Faculty Bibliography

STUDY DESIGN/UNASSIGNED:Classification development. OBJECTIVES/UNASSIGNED:The aim of our study was to develop a 3-tier classification for the levels of evidence for osteobiologics and provide a description of the principles by which osteobiologics can be evaluated. BOnE (Bone Osteobiologics and Evidence) classification evaluates each osteobiologic based on the available evidence, and if the published evidence is based on clinical, in vivo or in vitro studies. METHODS/UNASSIGNED:The process of establishing the BOnE classification included 5 face-to-face meetings and 2 web calls among members of the AOSpine Knowledge Forum Degenerative. RESULTS/UNASSIGNED:The 3 levels of evidence were determined based on the type of data on osteobiologics: level A for human studies, level B for animal studies, and level C for in vitro studies, with level A being the highest level of evidence. Each level was organized into 4 subgroups (eg, A1, A2, A3, and A4). CONCLUSIONS/UNASSIGNED:The use and the variety of osteobiologics for spine fusion has dramatically increased over the past few decades; however, literature on their effectiveness is inconclusive. Several prior systematic reviews developed by AOSpine Knowledge Forum Degenerative reported low level of evidence primarily due to the high risk of bias, small sample size, lack of control groups, and limited patient-reported outcomes. BOnE classification will provide a universal platform for research studies and journal publications to classify a new or an existing product and will allow for creating decision-making algorithms for surgical planning.

STUDY DESIGN/UNASSIGNED:Systematic literature review. OBJECTIVE/UNASSIGNED:Our primary objective was to compare reported fusion rates after anterior cervical discectomy and fusion (ACDF) using structural allograft versus polyetheretherketone (PEEK) interbody devices in patients with cervical spine degeneration. Our secondary objectives were to compare differences in rates of subsidence and reoperation and in patient-reported outcomes between the 2 groups. METHODS/UNASSIGNED:Through a systematic review of the English-language literature using various databases, we identified 4702 articles. After we applied inclusion and exclusion criteria, 14 articles (7 randomized controlled trials, 4 prospective studies, and 3 retrospective studies) reporting fusion rates of structural allograft or PEEK interbody devices were eligible for our analysis. No randomized controlled trials compared outcomes of structural allograft versus PEEK interbody devices. Extracted data included authors, study years, study designs, sample sizes, patient ages, duration of follow-up, types of interbody devices used, fusion rates, definition of fusion, reoperation rates, subsidence rates, and patient-reported outcomes. RESULTS/UNASSIGNED:Fusion rates were 82% to 100% for allograft and 88% to 98% for PEEK interbody devices. The reported data were insufficient to perform meta-analysis. Structural allograft had the highest reported rate of reoperation (14%), and PEEK interbody devices had the highest reported subsidence rate (18%). Patient-reported outcomes improved in both groups. There was insufficient high-quality evidence to compare the associations of various PEEK modifications with fusion rates. CONCLUSION/UNASSIGNED:Fusion rates were similar between structural allograft and PEEK interbody devices when used for ACDF for cervical spine degeneration. Currently, there is insufficient high-quality evidence to assess associations of PEEK modifications with fusion rates. LEVEL OF EVIDENCE/UNASSIGNED:II.

PURPOSE OF REVIEW/OBJECTIVE:To provide information on characteristics and use of various ceramics in spine fusion and future directions. RECENT FINDINGS/RESULTS:In most recent years, focus has been shifted to the use of ceramics in minimally invasive surgeries or implementation of nanostructured surface modification features to promote osteoinductive properties. In addition, effort has been placed on the development of bioactive synthetics. Core characteristic of bioactive synthetics is that they undergo change to simulate a beneficial response within the bone. This change is based on chemical reaction and various chemical elements present in the bioactive ceramics. Recently, a synthetic 15-amino acid polypeptide bound to an anorganic bone material which mimics the cell-binding domain of type-I collagen opened a possibility for osteogenic and osteoinductive roles of this hybrid graft material. Ceramics have been present in the spine fusion arena for several decades; however, their use has been limited. The major obstacle in published literature is small sample size resulting in low evidence and a potential for bias. In addition, different physical and chemical properties of various ceramics further contribute to the limited evidence. Although ceramics have several disadvantages, they still hold a great promise as a value-based graft material with being easily available, relatively inexpensive, and non-immunogenic.

The purpose of this study was to assess trends in the use of perioperative single and continuous peripheral nerve blocks (PNBs) and their associations with emergency department (ED) visits after arthroscopic rotator cuff repair (RCR) surgery. The authors used a large database from a private insurer to identify patients who received perioperative PNBs for arthroscopic RCR surgeries from 2007 to 2015. They analyzed patient demographics as well as trends in perioperative PNB use. They also assessed rates of single shot vs continuous PNB use and compared rates of postoperative ED visits according to PNB type. The rate of perioperative PNB for arthroscopic RCR was higher than previously reported (65.9%) and increased over time (52.8% in 2007 to 64.6% in 2015; P=.029). Single shot PNBs were more common than continuous, catheter-mediated PNBs (60.0% vs 6.6%; P<.001), although the use of continuous blocks increased at a greater rate during the study period. Patients who received a perioperative continuous PNB were significantly more likely to visit an ED within 7 days of their surgery than those who received a single shot PNB or no PNB (6.71% vs 4.78% vs 4.74%; P<.02). The rates of ED visits within each group did not change significantly over time. Continuous PNBs are increasingly common for patients undergoing arthroscopic RCR surgery but are associated with increased rates of postoperative ED visits. Studies are needed to identify the reasons for this increased rate of ED visits and strategies to decrease ED use. [Orthopedics. 2020; 43(2): 127-131.].

BACKGROUND CONTEXT:Posterior cervical foraminotomy (PCF) is a relatively safe procedure for the treatment of cervical radiculopathy. Though most often performed as an inpatient procedure, there is an increasing number of patients treated in an outpatient setting. PURPOSE:This study aimed to compare the perioperative complication rates associated with inpatient and outpatient single-level PCF. STUDY DESIGN/SETTING:Retrospective database study. PATIENT SAMPLE:Patients with cervical radiculopathy who underwent inpatient or outpatient single-level PCF between 2007 to the first quarter of 2016. OUTCOME MEASURES:Charlson Comorbidity Index (CCI) was used as a broad measure of comorbidity. Surgical complications included cervical nerve root injury, dural tear, wound complications, infection, dysphagia, cervicalgia, and revision surgery. Medical complications included pulmonary embolism and lower limb deep vein thrombosis, acute myocardial infarction, acute respiratory failure, pneumonia, sepsis, and urinary complications. METHODS:This study was a retrospective review of patients who received single-level PCF from 2007 to the first quarter of 2016 as either outpatients or inpatients using the Humana subset of the PearlDiver Patient Record Database. The incidence of perioperative medical and surgical complications was queried using relevant International Classification of Diseases (ICD-9-CM and ICD-10-CM) and Current Procedural Terminology codes. Multivariate logistic regression analysis, adjusted for age, gender, and CCI, was performed to calculate odds ratios (ORs) of complications among inpatients relative to outpatients treated with PCF. Propensity score matching was done, and comparisons were made for postoperative complications. RESULTS:Throughout the time period, 1,469 and 1,192 patients received inpatient and outpatient single-level PCF, respectively. The mean CCIs±standard deviation of inpatient and outpatient groups undergoing PCF were 2.83±3.11 and 1.46±2.21, respectively (p<.001). After propensity score matching, patients who received PCF in an inpatient setting showed significantly higher rates of wound complications (OR=1.53, 95% confidence interval [CI]=1.04-2.23; p=.029), infection (OR=1.91, CI=1.15-3.15; p=.012), acute respiratory failure (OR=2.50, CI=1.23-5.08; p=.011), and urinary tract infections and incontinence (OR=2.11, CI=1.32-3.38; p=.002). CONCLUSIONS:Outpatient single-level PCF was associated with a lower rate of perioperative medical and surgical complications. The PCF in the outpatient setting can potentially be a safe procedure for the treatment of cervical radiculopathy with appropriate patient selection.

PURPOSE/OBJECTIVE:To evaluate which cervical level is the most appropriate level to measure occipitocervical inclination (OCI). METHODS:Sixty-two patients with multi-positional MRI: 24 males and 38 females, who had cervical lordosis and had a disk degeneration grade of 3 or less were included. We measured patient's OCI at C3, C4, and C5, occipitocervical angle (OCA), occipitocervical distance (OCD), C2-7 angle, and cervical sagittal vertical axis (cSVA) in neutral, flexion, and extension position. The correlation between OCI and OCA, OCD, C2-7 angle, and cSVA on each cervical level in all three positions was tested using Pearson's correlation coefficient test. The difference between OCIs at each cervical level was tested by Wilcoxon signed-rank test. p value of less than 0.05 was set as a statistically significant level. RESULTS:C5 OCI showed statistically significant correlation with OCA, OCD, C2-7 angle, and cSVA in all three positions (p < 0.05, r = 0.214-0.525). C3 OCI in flexion (p = 0.393, r = 0.081) and C4 OCI in neutral and flexion (neutral p = 0.275, r 0.104; flexion p = 0.987, r = 0.002) did not show significant correlation with C2-7 angle. There was a statistically significant difference between C3, C4, and C5 OCIs in neutral and extension position (p < 0.05). At the same time, OCI showed statistically strong correlation between adjacent cervical levels (p < 0.001, r = 0.627-0.822). CONCLUSION/CONCLUSIONS:C5 cervical level is the most appropriate level for OCI measurement. OCI should be measured at the same cervical level at all time. C4 OCI can reliably substitute C5 OCI in case C5 which is invisible on radiographic image. These slides can be retrieved under Electronic Supplementary Material.

PURPOSE/OBJECTIVE:As the population continues to age, the number of lumbar spine surgeries continues to increase. While there are many complications associated with lumbar surgeries, a myocardial infarction (MI) is a particularly devastating one. This complication is of considerable importance with mortality rates of postoperative MI documented between 26.5 and 70%. This study aimed to determine the relationship between lumbar surgeries, preoperative diagnoses (risk factors), and myocardial infarction. METHODS:Data from the Humana database (PearlDiver) were analyzed from 2007 to 2016. Patients undergoing lumbar spine surgeries were identified and stratified based on procedural approach, patient demographics, and preoperative risk factors. Each group was analyzed to determine the incidence and relative risk. Chi-square analysis was used to determine the significance. RESULTS:A total of 105,505 patients who fit inclusion criteria were identified in the PearlDiver database between 2007 and 2016. A total of 644 patients (0.63%) experienced a postoperative myocardial infarction within 30 days of surgery. Patients undergoing fusion and non-fusion procedures showed significantly different rates of postoperative myocardial infarction (0.08% vs. 0.05%, p < 0.01). Male patients, older patients, and patients with a Charlson comorbidity index > 3 showed a considerable increase in incidence (p < 0.01). Furthermore, patients with preoperative risk factors (high cholesterol, obesity, depression, congestive heart failure, hypertension, and hypotension) exhibited risk ratios from 0.01 to 1.85 (p < 0.01). CONCLUSION/CONCLUSIONS:Preoperative risk factors, patient demographics, and procedure type had a significant effect on the incidence of postoperative myocardial infarction. These slides can be retrieved under Electronic Supplementary Material.

Study Design/UNASSIGNED:Case-control study. Objectives/UNASSIGNED:Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord injury in adults aged over 55 years. However, since the onset is typically insidious, accurately diagnosing CSM can be challenging, often requiring referral to a subspecialist and advanced imaging. To help identify patients at risk for CSM, this case-control study compared responses to a series of 4 questions (DOWN questionnaire) in myelopathic and non-myelopathic patients. Methods/UNASSIGNED:Ninety-two patients, 46 with and 46 without myelopathy, were recruited for the study. Each patient answered 4 questions encompassing common symptoms associated with CSM. Responses between patient groups were compared, and Cohen's κ was used to assess for agreement between responses and the diagnosis of myelopathy. Results/UNASSIGNED:We found a sensitivity of 91% and a κ of 0.54 to 3 positive responses and a sensitivity of 72% and a κ of 0.61 to 4 positive responses. Conclusions/UNASSIGNED:Positive responses to 3 or more DOWN questions has high sensitivity and moderate agreement with the diagnosis of myelopathy based on history, physical exam, and review of advanced imaging by an orthopedic or neurological surgeon. The DOWN questionnaire is a potentially useful screening tool to identify patients at risk for CSM.