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BACKGROUND CONTEXT Predicting which patients will benefit from cervical spine surgery remains a clinical challenge. While a number of studies have examined postoperative improvement in degenerative cervical disease, the proportion of patients who return to normal remains unknown. PURPOSE To assess whether preoperative patient-reported outcomes (PROs) can be used to predict which patients return to normative levels after cervical spine surgery. STUDY DESIGN/SETTING Prospective cohort. PATIENT SAMPLE Adult patients undergoing cervical spine surgery, excluding those undergoing surgery for instability due to trauma. OUTCOME MEASURES Correlation of baseline PROs with achieving postoperative normative and acceptable symptoms states. METHODS Patients undergoing cervical spine surgery between 2016-2018 were prospectively enrolled, completing questionnaires (Neck Disability Index [NDI] and Patient Reported Outcomes Measurement Information System [PROMIS] Pain Interference [PI] and Physical Function [PF]) preoperatively and at 6 months postoperatively. Logistic regression analysis was used to determine the association between preoperative outcome measures and achieving postoperative patient acceptable symptom state (PASS) for NDI and the normative mean (50) for PROMIS. RESULTS A total of 139 patients met inclusion criteria, with a mean age of 56.4 years and diagnoses of myelopathy (n=36), radiculopathy (n=48) and myeloradiculopathy (n=49). Overall, NDI and PROMIS PF demonstrated a statistically significant correlation between worse baseline scores and achieving postoperative PASS (NDI) and the PROMIS normative mean, while the association for PROMIS PI did not reach statistical significance. For NDI, a one-point worsening in the preoperative score resulted in OR of achieving PASS (NDI ≤ 17) of 0.96 (p 34, respectively. For PROMIS PF, the proportion of patients reaching the normative threshold was 62%, 46%, 30%, 33%, and 26% for baseline PF 47.7-66.2, 43.3-47.2, 40.1-43.1, 34.7-40.0, and 23.5-34.6, respectively. CONCLUSIONS Preoperative PROs can predict postoperative benefit for patients undergoing cervical spine surgery, with worse baseline function associated with a lower likelihood of attaining PASS for NDI and the PROMIS PF normative mean. PROMIS PI did not demonstrate this correlation and may not be as useful as a predictor of postoperative outcome. These data will better enable surgeons and patients to estimate prognosis after cervical spine surgery. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Patient reported outcome measures (PROMs) and minimal clinically importance difference (MCID) thresholds have emerged as effective, reliable parameters to assess improvement and surgical success. PURPOSE To investigate the risk factors associated with failure to achieve MCID following cervical disc replacement (CDR). STUDY DESIGN/SETTING Retrospective review of prospectively collected data. PATIENT SAMPLE A total of 107 patients who had undergone primary, one-or-two level CDR by three surgeons at a single academic institution. OUTCOME MEASURES Patient-reported outcome measures - Rates of MCID achievement in neck disability index (NDI), VAS (visual analogue score) neck, and VAS-arm were calculated with the following threshold values, based on previously published studies: NDI: -15.0, VAS-neck: -2.5, and VAS-arm: -2.5. METHODS Risk factors for failure to achieve MCID were identified using multivariate logistic regression models with alternating backward stepwise elimination and forward entry of removed variables (entry: 0.05, removal: 0.10). Receiver operating characteristic (ROC) curves were generated to assess the performance of each model. RESULTS A total of 107 patients met inclusion criteria (mean age: 42.99±9. Thirteen years, mean BMI: 26.02±4.01 kg/m2). There were 99 patients who presented for a follow-up visit within three months of their operation, of which 82 (89.1%) had achieved MCID in NDI, VAS-neck, or VAS-arm. Specific to the NDI, BMI≥25 kg/m2 (OR:153.75, p=0.002), depression (OR:50.32, p=0.016), myelopathy (OR:51.44, p=0.022), degenerative disc disease/spondylosis (OR:21.54, p=0.001), and two-level procedures (OR:6.59, p=0.027) were identified as risk factors for failure to achieve MCID within the first three months. Preoperative narcotic use (OR:0.11, p=0.027) was associated with a lower risk for failure to achieve MCID in NDI within the first three months. The area under the ROC curve (AUROC) assessing the logistic regression model's performance was 0.873 (p CONCLUSIONS The large majority of patients had achieved MCID in at least one of the three PROMs. Clinical depression, myelopathy and two-level procedures were associated with failure to achieve MCID in NDI by one year and also within the early postoperative period (first three months) following CDR. BMI≥ 25 kg/m2 and spondylosis were also significant factors associated with failure to achieve MCID in NDI within the early postoperative period. Although preoperative narcotic use was associated with achievement of MCID in NDI, these patients likely presented initially with more chronic and severe symptoms, potentiating greater improvements in PROMs. Future studies with larger cohorts may provide additional insight on the true impact of the identified risk factors on outcomes following CDR. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Odontoid fractures are the most common fracture of the axis and the most common cervical spine fracture in patients over 65. Despite their frequency, there is considerable ambiguity regarding optimal management strategies for these fractures in the elderly. Poor bone health and medical comorbidities contribute to increased surgical risk in this population; however, nonoperative management is associated with a risk of nonunion or fibrous union. We provide a review of the existing literature and discuss the classification and evaluation of odontoid fractures. The merits of operative vs nonoperative management, fibrous union, and the choice of operative approach in elderly patients are discussed. A treatment algorithm is presented based on the available literature. We believe that type I and type III odontoid fractures can be managed in a collar in most cases. Type II fractures with any additonal risk factors for nonunion (displacement, comminution, etc) should be considered for surgical management. However, the risks of surgery in an elderly population must be carefully considered on a case-by-case basis. In a frail elderly patient, a fibrous nonunion with close follow-up is an acceptable outcome. If operative management is chosen, a posterior approach is should be chosen when fracture- or patient-related factors make an anterior approach challenging. The high levels of morbidity and mortality associated with odontoid fractures should encourage all providers to pursue medical co-management and optimization of bone health following diagnosis.

STUDY DESIGN Retrospective cohort study of prospectively collected data from the National Surgical Quality Improvement Program (NSQIP) database. OBJECTIVE To determine the postoperative morbidity of one- and two-level outpatient anterior cervical discectomy and fusion (ACDF) relative to inpatient cases, and risk factors for postdischarge complications. SUMMARY OF BACKGROUND DATA ACDF is increasingly performed as an outpatient procedure, with evidence demonstrating outpatient one-level ACDF to be associated with fewer postoperative complications than inpatients. The postoperative morbidity and safety of outpatient two-level ACDF as a separate cohort is not well understood. METHODS ACDF cases from NSQIP 2011 to 2014 were identified. Differences in baseline characteristics between inpatient and outpatient cases were determined, and propensity score adjustment was used to account for selection bias. One- and two-level ACDF cohorts were analyzed separately. Unadjusted and propensity-adjusted multivariable logistic regressions were performed to determine the risk of postoperative complications in outpatient cases relative to inpatient cases, and predictors of postdischarge complications. RESULTS A total of 22,006 ACDF cases were included, of which 4759 were outpatient procedures. Propensity-adjusted differences in preoperative characteristics were all P > 0.5, indicating successful adjustment of selection bias. Among 6890 two-level cases, of which 1429 (20.7%) were outpatient, the overall unadjusted rate of complications was 1.47% for outpatients and 3.94% for inpatients, P

Background Context Patient satisfaction is becoming an increasing common proxy for surgical quality; however, the correlation between patient satisfaction and surgical outcomes 2 and 5 years after anterior cervical surgery has not been evaluated. Purpose The study aimed to determine if patient satisfaction is predicted by improvement in patient-reported outcomes (PRO) 2 and 5 years after anterior cervical spine surgery. Study Design This is a retrospective analysis of prospectively collected data. Patient Sample The sample included patients enrolled in the Food and Drug Administration investigational device exemption clinical trial comparing total disc replacement with Mobi-C cervical artificial disc and anterior cervical discectomy and fusion. Outcome Measures The outcome measures were visual analog scale (VAS) neck pain score, Neck Disability Index (NDI), and Short-Form 12-Item scores, as well as patient satisfaction. Methods Receiver operating characteristic curves were used to determine if improvement in different PRO metrics can accurately identify patient satisfaction. Additionally, a logistic regression analysis was performed on the results at 24 months and 60 months to identify independent predictors of patient satisfaction. This research was supported by LDR (Zimmer Biomet) 13785 Research Boulevard - Suite 200 Austin, TX 78750. Results Data were available for 512 patients at 60 months. At 24 months postoperatively, NDI score improvement (area under the curve [AUC]=0.806), absolute NDI score (AUC=0.823), and absolute VAS neck pain score (AUC=0.808) were all excellent predictors of patient satisfaction. At 60 months postoperatively, NDI score improvement (AUC=0.815), absolute NDI score (AUC=0.839), VAS neck pain score improvement (AUC=0.803), and absolute VAS neck pain score (AUC=0.861) were all excellent predictors of patient satisfaction. Conclusions In patients undergoing one- and two-level anterior cervical spine surgery, between 2 and 5 years postoperatively, patient satisfaction is significantly predicted by PROs, including the VAS neck score and the NDI.

BACKGROUND CONTEXT With the current prescription opioid crisis in the United States, extensive recent literature has demonstrated worse clinical outcomes and increased opioid dependence in patients taking preoperative opioids. However, no studies have demonstrated a link between preoperative opioids and reoperation. PURPOSE To demonstrate an association between preoperative opioid use and reoperation after adult spinal deformity (ASD) surgery. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE This study included 160 patients undergoing posterior spinal fusion for adult spinal deformity. OUTCOME MEASURES Reoperation for revision decompression or fusion within 5 years postoperatively. METHODS Preoperative use of five opioid medications (tramadol, hydromorphone, oxycodone, hydromorphone, and extended-release (ER) oxycodone) were assessed and categorized as acute (within 3 months), subacute (acute use and use between 3-6 months), and chronic (subacute use and use prior to 6 months). Multivariate regression (MVA), controlling for age, gender, Charlson Comorbidity Index, and the number of levels fused, was used to determine the association of preoperative opioid use and reoperations at 5 years. All patients were followed for 5 years postoperatively. RESULTS A total of 160 patients were identified. Of those, 70 patients (44%) were opioid naive preoperatively, while 90 patients (56%), 56 patients (35%), and 51 patients (32%) demonstrated acute, subacute, and chronic preoperative opioid use respectively. The most commonly used preoperative opioids were hydrocodone (62 patients), oxycodone (27 patients), and tramadol (16 patients). The rate of reoperation in opioid naive patients at 5 years was 5.7%, compared with 25.6%, 28.6%, and 29.4% in patients with acute, subacute, and chronic preoperative use. In MVA, acute use was associated with increased reoperations (odds ratio: 6.00; P=0.02), while subacute (P=0.99) and chronic (0.82) were not significantly associated with reoperations. CONCLUSIONS Patients with acute preoperative opioid use had the greatest relative association with reoperations at 5 years. This may be due to opioid-induced hyperalgesia resulting in poorly identified preoperative pain generators or uncontrolled postoperative pain. While further investigation of the potential benefit of preoperative weaning programs is warranted, this information is valuable for counseling patients on preoperative opioid cessation. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT There is limited long-term comparative data for patients with cervical radiculopathy treated with either anterior cervical discectomy and fusion (ACDF) or posterior cervical foraminotomy (PCF) procedures. Therefore, the aim of the current study is to compare 5-year rates of reoperation after either ACDF or PCF for cervical radiculopathy in an older Medicare population. PURPOSE To determine the relative rates of reoperation after ACDF or PCF for cervical radiculopathy, stratified by single or multilevel disease. STUDY DESIGN/SETTING Retrospective cohort study PATIENT SAMPLE A total of 3,639 patients with single-level radiculopathy, 2,895 (80%) undergoing ACDF and 744 (20%) undergoing PCF. OUTCOME MEASURES Reoperations of the cervical spine METHODS A national sample of Medicare patients was reviewed for patients undergoing either single-level or multiple-level ACDF or PCF with a diagnosis of cervical disc herniation without myelopathy. All patients were followed for a minimum of 3 years postoperatively and rates of all additional cervical spine surgery were assessed for up to 5 years. Multivariate logistic regression was used to determine the relative odds of additional fusion surgery controlling for age, gender, and Charlson Comorbidity Index (CCI) RESULTS A total of 3,639 patients with single-level disease were identified, with 2,895 (80%) undergoing ACDF and 744 (20%) undergoing PCF. The rates of additional cervical spine surgery within 5 years were 1.7% and 1.5%, after ACDF and PCF respectively. A total of 2,986 patients had multilevel disease, with 2,785 (93%) undergoing multilevel ACDF and 201 (7%) undergoing multilevel PCF. The rates of additional cervical spine surgery within 5 years were 5.3% and 0.5%, after ACDF and PCF respectively. In multivariate analysis controlling for age, gender, and comorbidities, there was no significant difference in reoperations between ACDF and PCF in the single-level cohort. However, in the multilevel cohort, significantly more patients that underwent ACDF required additional cervical spine surgery within 5 years (odds ratio: 3.21, P = 0.048). CONCLUSIONS In the Medicare population for multilevel radiculopathy, PCF resulted in less reoperation compared with multilevel ACDF. However, no difference was seen for single level radiculopathy. Therefore, there may be some benefit in choosing PCF over ACDF in certain patients with multilevel disease. Choice of surgical technique ultimately depends on an individual patient's history, physical examination, and radiographic findings. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Patients who are lost to follow up are a common source of selection bias for clinical outcomes research; systematic differences in outcomes between patients who follow up after spine surgeries vs those who do not could lead to skewed conclusions. PURPOSE The purpose of this study is to determine whether minimally invasive lumbar spine surgery outcomes are different between those who are lost to follow-up and those who are not. STUDY DESIGN/SETTING Retrospective review of prospectively collected data with telephone and email interviews. PATIENT SAMPLE 289 patients who underwent minimally invasive lumbar surgery and were at least 1-year postsurgery was performed. OUTCOME MEASURES PROMs (ODI, VAS back/leg, SF-12 Physical/Mental, PROMIS), return to activities, complications METHODS A retrospective review of prospectively collected data of 289 patients who underwent minimally invasive lumbar surgery and were at least 1-year postsurgery was performed. Patients were divided into two groups: (1) lost to follow-up (LTF), defined as patients who had missed >2 consecutive follow-up visits and had not attended their 1-year follow-up appointment; and (2) not lost to follow-up. For the not-LTF cohort, PROMs (ODI, VAS back/leg, SF-12 Physical/Mental, PROMIS) and return to activities data were collected prospectively at each follow-up visit as standard of care. For LTF patients, data were collected through emailed surveys or telephone interviews. PROMs and return to activities data of the two groups were compared. RESULTS Of the 289 patients treated, 99 (34.26%) were considered lost to follow-up and 190 (65.47%) were not. For the entire cohort, independent t-test analysis showed LTF patients had greater improvement in PROMIS Physical Function scores than those who were not-LTF (15.08 vs 10.38, p=0.026). For fusion surgeries, LTF patients showed a greater improvement in ODI (-30.94 vs -16.23, p=0.003) VAS back (-4.92 vs -2.99, p=0.044), and PROMIS-PF (16.09 vs 10.38, p=0.049). There were no significant differences in complication rates between LTF and not LTF patients. CONCLUSIONS Patients undergoing minimally invasive lumbar surgery – in particular lumbar fusions – who are lost to follow-up have improved self-reported outcomes (ODI, VAS back, PROMIS). This is counter to the common notion that patients who are lost to follow-up fare worse. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT While fusion in the context of anterior cervical discectomy and fusion (ACDF) has been reported to be as high as 97% at 4 years postop, little is known about the bridging of trabecular bone, radiolucency and interspinous motion (ISM) as definitive criterion for assessing fusion on radiographic X-ray imaging. While there is no conclusive method for quantifying interbody fusion (IBF), there is curiosity about whether these parameters can prove a spacer type to have a higher fusion rate than another. PURPOSE To determine whether the use of interbody cages (IC) promotes higher fusion rates in ACDF using plain X-ray studies. STUDY DESIGN/SETTING Single-center retrospective analysis of prospective consecutive database of multilevel ACDF. PATIENT SAMPLE This study included 94 patients and 232 levels were evaluated with 1-year postop images from August 2015 to November 2018. OUTCOME MEASURES Interspinous motion, bridging trabecular bone, fusion grade. METHODS A total of 32 published papers were reviewed to select the three best parameters for assessing cervical fusion: the passage of trabecula through the implant, the presence of a radiolucent line interfacing implant and vertebral plate, and the range of motion between two adjacent spinous processes. Radiolucency and bridging trabecular bone (BTB) parameters were combined to categorize each ACDF level as fused (≥75% BTB present) or not fused ( RESULTS A total of 234 surgical levels from 92 patients were included (age: 62.5, 42.4% F, BMI: 29.87). Median number of levels fused by patient was 2 (IQR: 1). Overall, 28.2% of the patients had at least 1 level with incomplete fusion. Patients with incomplete fusion (by BTM or ISM method) had longer ACDF than those with complete fusion (median=3 vs 2, p=0.022). No associations were found between demographic, smoking status and fusion rate (all p > 0.1). When investigating fusion level by level, using the BTB and ISM methods respectively, no significant differences were found based on IC type (bone graft vs cage; p=.867 and .585), iliac bone vs local (p =.869, .796) or allograft. Lower fusion rate was noticed for C6-C7 (58.1%) compared to more proximal disc spaces (71.4% to 78.7%, p = 0.049). Combination of IC and graft material revealed no significant difference (bonegraft + local=71.8% vs cage + iliac=66.7%, p = 0.517). Multivariate analysis, controlling for demographic and smoking status, demonstrated that only location of the fusion was an independent predictor of incomplete fusion. CONCLUSIONS There was no superiority within the allograft and autograft respective groups or between spacers, using the ISM or BTB techniques. More than 2mm of motion on dynamic X-ray studies, BTB and radiolucent interface between implant and endplates are efficient quantifiable methods to measure fusion on X-ray studies, as they are easily accessible and affordable within the health care field. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Study design A retrospective study of patients undergoing anterior cervical discectomy and fusion (ACDF) in the prospective National Surgical Quality Improvement Program (NSQIP) database. Objective To determine the most common reasons for readmission within 30 days after elective ACDF. Summary of background data ACDF is a commonly performed surgery that is safe and effective for treating a variety of cervical spine pathologies. With new quality-based reimbursements tied to readmissions within 30 days of discharge, better understanding of the causes of readmissions is, however, needed. Methods Patients undergoing ACDF in the NSQIP database from 2012 to 2014 were reviewed. The overall rate of readmission and documented reasons for readmission were collected. Multivariate regression was then used to determine risk factors for readmissions. Results A total of 17,088 patients undergoing elective ACDF were identified. There were 545 (3.2%) readmissions within 30 postoperative days. Of the readmitted patients, 293 (53.8%) were readmitted for nonsurgical site-related reasons, with neuropsychiatric (n = 44), cardiovascular (n = 39), and pneumonia (n = 37) being the most common reasons. A total of 184 patients (33.8%) were readmitted for surgical site-related reasons, with surgical site infection (n = 42), hemorrhage/hematoma (n = 42), and dysphagia (n = 32) being the most common reasons. A total of 84 patients (15.6%) had undocumented reasons for readmission. In multivariate analysis, only older age and higher American Society of Anesthesiologists class were independently associated with readmissions. Conclusion Most readmissions after ACDF were due to nonsurgical site-related reasons, suggesting the importance of careful patient selection, aggressive preoperative medical optimization, and adequate postoperative management. Level of evidence 3.

Prospective observational study OBJECTIVE.: The aim of this study was to record daily opioid use and pain levels after 1-level lumbar decompression or microdiscectomy.The standardization of opioid-prescribing practices through guidelines can decrease the risk of misuse and lower the number of pills available for diversion in this high-risk patient population. However, there is a paucity of quantitative data on the "minimum necessary amount" of opioid appropriate for post-discharge prescriptions.At two institutions between September 2017 and 2018, we prospectively enrolled 85 consecutive adult patients who underwent one-level lumbar decompression or microdiscectomy. Patients with a history of opioid dependence were excluded. Daily opioid consumption and pain scores were collected using an automated text-messaging-based platform for 6 weeks or until consumption ceased. Refills during the study period were monitored. Patients were asked for the number of pills left over and the method of disposal. Opioid use was converted to oral morphine equivalents (OMEs). Results are also reported in terms of "pills" (oxycodone 5 mg equivalents) to facilitate clinical applications. Risk factors were compared between patients in the top and bottom half of opioid consumption.Total opioid consumption ranged from 0 to 118 pills, with a median consumption of 32 pills (236.3 OME). Seventy-five percent of patients consumed ≤57 pills (431.3 OME). Mean Numeric Rating Scale pain scores declined steadily over the first 2 weeks. By postoperative day 7 half of the study population had ceased taking opioids altogether. Only 22.4% of patients finished their initial prescription, and only 9.4% of patients obtained a refill.These data may be used to formulate evidence-based opioid prescription guidelines, establish benchmarks, and identify patients at the higher end of the opioid use spectrum.2.

STUDY DESIGN Prospective Cohort Study OBJECTIVE.: The aim of this study was to validate the Patient Reported Outcomes Measurement Information System (PROMIS) against existing patient-reported outcomes in the cervical spine. SUMMARY OF BACKGROUND DATA Current patient-reported outcomes in cervical spine have substantial limitations. PROMIS offers the potential for improved psychometric properties with reduced questionnaire burden. METHODS Adult patients undergoing cervical spine surgery at a single institution between 2016 and 2018 were prospectively enrolled. Patients completed questionnaires (36-Item Short Form Health Survey [SF-36], Neck Disability Index (NDI), Visual Analog Scale arm/neck, and PROMIS pain Interference [PI], physical Function [PF], and Upper Extremity [UE]) preoperatively and at 6 months postoperatively. Demographic data, diagnosis, and procedural data were recorded. Validation of the instruments was completed with a Rasch Model as well as measurement of coverage, efficiency, test-retest reliability, responsiveness, and convergent validity. RESULTS Of 197 patients who completed the preoperative survey, 164 were eligible for 6-month follow-up and 139 completed 6-month postoperative surveys. The most common diagnoses were radiculopathy (37.6%), myeloradiculopathy (30.5%), and myelopathy (28.4%). All studied instruments had acceptable fit to a Rasch model. PROMIS computer adaptive testings (CATs) demonstrated improved average time to completion for PI (39 seconds), PF (47 seconds), and UE (54 seconds), compared to NDI (117 s) and SF-36 PCS (175 seconds). Responsiveness for PROMIS CATs was similar to NDI and SF-36, test-retest reliability was lower for PI (intraclass correlation: 0.68), PF (0.70), and UE (0.59), compared to NDI (0.86) and PCS (0.85). For convergent validity, PI was strongly correlated to NDI and PF to SF-36 PCS. There were no significant floor or ceiling effects for the PROMIS domains, although UE had preoperative clustering (n = 18) at a high score (56.4) and PI had postoperative clustering (n = 27) at a low score (38.7). CONCLUSION PROMIS CATs demonstrate several advantages, including efficiency and responsiveness, while demonstrating good convergent validity with legacy instruments. Nevertheless, CATs had lower test-retest reliability and had significant clustering at higher levels of function for the PI and UE CATs. These limitations must be considered before broad adoption of CATs in cervical spine patients. LEVEL OF EVIDENCE 3.

The symptoms of cervical spine and upper extremity injuries often overlap, which requires providers to distinguish between the two in order to accurately diagnose. Differentiating between the two involves a strong understanding of the neurologic exam, peripheral exam findings, and myotomal/dermatomal findings correlative to cervical spine levels. The most common dilemma encountered by providers assessing athletes with neck and arm pain is differentiating radicular symptoms from cervical pathology and musculoskeletal injuries. The diagnostic challenge is addressed by formulating a broad differential diagnosis and utilizing the physical exam and history to achieve a correct diagnosis.

BACKGROUND CONTEXT Pedicle screw placement is a demanding surgical skill as a spine surgeon can face challenges including variations in pedicle morphology and spinal deformities. Available CT simulators for spine pedicle placement can be very costly and hands-on cadaver courses are limited by specimen availability and are not readily accessible. PURPOSE To conduct validation of a simulated training device for essential spine surgery skills. DESIGN Cross-sectional, empirical study of physician performance on a surgical simulator model. SAMPLE Spine attending physicians and residents from four different academic institutions across the United States. OUTCOME MEASURES Performance metrics on two surgical simulator tasks. METHODS After IRB approval, an inexpensive ($30) simulator was developed to test two main psychomotor tasks (1) creation of the pedicle screw path with a standard gearshift probe without cortical breaks and (2) the ability to palpate for the presence or absence of cortical breaches as well as determine the location of wall defects. Orthopedic and neurosurgery residents (N=72) as well as spine attending surgeons (N=26) participated from four different institutions. To test construct validity, performance metrics were compared between participants of different training status through one-way analysis of variance and linear regression analysis, with significance set at p RESULTS Spine attending surgeons consistently scored higher than the residents, in the screw trajectory task with triangular base (p=.0027) and defect probing task (p=.0035). In defect probing, performance improved with linear trend by number of residency training years with approaching significance (p=.0721). In that task, independent of institutional affiliation, PGY-2 residents correctly identified an average of 1.25±0.43 fewer locations compared with attending physicians (p=.0049). More than 80% of the spine attendings reported they would use the simulator for training purposes. CONCLUSIONS This low-cost fundamentals of spine surgery simulator detected differences in performances between spine attending surgeons and surgical residents. Programs should consider implementing a simulator such as fundamentals of spine surgery to assess and develop pedicle screw placement ability outside of the operating room.

Aging is a major risk factor of intervertebral disc degeneration and a leading cause of back pain. Pathological changes associated with disc degeneration include the absence of large, vacuolated and reticular‐shaped nucleus pulposus cells, and appearance of smaller cells nested in lacunae. These small nested cells are conventionally described as chondrocyte‐like cells; however, their origin in the intervertebral disc is unknown. Here, using a genetic mouse model and a fate mapping strategy, we have found that the chondrocyte‐like cells in degenerating intervertebral discs are, in fact, nucleus pulposus cells. With aging, the nucleus pulposus cells fuse their cell membranes to form the nested lacunae. Next, we characterized the expression of sonic hedgehog (SHH), crucial for the maintenance of nucleus pulposus cells, and found that as intervertebral discs age and degenerate, expression of SHH and its target Brachyury is gradually lost. The results indicate that the chondrocyte‐like phenotype represents a terminal stage of differentiation preceding loss of nucleus pulposus cells and disc collapse.

Aims The aim of this study was to determine the general postoperative opioid consumption and rate of appropriate disposal of excess opioid prescriptions in patients undergoing primary unilateral total knee arthroplasty (TKA). Patients and Methods In total, 112 patients undergoing surgery with one of eight arthroplasty surgeons at a single specialty hospital were prospectively enrolled. Three patients were excluded for undergoing secondary procedures within six weeks. Daily pain levels and opioid consumption, quantity, and disposal patterns for leftover medications were collected for six weeks following surgery using a text-messaging platform. Results Overall, 103 of 109 patients (94.5%) completed the daily short message service (SMS) surveys. The mean oral morphine equivalents (OME) consumed during the six weeks post-surgery were 639.6 mg (sd 323.7; 20 to 1616) corresponding to 85.3 tablets of 5 mg oxycodone per patient. A total of 66 patients (64.1%) had stopped taking opioids within six weeks of surgery and had the mean equivalent of 18 oxycodone 5 mg tablets remaining. Only 17 patients (25.7%) appropriately disposed of leftover medications. Conclusion These prospectively collected data provide a benchmark for general opioid consumption after uncomplicated primary unilateral TKA. Many patients are prescribed more opioids than they require, and leftover medication is infrequently disposed of appropriately, which increases the risk for illicit diversion. Cite this article: Bone Joint J 2019;101-B(7 Supple C):98–103

As the focus in spine surgery has shifted from radiographic to patient-centric outcome, patient-reported outcomes measures (PROMs) are becoming increasingly important. They are linked to patient satisfaction, and are used to assess healthcare expenditure, determine compensation and evaluate cost-effectiveness. Thus, PROMs are important to various stakeholders, including patients, physicians, payers, and healthcare institutions. Thus, it is vital to establish methods to interpret and evaluate these outcome measures.To evaluate the correlation between Neck Disability Index (NDI), Patient Reported Outcome Measurement Information System Physical Function (PROMIS-PF) and Short Form-12 Physical Health Score (SF-12 PHS) in cervical spinal surgery in order to determine the validity of PROMIS-PF in these patients.Retrospective review of prospectively collected data.Consecutive patients who underwent cervical surgery for degenerative spinal pathology with a minimum of 3 months follow-up.Self-reported measures that is, PROMs including NDI, PROMIS-PF, and SF-12 PHS.No funding was received for this study. The authors report no relevant conflict of interest. PROM collected preoperatively and at each follow-up were analyzed using Pearson product-moment correlation.Of the 121 patients included, 66 underwent anterior cervical discectomy and fusion, 42 cervical disc replacement, 13 posterior cervical decompression with or without fusion. A statistically significant improvement was achieved in all PROMs by 6 weeks and maintained at 1 year. Furthermore, the percentage of patients achieving an improvement greater than minimum clinically important difference was similar for NDI and PROMIS-PF, particularly at a follow-up of 3 months or more. A statistically significant negative correlation was seen between NDI and PROMIS-PF, which was moderate preoperatively and in the early postoperative period (r=-0.565 to -0.600), and strong at 3 months or longer follow-up (r=-0.622 to -0.705). A statistically significant, negative correlation was also seen between SF-12 PHS and NDI, which was moderate preoperatively and at 6 weeks (r=-0.5551 to -0.566); and strong at all other time-points (r=-0.678 to -0.749). There was a statistically significant positive correlation between SF-12 PHS and PROMIS-PF, which was strong to very-strong at all time-points (r=0.644-0.822), except at 2 weeks (r=0.570).Although NDI and SF-12 have been used for several years, PROMIS is a new outcome measure that is increasingly being implemented. The results of our study demonstrate the convergent and discriminant validity of PROMIS-PF, supported by the strong correlation between SF-12 PHS and PROMIS-PF at all time-points and the moderate correlation between NDI and PROMIS-PF preoperatively and in the early postoperative period, respectively. Thus, while PROMIS-PF may not be a good surrogate for disease-specific outcome measures, it may extend value as a precise and efficient general health tool.

Study Design: Retrospective cohort study. Objective: Factors that predict outcomes for adult cervical spine deformity (ACSD) have not been well defined. To compare ACSD patients with best versus worst outcomes. Methods: This study was based on a prospective, multicenter observational ACSD cohort. Best versus worst outcomes were compared based on Neck Disability Index (NDI), Neck Pain Numeric Rating Scale (NP-NRS), and modified Japanese Orthopaedic Association (mJOA) scores. Results: Of 111 patients, 80 (72%) had minimum 1-year follow-up. For NDI, compared with best outcome patients (n = 28), worst outcome patients (n = 32) were more likely to have had a major complication ( P = .004) and to have undergone a posterior-only procedure ( P = .039), had greater Charlson Comorbidity Index ( P = .009), and had worse postoperative C7-S1 sagittal vertical axis (SVA; P = .027). For NP-NRS, compared with best outcome patients (n = 26), worst outcome patients (n = 18) were younger ( P = .045), had worse baseline NP-NRS ( P = .034), and were more likely to have had a minor complication ( P = .030). For the mJOA, compared with best outcome patients (n = 16), worst outcome patients (n = 18) were more likely to have had a major complication ( P = .007) and to have a better baseline mJOA ( P = .030). Multivariate models for NDI included posterior-only surgery ( P = .006), major complication ( P = .002), and postoperative C7-S1 SVA ( P = .012); models for NP-NRS included baseline NP-NRS ( P = .009), age ( P = .017), and posterior-only surgery ( P = .038); and models for mJOA included major complication ( P = .008). Conclusions: Factors distinguishing best and worst ACSD surgery outcomes included patient, surgical, and radiographic factors. These findings suggest areas that may warrant greater awareness to optimize patient counseling and outcomes.

Study Design: Retrospective cohort study. Objective: Determine the indications, complications, and clinical outcomes in patients requiring fusions from the cervical spine to the pelvis. Several investigators have examined fusions from the thoracic spine to the sacrum, but no similar study has been performed for cervical-to-pelvis fusions. Methods: Patients from 2003 to 2014 with an upper instrumented vertebrae (UIV) in the cervical spine (any level) and a lower instrumented vertebrae (LIV) in the sacrum or pelvis were included in the study. Those with infectious or acute trauma-related deformities were excluded. Patient demographics, medical history, diagnosis, operative procedure, and health-related quality of life measures were analyzed. Student’s t test, Kruskal-Wallis test, and χ2 test were used as appropriate; significance was set at P < .05 for all tests. Results: Fifty-five patients met inclusion criteria for the study. Average follow-up was 2.8 years. Proximal junctional kyphosis was the most common indication for cervical-to-pelvis fusions (36%). The most common UIV was C2 (29%) followed by C7 (24%). There was an average 31° correction in maximum kyphosis and a 3.3 cm improvement in sagittal vertical axis. In adults, the rate of complication was 71.4%, with a major complication rate of 39.3% and reoperation rate of 53.6%. There was significant improvement in the Scoliosis Research Society (SRS-22r) score (3.0 to 3.5; P < .01). Conclusion: Proximal junctional kyphosis is the most common indication for patients requiring fusion to the cervical spine. Adult patients incur a significant risk of major complications and reoperations. However, significant improvement in SRS-22r outcomes are noted in these patients.

This was a retrospective cohort study.The main objectives of this study were to identify epidemiological trends, differences, and complications in patients undergoing surgical treatment for single-level cervical radiculopathy (SLCR).SLCR that fails nonoperative management is effectively treated with either anterior cervical discectomy and fusion (ACDF), cervical disc replacement (CDR), or posterior cervical foraminotomy (PCF). Although studies have shown that all 3 options are clinically effective, trends in usage, differences in patient population, and differences in complications remain unknown.Patients who underwent either ACDF, CDR, or PCF in the treatment of SLCR from 2010 to 2016 were retrospectively reviewed using the National Surgical Quality Improvement Program (NSQIP) database. Demographic data consisted of sex, age, ASA class, body mass index, and inpatient/outpatient status. Complications included surgical site infection, pneumonia, reintubation, pulmonary embolism, deep vein thrombosis, readmissions, reoperations, operating time, and hospital length of stay. Utilization trends by year among the 3 procedures were also analyzed.A total of 1102 patients with SLCR treated with single-level ACDF, CDR, or PCF were identified in NSQIP from 2010 to 2016. There was a relative increase in the number of CDR procedures (7.7%-16.1%) and a corresponding decrease in PCF procedures (20.3%-10.6%) without a significant effect on ACDF procedures (72.0%-73.3%). Patients who underwent CDR were younger and in a lower ASA class than those undergoing ACDF or PCF. Patients undergoing PCF were more likely to be treated as an outpatient. PCF procedures also had the shortest operating time and hospital length of stay. There were no significant differences in complications among the 3 procedures. Moreover, there were no significant trends in demographics or outcome measures.ACDF remains the most common surgical treatment for patients with SLCR, and its utilization has remained consistent. Meanwhile, the increased utilization of CDR for the treatment of SLCR has resulted in a corresponding decrease in the utilization of PCF.

Background Current research on opioid use within orthopedic surgery has focused on efforts to identify patients at risk for chronic opioid use. Studies addressing prevention of opioid misuse related to orthopedic care are lacking. Evidence-based interventions to reduce the reliance on opioids for post-operative pain relief will be a key component of any comprehensive institutional opioid policy. Questions/Purposes The purpose of this systematic review was to evaluate institutional strategies that reduce opioid administration or consumption after orthopedic surgery. Methods Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist, a search was conducted of the PubMed database for English-language articles that analyzed interventions by physicians, nurses, pharmacists, physical therapists, or other hospital staff to reduce post-operative opioid use or narcotic prescription amounts after surgery. Studies that contained objective outcome measures (i.e., no expert opinion articles) were selected. Investigations on the effect of pharmacologic adjuvants, cryotherapy, or regional nerve blockades on opioid use were excluded. Results The initial search yielded 6598 titles, of which 13 full-text articles were ultimately selected for inclusion in this systematic review. The review identified two major categories of interventions—patient-focused and provider-focused (e.g., physicians, nurses, physical therapists, pharmacists). Formal patient education programs were most effective in reducing opioid use. On the provider side, prescribing guidelines appear to decrease the overall number of pills prescribed, often without changes in patient satisfaction or requests for refills. Conclusions Researchers are just beginning to establish the most effective ways for institutions to reduce opioid use and promote responsible post-operative prescribing. Institutional prescribing guidelines, standardized bedside pain-management programs, and formal patient education curriculums are all evidence-based interventions that can achieve these goals. The available research also supports an interprofessional approach in any institutional opioid-reduction strategy.

Cervical disc replacement (CDR) has a high success rate. However, failure may occur due to persistent radiculopathy or myelopathy, malposition, heterotopic ossification, infection, subsidence, bearing wear, sizing error, and vertebral body fracture. Preoperative planning prior to revision surgery requires a complete history and physical, operative note from the index surgery, identification of implant information, imaging (radiographs, CT, and/or MRI), and determination of the etiology of CDR failure. Explanting the device and performing a fusion with a cage or graft may be performed for one-level revision. Corpectomy and fusion should be considered for two or greater levels of CDR revision because it reduces the number of graft-bone interfaces that require fusion, provides a large amount of autograft, affords stability, and removes the fibrinous on growth that occurs under the baseplates from the original surgery. Revision is associated with a greater complication rate than primary CDR, and consideration must be given to mitigating factors that predispose to adverse events.

The cost of healthcare and spine surgery, in particular, continues to rise. The ever-increasing volume of spine surgery being performed, as well as the use of instrumentation, biologics, and advanced technology, keeps shifting the cost curve upward. The value of healthcare is defined as the overall quality of care provided divided by the cost. Cervical radiculopathy and myelopathy can be effectively treated via numerous surgical interventions – all with proven quality – but, sometimes, with very different costs. All medical interventions should not only be scrutinized for their success rates but also for their overall value. Anterior cervical discectomies and fusions, cervical disc replacements, and posterior cervical foraminotomies are all valuable surgical options for the treatment of one-level cervical radiculopathy. However, there is a trend in the literature to suggest that, in properly indicated patients, CDRs and PCFs potentially provide a greater value to the patient. The treatment of degenerative cervical myelopathy has been shown to be extremely valuable regardless of the surgical approach used. Additionally, current data implies that the use of outpatient surgical centers should be considered in an effort to reign in the overall costs of cervical spine surgery. There are numerous options in the treatment of the degenerative cervical spine. Given the economic costs of modern healthcare, it is imperative that surgeons examine the value of these specific treatments as opposed to simply focusing on the quality.

OBJECTIVEEnhanced recovery after surgery (ERAS) and multimodal analgesia are established care models that minimize perioperative opioid consumption and promote positive outcomes after spine surgery. Opioid-free anesthesia (OFA) is an emerging technique that may achieve similar goals. The purpose of this study was to evaluate an OFA regimen within an ERAS pathway for lumbar decompressive surgery and to compare perioperative opioid requirements in a matched cohort of patients managed with traditional opioid-containing anesthesia (OCA).METHODSThe authors performed a retrospective analysis of prospectively collected data. They included 36 patients who underwent lumbar decompression under their ERAS pathway for spinal decompression between February and August 2018. Eighteen patients who received OFA were matched in a 1:1 ratio to a cohort managed with a traditional OCA regimen. The primary outcome was total perioperative opioid consumption. Postoperative pain scores (measured using the numerical rating scale [NRS]), opioid consumption (total morphine equivalents), and length of stay (time to readiness for discharge) were compared in the postanesthesia care unit (PACU). The authors also assessed compliance with ERAS process measures and compared compliance during 3 phases of care: pre-, intra-, and postoperative.RESULTSThere was a significant reduction in total perioperative opioid consumption in patients who received OFA (2.43 ± 0.86 oral morphine equivalents [OMEs]; mean ± SEM), compared to patients who received OCA (38.125 ± 6.11 OMEs). There were no significant differences in worst postoperative pain scores (NRS scores 2.55 ± 0.70 vs 2.58 ± 0.73) or opioid consumption (5.28 ± 1.7 vs 4.86 ± 1.5 OMEs) in the PACU between OFA and OCA groups, respectively. There was a clinically significant decrease in time to readiness for discharge from the PACU associated with OFA (37 minutes), although this was not statistically significantly different. The authors found high overall compliance with ERAS process measures (91.4%) but variation in compliance according to phase of care. The highest compliance occurred during the preoperative phase (94.71% ± 2.88%), and the lowest compliance occurred during the postoperative phase of care (85.4% ± 5.7%).CONCLUSIONSOFA within an ERAS pathway for lumbar spinal decompression represents an opportunity to minimize perioperative opioid exposure without adversely affecting pain control or recovery. This study reveals opportunities for patient and provider education to reinforce ERAS and highlights the postoperative phase of care as a time when resources should be focused to increase ERAS adherence.

Study design A retrospective state database analysis. Objective The aim of this study was to describe the epidemiology and complications of as well as indications for primary isolated atlantoaxial fusion. Summary of background data Atlantoaxial fusion involves unique indications, techniques, and complications. There is limited epidemiologic literature focused specifically on this procedure. Methods New York's Statewide Planning and Research Cooperative System database, an all-payer hospitalization reporting system, was queried to identify all patients undergoing primary isolated atlantoaxial fusion in the state from 1997 to 2012. Demographic and clinical data were extracted and analyzed. United States Census Bureau figures were used to calculate population-adjusted surgical rates. Results One thousand five hundred fifty-nine patients underwent isolated primary atlantoaxial fusion during the study period. The overall population-adjusted annual surgical rate did not change significantly over time. By 2012, individuals aged ≥70 years had the highest incidence of surgery [2.37 per 100,000 population; 95% confidence interval (95% CI) 1.68-3.07]. Medicare was the most common payer (44.0% of claims). Approximately 85% of patients had a Charlson/Deyo Comorbidity Index of zero or one. Over time, a significantly lower proportion of atlantoaxial fusions were attributable to rheumatic disease, and a significantly higher proportion were due to fracture. By 2012, management of fractures was the most common indication for C1-C2 fusion (44.1% of cases). Dysphagia or dysphonia occurred after 0.8% of cases, dural tear after 0.3%, infection after 0.5%, and seroma, hematoma, or hemorrhage after 0.5%. In-hospital mortality was 2.7%, of which 76% had fracture as the surgical indication. Conclusion Isolated atlantoaxial fusions have been performed at a stable, low level over the past 16 years in New York. Although most of these patients are relatively healthy pre-operatively, approximately one in 10 experience an in-hospital complication and nearly 3% die in-hospital. Knowledge of these risks will hopefully spur further efforts to minimize them and allow for more accurate counseling of patients and their families. Level of evidence 4.

Background: Limited data exist on long-term revision rates following cervical spine arthrodeses. The purposes of this study were to define reoperation rates after primary cervical arthrodeses and to identify risk factors for revisions. Methods: New York State’s all-payer health-care database was queried to identify all primary subaxial cervical arthrodeses occurring in the 16 years from 1997 through 2012. A total of 87,042 patients were included in the study cohort. Demographic information was extracted. Patients’ preoperative medical comorbidities, surgical indications, and operative approaches were assembled using codes from the ICD-9-CM (International Classification of Diseases, Ninth Revision, Clinical Modification). The cohort was followed to revision surgical procedures, death, or the end of the study period. All subsequent contiguous spinal arthrodeses, including in the subaxial cervical spine, were considered revisions. The overall revision risk and the risk associated with various preoperative characteristics, surgical indications, and operative approaches were assessed using a Cox proportional hazard model. Results: During the study period, 6,721 patients (7.7%) underwent revision. The median time to revision was 24.5 months. The probability of undergoing at least one revision by 192 months was 12.6%. Arthrodeses performed via anterior-only approaches had a significantly higher probability of revision (p < 0.001) at 13.4% (95% confidence interval [95% CI], 12.9% to 13.9%) than those performed via posterior approaches at 7.4% (95% CI, 6.6% to 8.4%) or circumferential (anterior and posterior) approaches at 5.2% (95% CI, 4.0% to 6.8%). This relationship persisted in multivariate analysis; compared with anterior surgical procedures, there was a significantly lower risk of revision (p < 0.001) for posterior surgical approaches at a hazard ratio of 0.76 (95% CI, 0.69 to 0.84) and circumferential approaches at a hazard ratio of 0.53 (95% CI, 0.42 to 0.66). Patient age of 18 to 34 years, white race, insurance status of Workers’ Compensation or Medicare, and surgical procedures for spinal stenosis, spondylosis, deformity, and neoplasm were associated with elevated revision risk. Arthrodeses spanning few levels and those performed for fractures had a lower revision risk. Conclusions: Primary subaxial cervical spine arthrodeses had a probability of revision approaching 13% over a 16-year period, with elevated reoperation rates in patients undergoing anterior-only surgical procedures. Age, race, insurance status, surgical indication, and number of spinal levels included in the arthrodesis were also associated with reoperation risk. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Purpose Survival after metastatic cancer has improved at the cost of increased presentation with metastatic spinal disease. For patients with pathologic spinal fractures and/or spinal cord compression, surgical intervention may relieve pain and improve quality of life. Surgery is generally considered to be inappropriate if anticipated survival is < 3 months. The aim of this international multicenter study was to analyze data from patients who died within 3 months or 2 years after surgery, to identify preoperative factors associated with poor or good survival, and to avoid inappropriate selection of patients for surgery in the future. Patients and Methods A total of 1,266 patients underwent surgery for impending pathologic fractures and/or neurologic deficits and were prospectively observed. Data collected included tumor characteristics, preoperative fitness (American Society of Anesthesiologists advisory [ASA]), neurologic status (Frankel scale), performance (Karnofsky performance score [KPS]), and quality of life (EuroQol five-dimensions questionnaire [EQ-5D]). Outcomes were survival at 3 months and 2 years postsurgery. Univariable and multivariable logistic regression analyses were used to find preoperative factors associated with short-term and long-term survival. Results In univariable analysis, age, emergency surgery, KPS, EQ-5D, ASA, Frankel, and Tokuhashi/Tomita scores were significantly associated with short survival. In multivariable analysis, KPS and age were significantly associated with short survival (odds ratio [OR], 1.36; 95% CI, 1.15 to 1.62; and OR, 1.14; 95% CI, 1.02 to 1.27, respectively). Associated with longer survival in univariable analysis were age, number of levels included in surgery, KPS, EQ-5D, Frankel, and Tokuhashi/Tomita scores. In multivariable analysis, the number of levels included in surgery (OR, 1.21; 95% CI, 1.06 to 1.38) and primary tumor type were significantly associated with longer survival. Conclusion Poor performance status at presentation is the strongest indicator of poor short-term survival, whereas low disease load and favorable tumor histology are associated with longer-term survival.

OBJECTIVE The purpose of this study was to report the outcome of a study of 2-level cervical total disc replacement (Mobi-C) versus anterior cervical discectomy and fusion (ACDF). Although the long-term outcome of single-level disc replacement has been extensively described, there have not been previous reports of the 5-year outcome of 2-level cervical disc replacement. METHODS This study reports the 5-year results of a prospective, randomized US FDA investigational device exemption (IDE) study conducted at 24 centers in patients with 2-level, contiguous, cervical spondylosis. Clinical outcomes at up to 60 months were evaluated, including validated outcome measures, incidence of reoperation, and adverse events. The complete study data and methodology were critically reviewed by 3 independent surgeon authors without affiliation with the IDE study or financial or institutional bias toward the study sponsor. RESULTS A total of 225 patients received the Mobi-C cervical total disc replacement device and 105 patients received ACDF. The Mobi-C and ACDF follow-up rates were 90.7% and 86.7%, respectively (p = 0.39), at 60 months. There was significant improvement in all outcome scores relative to baseline at all time points. The Mobi-C patients had significantly more improvement than ACDF patients in terms of Neck Disability Index score, SF-12 Physical Component Summary, and overall satisfaction with treatment at 60 months. The reoperation rate was significantly lower with Mobi-C (4%) versus ACDF (16%). There were no significant differences in the adverse event rate between groups. CONCLUSIONS Both cervical total disc replacement and ACDF significantly improved general and disease-specific measures compared with baseline. However, there was significantly greater improvement in general and disease-specific outcome measures and a lower rate of reoperation in the 2-level disc replacement patients versus ACDF control patients. Clinical trial registration no. NCT00389597 (clinicaltrials.gov)

Background: Developmental cervical stenosis of the spinal canal predisposes patients to neural compression and loss of function. The Torg-Pavlov ratio has been shown to provide high sensitivity but low specificity for identifying developmental cervical stenosis. A more sensitive and specific radiographic index has not been reported to our knowledge. The objective of this study was to develop and provide an objective, sensitive, and specific radiographic index to assess for developmental cervical stenosis. Methods: The C3 through C6 levels of the cervical spine were analyzed on lateral radiographs of 150 adult patients to determine the spinolaminar line-to-lateral mass distance (SL), lateral mass-to-posterior vertebral body distance (LM), spinolaminar line-to-vertebral body (canal) diameter (CD), and vertebral body diameter (VB). Ratios of these measurements were calculated to eliminate magnification effects. The corresponding true spinal canal diameter was measured using computed tomography (CT) midsagittal sections. Receiver operating characteristic (ROC) curve analysis was performed to identify a radiographic measurement ratio with optimal sensitivity and specificity, using a true canal diameter of

Background: It has been suggested, although not proven, that presence of concomitant psychiatric disorders may increase the inpatient costs for patients undergoing elective surgery. This study was designed to test the hypothesis that elective lumbar fusion surgery is more costly in patients with under treatment for depression. Methods: This is a retrospective case-control study of 142 patients who underwent elective lumbar fusion. Of those 142 patients, 41 patients were chronically using an antidepressant medication that considered as a "study group", and 101 patients were not taking an antidepressant medication that considered as a "control group". Data was collected for this cohort regarding antidepressant usage patient demographics, length of stay (LOS), age-adjusted Charlson comorbidity index scores and cost. Costs were compared between those with a concomitant antidepressant usage and those without antidepressant usage using multivariate analysis. Results: Patients using antidepressants and those with no history of antidepressant usage were similar in terms of gender, age and number of operative levels. The LOS demonstrated a non-significant trend towards longer stays in those using anti-depressants. Total charges, payments, variable costs and fixed costs were all higher in the antidepressant group but none of the differences reached statistical significance. Using Total Charges as the dependent variable, gender and having psychiatric comorbidities were retained independent variables. Use of an antidepressant was independently predictive of a 36% increase in Total Charges . Antidepressant usage as an independent variable also conferred a 22% increase in cost and predictive of a 19% increase in Fixed Cost . Male gender was predictive of a 30% increase in Total Charges . Conclusion: This study suggests use of antidepressant in patients who undergo elective spine fusion compared with control group is associated with increasing total cost and length of hospitalization, although none of the differences reached statistical significance.

A retrospective case series describing teardrop fracture of the axis.The purpose of the study was to clarify the clinical features, the mechanism of injury, and the potential instability of extension teardrop fractures of the axis, so as to emphasize the importance of recognizing this injury as a separate entity.Teardrop fractures of the axis are rare spinal fractures, comprising only a small percentage of all injuries of the cervical spine. The stability of this fracture pattern has been a matter of debate leading to controversy regarding treatment strategies and the need for stabilization.We retrospectively reviewed data collected from 16 patients to document the mechanism of injury, neurological deficit, treatment and clinical outcome, and imaging findings.Extension teardrop fractures accounted for approximately 8.9% of the upper cervical spinal injuries and 12.7% of axis fractures at the authors' institution over the same period. Six patients (4 males and 2 females) underwent surgery (4 by an anterior approach, 2 by a posterior approach). Ten cases underwent Halo-vest immobilization for a period between 6 and 12 weeks. At final follow-up, 14 cases achieved excellent results, whereas 2 patients complained of mild residual neck pain. Maximum cranial-caudal dimensions of the fragments were between 5 and 24 mm (average, 12.9 mm), and the transverse dimensions were between 5 and 22 mm (average, 11.1 mm). Fragment displacement ranged from 1 to 9 mm (average, 3.5 mm), whereas fragment rotation ranged from 10 to 52 degrees (average, 24.4 degrees) in the sagittal plane.Most patients with an extension teardrop fracture of the axis can be treated conservatively. On the basis of this case series, the authors suggest that large fragment size, displacement or angulation, intervertebral disk injury, neurologic deficit, or signs of instability are reasonable indications for surgical treatment.

BACKGROUND CONTEXT Recent literature has demonstrated that preoperative opioid use is associated with both worse postoperative outcomes and increased postoperative opioid dependence after anterior cervical discectomy and fusion (ACDF). However, no studies have demonstrated a relationship between acute, subacute, and chronic preoperative opioid use and reoperation on the cervical spine. This information would be valuable for counseling patients for preoperative opioid cessation. PURPOSE To demonstrate an association between preoperative use of five different opioid medications on reoperation after ACDF in patients without myelopathy. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE This study included 445 patients undergoing single-level ACDF without myelopathy. OUTCOME MEASURES Reoperation on the cervical spine within 5 years postoperatively. METHODS Preoperative use of five opioid medications (tramadol, hydromorphone, oxycodone, hydromorphone, and extended-release (ER) oxycodone) were assessed and categorized as acute (within 3 months), subacute (acute use and use between 3-6 months), and chronic (subacute use and use prior to 6 months). Multivariate regression was used to determine the relative association of each medication on reoperations during the acute, subacute, and chronic periods. All patients were followed for 5 years postoperatively. RESULTS The most commonly used preoperative opioid was hydrocodone (50.3% acute use, 24.7% chronic use), followed by oxycodone (19.6% acute use, 6.7% chronic use), and tramadol (14.4% acute use, 5.4% chronic use). Hydromorphone and ER-oxycodone were only used in 1.8% and 0.4% of patients, respectively, and were excluded from further analyses. A total of 42 patients (9.4%) underwent reoperation within 5 years. At 5 years postoperatively patients who had acute, subacute, and chronic preoperative use of hydrocodone had reoperation rates of 9.4%, 14.8%, and 15.5%, respectively, compared to 4.7% in opioid naive patients (P 0.05). CONCLUSIONS Both subacute and chronic use of common opioid medications are associated with increased reoperations after single-level ACDF in non-myelopathic patients. While the reasons for this are unclear, chronic mu-receptor agonism is known to result in opioid-induced hyperalgesia. This may make identification of pain generators difficult in non-myelopathic patients or lead to chronic postoperative pain. This information is also critical when counseling patients on preoperative opioid cessation. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT The decrease of psoas cross-sectional area has been used as a parameter of sarcopenia and reported to be a predictor of increased risk of mortality and complications in various surgeries, including spine surgery. However, it is unclear whether psoas size impacts postoperative functional outcomes in spine surgery. PURPOSE To investigate the impact of psoas cross-sectional area on short-term clinical outcomes of MI-TLIF for degenerative diseases. STUDY DESIGN/SETTING Retrospective study. PATIENT SAMPLE A total of 108 patients who underwent minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) at a single level for degenerative lumbar diseases. Patients with previous anterior-approached lumbar surgery history were excluded. OUTCOME MEASURES Oswestry Disability Index (ODI), Visual Analog Scale at Back (VAS Back) and at leg (VAS Leg), Short Form 12 Physical Component Summary (SF-12 PCS) and Mental Component Summary (SF-12 MCS) and Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS PF) at pre-op, 2 weeks, 6 weeks, 3 months and 6 months, intra- and postoperative complications, length of stay (LOS). METHODS The cross-sectional area of psoas muscle was measured at the level of L3/4 on T2-weighted axial images of preoperative MRI by 2 observers. Normalized total psoas area (NTPA) was calculated as total psoas area normalized to patient height. Outcomes in patients with the lowest sex-specific quartile of NTPA (Low NTPA group) were compared to the other 3 quartiles (High NTPA group). RESULTS A total of 108 patients (age [58.5±13.4], gender [62 males, 46 female], diagnosis [68 lumbar degenerative spondylolisthesis, 30 lumbar canal stenosis, 8 lumbar disc herniation]) were included in this study. The lowest quartile of NTPA threshold was 780 mm2/m2 in male and 486 mm2/m2 in female. The inter-rater reliability for NTPA was excellent. (ICC = 0.989, 95% CI 0.984-0.993) There were no significant differences between the two cohorts regarding demographics (age, gender, race, diagnosis, type of surgery, surgical level) including factors affecting clinical outcomes of lumbar surgery (BMI, smoking status, mental disorders, worker's compensation, previous lumbar surgery history). At 2- and 6-weeks preop, there was no significant difference between cohorts in all parameters. At 3 and 6 months, all parameters for the Low NTPA group showed a tendency for worse outcomes compared to those in the High NTPA group. In particular, ODI at 6 months (Low NTPA group 30.1 vs High NTPA group 16.4, P=0.011), VAS back at 6 months (Low NTPA group 3.6 vs High NTPA group 1.9, P=0.022), SF-12 MCS at 3 months (Low NTPA group 48.8 vs High NTPA group 54.0, P=0.043) and at 6 months (Low NTPA group 49.0 vs High NTPA group 55.2, P=0.016) were significantly worse in the Low NTPA group. There was no significant difference in intra- and postoperative complications and LOS in this study. CONCLUSIONS The decrease of psoas cross-sectional area had a negative impact on short-term functional outcomes of MI-TLIF. This parameter is highly reliable and easy to measure with preoperative MRI. Along with the progress of the aging society, this sarcopenia-related parameter may play an important role in preoperative decision making in the treatment for degenerative lumbar diseases. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT There is a lack of data informing opioid prescription quantities after ACDF or CDA. PURPOSE To record daily opioid use and pain levels after one- or two-level ACDF or CDA using an automated text-messaging based data collection system. STUDY DESIGN/SETTING Dual-institutional prospective observational study. PATIENT SAMPLE This study included 57 patients who underwent ACDF or CDA at one of two institutions (66.7% ACDF, 33.3% CDA; 64.6% one level, 35.4% two levels). OUTCOME MEASURES Daily opioid consumption, daily pain scores (NRS scale), initial prescription amount and type, number of pills left over, method of disposal, refill rate. METHODS All adult patients undergoing one- or two-level primary ACDF or CDA were enrolled at two high-volume institutions. Patients with daily opioid dependence were excluded, while those patients who utilized opioids on a non-daily basis in the 6 months before surgery were categorized as “intermittent opioid users.” Starting POD1, daily opioid use and pain scores were collected through a HIPAA-compliant, automated text-messaging system. To facilitate clinical applications, opioid use was converted from oral morphine equivalents (OME) into “pills” (oxycodone 5 mg equivalents). After 6 weeks or upon patient-reported cessation of opioid use, final survey questions were asked. Refill and prescription data were verified from the state registry. Risk factors for patients in top 25% of opioid use were analyzed. RESULTS A total of 48 patients completed the daily queries (84.2%). Average age of the patient sample was 50.2±10.9 years, with a BMI of 27.4±4.2 kg/m2. Thirty-two patients (66.7%) underwent ACDF and 10 CDA (33.3%); 64.6% one level and 35.4% two levels. In the six months before surgery, 18.8% used opioids on a non-daily basis. Total postdischarge opioid use ranged from 0-160 “pills” (oxycodone 5mg equivalents), median of 6.7 pills (IQR 0-30). Use did not vary between the one- and two-level groups (10 IQR [1.3-31.3] vs 4 pills IQR [0-18], respectively, p=0.085). Thirteen patients (27.1%) used no opioids after discharge. Out of those patients who took opioids, use dropped from median 2.6 pills POD1 to 1 pill POD5. By POD12, 91.4% stopped opioids. Only 6 patients (14.2%) obtained a refill. Preoperative intermittent opioid use was associated with the top 25% of opioid consumption (9.1% vs 50%, p=0.006). In all patients, pain scores declined from a median 6 on POD1 to 4 on POD7. CONCLUSIONS Most patients fall at the low end of the opioid-use spectrum, with a quarter taking no opioids postdischarge. A prescription equivalent to 10 oxycodone 5 mg pills (75 OME) would allow for pain relief while minimizing the number of leftover pills. Prescribing guidelines must reflect these numbers to avoid excess leftover pills in the home. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Real time image-guidance and intra-operative 3-dimensional navigation (ION) are increasingly being utilized in spine surgery to provide better visualization, improve accuracy and enable less invasive procedures. Studies have shown effective early adaption and radiation reduction with this technology in minimally invasive lumbar spine surgery. However, the novel use of a noninvasive skin-anchored tracker has not yet been described for cervical spine surgery. PURPOSE To describe the time demand, radiation exposure and outcomes of ION using a skin-anchored tracker in minimally invasive posterior cervical laminoforaminotomy (MI-PCLF). STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE All patients who underwent MI-PCLF by a single surgeon from April17-November 19. OUTCOME MEASURES Time for navigation set-up, operative time, estimated blood loss (EBL), radiation exposure to operating room (OR) personnel and the patient, complications and length of stay. METHODS Operative variables, radiation exposure and perioperative outcomes were summarized using descriptive statistics. RESULTS Twenty-one patients (36Levels) with a mean age of 55+11.79yrs, BMI of 27.36+2.95kg/m2, and comprising 17(81%) males were included. A majority of cases were 1-level (9; 42.9%) or 2-level (10; 47.6%), with only one 3-level and one 4-level surgery. The operative levels were: C3C4 (11.1%), C4C5 (19.4%), C5C6 (22.2%), C6C7 (25%), C7T1 (22.2%). Time required for ION set-up, measured as the time from end of anesthesia induction to the start of the surgical procedure was a median of 34 mins [IQR 30-37]. This accounts for the time required for patient positioning, preparing and draping the incision site, placing the skin-anchored navigation tracker and acquiring a 3D image for real-time navigation. The total fluoroscopy time was a median of 10 sec [IQR 9-11], almost entirely attributable to ION image-acquisition; and radiation dose was a median of 2.5mGy [IQR 1.8-4.9]. Thus, radiation exposure to the patient was minimal. Since all OR personnel are behind a protective lead shield during ION image-acquisition, radiation exposure to the surgeon and OR team was negligible. One patient required a repeat ION spin, resulting in the fluoroscopy time for ION image-capture being 20sec. In two patients, ION was abandoned and the procedure was completed using fluoroscopy resulting in the total fluoroscopy time being 17&27sec (9sec for ION spin; rest for fluoroscopic guidance). Additionally, one patient had a radiation dose of 13.9mGy, which is almost three times the 75th percentile dose. Although the exact reason could not be determined, this may be attributable to a number of factors including deliberate or inadvertent higher dose settings, difference in C-arm position, calibration error, etc. Operative time was 62 mins [IQR 53-74] and EBL was low (25ml [IQR 25-25]. There were no wrong level surgeries, or any intra or post-operative complications. Median post-operative length of stay was 6hrs [IQR 4.4-20.9], with a majority (66.7%) of patients being discharged on the day of surgery. CONCLUSIONS The results of our study suggest that the use of intraoperative navigation using a skin-anchored tracker for posterior cervical laminoforaminotomy is a feasible, safe and accurate technique, resulting in short operative times and minimal complications. Further, it results in negligible radiation exposure to the OR team and low radiation exposure to the patient. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Cervical spine steroid injections are increasingly being used for diagnosis and treatment of degenerative pathology. For cervical spondylotic myelopathy traditionally treated with surgery, there has been little investigation of the possible therapeutic or preventive effects of targeted injections. As injections may be targeted to the epidural space, the transforaminal region, or the zygapophyseal joints, differing injection modalities may also have variable therapeutic effects. PURPOSE To determine the potential for cervical spine steroid injections to delay surgical treatment for cervical spondylotic myelopathy. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE A total of 39,590 patients with a new diagnosis of cervical spondylotic myelopathy, without previous cervical spine surgery. OUTCOME MEASURES Timing of surgical treatment (cervical decompression, fusion, or arthroplasty, from anterior or posterior approaches). METHODS Administration of cervical epidural, transforaminal, or zygapophyseal steroid injections was determined based on Current Procedural Terminology (CPT) codes. Timing of surgical treatment (cervical decompression, fusion, or arthroplasty, from anterior or posterior approaches) was also determined based on CPT codes. Multivariate logistic regression was used to determine the association of steroid injection administration with surgical treatment at various time points after initial diagnosis (1, 3, 6 months, and 1, 2, 5 years). RESULTS A total of 39,590 patients with a new diagnosis of cervical spondylotic myelopathy were identified. A total of 6,405 patients (16.2%) underwent cervical epidural steroid injections, 1,426 (3.6%) underwent transforaminal steroid injections, and 647 (1.6%) underwent zygapophyseal injections. Mean time from initial diagnosis to surgery was 180.2 days (standard deviation=345.9 days). In multivariate analysis epidural injections were associated with decreased odds of surgery within 1 month of diagnosis (odds ratio [OR]=0.69, P CONCLUSIONS Epidural steroid injections do not prevent surgical treatment of cervical spondylotic myelopathy in the long run. There may be some short-term symptomatic benefits that lead to delayed surgical treatment, although the clinical benefits have yet to be demonstrated. No significant benefit is seen with transforaminal or zygapophyseal injections for treatment of cervical myelopathy. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Quality of life (QoL) is impacted by the ability for patients to participate in physical activities which interest them. Surgeons may not systematically ask about related activity goals. PURPOSE To determine what specific physical activity goals elective spine surgery patients have and which of these goals surgeons suggest modifying. STUDY DESIGN/SETTING Retrospective cohort. PATIENT SAMPLE Elective spine surgery patients at Hospital for Special Surgery (NY, USA). OUTCOME MEASURES Patient reported outcome measures (PROMs). METHODS A standard-of-care survey previously developed for hip and knee arthroplasty patients was adapted for the elective spine surgery population with degenerative spinal conditions to solicit patient physical activity goals, current and future desired performance, current difficulty performing these activities, and time since the activities could last be performed at the desired level. This pilot survey was administered to new adult patients contemplating spine surgery for degenerative pathology between May 2019 and July 2019. Patient responses were individually reviewed by their respective spine surgeon (seven surgeons participated). Each surgeon recorded whether they agreed with the patient's goal or discussed how to modify the goal. These data were retrospectively assessed for significant associations (p RESULTS During this study, 173 patients were surveyed with 169 (97.7%) having one or more reported physical activity goals (215 total goals). After excluding workers compensation patients (n=5), average patient age was 59.9 years (σ=16.4, range: 19.0–93.0 years). Average patient BMI was 27.4 (σ=5.3, range: 16.0–47.9). This study population included patients with lumbar spine degeneration (72.0%), cervical spine degeneration (23.8%), as well as thoracic and combined regional degeneration (4.3%). Patient activity goals involved: exercise (31.1%), walking (28.2%), recreational activities not including golf (12.9%), golf (7.2%), activities of daily living or ADLs (11.5%), and hobbies (9.1%). Activity goals could be performed at a satisfactory level on average 3.2 years prior to being surveyed (range: 2.0 days–28.0 years) with a longer period associated with higher BMI (p=0.046). Older age was associated with having exercise goals (p CONCLUSIONS Patient activity goals were related to region of spinal degeneration, age and BMI. The low rate of suggested goal modification by surgeons in this study reflects the central role of communication, education, as well as shared decision-making during presurgical assessment and care planning when treating patients with spine conditions. Most patients undergoing elective spine surgery have very particular activity goals that are not currently captured by patient-reported outcome measure (PROM) questionnaires. However, these activity goals are generally not systematically communicated to surgeons. Awareness of patient physical activity goals is important and may ultimately impact patient satisfaction with spine surgery. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT While ODI has historically been the most commonly used patient-reported outcome measure for patients with lumbar spinal pathology, Patient-Reported Outcome Measurement Information System (PROMIS) is increasingly being utilized. However, there are few studies assessing the psychometric properties of PROMIS in minimally invasive (MIS) spine surgery. PURPOSE To perform a psychometric evaluation of PROMIS Physical Function Computer Adaptive Testing (PROMIS-PF CAT) in MIS lumbar surgery. STUDY DESIGN/SETTING Retrospective review of prospectively collected data. PATIENT SAMPLE A total of 421 patients who underwent MIS lumbar surgery. OUTCOME MEASURES Patient-reported outcome measures [Oswestry disability Index – ODI, PROMIS-PF CAT, Short Form (SF)-12]. METHODS Patient-reported outcome measure (PROMs) collected pre- and post-operatively of patients undergoing MIS lumbar surgery were retrospectively analyzed to assess responsiveness, coverage, discriminant validity and concurrent validity of PROMIS-PF CAT. Responsiveness was assessed using paired t-test, effect size (ES) and standardized response mean (SRM). Coverage was measured by assessing floor and ceiling effects. Discriminant validity was assessed pre- and post-op using independent t-test to identify difference in PROMIS-PF scores in known groups. Concurrent validity was assessed by evaluating the correlation with legacy PROMs, ODI and SF12. RESULTS Responsiveness 1. Decompression cohort: SF-12 PHS and PROMIS-PF have lower responsiveness than ODI in detecting an improvement at 2 weeks; PROMIS-PF also has lower responsiveness in detecting improvement at 1 year. 2. Fusion cohort: ODI and PROMIS-PF demonstrate equivalent responsiveness at all time-points; however, the responsiveness of SF-12 is lower than that of ODI and PROMIS-PF at all time-points. Coverage No floor effect was seen for any PROMs. ODI showed a ceiling effect (% having the best possible score: 0.5% pre-operatively; gradually increasing at 16.7% at 1-year). SF-12 PHS and PROMIS-PF did not show a ceiling effect, and clustering at higher levels was CONCLUSIONS Although PROMIS-PF showed lower responsiveness than ODI, particularly in the decompression sub-group, it demonstrated discriminant validity pre- and post-operatively, convergent validity with ODI and better coverage than ODI. These findings suggest that PROMIS-PF CAT demonstrates reasonable psychometric properties and may be a good surrogate for ODI. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT Recent literature has demonstrated that preoperative opioid use is associated with both worse postoperative outcomes and increased postoperative opioid dependence after lumbar spine surgery. However, no studies have demonstrated a relationship between acute, subacute and chronic preoperative opioid use and reoperation on the lumbar spine. This information would be valuable for counseling patients for preoperative opioid cessation. PURPOSE To demonstrate an association between preoperative use of five different opioid medications on reoperation after lumbar decompression (LD) and after lumbar posterior or transforaminal interbody fusion (PLIF/TLIF). STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE A total of 11,388 patients undergoing LD and 3,302 patients undergoing PLIF/TLIF without prior lumbar spine surgery. OUTCOME MEASURES Reoperation on the lumbar spine within 5 years postoperatively (decompression or fusion). METHODS Preoperative use of five opioid medications (tramadol, hydromorphone, oxycodone, hydromorphone, and extended-release (ER) oxycodone) were assessed and categorized as acute (within 3 months), subacute (acute use and use between 3-6 months), and chronic (subacute use and use prior to 6 months). Multivariate regression was used to determine the relative association of each medication on reoperations. All patients were followed for 5 years postoperatively. RESULTS In the LD group a total of 532 patients (4.6%) underwent reoperation in 5 years postoperatively. Opioid naive patients had a 5-year reoperation rate of 4.2%, compared with 23.1%, 8.6%, 5.5%, 5.8%, and 0.0% with chronic preoperative use of hydromorphone, oxycodone, hydrocodone, tramadol and ER-oxycodone. These rates were higher than in patients with acute and subacute preoperative use. In multivariate analysis of group LD, controlling for multilevel surgery, age, gender and Charlson Comorbidity Index, chronic use of both oxycodone (odds ratio [OR] = 1.67, P CONCLUSIONS Both chronic use of the higher-potency opioid medications, oxycodone and hydromorphone, are associated with increased reoperations after lumbar decompression and lumbar interbody fusion procedures. The etiology of this association is not currently known and warrants further investigation. One explanation may be that opioid-induced hyperalgesia may result in difficult identification of preoperative pain generators and also chronic uncontrolled postoperative pain. Nevertheless, the information will valuable during patient counseling and when recommending preoperative opioid weaning. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND Cervical alignment is vital for maintaining horizontal gaze and sagittal balance. The aims of this study were to summarize previously published descriptions of normative cervical alignment and to analyze a cohort of asymptomatic volunteers in order to identify natural clusters of normal radiographic parameters. METHODS We performed a systematic review of the literature on radiographic measurements of asymptomatic volunteers through a search of MEDLINE and ScienceDirect databases. We then performed an analysis of demographic and radiographic parameters of volunteers without back or neck complaints. Only subjects with a chin-brow vertical angle (CBVA) within previously published normal limits were retained for analysis. A 2-step cluster analysis was used to find natural groups of cervical alignment. Differences among groups were investigated with a post hoc analysis of variance (ANOVA). RESULTS We included 37 articles in our analysis. There was a broad spectrum of both C2-C7 lordosis-kyphosis and T1 slope across ages and sexes. Of the 119 asymptomatic volunteers who were available for analysis, 84 (with a mean age [and standard deviation] of 49.0 ± 17.1 years) had a CBVA ranging from -4.7° to 17.7°. The cluster analysis identified 3 alignment groups based on cervical lordosis-kyphosis and T1 slope (silhouette measure of cohesion, >0.6). Twenty-seven volunteers (32.1%) were identified as the "kyphotic curve cohort" (KCC) (mean C2-C7 Cobb angle, -8.6° ± 7.3°; mean T1 slope, 17.4° ± 6.6°), 43 volunteers (51.2%) were identified as the "medium lordosis cohort" (MLC) (mean C2-C7 Cobb angle, 8.7° ± 7.2°; mean T1 slope, 26.6° ± 4.0°), and 14 volunteers (16.7%) were identified as the "large lordosis cohort" (LLC) (mean C2-C7 Cobb angle, 21.2° ± 7.2°, mean T1 slope, 39.5° ± 6.4°) (p < 0.001 for both). Moving from KCC to LLC, there was a significant decrease in C0-C2 lordosis (p = 0.016). Examination of the cervical vertebral orientation demonstrated that C4 had a constant orientation relative to the horizontal (p = 0.665). Correlation analysis between C2-C7 and vertebral orientations again demonstrated that C4 orientation was independent of C2-C7 alignment. CONCLUSIONS We have identified 3 morphotypes of the cervical spine based on C2-C7 alignment and T1 slope. These findings demonstrate the broad definition of normal cervical alignment and the range of cervical lordosis-kyphosis that is acceptable.

Background: Procedure-specific opioid-prescribing guidelines have the potential to decrease the number of unused pills in the home without compromising patient satisfaction. However, there is a paucity of data on the minimum necessary quantity to prescribe for outpatient orthopaedic surgeries. Purpose: To prospectively record daily opioid use and pain levels after arthroscopic meniscal procedures and anterior cruciate ligament reconstruction (ACLR) at a single institution. Study Design: Case series; Level of evidence, 4. Methods: A total of 95 adult patients who underwent primary arthroscopic knee surgery (meniscectomy, repair, or ACLR) were enrolled. Patients with a history of opioid dependence were ineligible. Daily opioid consumption and Numeric Rating Scale pain scores were collected through an automated text-messaging platform starting on postoperative day 1 (POD1). At 6 weeks or at patient-reported cessation of opioid use, final survey questions were asked. Patients who failed to complete data collection were excluded. Opioid use was converted into “pills” (oxycodone 5-mg equivalents) to facilitate comparisons and clinical applications. Factors associated with high and low opioid use were compared. Results: Of the 95 patients enrolled, 71 (74.7%) were included in the final analysis. Of these, 40 (56.3%) underwent meniscal surgery and 31 (43.7%) underwent ACLR. After outpatient arthroscopic meniscectomy or repair, the total median postdischarge opioid use was 0.3 pills (oxycodone 5-mg equivalents), with 75% of patients consuming 3.3 or fewer pills (range, 0-19 pills). For ACLR, the median postdischarge consumption was 7 pills (75th percentile, 23.3 pills; range, 0-41 pills). Almost one-third of patients (32.3%) took no opioids after surgery (3 ACLR, 20 meniscus). All meniscus patients and 71% of ACLR patients ceased opioid consumption by postoperative day 7. Conclusion: Opioids may not be necessary in all patients, particularly after meniscal surgery and in comparison with ACLR. For patients requesting opioids for pain relief, reasonable prescription quantities are 5 oxycodone 5-mg pills after arthroscopic meniscal procedures and 20 5-mg pills after ACLR. Slowing the current opioid epidemic and preventing future crises is dependent on refining prescribing habits. Clinicians should strongly consider patient education regarding expected pain as well as pain management strategies.

Background Anterior lumbar interbody fusion (ALIF) has been used for treatment of a variety of spinal conditions including degenerative disc disorders and low-grade spondylolisthesis. Expected fusion rate of stand-alone ALIF constructs is currently unclear. The aim of this study was to examine the fusion rate for ALIF without supplemental posterior fusion or instrumentation (stand-alone ALIF). Methods We queried the MEDLINE, COCHRANE, and EMBASE databases for all literature related to spine fusion rates using a stand-alone ALIF procedure with a publication cutoff date of July 19, 2018. Supplementary combinations of search terms included spine, fusion, fixation, rate(s), and arthrodesis. ALIF surgery was considered stand-alone when not paired with supplemental posterior fusion or posterior spinal instrumentation. Nonhuman and non-English publications were excluded. Cohort fusion rate differences were calculated using Student t test with significance assigned if p value was less than .05. Results Title and abstract level review required assessing 840 unique publications. Across the 55 studies that met the inclusion criteria of this systematic review, 5,517 patients and 6,303 vertebral levels were fused. The overall weighted average patient fusion rate following stand-alone ALIF was 88.2% (range: 16.6%–100%). In the 31 studies with at least 50 subjects, the weighted average fusion rate following stand-alone ALIF was 88.6% (range: 57.5%–99.0%). Use of anterior fixation plate devices yielded a fusion rate of 94.2%. Newer zero-profile interbody implants had a fusion rate of 89.2%. Fusion rates were lower in studies with 50% or more subjects having positive smoking and worker's compensation status, however these results were found to be statistically insignificant (p>.05). Fusion rate for subjects in the eight rhBMP-2 study groups was 94.4% (n=889) compared with 84.8% (n=3,102) in 38 study groups without rhBMP-2 used. Conclusions Based on the available data, stand-alone ALIF procedures yield high fusion rates overall. Fusion failure and pseudoarthrosis rates are higher in study populations involving a high percentage of smokers or positive workers compensation status. Allograft utilization does not significantly improve fusion rate when compared with autograft in stand-alone ALIF constructs.

Quality assessment in spine care has undergone a necessary transition over the last several decades. Initially, quality was measured by clinician-centered approaches that relied on clinician-centered metrics such as length of hospital stay, quality of fusion, need for blood transfusion, or amount of deformity correction. This narrow focus of quality assessment did not consider the perspective of the patient and therefore did not grasp the burden of spine disease from a societal perspective. Clinicians were soon able to understand the need to model quality from the perspective of the patient and society, and therefore the development of patient-related outcome (PRO) tools was commenced. Advancement in the application of PRO instruments continues. Simultaneously, given the current healthcare economic crisis, there is a greater push to create value in spine care: to provide the highest quality care in the most cost-efficient manner. The complex ideology of value and how it is modeled is a burgeoning topic in spine care. The current methods for assessing value have opportunity for improvement and may attain more sophistication and refinement in the future.

With the increased burden of low back pain (LBP) in our globally aging population there is a need to develop preclinical models of LBP that capture clinically relevant features of physiological aging, degeneration, and disability. Here we assess the validity of using a mouse model system for age-related LBP by characterizing aging mice for features of intervertebral disc (IVD) degeneration, molecular markers of peripheral sensitization, and behavioral signs of pain. Compared to three-month-old and one-year-old mice, two-year-old mice show features typical of IVD degeneration including loss of disc height, bulging, innervation and vascularization in the caudal lumbar IVDs. Aging is also associated with the loss of whole-body bone mineral density in both male and female mice, but not associated with percent lean mass or body fat. Additionally, two-year-old mice have an accumulation of TRPA1 channels and sodium channels Na(v)1.8 and Na(v)1.9 in the L4 and L5 lumbar dorsal root ganglia consistent with changes in nociceptive signaling. Lastly, the effect of age, sex, and weight on mobility, axial stretching and radiating pain measures was assessed in male and female mice ranging from two months to two years in a general linear model. The model revealed that regardless of sex or weight, increased age was a predictor of greater reluctance to perform axial stretching and sensitivity to cold, but not heat in mice.