Faculty Bibliography

BACKGROUND CONTEXT/BACKGROUND:Previous research has identified a specific subtype known as failure of pelvic compensation (FPC) in patients with adult spinal deformity (ASD). However, the criteria for assessing FPC remain inconsistent, and its impacts on spinal sagittal alignment and health-related quality-of-life (HRQoL) scores remain unclear. PURPOSE/OBJECTIVE:To propose a novel criterion for identifying FPC based on variations in spinopelvic alignment during the transition from the supine to upright position and to evaluate the effects of FPC on patients' spinal sagittal alignment and HRQoL scores. STUDY DESIGN/SETTING/METHODS:Retrospective cross-sectional study. PATIENT SAMPLE/METHODS:Patients with ASD from a monocenter database. OUTCOME MEASURES/METHODS:Radiographic measures, including thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt, pelvic incidence (PI), and sagittal vertical axis (SVA), were measured on lateral whole-spine radiographs. LL and SS were also measured on reconstructed lumbar computed tomography images in the sagittal view taken in the supine position. The relative functional cross-sectional area (rFCSA) of paraspinal muscles was evaluated via lumbar magnetic resonance imaging. HRQoL measures, encompassing visual analog scale for back pain (VAS-BP), Oswestry Disability Index (ODI), and Scoliosis Research Society-22R (SRS-22R), were collected. METHODS:A total of 154 patients were enrolled. Based on the calculated minimum detectable change of SS, FPC was defined as the change in SS of less than 3.4° between supine and upright positions. Patients were divided into 3 groups: sagittal balance with pelvic compensation (SI-PC), sagittal imbalance with pelvic compensation (SI-PC), and sagittal imbalance with failure of pelvic compensation (SI-FPC). Radiographic parameters and HRQoL scores were compared among the groups. RESULTS:Thirty-six patients were categorized into the SB-PC group, 87 into the SI-PC group, and 31 into the SI-FPC group. Patients with low PI and small paraspinal muscles rFCSA were more prone to experiencing FPC accompanied by severe sagittal imbalance. The SI-FPC group exhibited less TK and a larger SS than the SI-PC group exhibited and had a similar SVA as that of the SI-PC group. Additionally, they displayed worse VAS-BP, ODI, SRS-function, and SRS-22 total scores than the SB-PC group displayed. CONCLUSIONS:In patients with ASD, an inherently low pelvic compensatory reserve and a high fatty infiltration in paraspinal muscles are pivotal factors contributing to FPC. Compared with SI-PC patients, SI-FPC patients demonstrate a thoracic-dominant compensatory pattern for sagittal malalignment. In addition, these patients experienced more severe pain and functional decline than the SB-PC patients experienced.

STUDY DESIGN/METHODS:Systematic review and meta-analysis. OBJECTIVES/OBJECTIVE:To assess the radiographic risk factors for adjacent segment disease (ASD) following anterior cervical discectomy and fusion (ACDF) for degenerative cervical spine pathologies. METHODS:PubMed, Embase and the Cochrane Library databases were searched up to December 2023. The primary inclusion criteria were degenerative spinal conditions treated with ACDF, comparing radiological parameters in patients with and without postoperative ASD. The radiographic parameters included intervertebral disc height, cervical sagittal alignment, sagittal segmental alignment, range of motion, segmental height, T1 slope, sagittal vertical axis (SVA), thoracic inlet angle (TIA), and plate to disc distance (PPD). Risk of bias was assessed for all studies. The Cochrane Review Manager was utilized to perform the meta-analysis. RESULTS:< .001). CONCLUSIONS:Decreased postoperative cervical lordosis, greater change in cervical sagittal alignment and developmental cervical canal stenosis were associated with an increased risk of ASD following ACDF.

BACKGROUND:The aim of the current study was to compare the incidence of postoperative complications among minimally invasive surgery (MIS) tubular, endoscopic, and robot-assisted transforaminal lumbar interbody fusion (TLIF) techniques. METHODS:We studied consecutive patients who underwent single-level or multilevel TLIF between 2020 and 2022. Preoperative and postoperative patient-reported outcomes (Visual Analog Scale leg score and Oswestry Disability Index), demographic, and intraoperative variables were recorded. One-way analysis of variance with Bartlett's equal-variance and Pearson chi-squared tests were used. RESULTS:The study included 170 TLIF patients: 107 (63%) tubular, 42 (25%) endoscopic, and 21 (12%) robot assisted. All 3 TLIF techniques had similar complication rates: tubular 6 (5.6%), endoscopic 2 (4.8%), and robot assisted 1 (4.8%) all occurring within the first 2 weeks. Tubular TLIF reported the lowest incidence of new-onset neurologic symptoms, primarily radiculitis or numbness/tingling, at 2 weeks postoperatively (P < 0.05) with 21 (20%) tubular, 17 (41%) endoscopic, and 9 (43%) robot-assisted patients. There were 2 revisions in the robot-assisted group, while tubular and endoscopic each had one within 1 year. There was no statistical difference in preoperative or postoperative patient-reported outcomes between the TLIF groups. CONCLUSIONS:The current study demonstrated that tubular, endoscopic, and robot-assisted TLIF procedures had similar complication rates. The tubular MIS TLIF reported fewer new neurologic symptoms compared with endoscopic and robot-assisted TLIF procedures at 2 weeks postoperative, with all groups declining in symptom persistency at later time intervals. Average Visual Analog Scale scores continuously improved up to 1 year postoperatively among all groups.

OBJECTIVE:Enhanced Recovery after Surgery (ERAS) protocols were developed to counteract the adverse effects of the surgical stress response, aiming for quicker postoperative recovery. Initially applied in abdominal surgeries, ERAS principles have extended to orthopedic spine surgery, but research in this area is still in its infancy. The current study investigated the impact of ERAS on postoperative pain and opioid consumption in elective spine surgeries. METHODS:A single-center retrospective study of patients undergoing elective spine surgery from May 2019 to July 2020. Patients were categorized into two groups: those enrolled in the ERAS pathway and those adhering to traditional surgical protocols. Data on demographics, comorbidities, length of stay (LOS), surgical procedures, and postoperative outcomes were collected. Postoperative pain was evaluated using the Numerical Rating Scale (NRS), while opioid utilization was quantified in morphine milligram equivalents (MME). NRS and MME were averaged for each patient across all days under observation. Differences in outcomes between groups (ERAS vs. treatment as usual) were tested using the Wilcoxon rank sum test for continuous variables and Pearson's or Fisher's exact tests for categorical variables. RESULTS:The median of patient's mean daily NRS scores for postoperative pain were not statistically significantly different between groups (median = 5.55 (ERAS) and 5.28 (non-ERAS), p=.2). Additionally, the median of patients' mean daily levels of MME were similar between groups (median = 17.24 (ERAS) and 16.44 (non-ERAS), p=.3) ERAS patients experienced notably shorter LOS (median=2 days) than their non-ERAS counterparts (median=3 days, p=.001). The effect of ERAS was moderated by whether the patient had ACDF surgery. ERAS (vs. non-ERAS) patients who had ACDF surgery had 1.64 lower average NRS (p=.006). ERAS (vs. non-ERAS) patients who had a different surgery had 0.72 higher average NRS (p=.02) but had almost half the length of stay, on average (p<.001). CONCLUSIONS:The current study underscores the dynamic nature of ERAS protocols within the realm of spine surgery. While ERAS demonstrates advantages such as reduced LOS and improved patient-reported outcomes, it requires careful implementation and customization to address the specific demands of each surgical discipline. The potential to expedite recovery, optimize resource utilization, and enhance patient satisfaction cannot be overstated. However, the fine balance between achieving these benefits and ensuring comprehensive patient care, especially in the context of postoperative pain management, must be maintained. As ERAS continues to evolve and find its place in diverse surgical domains, it is crucial for healthcare providers to remain attentive to patient needs, adapting ERAS protocols to suit individual patient populations and surgical contexts.

PURPOSE/OBJECTIVE:To compare the clinical effectiveness of reduction and fusion with in situ fusion in the management of patients with degenerative lumbar spondylolisthesis (DLS). METHODS:The systematic review was conducted following the PRISMA guidelines. Relevant studies were identified from PubMed, Embase, Scopus, Cochrane Library, ClinicalTrials.gov, and Google Scholar. The inclusion criteria were: (1) comparative studies of reduction and fusion versus in situ fusion for DLS patients, (2) outcomes reported as VAS/NRS, ODI, JOA score, operating time, blood loss, complication rate, fusion rate, or reoperation rate, (3) randomized controlled trials and observational studies published in English from the inception of the databases to January 2023. The exclusion criteria included: (1) reviews, case series, case reports, letters, and conference reports, (2) in vitro biomechanical studies and computational modeling studies, (3) no report on study outcomes. The risk of bias 2 (RoB2) tool and the Newcastle-Ottawa scale was conducted to assess the risk of bias of RCTs and observational studies, respectively. RESULTS:Five studies with a total of 704 patients were included (375 reduction and fusion, 329 in situ fusion). Operating time was significantly longer in the reduction and fusion group compared to in situ fusion group (weighted mean difference 7.20; 95% confidence interval 0.19, 14.21; P = 0.04). No additional significant intergroup differences were noted in terms of other outcomes analyzed. CONCLUSION/CONCLUSIONS:While the reduction and fusion group demonstrated a statistically longer operating time compared to the in situ fusion group, the clinical significance of this difference was minimal. The findings suggest no substantial superiority of lumbar fusion with reduction over without reduction for the management of DLS.

STUDY DESIGN/METHODS:Systematic literature review. OBJECTIVES/OBJECTIVE:To analyze the evidence available reporting complications in single or two-level anterior cervical discectomy and fusion (ACDF) using a demineralized bone matrix (DBM), hydroxyapatite (HA), or beta-tricalcium phosphate (β-TCP). METHODS:A systematic review of the literature using PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov databases was performed in August 2020 to identify studies reporting complications in one or two-level ACDF surgery using DBM, HA, or β-TCP. The study was reported following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. RESULTS:A total of 1857 patients were included, 981 male and 876 female, across 17 articles; 5 prospective, and 12 retrospectives. We noted heterogeneity among the included studies concerning the study design and combination of graft materials utilized in them. However, we noted a higher incidence of adjacent segment disease (17.7%) and pseudoarthrosis (9.3%) in fusion constructs using DBM. Studies using β-TCP reported a higher incidence of pseudoarthrosis (28.2%) and implant failures (17.9%). CONCLUSIONS:Degenerative cervical conditions treated with one or two-level ACDF surgery using DBM, HA, or β-TCP with or without cervical plating are associated with complications such as adjacent segment disease, dysphagia, and pseudarthrosis. However, consequent to the study designs and clinical heterogeneity of the studies, it is not possible to correlate these complications accurately with any specific graft material employed. Further well-designed prospective studies are needed to correctly know the related morbidity of each graft used for achieving fusion in ACDF.

STUDY DESIGN/METHODS:Systematic literature review. OBJECTIVE:To analyze the literature and describe the evidence supporting osteobiologic use in revision anterior cervical discectomy and fusion (ACDF) surgery. METHODS:A systematic search of PubMed/MEDLINE, EMBASE, Cochrane library, and ClinicalTrials.gov databases was conducted for literature reporting the use of osteobiologics in revision ACDF. We searched for studies reporting outcomes of using any osteobiologic use in revision ACDF surgeries (independently of the number of levels) in the above databases. RESULTS:There are currently no studies in the literature describing the outcome and comparative efficacy of diverse osteobiologic agents in the context of revision ACDF surgery. A majority of the current evidence is based only upon studies involving primary ACDF surgery. CONCLUSION/CONCLUSIONS:The current study highlights the paucity of literature evidence on the role of diverse osteobiologics in revision ACDF, and foregrounds the need for high-quality evidence on this subject.

STUDY DESIGN/METHODS:Systematic review. OBJECTIVES/OBJECTIVE:The study's primary objective was to determine how osteobiologic choice affects fusion rates in patients undergoing anterior cervical discectomy and fusion (ACDF). The study's secondary objectives were to 1) determine the optimal timing of fusion assessment following ACDF and 2) determine if osteobiologic type affects the timing and optimal modality of fusion assessment. METHODS:A systematic search of PubMed/MEDLINE was conducted for literature published from 2000 through October 2020 comparing anterior fusion in the cervical spine with various osteobiologics. Both comparative studies and case series of ≥10 patients were included. RESULTS:A total of 74 studies met the inclusion criteria. Seventeen studies evaluated the efficacy of autograft on fusion outcomes, and 23 studies assessed the efficacy of allograft on fusion outcomes. 3 studies evaluated the efficacy of demineralized bone matrix, and seven assessed the efficacy of rhBMP-2 on fusion outcomes. Other limited studies evaluated the efficacy of ceramics and bioactive glasses on fusion outcomes, and 4 assessed the efficacy of stem cell products. Most studies utilized dynamic radiographs for the assessment of fusion. Overall, there was a general lack of supportive data to determine the optimal timing of fusion assessment meaningfully or if osteobiologic type influenced fusion timing. CONCLUSIONS:Achieving fusion following ACDF appears to remain an intricate interplay between host biology and various surgical factors, including the selection of osteobiologics. While alternative osteobiologics to autograft exist and may produce acceptable fusion rates, limitations in study methodology prevent any definitive conclusions from existing literature.

STUDY DESIGN/METHODS:Systematic literature review. OBJECTIVES/OBJECTIVE:In this study we assessed evidence for the use of osteobiologics in single vs multi-level anterior cervical discectomy and fusion (ACDF) in patients with cervical spine degeneration. The primary objective was to compare fusion rates after single and multi-level surgery with different osteobiologics. Secondary objectives were to compare differences in patient reported outcome measures (PROMs) and complications. METHODS:After a global team of reviewers was selected, a systematic review using different repositories was performed, confirming to PRISMA and GRADE guidelines. In total 1206 articles were identified and after applying inclusion and exclusion criteria, 11 articles were eligible for analysis. Extracted data included fusion rates, definition of fusion, patient reported outcome measures, types of osteobiologics used, complications, adverse events and revisions. RESULTS:Fusion rates ranged from 87.7% to 100% for bone morphogenetic protein 2 (BMP-2) and 88.6% to 94.7% for demineralized bone matrix, while fusion rates reported for other osteobiologics were lower. All included studies showed PROMs improved significantly for each osteobiologic. However, no differences were reported when comparing osteobiologics, or when comparing single vs multi-level surgery specifically. CONCLUSION/CONCLUSIONS:The highest fusion rates after 2-level ACDF for cervical spine degeneration were reported when BMP-2 was used. However, PROMs did not differ between the different osteobiologics. Further blinded randomized trials should be performed to compare the use of BMP-2 in single vs multi-level ACDF specifically.

STUDY DESIGN/METHODS:Systematic review. OBJECTIVE:Examine the clinical evidence for the use of osteobiologics in hybrid surgery (combined anterior cervical discectomy and fusion (ACDF) and total disc replacement (TDR)) in patients with multilevel cervical degenerative disc disease (DDD). METHODS:PubMed and Embase were searched between January 2000 and August 2020. Clinical studies investigating 18-80 year old patients with multilevel cervical DDD who underwent hybrid surgery with or without the use of osteobiologics were considered eligible. Two reviewers independently screened and assessed the identified articles. The methodological index for non-randomized studies (MINORS) tool and the risk of bias (RoB 2.0) assessment tool were used to assess risk of bias. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) was used to evaluate quality of evidence across studies per outcome. RESULTS:Eleven studies were included. A decrease in cervical range of motion was observed in most studies for both the hybrid surgery and the control groups consisting of stand-alone ACDF or TDR. Fusion rates of 70-100% were reported in both the hybrid surgery and control groups consisting of stand-alone ACDF. The hybrid surgery group performed better or comparable to the control group in terms of adjacent segment degeneration. Studies reported an improvement in visual analogue scale for pain and neck disability index values after surgery compared to preoperative scores for both treatment groups. The included studies had moderate methodological quality. CONCLUSIONS:There is insufficient evidence for assessing the use of osteobiologics in multilevel hybrid surgery and additional high quality and controlled research is deemed essential.