Cervical Sagittal Range of Motion as a Predictor of Symptom Severity in Cervical Spondylotic Myelopathy.

STUDY DESIGN: A retrospective review of radiographic data and functional outcomes. OBJECTIVE: The aim of this study was to evaluate whether myelopathy symptom severity upon presentation corresponds to sagittal plane alignment or nonmyelopathy symptoms, such as pain, in patients with cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA: Cervical sagittal balance is an important parameter in the outcome of surgical reconstruction. However, the effect of sagittal alignment on symptom severity in patients who have not undergone spine surgery is not well defined. METHODS: A consecutive series of CSM patients was identified at an academic institution. Preoperative radiographs were analyzed for sagittal vertical axis (C2SVA), C7 slope (C7S), C2-C7 angle in neutral (C27N), flexion (C27F), and extension (C27E), and range of motion (C27ROM). Neutral alignment was categorized as lordotic, kyphotic, or sigmoid/straight. Outcomes collected were SF-12, neck disability index, arm pain, neck pain, and modified JOA (mJOA). Pearson coefficients determined correlations between radiographic and outcome parameters. Multivariate regression evaluated predictive factors of mJOA. RESULTS: Radiographic parameters did not correlate with pain. Increasing age, smaller C27ROM, and smaller flexion angles correlated to lower (more severe) baseline mJOA scores. ROM (and not static alignment) was the only significant predictor of mJOA in the multivariate regression. Despite significant radiographic differences between lordotic, kyphotic, and sigmoid/straight alignment groups, myelopathy severity did not differ between these groups. CONCLUSION: Static, neutral alignment, including SVA and lordosis, did not correlate with myelopathy or pain symptoms. Greater C27ROM and increased maximal flexion corresponded to milder myelopathy symptoms, suggesting that patients with myelopathy may compensate for cervical stenosis with hyperflexion, similar to that which is observed in the lumbar spine. In a CSM patient population, dynamic motion and compensatory deformities may play a more significant role in myelopathy symptom severity than what can be discerned from standard, neutral position radiographs. LEVEL OF EVIDENCE: 3.

The Effect of Dynamic Versus Static Plating Systems on Fusion Rates and Complications in 1-Level and/or 2-Level Anterior Cervical Discectomy and Fusion: A Systematic Review.

STUDY DESIGN: A systematic review. OBJECTIVE: To determine the effect of plate design on fusion rates in patients undergoing a 1- and 2-level anterior cervical discectomy and fusion (ACDF). METHODS: Articles published between January 1, 2002 and January 1, 2015 were systematically reviewed to determine the fusion rate of 1- and 2-level ACDFs using either a fully constrained or semiconstrained locking plate. Additional variables that were collected included the number of levels, the type of graft/cage used, the study design, the method for determining fusion, and complications. RESULTS: Fifty-two articles and 3053 patients were included. No significant difference in the fusion rate for 1- and 2-level ACDF using a fully constrained plate (96.1%) and a semiconstrained plate (95.29%) was identified (P=0.84). No difference (P=0.85) in the total complication rate between fully constrained plates (3.20%) and semiconstrained plates (3.66%), or the rate of complications that required a revision (2.17% vs. 2.41%, P=0.82) was identified. However, semiconstrained plates had a nonsignificant increase in total dysphagia rates (odds ratio=1.660, P=0.28) and short-term dysphagia rates (odds ratio=2.349, P=0.10). CONCLUSIONS: In patients undergoing a 1- or 2-level ACDF, there is no significant difference in the fusion or complication rate between fully constrained plates and semiconstrained plates. LEVEL OF EVIDENCE: Level II-systematic review.

Bone substitutes and expanders in Spine Surgery: A review of their fusion efficacies.

STUDY DESIGN: A narrative review of literature. OBJECTIVE: This manuscript intends to provide a review of clinically relevant bone substitutes and bone expanders for spinal surgery in terms of efficacy and associated clinical outcomes, as reported in contemporary spine literature. SUMMARY OF BACKGROUND DATA: Ever since the introduction of allograft as a substitute for autologous bone in spinal surgery, a sea of literature has surfaced, evaluating both established and newly emerging fusion alternatives. An understanding of the available fusion options and an organized evidence-based approach to their use in spine surgery is essential for achieving optimal results. METHODS: A Medline search of English language literature published through March 2016 discussing bone graft substitutes and fusion extenders was performed. All clinical studies reporting radiological and/or patient outcomes following the use of bone substitutes were reviewed under the broad categories of Allografts, Demineralized Bone Matrices (DBM), Ceramics, Bone Morphogenic proteins (BMPs), Autologous growth factors (AGFs), Stem cell products and Synthetic Peptides. These were further grouped depending on their application in lumbar and cervical spine surgeries, deformity correction or other miscellaneous procedures viz. trauma, infection or tumors; wherever data was forthcoming. Studies in animal populations and experimental in vitro studies were excluded. Primary endpoints were radiological fusion rates and successful clinical outcomes. RESULTS: A total of 181 clinical studies were found suitable to be included in the review. More than a third of the published articles (62 studies, 34.25%) focused on BMP. Ceramics (40 studies) and Allografts (39 studies) were the other two highly published groups of bone substitutes. Highest radiographic fusion rates were observed with BMPs, followed by allograft and DBM. There were no significant differences in the reported clinical outcomes across all classes of bone substitutes. CONCLUSIONS: There is a clear publication bias in the literature, mostly favoring BMP. Based on the available data, BMP is however associated with the highest radiographic fusion rate. Allograft is also very well corroborated in the literature. The use of DBM as a bone expander to augment autograft is supported, especially in the lumbar spine. Ceramics are also utilized as bone graft extenders and results are generally supportive, although limited. The use of autologous growth factors is not substantiated at this time. Cell matrix or stem cell-based products and the synthetic peptides have inadequate data. More comparative studies are needed to evaluate the efficacy of bone graft substitutes overall.

Is It Necessary to Extend a Multilevel Posterior Cervical Decompression and Fusion to the Upper Thoracic Spine?

STUDY DESIGN: A retrospective cohort analysis. OBJECTIVE: The aim of this study was to determine if there is a difference in the revision rate in patients who undergo a multilevel posterior cervical fusions ending at C7, T1, or T2-T4. SUMMARY OF BACKGROUND DATA: Multilevel posterior cervical decompression and fusion is a common procedure for patients with cervical spondylotic myelopathy, but there is little literature available to help guide the surgeon in choosing the caudal level of a multilevel posterior cervical fusion. METHODS: Patients who underwent a three or more level posterior cervical fusion with at least 1 year of clinical follow-up were identified. Patients were separated into three groups on the basis of the caudal level of the fusion, C7, T1, or T2-T4, and the revision rate was determined. In addition, the C2-C7 lordosis and the C2-C7 sagittal vertical axis (SVA) was recorded for patients with adequate radiographic follow-up at 1 year. RESULTS: The overall revision rate was 27.8% (61/219 patients); a significant difference in the revision rates was identified between fusions terminating at C7, T1, and T2-T4 (35.3%, 18.3%, and 40.0%, P = 0.008). When additional variables were taken into account utilizing multivariate linear regression modeling, patients whose construct terminated at C7 were 2.29 (1.16-4.61) times more likely to require a revision than patients whose construct terminated at T1 (P = 0.02), but no difference between stopping at T1 and T2-T4 was identified. CONCLUSION: Multilevel posterior cervical fusions should be extended to T1, as stopping a long construct at C7 increases the rate of revision. LEVEL OF EVIDENCE: 3.

Performing an Anterior Cervical Discectomy and Fusion.

An anterior cervical discectomy and fusion is one of the most common procedures performed in spine surgery. It allows for a direct decompression of the spinal cord and the neural foramen. When performed properly, the results of this procedure are some of the best in spine surgery.

Level of Evidence Descriptions With Examples.

The level of evidence (LOE) method provides journal readers with a quick appraisal of study quality. The most widely recognized LOE assessment tool is that from the Oxford Centre for Evidence-Based Medicine, and these guidelines are often adapted for other purposes. The assigned LOE typically depends on the design and quality of the study as well as the impact of the results. Because of the differing methods for classifying LOE, the author or journal reader should fully understand the criteria before assimilating data.

Guidelines on What Constitutes Plagiarism and Electronic Tools to Detect it.

Plagiarism is a serious ethical problem among scientific publications. There are various definitions of plagiarism, and the major categories include unintentional (unsuitable paraphrasing or improper citations) and intentional. Intentional plagiarism includes mosaic plagiarism, plagiarism of ideas, plagiarism of text, and self-plagiarism. There are many Web sites and software packages that claim to detect plagiarism effectively. A violation of plagiarism laws can lead to serious consequences including author banning, loss of professional reputation, termination of a position, and even legal action.

L5/S1 Fusion Rates in Degenerative Spine Surgery: A Systematic Review Comparing ALIF, TLIF, and Axial Interbody Arthrodesis.

STUDY DESIGN: Systematic review. OBJECTIVE: To determine the fusion rate of an anterior lumbar interbody fusion (ALIF), transforaminal lumbar interbody fusion (TLIF), and axial arthrodesis at the lumbosacral junction in adult patients undergoing surgery for 1- and 2-level degenerative spine conditions. SUMMARY OF BACKGROUND DATA: An L5/S1 interbody fusion is a commonly performed procedure for pathology such as spondylolisthesis with stenosis; however, it is unclear if 1 technique leads to superior fusion rates. MATERIALS AND METHODS: A systematic search of MEDLINE was conducted for literature published between January 1, 1992 and August 17, 2014. All peer-reviewed articles related to the fusion rate of L5/S1 for an ALIF, TLIF, or axial interbody fusion were included. RESULTS: In total, 42 articles and 1507 patients were included in this systematic review. A difference in overall fusion rates was identified, with a rate of 99.2% (range, 96.4%-99.8%) for a TLIF, 97.2% (range, 91.0%-99.2%) for an ALIF, and 90.5% (range, 79.0%-97.0%) for an axial interbody fusion (P=0.005). In a paired analysis directly comparing fusion techniques, only the difference between a TLIF and an axial interbody fusion was significant. However, when only cases in which bilateral pedicle screws supported the interbody fusion, no statistical difference (P>0.05) between the 3 techniques was identified. CONCLUSIONS: The current literature available to guide the treatment of L5/S1 pathology is poor, but the available data suggest that a high fusion rate can be expected with the use of an ALIF, TLIF, or axial interbody fusion. Any technique-dependent benefit in fusion rate can be eliminated with common surgical modifications such as the use of bilateral pedicle screws.

Authorship Considerations: What Qualifies?

Publications indicate academic achievement. Unjustified authorship is a violation of scientific integrity. However, many different authorship guidelines have been purposed. Subjective assessments of contributions may differ substantially when made by individual authors. Complex research structures including multicenter multidisciplinary studies further cloud the definition of authorship. New quantitative measurement of research contributions may help guide who deserves to be recognized as an author. Agreement of authorship and order of listing should be discussed at the beginning of any project likely to result in a publication.

The Role of Strategy in Health Care.

Significant changes are occurring in the health care field, and spine surgeons must have an understanding of business strategy if they are going to adapt to the new health care environment. Spine surgeons will be required to demonstrate how their service provides a unique value to their patients or else the patients will obtain care from competitors. Classic methods for demonstrating value such as academic prestige and superior clinical outcomes may no longer be sufficient in the evolving health care field, and surgeons will need to demonstrate a comprehensive and cost-effective treatment algorithm for a diagnosis. This article will discuss the basics of business strategy for the spine surgeon, and ways in which the surgeon may demonstrate value to their patients.

Lateral Mass Fixation in the Subaxial Cervical Spine.

The use of lateral mass screws and rods in the subaxial spine has become the standard method of fixation for posterior cervical spine fusions. Multiple techniques have been described for the placement of lateral mass screws, including the Magerl, the Anderson, and the An techniques. While these techniques are all slightly different, the overall goal is to obtain solid bony fixation while avoiding the neurovascular structures. The use of lateral mass screws has been shown to be a safe and effective technique for achieving a posterior cervical fusion.