIF) are 2 popular minimally invasive spinal fusion techniques with unique approach-related complication profiles. Accordingly, patient-specific anatomical factors, such as vascular anatomy or iliac crest height, greatly influence which technique to use. Previous studies comparing these approaches do not account for the inability of XLIF to access the L5-S1 disc space and therefore do not exclude this level in their analysis. The purpose of this study was to compare radiological and clinical outcomes of these techniques in the L1-L5 region. METHODS/UNASSIGNED:A query of 3 electronic databases (PubMed, CINAHL plus, and SCOPUS) was performed, without time restriction, to identify studies that evaluated outcomes of single-level OLIF and/or XLIF between L1 and L5. Based on heterogeneity, a random effects meta-analysis was performed to evaluate the pooled estimation of each variable between the groups. An overlap of 95% confidence intervals suggests no statistically significant difference at the p<.05 level. RESULTS/UNASSIGNED:A total of 1,010 patients (408 OLIF, 602 XLIF) were included from 24 published studies. Improvements in disc height (OLIF: 4.2 mm; XLIF: 5.3 mm), lumbar segmental (OLIF: 2.3°; XLIF: 3.1°), and lumbar lordotic angles (OLIF: 5.3°; XLIF: 3.3°) showed no significant difference. The rate of neuropraxia was significantly greater in the XLIF group at 21.2% versus 10.9% in the OLIF group (p<.05). However, the rate of vascular injury was higher in the OLIF cohort at 3.2% (95% CI:1.7-6.0) as compared to 0.0 (95% CI: 0.0-1.4) in the XLIF cohort. Improvements in VAS-b (OLIF: 5.6; XLIF: 4.5) and ODI (OLIF: 37.9; XLIF: 25.6) scores were not significantly different between the 2 groups. CONCLUSIONS/UNASSIGNED:This meta-analysis demonstrates similar clinical and radiological outcomes between single-level OLIF and XLIF from L1 to L5. XLIF had significantly higher rates of neuropraxia, whereas OLIF had greater rates of vascular injury.

BACKGROUND/UNASSIGNED:The 5-factor modified frailty index (mFI-5) has been shown to be a concise and effective tool for predicting adverse events following various spine procedures. However, there have been no studies assessing its utility in patients undergoing anterior lumbar interbody fusion (ALIF). Therefore, the aim of this study was to analyze the predictive capabilities of the mFI-5 for 30-day postoperative adverse events following elective ALIF. METHODS/UNASSIGNED:The National Surgical Quality Improvement Program (NSQIP) database was queried from 2010 through 2019 to identify patients who underwent elective ALIF using Current Procedural Terminology (CPT) codes in patients over the age of 50. The mFI-5 score was calculated using variables for hypertension, congestive heart failure, comorbid diabetes, chronic obstructive pulmonary disease, and partially or fully dependent functional status which were each assigned 1 point. Univariate analysis and multivariate logistic regression models were utilized to identify the associations between mFI-5 scores, and 30-day rates of overall complications, readmissions, reoperations, and mortality. RESULTS/UNASSIGNED:11,711 patients were included (mFI-5=0: 4,026 patients, mFI-5=1: 5,392, mFI-5=2: 2,102, mFI-5=3+: 187. Multivariate logistic regression revealed that mFI-5 scores of 1 (OR: 2.2, CI: 1.2-4.2, p=0.02), 2 (OR: 3.6, CI: 1.8-7.3, p<0.001), and 3+ (OR: 7.0, CI: 2.5-19.3, p<0.001) versus a score of 0 were significant predictors of pneumonia. An mFI-5 score of 2 (OR: 1.3; CI: 1.01-1.6, p=0.04), and 3+ (OR: 1.9; CI: 1.1-3.1; p=0.01) were both independent predictors of related readmissions. An mFI score of 3+ was an independent predictor of any complication (OR: 1.5, CI: 1.01-2.2, p=0.004), UTI (OR: 2.4, CI: 1.1-5.2, p=0.02), and unplanned intubation (OR: 4.5, CI: 1.3-16.1, p=0.02). CONCLUSIONS/UNASSIGNED:The mFI-5 is an independent predictor for 30-day postoperative complications, readmissions, UTI, pneumonia, and unplanned intubations following elective ALIF surgery in adults over the age of 50.

BACKGROUND/UNASSIGNED:. DESCRIPTION/UNASSIGNED:. The end plates are prepared, and an interbody device is placed after the disc is removed. Pedicle screws and rods are then placed for posterior fixation. ALTERNATIVES/UNASSIGNED:Nonoperative alternatives include physical therapy and corticosteroid injections. Other operative techniques include open TLIF or other types of lumbar fusion approaches, such as posterior lumbar interbody fusion (PLIF), anterior lumbar interbody fusion, lateral or extreme lateral interbody fusion, or oblique lumbar interbody fusion. RATIONALE/UNASSIGNED:. EXPECTED OUTCOMES/UNASSIGNED:. IMPORTANT TIPS/UNASSIGNED:prior to performing the facetectomy. Protect the exiting and traversing nerve roots by placing small cottonoids around them and retracting delicately.Bone removed during facetectomy can be utilized as autograft for the interbody cage.Avoid removing pedicle bone during decompression.If central stenosis is present, the neural decompression should be extended medial to the epidural fat so that the dura mater can be visualized all of the way to the contralateral pedicle.Perform an adequate end plate preparation prior to interbody insertion while being mindful to avoid injuring the end plate, to minimize the risk of future cage subsidence.Confirm correct placement of the interbody device on intraoperative fluoroscopy.If bone morphogenic protein is utilized, be careful not to pack too much posteriorly as this may cause nerve irritation. ACRONYMS AND ABBREVIATIONS/UNASSIGNED:TLIF = transforaminal lumbar interbody fusionMI-TLIF = minimally invasive TLIFPLIF = posterior lumbar interbody fusionALIF = anterior lumbar interbody fusionLLIF = lateral lumbar interbody fusionXLIF = extreme lateral interbody fusionOLIF = oblique lumbar interbody fusionDLIF = direct lateral interbody fusionMRI = magnetic resonance imagingA/P = anteroposteriorEMG = electromyographicBMP = bone morphogenic proteinXR = x-ray (radiograph)OTC = over the counterDVT = deep vein thrombosisPE = pulmonary embolismMI = myocardial infarctionMIS = minimally invasive surgeryOR = operating roomLOS = length of stayVAS = visual analog scaleODI = Oswestry Disability IndexM-H = Mantel-HaenszelRR = risk ratioCI = confidence intervalNSAIDs = nonsteroidal anti-inflammatory drugs.

OBJECTIVE:Long posterior cervical decompression and fusion (PCF) is commonly performed to surgically treat patients with multilevel cervical pathology. In cases in which constructs may necessitate crossing the cervicothoracic junction (CTJ), recommendations for appropriate caudal fusion level vary in the literature. The aim of this study was to report the clinical and radiological outcomes of multilevel PCFs ending at C7 versus those crossing the CTJ. METHODS:A systematic search of PubMed, CINAHL Plus, and Scopus was conducted to identify articles that evaluated clinical and radiological outcomes of long PCFs that ended at C7 (cervical group) or crossed the CTJ (thoracic group). Based on heterogeneity, random-effects models of a meta-analysis were used to estimate the pooled estimates and the 95% confidence intervals. RESULTS:PCF outcome data of 1120 patients from 10 published studies were included. Compared with the cervical group, the thoracic group experienced greater mean blood loss (453.0 ml [95% CI 333.6-572.5 ml] vs 303.5 ml [95% CI 203.4-403.6 ml]), longer operative times (235.5 minutes [95% CI 187.7-283.3 minutes] vs 198.5 minutes [95% CI 157.9-239.0 minutes]), and a longer length of stay (6.7 days [95% CI 3.3-10.2 days] vs 6.2 days [95% CI 3.8-8.7 days]); however, these differences were not statistically significant. None of the included studies specifically investigated factors that led to the decision of whether to cross the CTJ. The cervical group had a mean fusion rate of 86% (95% CI 71%-94%) compared with the thoracic group with a rate of 90% (95% CI 81%-95%). Of patients in the cervical group, 17% (95% CI 10%-28%) required revision surgery compared with 7% (95% CI 4%-13%) of those in the thoracic group, but this difference was not statistically significant. The proportion of patients who experienced complications in the cervical group was found to be 28% (95% CI 12%-52%) versus 14% (95% CI 7%-26%) in the thoracic group; however, this difference was not statistically significant. There was no significant difference (no overlap of 95% CIs) in the incidence of adjacent-segment disease, pseudarthrosis, or wound-related complications between groups. CONCLUSIONS:This meta-analysis suggests similar clinical and radiographic outcomes in multilevel PCF, regardless of inclusion of the CTJ. The lowest instrumented level did not significantly affect revision rates or complications. The ideal stopping point must be tailored to each patient on an individualized basis.

STUDY DESIGN/METHODS:Retrospective Cohort Study. OBJECTIVE:To compare MI-PCF and ACDF in the treatment of unilateral cervical radiculopathy. SUMMARY OF BACKGROUND DATA/BACKGROUND:Minimally invasive posterior cervical foraminotomy (MI-PCF) has been shown to be equally effective as ACDF in treating cervical radiculopathy due to foraminal stenosis and similar pathologies. Additionally, it has been hypothesized that preserving motion and avoiding fusion reduces risk for adjacent segment disease (ASD), but potentially increases risk for subsequent revision to an ACDF. With similar short-term outcomes and substantial advantages, MI-PCF may be an effective alternative to ACDF for addressing appropriate cervical pathology. METHODS:A retrospective review was performed to identify patients between 2009-2013 who underwent ACDF or MI-PCF with a minimum follow-up of 7-years. Demographic data was recorded. Revision rates and average time to revision between cohorts were compared. Clinical outcomes were assessed at each follow-up visit with Neck Disability Index (NDI) and Visual Analog Scale for neck and arm pain (VAS-n and VAS-a) scores. All complications were reviewed. Standard binomial and categorical comparative analysis were performed. RESULTS:A total of 251 consecutive patients were included (205 ACDF, 46 MI-PCF). Mean follow-up for the ACDF and MI-PCF groups were 98.3 and 95.9 months, respectively. Complication rates were 2.9% and 2.2% for the ACDF and MI-PCF cohorts, respectively (p = 0.779). Revision rates were 7.8% for the ACDF cohort and 8.7% for the MI-PCF cohort (p = 0.840). Both cohorts experienced significant improvements in their clinical scores compared to their preoperative values. Final VAS-n (ACDF: 2.6; MI-PCF: 1.6) and VAS-a (ACDF: 1.1; MI-PCF: 0.4) scores differed significantly at final follow-up (p =  < 0.001; p =  < 0.001). CONCLUSION/CONCLUSIONS:MI-PCF is a safe and effective alternative to ACDF in the treatment of cervical radiculopathy, demonstrating substantial benefit. After final follow-up, MI-PCF demonstrated superior improvements in VAS scores, without increased complication or revision rates.Level of Evidence: 3.

The literature has shown the importance of long-term follow-up for adults with scoliosis treated surgically because complication and revision rates are high. The goal of this study was to determine long-term outcomes and complications of lateral lumbar interbody fusion (LLIF) with posterior instrumentation for adult patients with scoliosis. A retrospective review of our institution's database was performed to identify adult patients with scoliosis treated with LLIF between 2008 and 2013 with a minimum follow-up of 4 years. Medical records were reviewed for complications and revisions. Pre- and postoperative deformity Cobb angle measurements were taken as well as pelvic incidence (PI) and lumbar lordosis (LL). Functional outcome scores, including Oswestry Disability Index and visual analog scale score for back and leg pain, were assessed preoperatively and at follow-up. Standard binomial and categorical comparative analysis was performed. The 26 patients included had a mean age of 62 years, mean follow-up of 89 months, and mean of 1.8 levels per operation. Four patients (15.4%) required revisions. Mean deformity Cobb angle was 26° preoperatively and 14° postoperatively. Mean PI-LL mismatch was 11.7° preoperatively and 5.9° postoperatively. Nineteen (73%) patients had a PI-LL mismatch greater than 10° preoperatively, whereas only 2 (7.7%) had a mismatch postoperatively. Improvement was seen in all functional outcome scores. Long-term clinical results of LLIF for adults with deformity showed a low proportion of revision in the treatment of a condition with an established high rate of revision. The ability to reduce pelvic mismatch may further reduce the rate of revision. In this study, LLIF resulted in improved functional outcomes and patient satisfaction. [Orthopedics. 2022;45(3):e134-e139.].

Given the shift toward value-based healthcare, strategies that decrease risk in commonly performed procedures such as anterior cervical discectomy and fusion (ACDF) are of interest. The objective of this study was to analyze the effect of a two-attending surgeon team on the outcomes of patients undergoing single-level ACDF. A retrospective matched-cohort study of patients undergoing single-level ACDF for degenerative cervical spondylosis, with minimum 2-year follow-up was performed. Patients were subdivided into two cohorts: cases with procedures performed by one attending surgeon assisted by a resident physician and cases with procedures performed by an attending surgeon with another attending surgeon as first-assist. Patients were matched by age, sex, body mass index, smoking status, American Society of Anesthesia grade and Charlson Comorbidity Index. Perioperative data and complications were compared. Standard binomial and categorical comparative analysis were performed. Forty-two patients were included (21 in each group). There were 22 males and 20 females, with a mean age of 47.7 years and mean follow-up of 43.4 months. There were no differences in any demographic variable between groups, indicating successful matching. Cohort B had decreased anesthesia time (114.9 vs. 157.1 minutes, P < 0.001), operative time (58.1 vs. 98.9 minutes, P < 0.001) and blood loss (14.8 vs. 24.3 mL, P = 0.012). There were no significant differences in terms of post-operative complications including dysphagia, wound infection, neurologic or cardiovascular related complications. A two-attending surgeon team significantly reduces anesthesia time, surgical time, and blood loss in single-level ACDF procedures without an increase in complications or a decrease in fusion rates.

Minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) is an established technique for the treatment of degenerative spine disease. The larger body habitus of obese patients increases the intraoperative complexity of MI-TLIF. Therefore, it is unclear whether this procedure is appropriate for this population. The goal of this study was to compare postoperative outcomes for obese patients vs nonobese patients undergoing MI-TLIF through a matched cohort analysis. A retrospective review was performed to identify patients who underwent MI-TLIF at a single institution with a minimum follow-up of 5 years. Patients were divided into 2 cohorts: nonobese (body mass index <30 kg/m²) and obese (body mass index ≥30 kg/m²). Each cohort was matched for age, sex, and levels operated. Perioperative data and patient-reported outcomes were compared. Radiographic outcomes were measured at final follow-up. Standard binomial and categorical comparative analyses were performed. A total of 148 patients were included. Of obese patients, 17.6% required revision surgery compared with 16.2% of nonobese patients (P=.826). Both cohorts had a similar proportion of pelvic incidence-lumbar lordosis mismatch correction (P=.780). Mean change in functional outcome scores for each cohort did not differ significantly. Obese patients had clinically minor but statistically significantly greater blood loss and longer operative times than nonobese patients (P<.001). Obese and non-obese patients undergoing MI-TLIF showed no long-term differences in revision rate, radiologic outcome, or functional outcome after long-term follow-up. Obese patients had slightly greater blood loss and longer operative times. Our findings suggest that MI-TLIF is an appropriate alternative to traditional open lumbar fusion for obese patients. [Orthopedics. 2022;45(4):203-208.].

BACKGROUND CONTEXT/BACKGROUND:Although highlighted in joint arthroplasty studies, long-term outcomes between differing biomaterial composites, such as metal-on-metal (MoM) and metal-on-plastic (MoP) in anterior cervical disc replacement (ACDR) have not been thoroughly investigated. PURPOSE/OBJECTIVE:The purpose of this study was to evaluate the patient-reported clinical outcomes, overall reoperation rates, complications, and rates of ASD of MoM versus MoP artificial discs in two-level ACDR for the treatment of cervical DDD. STUDY DESIGN/SETTING/METHODS:Meta-analysis and systematic review PATIENT SAMPLE: 980 patients (442 MoM, 538 MoP) across 7 studies OUTCOME MEASURES: Patient reported clinical outcomes (NDI, VAS-n, VAS-a), overall reoperation rates, complications and rates of ASD METHODS: A systematic search strategy of three electronic databases (PubMed, CINAHL Plus, and SCOPUS) was conducted utilizing terms related to two-level ACDR. All studies included had a sample size of >10 patients, had a minimum 5-year follow-up, and reported data on adjacent segment disease. Cadaver studies, non-English manuscripts, articles with less than 5-year follow-up and studies in which only single-level ACDR was investigated were excluded. A total of 7 studies were included in this analysis. Studies were analyzed for demographic data, clinical outcome scores (NDI, VAS-neck, and VAS-arm), overall reoperation rates, complications, and rates of ASD. A random-effects model of meta-analysis was used for groups that were determined to be heterogenous and a fixed-effects model was utilized for groups that were not. An overlap of 95% confidence intervals suggests no statistically significant difference at the p<0.05 level. RESULTS:Seven studies were included with data on 980 patients (442 MoM, 538 MoP). The study population was 52.84% female, with a mean age of 48.01 years, and a mean follow-up of 85.66 months. The mean improvement in NDI was 34.42 (95% CI, 32.49-36.36) and 29.72 (95% CI, 27.15-32.29) for the MoM and MoP groups, respectively. The mean improvement in VAS-neck was 11.20 (95% CI, 10.69-11.70) and 8.78 (95% CI, 7.81-9.74) for the MoM and MoP groups, respectively. The mean improvement in VAS-arm was 10.73 (95% CI, 9.83-11.63) and 8.49 (95% CI, 7.59-9.39) for the MoM and MoP groups, respectively. 3.85% (95% CI, 2.40-6.10) of patients who underwent ACDR with a MoM implant required reoperation compared to 5.33% (95% CI, 3.68-7.65) of patients with a MoP implant. Heterotopic ossification and dysphagia were the most common complications in both groups. The MoM cohort showed a higher incidence of HO (72.62% vs. 21.07%), but a lower incidence of dysphagia (0.96% vs 16.31%) compared to the MoP cohort. The MoM cohort had a larger proportion of patients with ASD who underwent subsequent surgery at an adjacent level (7.89% MoM versus 1.91% MoP). CONCLUSIONS:Our present meta-analysis suggests that the use of MoM artificial discs in two-level ACDR results in superior clinical outcome score improvement, but higher rates of ASD requiring secondary surgery compared to MoP discs after a follow-up period of 5 years or more.