Citations

OBJECTIVE Awake transforaminal lumbar interbody fusion (TLIF) is a novel technique for performing spinal fusions in patients under conscious sedation. Whether awake TLIF can reduce operative times and decrease the hospital length of stay (LOS) remains to be shown. In this study, the authors sought to assess the differences in clinical outcomes between patients who underwent awake TLIF and those who underwent TLIF under general anesthesia by using institutional experience at the Mayo Clinic and the National Surgical Quality Improvement Program (NSQIP) database. METHODS Chart review was performed for a consecutive series of patients who underwent single-level minimally invasive surgery (MIS)–TLIF performed by a single surgeon (K.A.I.) at a single institution. Additionally, the NSQIP database was queried from 2016 to 2019 for patients who underwent awake TLIF as well as propensity score–matched patients who underwent TLIF under general anesthesia. RESULTS A total of 20 patients at Mayo Clinic underwent awake single-level MIS-TLIF. The mean operative time was 122 ± 16.68 minutes, and the mean estimated blood loss was 39 ± 30.24 ml. No intraoperative complications were reported. A total of 96 patients who underwent TLIF (24 awake and 72 under general anesthesia) were analyzed from the NSQIP database. The mean LOS was less in the awake cohort (1.4 ± 1.381 days) than the general anesthesia cohort (3 ± 2.274 days) (p = 0.002). CONCLUSIONS Evidence from the authors’ institutional experience and national analysis has demonstrated that awake MIS-TLIF is efficient and can reduce hospital LOS.

OBJECTIVE Degenerative cervical myelopathy (DCM) results in significant morbidity. The duration of symptoms prior to surgical intervention may be associated with postoperative surgical outcomes and functional recovery. The authors’ objective was to investigate whether delayed surgical treatment for DCM is associated with worsened postoperative outcomes. METHODS Data from 1036 patients across 14 surgical centers in the Quality Outcomes Database were analyzed. Baseline demographic characteristics and findings of preoperative and postoperative symptom evaluations, including duration of symptoms, were assessed. Postoperative functional outcomes were measured using the Neck Disability Index (NDI) and modified Japanese Orthopaedic Association (mJOA) scale. Symptom duration was classified as either less than 12 months or 12 months or greater. Univariable and multivariable regression were used to evaluate for the associations between symptom duration and postoperative outcomes. RESULTS In this study, 513 patients (49.5%) presented with symptom duration < 12 months, and 523 (50.5%) had symptoms for 12 months or longer. Patients with longer symptom duration had higher BMI and higher prevalence of anxiety and diabetes (all p < 0.05). Symptom duration ≥ 12 months was associated with higher average baseline NDI score (41 vs 36, p < 0.01). However, improvements in NDI scores from baseline were not significantly different between groups at 3 months (p = 0.77) or 12 months (p = 0.51). Likewise, the authors found no significant differences between groups in changes in mJOA scores from baseline to 3 months or 12 months (both p > 0.05). CONCLUSIONS Surgical intervention resulted in improved mJOA and NDI scores at 3 months, and this improvement was sustained in both patients with short and longer initial symptom duration. Patients with DCM can still undergo successful surgical management despite delayed presentation.

OBJECTIVE Hybrid surgery (HS) is the combination of anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) at different levels in the same operation. The aim of this study was to investigate perioperative variables, 30-day postoperative outcomes, and complications of HS in comparison with those of CDA and ACDF. METHODS The authors queried the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) registry for patients who underwent multilevel primary HS, CDA, and ACDF for degenerative disc disease from 2015 to 2019. The authors compared these three operations in terms of 30-day postoperative outcomes, specifically readmission and reoperation rates, discharge destination, and complications. RESULTS This analysis included 439 patients who underwent HS, 976 patients who underwent CDA, and 27,460 patients who underwent ACDF. Patients in the HS and CDA groups were younger, had fewer comorbidities, and myelopathy was less often the indication for surgery compared with patients who underwent ACDF. For the HS group, the unplanned readmission rate was 0.7%, index surgery–related reoperation rate was 0.3%, and nonroutine discharge rate was 2.1%. Major and minor complications were also rare, with rates of 0.2% for each. The mean length of stay in the HS group was 1.5 days. The association of HS with better outcomes in univariate analysis was not evident after adjustment for confounding factors. CONCLUSIONS The authors found that HS was noninferior to ACDF and CDA in terms of early postoperative outcomes among patients treated for degenerative disc disease.

Abstract IntroductionRadiotherapy is considered standard of care for adjuvant peri-operative treatment of many spinal tumors, including those with instrumented fusion. Unfortunately, radiation treatment has been linked to increased risk of pseudoarthrosis. Newerfocused radiotherapy strategies with enhanced conformalitycould offer improved fusion rates for these patients, but this has not been confirmed.MethodsWe performed a retrospective analysis of patients at three tertiary care academic institutions withprimary and secondary spinal malignancies that underwent resection, instrumented fusion, and peri-operative radiotherapy. Two board certified neuro-radiologists used theLenke fusion score to grade fusion status at6 and 12-months after surgery. Secondary outcomes includedclinical pseudoarthrosis, wound complications, and the effect of radiation timing, radiobiological dose delivered, the use of photons versus protons, tumor type, tumor location,and use of autograft on fusion outcomes.ResultsAfter reviewof 1252 spinal tumor patients, there were 60 patients with at least 6 months follow-up that were included in our analyses. Twenty-five of these patients received focused radiotherapy,20 patients received conventional radiotherapy, and 15 patients were treated with protons. There was no significant difference between the groups for covariates such assmoking status,obesity, diabetes, intraoperative use of autograft, and use of peri-operative chemotherapy. There was a significantly higher rate of fusion for patients treated with focused radiotherapy compared to those treated with conventional radiotherapy at 6-months (64.0% versus 30.0%, Odds ratio: 4.15, p=0.036) and 12-months (80.0% versus 42.1%, OR: 5.50, p=0.022). There was a significantly higher rate of clinical pseudoarthrosis in the conventional radiotherapy cohortcompared to patients in the focused radiotherapy cohort (19.1% versus 0%,p=0.037). There was no difference in fusion outcomes for any of the secondary outcomes except for use of autograft. The use ofintra-operative autograft was associated with an improved fusion at 12-months (66.7% versus 37.5%, OR: 3.33, p=0.043). ConclusionFocused radiotherapy may be associated withan improved rate of fusion and clinical pseudoarthrosis when compared to conventional radiation delivery strategiesin patients with spinal tumors.Use of autograft at the time of surgery may be associated with improved 12-month fusion rates.Further large-scale prospective and randomized controlled studies are needed to better stratify the effects of radiation delivery modality in these patients.

Study Design: This was a research methodology study. Objective: This review discusses the most commonly utilized consensus group methodologies for formulating clinical practice guidelines and current methods for accessing rigorous up-to-date clinical practice guidelines. Summary of Background Data: In recent years, clinical practice guidelines for the management of several conditions of the spine have emerged to provide clinicians with evidence-based best-practices. Many of these guidelines are used routinely by administrators, payers, and providers to determine the high-quality and cost-effective surgical practices. Most of these guidelines are formulated by consensus groups, which employ methodologies that are unfamiliar to most clinicians. Methods: An extensive literature review was performed. The literature was then summarized in accordance with the authors’ clinical experience. Results: The Nominal Group Technique, Delphi method, and RAND-UCLA Appropriateness Model are 3 commonly utilized consensus group methodologies employed in the creation of clinical practice guidelines. Each of these methodologies has inherent advantages and disadvantages, is dependent on rigorously performed systematic reviews and meta-analyses to inform the panel of experts, and can be used to answer challenging clinical questions that remain unanswered due to a paucity of class I evidence. Conclusions: This review highlights the most commonly utilized consensus group methodologies and informs spine surgeons regarding options to access current clinical practice guidelines. Level of Evidence: Level V.

OBJECTIVE Reduction of Meyerding grade is often performed during fusion for spondylolisthesis. Although radiographic appearance may improve, correlation with patient-reported outcomes (PROs) is rarely reported. In this study, the authors’ aim was to assess the impact of spondylolisthesis reduction on 24-month PRO measures after decompression and fusion surgery for Meyerding grade I degenerative lumbar spondylolisthesis. METHODS The Quality Outcomes Database (QOD) was queried for patients undergoing posterior lumbar fusion for spondylolisthesis with a minimum 24-month follow-up, and quantitative correlation between Meyerding slippage reduction and PROs was performed. Baseline and 24-month PROs, including the Oswestry Disability Index (ODI), EQ-5D, Numeric Rating Scale (NRS)–back pain (NRS-BP), NRS-leg pain (NRS-LP), and satisfaction (North American Spine Society patient satisfaction questionnaire) scores were noted. Multivariable regression models were fitted for 24-month PROs and complications after adjusting for an array of preoperative and surgical variables. Data were analyzed for magnitude of slippage reduction and correlated with PROs. Patients were divided into two groups: < 3 mm reduction and ≥ 3 mm reduction. RESULTS Of 608 patients from 12 participating sites, 206 patients with complete data were identified in the QOD and included in this study. Baseline patient demographics, comorbidities, and clinical characteristics were similarly distributed between the cohorts except for depression, listhesis magnitude, and the proportion with dynamic listhesis (which were accounted for in the multivariable analysis). One hundred four (50.5%) patients underwent lumbar decompression and fusion with slippage reduction ≥ 3 mm (mean 5.19, range 3 to 11), and 102 (49.5%) patients underwent lumbar decompression and fusion with slippage reduction < 3 mm (mean 0.41, range 2 to −2). Patients in both groups (slippage reduction ≥ 3 mm, and slippage reduction < 3 mm) reported significant improvement in all primary patient reported outcomes (all p < 0.001). There was no significant difference with regard to the PROs between patients with or without intraoperative reduction of listhesis on univariate and multivariable analyses (ODI, EQ-5D, NRS-BP, NRS-LP, or satisfaction). There was no significant difference in complications between cohorts. CONCLUSIONS Significant improvement was found in terms of all PROs in patients undergoing decompression and fusion for lumbar spondylolisthesis. There was no correlation with clinical outcomes and magnitude of Meyerding slippage reduction.

Study Design Retrospective cohort study Objective Substantial variability in both the measurement and classification of subsidence limits the strength of conclusions that can be drawn from previous studies. The purpose of this study was to precisely characterize patterns of cervical cage subsidence utilizing computed tomography (CT) scans, determine risk factors for cervical cage subsidence, and investigate the impact of subsidence on pseudarthrosis rates. Methods We performed a retrospective review of patients who underwent one- to three-levels of anterior cervical discectomy and fusion (ACDF) utilizing titanium interbodies with anterior plating between the years 2018 and 2020. Subsidence measurements were performed by two independent reviewers on CT scans obtained 6 months postoperatively. Subsidence was then classified as mild if subsidence into the inferior and superior endplate were both ≤2 mm, moderate if the worst subsidence into the inferior or superior endplate was between 2 to 4 mm, or severe if the worst subsidence into the inferior or superior endplate was ≥4 mm. Results A total of 51 patients (100 levels) were included in this study. A total of 48 levels demonstrated mild subsidence (≤2 mm), 38 demonstrated moderate subsidence (2-4 mm), and 14 demonstrated severe subsidence (≥4 mm). Risk factors for severe subsidence included male gender, multilevel constructs, greater mean vertebral height loss, increased cage height, lower Taillard index, and lower screw tip to vertebral body height ratio. Severe subsidence was not associated with an increased rate of pseudarthrosis. Conclusion Following ACDF with titanium cervical cages, subsidence is an anticipated postoperative occurrence and is not associated with an increased risk of pseudarthrosis.

Currently, large numbers of clinical trials are performed to investigate different forms of experimental therapy for patients suffering from chronic spinal cord injury (SCI). However, for the enrollment process, there are different views on how the time period between injury and interventions should be determined. Herein, we sought to evaluate the impact of time-to-enrollment in chronic SCI clinical trials. A data set comprising 957 clinical studies from clinicalTrials.gov was downloaded and analyzed focusing on the eligibility criteria for post-injury time-to-enrollment. We also aggregated individual patient data from nine clinical trials of regenerative interventions for chronic SCI selected by a systematic literature search from 1990 to 2018. Characteristics of the studies were assessed and compared by dividing into three groups based on time-to-enrollment (group 1 ≤ 12 months, group 2 = 12–23 months and group 3 ≥ 24 months). In ClinicalTrials.gov registry, 445 trials were identified for chronic SCI where 87% (385) were unrestricted in the maximum post-injury time for trial eligibility. From systematic literature search, nine studies and 156 patients (group 1 = 30, group 2 = 55 and group 3 = 71) were included. The range of time-to-enrollment was 0.5 to 321 months in those studies. We also observed various degrees of motor and sensory improvement in between three time-to-enrollment groups. Our results indicate that enrolling wide ranges of time-to-enrollment in a group may present imprecise outcomes. Clinical trial designs should consider appropriate post-injury time frames to evaluate therapeutic benefit.

Abstract BACKGROUND Trials of lumbar spondylolisthesis are difficult to compare because of the heterogeneity in the populations studied. OBJECTIVE To define patterns of clinical presentation. METHODS This is a study of the prospective Quality Outcomes Database spondylolisthesis registry, including patients who underwent single-segment surgery for grade 1 degenerative lumbar spondylolisthesis. Twenty-four-month patient-reported outcomes (PROs) were collected. A k-means clustering analysis—an unsupervised machine learning algorithm—was used to identify clinical presentation phenotypes. RESULTS Overall, 608 patients were identified, of which 507 (83.4%) had 24-mo follow-up. Clustering revealed 2 distinct cohorts. Cluster 1 (high disease burden) was younger, had higher body mass index (BMI) and American Society of Anesthesiologist (ASA) grades, and globally worse baseline PROs. Cluster 2 (intermediate disease burden) was older and had lower BMI and ASA grades, and intermediate baseline PROs. Baseline radiographic parameters were similar ( P > .05). Both clusters improved clinically ( P < .001 all 24-mo PROs). In multivariable adjusted analyses, mean 24-mo Oswestry Disability Index (ODI), Numeric Rating Scale Back Pain (NRS-BP), Numeric Rating Scale Leg Pain, and EuroQol-5D (EQ-5D) were markedly worse for the high-disease-burden cluster (adjusted- P < .001). However, the high-disease-burden cluster demonstrated greater 24-mo improvements for ODI, NRS-BP, and EQ-5D (adjusted- P < .05) and a higher proportion reaching ODI minimal clinically important difference (MCID) (adjusted- P = .001). High-disease-burden cluster had lower satisfaction (adjusted- P = .02). CONCLUSION We define 2 distinct phenotypes—those with high vs intermediate disease burden—operated for lumbar spondylolisthesis. Those with high disease burden were less satisfied, had a lower quality of life, and more disability, more back pain, and more leg pain than those with intermediate disease burden, but had greater magnitudes of improvement in disability, back pain, quality of life, and more often reached ODI MCID.