Citations

OBJECTIVE The goal of this study was to determine independent risk factors for vertebral compression fracture (VCF) following radiation for metastatic spine disease, including low bone mineral density as estimated by Hounsfield units (HU). METHODS A retrospective chart review identified patients with a single vertebral column metastasis treated with radiation therapy, a pretreatment CT scan, and a follow-up CT scan at least 6 weeks after treatment. Patients with primary spine tumors, preradiation vertebroplasty, preradiation spine surgery, prior radiation to the treatment field, and proton beam treatment modality were excluded. The HU were measured in the vertebral bodies at the level superior to the metastasis, within the tumor and medullary bone of the metastatic level, and at the level inferior to the metastasis. Variables collected included basic demographics, Spine Instability Neoplastic Score (SINS), presenting symptoms, bone density treatment, primary tumor pathology, Weinstein-Boriani-Biagini (WBB) classification, Enneking stage, radiation treatment details, chemotherapy regimen, and prophylactic vertebroplasty. RESULTS One hundred patients with an average age of 63 years and average follow-up of 18 months with radiation treatment dates ranging from 2017 to 2020 were included. Fifty-nine patients were treated with external-beam radiation therapy, with a median total dose of 20 Gy (range 8–40 Gy). Forty-one patients were treated with stereotactic body radiation therapy, with a median total dose of 24 Gy (range 18–39 Gy). The most common primary pathologies included lung (n = 22), prostate (n = 21), and breast (n = 14). Multivariable logistic regression analysis (area under the curve 0.89) demonstrated pretreatment HU (p < 0.01), SINS (p = 0.02), involvement of ≥ 3 WBB sectors (p < 0.01), primary pathology other than prostate (p = 0.04), and ongoing chemotherapy treatment (p = 0.04) to be independent predictors of postradiation VCF. Patients with pretreatment HU < 145 (n = 32), 145–220 (n = 31), and > 220 (n = 37) had a fracture rate of 59%, 39%, and 11%, respectively. An HU cutoff of 157 was found to maximize sensitivity (71%) and specificity (75%) in predicting postradiation VCF. CONCLUSIONS Low preradiation HU, higher SINS, involvement of ≥ 3 WBB sectors, ongoing chemotherapy, and nonprostate primary pathology were independent predictors of postradiation VCF in patients with metastatic spine disease. Low bone mineral density, as estimated by HU, is a novel and potentially modifiable risk factor for VCF.

Study Design Systematic Review and Meta-analysis Objective The purpose of this study is to synthesize recommendations for perioperative medical management of RA patients and quantify outcomes after spine surgery when compared to patients without RA. Methods A search of available literature on patients with RA and spine surgery was performed. Studies were included if they provided a direct comparison of outcomes between patients undergoing spine surgery with or without RA diagnosis. Meta-analysis was performed on operative time, estimated blood loss, hospital length of stay, overall complications, implant-related complications, reoperation, infection, pseudarthrosis, and adjacent segment disease. Results Included in the analysis were 9 studies with 703 patients with RA undergoing spine surgery and 2569 patients without RA. In RA patients compared to non-RA patients undergoing spine surgery, the relative risk of infection was 2.29 times higher (P = .036), overall complications 1.61 times higher (P < .0001), implant-related complications 3.93 times higher (P = .009), and risk of reoperation 2.45 times higher (P < .0001). Hospital length of stay was 4.6 days longer in RA patients (P < .0001). Conclusions Treatment of spinal pathology in patients with RA carries an increased risk of infection and implant-related complications. Spine-specific guidelines for perioperative management of antirheumatic medication deserve further exploration. All RA patients should be perioperatively co-managed by a rheumatologist. This review helps identify risk profiles in RA specific to spine surgery and may guide future studies seeking to medically optimize RA patients perioperatively.

Study Design: This was a multicenter retrospective cohort study. Objective: The purpose of this study was to compare the surgical and radiographic outcomes of patients undergoing posterior cervical fusion (PCF) with constructs extending from C2 to T2 to patients with constructs extending from C3 to T1. Summary of Background Data: Limited evidence exists regarding the appropriate level of proximal and distal extension of PCF constructs. Methods: A multicenter retrospective cohort study of patients who underwent PCF between 2012 and 2020 was performed. Surgical and radiographic outcomes were compared between those who had C3–T1 or C2–T2 constructs. Results: A total of 155 patients were included in the study (C2–T2: 106 patients, C3–T1: 49 patients). There were no significant differences in demographics or preoperative symptoms between cohorts. Fusion rates were significantly higher in the C2–T2 (93%) than the C3–T1 (80%, P=0.040) cohort. When comparing the C2–T2 to the C3–T1 cohort, the C3–T1 cohort had a significantly greater rate of proximal junctional failure (2% vs. 10%, P=0.006), distal junctional failure (1% vs. 20%, P<0.001) and distal screw loosening (4% vs. 15%, P=0.02). Although ∆C2–C7 sagittal vertical axis increased significantly in both cohorts (C2–T2: 6.2 mm, P=0.04; C3–T1: 8.4 mm, P<0.001), correction did not significantly differ between groups (P=0.32). The C3–T1 cohort had a significantly greater increase in ∆C2 slope (8.0 vs. 3.1 degrees, P=0.03) and ∆C0–C2 Cobb angle (6.4 vs. 1.2 degrees, P=0.04). Conclusion: In patients undergoing PCF, a C2–T2 construct demonstrated lower rates of pseudarthrosis, distal junctional failure, proximal junctional failure, and compensatory upper cervical hyperextension compared with a C3–T1 construct.

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.

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.

Study Design: This was a narrative review. Objective: This review discusses our current knowledge regarding cellular-based allografts while highlighting the key gaps in the literature that must be addressed before their widespread adoption. Summary of Background Data: Iliac crest bone graft is the gold-standard bone graft material but is associated with donor site morbidity. Commonly utilized bone graft extenders such as demineralized bone matrix and bone morphogenetic protein have conflicting data supporting their efficacy and lack the osteogenic potential of new cellular-based allograft options. Methods: An extensive literature review was performed. The literature was then summarized in accordance with the authors’ clinical experience. Results: There is not widespread evidence thus far that the addition of the osteogenic cellular component to allograft enhances spinal fusion, as a recent study by Bhamb and colleagues demonstrated superior bone formation during spine fusion in an aythmic rat model when demineralized bone matrix was used in comparison to Osteocel Plus. Furthermore, the postimplantation cellular viability and osteogenic and osteoinductive capacity of cellular-based allografts need to be definitively established, especially given that a recent study by Lina and colleagues demonstrated a paucity of bone marrow cell survival in an immunocompetent mouse posterolateral spinal fusion model. Conclusions: This data indicates that the substantially increased cost of these cellular allografts may not be justified. Level of Evidence: Level V.

Transdiscal screw fixation through the Boachie screw technique at the lumbosacral junction is a well-accepted procedure in the treatment of high-grade spondylolisthesis. This technique allows for partial reduction of the spondylolisthesis, decompression of the neural elements, and reliable posterior lumbosacral fixation. When performed properly, this procedure produces reliable results and high rates of arthrodesis with relief of preoperative neurological symptoms.

Study Design This study is a retrospective case control. Objectives This study aims to determine whether cervical degenerative spondylolisthesis (DS) is associated with increased baseline neck/arm pain and inferior health quality states compared to a similar population without DS. Methods Patient demographics, pre-operative radiographs, and baseline PROMs were reviewed for 315 patients undergoing anterior cervical decompression and fusion (ACDF) with at least 1 year of follow-up. Patients were categorized based on the presence (S) or absence of a spondylolisthesis (NS). Statistically significant variables were further explored using multiple linear regression analysis. Results 49/242 (20%) patients were diagnosed with DS, most commonly at the C4–5 level (27/49). The S group was significantly older than the NS group (58.0 ± 10.7 vs 51.9 ± 9.81, P = .001), but otherwise, no demographic differences were identified. Although a higher degree of C2 slope was found among the S cohort (22.5 ± 8.63 vs 19.8 ± 7.78, P = .044), no differences were identified in terms of preoperative visual analogue scale (VAS) neck pain or NDI. In the univariate analysis, the NS group had significantly increased VAS arm pain relative to the S group (4.93 ± 3.16 vs 3.86 ± 3.30, P = .045), which was no longer significant in the multivariate analysis. Conclusions Although previous reports have suggested an association between cervical DS and neck pain, we could not associate the presence of DS with increased baseline neck or arm pain. Instead, DS appears to be a relatively frequent (20% in this series) age-related condition reflecting radiographic, rather than necessarily clinical, disease.

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.