Surgeon Experience Is the Most Important Predictor of Case Failure Rate for Anterior Odontoid Screw Fixation: A Large Database Study.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: Determine risk factors and failure rate of anterior odontoid screw fixation surgery. SUMMARY OF BACKGROUND DATA: Anterior odontoid screw fixation (AOSF) stabilizes type II dens fractures while preserving cervical motion. Despite having potential advantages, AOSF's failure rate and factors contributing to failure remain unknown. MATERIALS AND METHODS: We identified AOSF patients in the national claims database Pearldiver using CPT code 22318. Failure was defined as the requirement of supplementary posterior fusion surgery in the C1-C2 or occiput-C2 region after the AOSF. We considered potential predictors of failure including age, sex, Charlson Comorbidity Index (CCI), surgeon experience, history of osteoporosis, obesity, and tobacco use. Univariate comparison analysis and logistic regression were conducted to identify factors associated with the need for additional posterior surgery. RESULTS: For 2008 identified cases of AOSF, 249 cases (12.4%) required additional posterior fusion. Seventy-one of the 249 cases (28.5%) underwent revision surgery on the same day as the AOSF. Over 86% of revisions (215 cases) occurred within 200 days of the initial procedure. Posterior fusion rates are inversely correlated with surgeon experience, with the most experienced surgeons having a rate of 10.0%, followed by 11.5% for moderately experienced surgeons, and 15.0% for the least experienced surgeons. When comparing moderate and inexperienced surgeons to experienced surgeons, the odds ratios for posterior fusion were 1.18 ( P >0.05) and 1.61 ( P <0.006), respectively. Logistic regression revealed that both lesser experience (odds ratio=1.50) and osteoporosis (odds ratio=1.44) were the only factors significantly associated with failure ( P <0.05). CONCLUSIONS: Our findings indicate a correlation between AOSF success and surgeon experience. While currently published results suggest higher success rates, most of this data originates from experienced surgeons and specialized centers, therefore, they may not accurately reflect the failure rate encountered in a more general practice setting. LEVEL OF EVIDENCE: Level III.

Quantifying Risk Factors for Slipped Capital Femoral Epiphysis and Postslip Osteonecrosis.

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is a disorder of the proximal femoral physis occurring in late childhood and adolescence. Previously postulated risk factors include obesity and endocrinopathies. The purpose of this investigation was to identify risk factors for developing SCFE, as well as postslip osteonecrosis (ON), among the United States pediatric population. METHODS: A national database investigation was performed using PearlDiver Technologies, Inc., queried for SCFE and ON using International Classification of Disease codes (2010 to 2020). Regression analyses to determine the risk of developing a SCFE, and ON after a patient has already been diagnosed with a SCFE ("postslip"). Propensity matching between SCFE and control groups generated a pseudo-randomization model to compare the relative risk. RESULTS: There were 11,465 patients with SCFE available in the database, matched with 134,680 controls. After matching, vitamin D deficiency, obesity, hypothyroidism, and growth hormone use were risk factors for developing SCFE [relative risk ranges from 1.42 (95% CI: 1.21-1.39, vitamin D deficiency) to 3.45 (95% CI: 3.33-3.57, obesity)]. ON risk factors were vitamin D deficiency [1.65 (1.26-2.14)] and hypothyroidism [1.49 (1.10-2.07)]. CONCLUSIONS: This United States national database study quantified risk factors of developing an SCFE and postslip ON. Obesity is the most significant risk factor for the development of a slip, but not ON. Growth hormone use, hypothyroidism, and vitamin D deficiency are also risk factors for SCFE development, whereas only the latter two were associated with ON. These findings demonstrate the public health implications of obesity and comorbid conditions in pediatric hip pathology. LEVEL OF EVIDENCE: Level III.

Impact of State Laws on Dispensing Opioid Prescriptions Following Posterior Lumbar Interbody Fusion Procedures: A Retrospective Large National Database Study.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVES: This study aimed to examine the effect of state legislation on prescribing behavior after a commonly performed spinal procedure, posterior lumbar interbody fusion (PLIF). METHODS: Two cohorts of patients from the Pearl Diver Database were created based on patients who underwent PLIF surgery in 2014-15 and 2018-19. We compared opioid prescription rates and morphine-milli-equivalent (MME) between states with and without prescription legislation. RESULTS: We analyzed 50 958 PLIF patients from 2014-15 and 46 751 patients from 2018-19. Among them, 38 states passed opioid prescription laws in 2016-2017, while 12 states did not. The percentage of patients receiving opioid prescriptions within 365 days post-surgery remained similar in both time periods (49% in 2014-15 and 48% in 2018-2019). This trend was consistent across states with and without prescription legislation (50% vs 48% in 2014-2015, and similar in 2018-19). Opioid prescription quantity significantly decreased in all states between 2014-15 and 2018-19. In states with legislation, average MME dropped from 9198 ± 21 002 to 4932 ± 13 213 (46.4% decrease), and in states without legislation, it decreased from 9175 ± 21 032 to 4994 ± 11 687 (45.6% decrease). However, these differences were not statistically significant (P = .7985). CONCLUSION: From 2014 to 2018, there was a significant decrease in the number of opioids prescribed after PLIF. However, this decrease occurred irrespective of state legislation on prescribing practices being passed. We believe the reduction in opioids prescribed was due to increased awareness surrounding the dangers of opioids among physicians.

Reaming the intramedullary canal during tibial nailing does not affect in vivo intramuscular pH of the anterior tibialis.

Many investigations have evaluated local and systemic consequences of intramedullary (IM) reaming and suggest that reaming may cause, or exacerbate, injury to the soft tissues adjacent to fractures. To date, no study has examined the effect on local muscular physiology as measured by intramuscular pH (IpH). Here, we observe in vivo IpH during IM reaming for tibia fractures. Methods: Adults with acute tibia shaft fractures (level 1, academic, 2019-2021) were offered enrollment in an observational cohort. During IM nailing, a sterile, validated IpH probe was placed into the anterior tibialis (<5 cm from fracture, continuous sampling, independent research team). IpH before, during, and after reaming was averaged and compared through repeated measures ANOVA. As the appropriate period to analyze IpH during reaming is unknown, the analysis was repeated over periods of 0.5, 1, 2, 5, 10, and 15 minutes prereaming and postreaming time intervals. Results: Sixteen subjects with tibia shaft fractures were observed during nailing. Average time from injury to surgery was 35.0 hours (SD, 31.8). Starting and ending perioperative IpH was acidic, averaging 6.64 (SD, 0.21) and 6.74 (SD, 0.17), respectively. Average reaming time lasted 15 minutes. Average IpH during reaming was 6.73 (SD, 0.15). There was no difference in IpH between prereaming, intrareaming, and postreaming periods. IpH did not differ regardless of analysis over short or long time domains compared with the duration of reaming. Conclusions: Reaming does not affect IpH. Both granular and broad time domains were tested, revealing no observable local impact.

How Do Standing Neutral, Supine Lateral, Standing Flexion, and Standing Extension Radiographs Compare in Detecting the Presence and Magnitude of Stable and Dynamic Spondylolisthesis?

BACKGROUND: Clinical guidelines recommend standing radiographs as the most appropriate imaging for detecting degenerative spondylolisthesis, although reliable evidence about the standing position is absent. To our knowledge, no studies have compared different radiographic views and pairings to detect the presence and magnitude of stable and dynamic spondylolisthesis. QUESTIONS/PURPOSES: (1) What is the percentage of new patients presenting with back or leg pain with stable (3 mm or greater listhesis on standing radiographs) and dynamic (3 mm or greater listhesis difference on standing-supine radiographs) spondylolisthesis? (2) What is the difference in the magnitude of spondylolisthesis between standing and supine radiographs? (3) What is the difference in the magnitude of dynamic translation among flexion-extension, standing-supine, and flexion-supine radiographic pairs? METHODS: This cross-sectional, diagnostic study was performed at an urban, academic institution between September 2010 and July 2016; 579 patients 40 years or older received a standard radiographic three-view series (standing AP, standing lateral, and supine lateral radiographs) at a new patient visit. Of those individuals, 89% (518 of 579) did not have any of the following: history of spinal surgery, evidence of vertebral fracture, scoliosis greater than 30°, or poor image quality. In the absence of a reliable diagnosis of dynamic spondylolisthesis using this three-view series, patients may have had flexion and extension radiographs, and approximately 6% (31 of 518) had flexion and extension radiographs. A total of 53% (272 of 518) of patients were female, and the patients had a mean age of 60 ± 11 years. Listhesis distance (in mm) was measured by two raters as displacement of the posterior surface of the superior vertebral body in relation to the posterior surface of the inferior vertebral body from L1 to S1; interrater and intrarater reliability, assessed with intraclass correlation coefficients, was 0.91 and 0.86 to 0.95, respectively. The percentage of patients with and the magnitude of stable spondylolisthesis was estimated on and compared between standing neutral and supine lateral radiographs. The ability of common pairs of radiographs (flexion-extension, standing-supine, and flexion-supine) to detect dynamic spondylolisthesis was assessed. No single radiographic view or pair was considered the gold standard because stable or dynamic listhesis on any radiographic view is often considered positive in clinical practice. RESULTS: Among 518 patients, the percentage of patients with spondylolisthesis was 40% (95% CI 36% to 44%) on standing radiographs alone, and the percentage of patients with dynamic spondylolisthesis was 11% (95% CI 8% to 13%) on the standing-supine pair. Standing radiographs detected greater listhesis than supine radiographs did (6.5 ± 3.9 mm versus 4.9 ± 3.8 mm, difference 1.7 mm [95% CI 1.2 to 2.1 mm]; p < 0.001). Among 31 patients, no single radiographic pairing identified all patients with dynamic spondylolisthesis. The listhesis difference detected between flexion-extension was no different from the listhesis difference detected between standing-supine (1.8 ± 1.7 mm versus 2.0 ± 2.2 mm, difference 0.2 mm [95% CI -0.5 to 1.0 mm]; p = 0.53) and flexion-supine (1.8 ± 1.7 mm versus 2.5 ± 2.2 mm, difference 0.7 mm [95% CI 0.0 to 1.5]; p = 0.06). CONCLUSION: This study supports current clinical guidelines that lateral radiographs should be obtained with patients in the standing position, because all cases of stable spondylolisthesis of 3 mm or greater were detected on standing radiographs alone. Each radiographic pair did not detect different magnitudes of listhesis, and no single pair detected all cases of dynamic spondylolisthesis. Clinical concern for dynamic spondylolisthesis may justify standing neutral, supine lateral, standing flexion, and standing extension views. Future studies could identify and evaluate a set of radiographic views that provides the greatest capacity to diagnose stable and dynamic spondylolisthesis. LEVEL OF EVIDENCE: Level III, diagnostic study.

Utilization of Vertebroplasty/Kyphoplasty in the Management of Compression Fractures: National Trends and Predictors of Vertebroplasty/Kyphoplasty.

OBJECTIVE: The purpose of this study is to examine the utilization of kyphoplasty/vertebroplasty procedures in the management of compression fractures. With the growing elderly population and the associated increase in rates of osteoporosis, vertebral compression fractures have become a daily encounter for spine surgeons. However, there remains a lack of consensus on the optimal management of this patient population. METHODS: A retrospective analysis of 91 million longitudinally followed patients from 2016 to 2019 was performed using the PearlDiver Patient Claims Database. Patients with compression fractures were identified using International Classification of Disease, 10th Revision codes, and a subset of patients who received kyphoplasty/vertebroplasty were identified using Common Procedural Terminology codes. Baseline demographic and clinical data between groups were acquired. Multivariable regression analysis was performed to determine predictors of receiving kyphoplasty/vertebroplasty. RESULTS: A total of 348,457 patients with compression fractures were identified with 9.2% of patients receiving kyphoplasty/vertebroplasty as their initial treatment. Of these patients, 43.5% underwent additional kyphoplasty/vertebroplasty 30 days after initial intervention. Patients receiving kyphoplasty/vertebroplasty were significantly older (72.2 vs. 67.9, p < 0.05), female, obese, had active smoking status and had higher Elixhauser Comorbidity Index scores. Multivariable analysis demonstrated that female sex, smoking status, and obesity were the 3 strongest predictors of receiving kyphoplasty/vertebroplasty (odds ratio, 1.27, 1.24, and 1.14, respectively). The annual rate of kyphoplasty/vertebroplasty did not change significantly (range, 8%-11%). CONCLUSION: The majority of vertebral compression fractures are managed nonoperatively. However, certain patient factors such as smoking status, obesity, female sex, older age, osteoporosis, and greater comorbidities are predictors of undergoing kyphoplasty/vertebroplasty.

Risk Factors, Incidence and Mortality of Vertebral Artery Injury in Patients Undergoing Anterior Cervical Corpectomy: A Retrospective Large National Data Base Study.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: To determine the incidence of vertebral artery injury (VAI), risk factors, intervention, associated complications, and mortality in patients undergoing anterior cervical corpectomy. METHODS: We performed a retrospective review of the incidence of VAI during anterior cervical corpectomy using the PearlDiver database from 2010-2017. The CPT code 63 081 to identify corpectomy patients. Patient data extracted included, incidence of VAI, demographic factors, intervention, and future complications of death and stroke. The risk were calculated compared with those patients who did not have VAI. RESULTS: 26 126 patients were identified to have undergone cervical corpectomy. Multivariate analysis of risk factors showed that younger age and male sex were associate with higher rate of injury (t = -11.5; P < .0001 and t = 3.8; P = .0001, respectively). Vertebral artery injuries occurred in 78 patients at an incidence of .3%. 11 (14%) VAI patients had a cerebral infarction compared with 1705 (7%) for non-VAI patients (OR = 2.13; 95% CI = [1.18 - 3.85; P = .0179]) during the follow up period. 1-year mortality rates were higher in patients who suffered a VAI (14%) compared to those who did not suffer a VAI (4%; OR = 3.85; CI = [2.04 - 7.14]; P < .0001). CONCLUSION: Consequence of VAI may not be known for months following the injury. Although the same admission mortality is rare with this injury, there is a significant increase in post-discharge complications. This study suggests that further investigations into long term health risk of VAI is needed.

Surgical Management of Type II Displaced Dens Fractures Improves One-year Mortality in Elderly Patients.

STUDY DESIGN: Retrospective cross-sectional analysis of US national data collected by PearlDiver Inc. database. OBJECTIVE: To determine the rates of surgical/nonsurgical treatments and associated one-year mortality for displaced type II dens fractures without neurological deficit. SUMMARY OF BACKGROUND DATA: Existing literature on dens fractures includes small series of patients with highly variable surgical rates. These studies contain insufficient data to determine the benefits of surgical or nonsurgical treatment as surgeon bias in treatment and selection of patients have significant effects on the results. MATERIALS AND METHODS: Displaced type II dens fractures and upper cervical surgeries were identified using their respective International Classification of Diseases, 10th Revision (ICD-10) diagnosis and Current Procedural Terminology (CPT) codes. Inclusion criteria included patients older than 65, diagnosed with a displaced type II dens fracture, absent neurological damage, during the years 2015 to 2018. Age, sex, ICD-10 diagnosis codes, CPT codes, displacement type, and Elixhauser Comorbidity Index scores were obtained through the PearlDiver database. Patient-related variables and one-year mortality associated with surgical versus nonsurgical treatment were compared using univariate χ 2 analysis, odds ratios, and multivariate logistic regression analysis. RESULTS: Among the 5300 patients who met our inclusion criteria, 59% (n=3108) were female, the mean age was 76.6 (±3.9) years old, and the average Elixhauser Comorbidity Index was 7.1 (±4.0). Only 8.3% (n=437) had surgical treatment for the displaced dens fracture. Multivariate logistic regression analysis for one-year mortality showed surgery was associated with decreased one-year mortality in all patients ( z =-6.26; P <0.001), patients between the ages of 65 and 74 ( z =-2.53; P =0.012), and patients over the age of 75 ( z =-5.81; P <0.001). CONCLUSION: Despite surgery improving survival in elderly patients with type II dens fractures, surgical management is rarely pursued. Factors that independently increase the likelihood of surgery include younger age, male sex, and posterior displacement. LEVEL OF EVIDENCE: 4.

Insurance and Employment Status Are Correlated With the Presence of Waddell Signs.

OBJECTIVE: The aim of the study was to determine whether employment or insurance status is associated with the presence and number of Waddell signs. DESIGN: In this cross-sectional study, adult low back pain patients were seen at a tertiary academic center for thoracic or lumbar back pain, due to a degenerative condition. Frequency data were compared with contingency table analysis, including χ2 and logistic regression. RESULTS: Of 462 patients, 26% had any Waddell signs and 10% had clinically significant Waddell signs. Nonemployed patients had a higher prevalence of Waddell signs than employed and retired patients (P = 0.0004 and P = 0.001, respectively). Subgroups of Medicaid participants as well as patients with secondary gain issues, including worker's compensation and motor vehicle accident, had a higher prevalence of 1+ Waddell signs than patients of other insurances (P < 0.0001 and P = 0.01, respectively). Medicaid participants had a higher prevalence of 3+ Waddell signs than other insurances (P = 0.002). CONCLUSIONS: The presence of Waddell signs is associated with employment and insurance status. This suggests that social factors may affect patients' perceptions of their thoracic or low back pain. Clinicians aware of these factors can provide individualized care to their patients prone to poor outcomes.

Factors Associated With Nonunion and Infection Following Ankle Arthrodesis Using a Large Claims Database: Who Has Elevated Risk?

Background: Complications such as nonunion and infection following ankle arthrodesis can lead to increased patient morbidity and financial burden from repeat operations. Improved knowledge of risk factors can improve patient selection and inform post-ankle arthrodesis surveillance protocols. Methods: This is a large retrospective, database study with structured query of a national insurance claims database (PearlDiver Technologies) for patients treated with ankle arthrodesis from 2015 to 2019 as identified by International Classification of Diseases, Tenth Revision (ICD-10), codes. Patients with any operation 1 year prior to or following ankle arthrodesis were excluded from analysis to prevent attributing complications to another operation. Likelihoods of nonunion and infection within 1 year and 3 years following ankle arthrodesis were analyzed using Kaplan-Meier estimations. Patient characteristics associated with the identified complications following ankle arthrodesis were analyzed using multivariable logistic regression analyses. Results: Our query yielded 2463 patients in the 5-year period who underwent ankle arthrodesis. Nonunion occurred in 11% (95% CI 10-12) of patients within 1 year of ankle arthrodesis and 16% (95% CI 14-17) of patients within 3 years. Infection occurred in 3.9% (95% CI 3.1-4.7) of patients within 1 year of ankle arthrodesis and in 6.2% (95% CI 5.1-7.2) of patients within 3 years. Obese patients increased odds of nonunion on multivariable analysis (OR 1.6, 95% CI 1.3-2.0; P < .001). On multivariable analysis, diabetes (OR 1.7, 95% CI 1.2-2.6; P = .010) and each 1-unit increase in Elixhauser Comorbidity Index scores (OR 1.1, 95% CI 1.1-1.2; P < .001) contributed to increased odds of infection after ankle arthrodesis. Conclusion: Nonunion and infection following ankle arthrodesis have a 3-year probability of 16% and 6%, respectively. More than one-quarter of patients with nonunion following ankle arthrodesis experience a delay in diagnosis beyond 1 year. The risk of post-ankle arthrodesis nonunion is highest in patients with obesity; the risk of post-ankle arthrodesis infection is highest in patients with diabetes or an elevated Elixhauser Comorbidity Index score. Level of Evidence: Level III, prognostic study.

Utility of upright radiographs in traumatic thoracolumbar fracture management.

BACKGROUND: It is common practice to use a combination approach of computed tomography (CT) scan followed by upright radiographs when assessing traumatic thoracolumbar (TL) vertebral fractures. The purpose of this study was to determine the clinical utility of upright spine radiographs in the setting of traumatic TL fracture management. Our null hypothesis is that upright TL radiographs rarely change management of acute vertebral fractures. METHODS: A retrospective study was performed on patients with an initial plan of non-operative management for a TL fracture between January 2014 and June 2020 at a single Level 1 trauma center. Patients were followed from time of initial consult to either conversion to surgery (operative) or last available outpatient follow up imaging (non-operative). Lateral kyphotic angle of the fractured vertebra and anterior vertebral body height% loss on initial CT, first upright radiograph, and endpoint upright radiograph imaging were measured. Measurements were compared between and within operative and non-operative groups using t-tests and Mann-Whitney U tests when appropriate. P-values ≤ 0.05 were considered statistically significant. RESULTS: The study included 70 patients with an average age of 54 years and 37 (52.9%) were women. Six (8.6%) of 70 patients had a change from non-operative to operative management based on upright radiographs. The mean (standard deviation) change in degrees of kyphosis from CT scan to first X-ray was 4.6 (7.0) in the non-operative group and 11.5 (8.1) in the operative group (P = 0.03). Delta degrees of kyphosis from CT scan to endpoint X-ray was 6.4 (9.0) and 16.2 (6.2) in the non-operative and operative groups, respectively (P = 0.01). In the operative group, mean degrees of kyphosis increased from 1.6 (7.6) in initial CT to 13.1 (8.9) in first X-ray (P = 0.02). First X-ray mean anterior body height% loss was 37.5 (17.6) and 53.2 (16.1) in the non-operative and operative groups, respectively (P = 0.04). CONCLUSIONS: Upright radiographs are useful in guiding traumatic vertebral fracture management decisions. Larger studies are needed to determine the degree of change in kyphosis between CT and first standing radiograph that is suggestive of operative management. TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION: Not applicable.

Effects of delayed postoperative void and preoperative urologic symptoms on delay in time of discharge for elective lumbar decompression surgery.

BACKGROUND CONTEXT: Almost half of all patients undergoing lumbar spine surgery have preoperative lower urinary tract symptoms (LUTS). These symptoms could affect postoperative voiding and subsequently length of stay. PURPOSE: To investigate the association between preoperative LUTS and time to first void and between time to first void and time to discharge among patients undergoing elective lumbar decompression surgery. STUDY DESIGN/SETTING: Retrospective analysis of prospectively collected data among patients at a single academic medical center. PATIENT SAMPLE: All patients ≥18 years of age undergoing elective lumbar decompression surgery between July 2017 and March 2020. OUTCOME MEASURES: The physiologic measure of a delayed time to first void was defined as an initial postoperative void of > 4 hours after anesthesia stop time. The outcome of prolonged time to discharge was defined as a stay of >24 hours after anesthesia stop time. METHODS: At their preoperative visit, patients completed the validated International Prostate Symptom Score (IPSS) (range, 0-35 points), which is applicable for LUTS assessment in both sexes. Clinically relevant LUTS are defined as an IPSS score of ≥8. Patients were followed from their preoperative visit to surgery admission discharge. Association of LUTS with time to first void and time to first void with admission discharge were estimated using risk ratios (RR) and 95% confidence intervals (CI) from a multivariable Poisson regression with a robust variance estimate adjusted for potential confounding variables including age, sex, IPSS, and intraoperative Foley catheter use. RESULTS: The analytic cohort included 170 patients with an average age of 57 years and 103 (61%) were men. Preoperative LUTS prevalence was 45%, and 111 (65%) of patients voided within 4 hours after surgery. For patients with preoperative LUTS, the unadjusted RR for a first void of >4 hours was 1.04 (95% CI: 0.82-1.32) (p=.77). Adjustment for age, sex, intraoperative Foley catheter use, revision surgery, previous spine surgery, single versus multiple levels, and lumbar location did not materially alter the risk: the multivariable RR was 1.04 (95% CI: 0.82-1.31) (p=.74). The unadjusted RR for a discharge of > 24 hours for patients with a time to first void of > 4 hours was 2.17 (95% CI: 1.51-3.10) (p<.001). After adjusting for age, sex, intraoperative Foley catheter use, IPSS, revision surgery, previous spine surgery, single versus multiple levels, and lumbar location, the multivariable RR was 1.72 (95% CI: 1.22-2.41) (p=.002). CONCLUSIONS: Regardless of preoperative LUTS status, an initial first void of >4 hours after surgery is associated with a longer time to discharge among patients undergoing elective lumbar decompression surgery. Future studies are needed to determine if encouraging early postoperative voiding results in timely discharge and shorter length of stay.

Risk Factors Associated With Femoral Ring Allograft Breakage in ALIF.

STUDY DESIGN: This is a retrospective chart review. OBJECTIVES: To identify the incidence of, and variables correlated with, femoral ring allograft (FRA) fracture following anterior lumbar interbody fusion (ALIF). METHODS: All patients who underwent ALIF using FRAs at an academic institution over 10 years were included. Postoperative radiographs were reviewed by both the primary and senior authors; fracture and no-fracture groups were created for comparison. Patient and surgical characteristics were extracted from electronic medical records. Frequency data comparisons were performed using contingency table analysis; comparisons of means were analyzed for continuous variables. A multivariate linear regression model was developed using screw use, graft height <12 mm, index level, and weight as variables. RESULTS: A total of 76 FRAs in 59 patients were identified, 13 (17%) of which fractured. Age, sex, smoking status, use of buttress screws, weight, index level, and presence of spondylolisthesis were not correlated with incidence of fracture (P > .05). There was a significant correlation between the height of FRA and incidence of fracture; 2% (1/52) of grafts ≥12 mm and 50% (12/24) of grafts <12 mm fractured (P < .0001). Using ordinary least-squares regression, this result was independent of patient weight, use of screws, and index level. Of 10 patients, 9 did not require revision surgery to achieve fusion. CONCLUSIONS: Graft height was the only variable correlated with incidence of FRA fracture. Graft height <12 mm is an independent risk factor for FRA fracture in patients undergoing ALIF, and their use should be avoided in ALIF procedures.

Anterior Cervical Arthrodesis With Polyetheretherketone Spacers: What is the Role of the Grafting Material?

STUDY DESIGN: This was a retrospective study of 2 surgeons' use of a single polyetheretherketone (PEEK) device. OBJECTIVE: Our objective was to investigate the fusion adjunct placed within PEEK devices to examine the likelihood of an arthrodesis, regardless of the PEEK interbody device itself. SUMMARY OF BACKGROUND DATA: The effectiveness of PEEK interbody devices in anterior cervical arthrodesis has been questioned. METHODS: The authors retrospectively reviewed the results of 121 patients with demineralized bone matrix (DBM) and 96 with local autograft bone placed within identical PEEK devices for anterior cervical arthrodesis (from 2011 to 2018); 1 surgeon used DBM and another local autograft bone. Arthrodesis was determined independently by a surgeon and 2 blinded neuroradiologists. RESULTS: For DBM versus autograft; mean age was 60 versus 61 years, smoking status 42.1% versus 31%, diabetes mellitus 18.2% versus 28%, mean body mass index 31 versus 30, and follow up averaged 17 months in both groups. For DBM versus autograft; a radiographic arthrodesis was observed in 22.3% versus 76% of patients. Refusion at the index level was required in 5.8% of the DBM and 0% of the autograft patients. CONCLUSIONS: A PEEK interbody device filled with local autograft resulted in a higher radiographic fusion rate and a lower need for reoperation at the index level than an identical device filled with DBM. Caution is warranted in assigning fusion failure to the PEEK device alone in anterior cervical discectomy and fusion surgery.

Lower Urinary Tract Symptoms and Urinary Bother Are Common in Patients Undergoing Elective Cervical Spine Surgery.

BACKGROUND: Lower urinary tract symptoms (LUTS) and urinary bother have been reported in adults undergoing surgery and have been associated with urinary tract infections, longer hospital stays, increased surgical costs, and decreased patient satisfaction. Previous reports indicate that up to one in two patients with lumbar spine pathology have moderate-to-severe LUTS, but little is known about LUTS in patients with cervical spine conditions. QUESTIONS/PURPOSES: (1) What is the prevalence of moderate-to-severe LUTS and clinically relevant urinary bother among patients undergoing elective cervical spine surgery? (2) Does the presence of myelopathy affect frequency of moderate-to-severe LUTS or clinically relevant urinary bother among patients undergoing elective cervical spine surgery? (3) Do MRI findings of spinal cord injury or compression correlate with presence and severity of LUTS? METHODS: We performed a cross-sectional study using clinical data collected from adult patients undergoing elective cervical spine surgery. Over an approximately 30-month period, we approached all patients who were evaluated in the preoperative clinic before undergoing elective cervical spine surgery. Of the 257 approached, 242 participated (94%). Study participants ranged in age from 34 to 83 years with a mean age of 58 years (SD 12). There were 108 males (45%) and 134 females (55%). A validated questionnaire, the International Prostate Symptom Score (IPSS), was used to identify LUTS. The IPSS score ranges from 0 to 35 points with LUTS presence defined as a score of ≥ 8 and LUTS severity categorized as mild (IPSS 0-7), moderate (IPSS 8-19), or severe (IPSS 20-35). Quality of life resulting from urinary bother is scored 0 to 6 with scores ≥ 4 considered clinically relevant urinary bother. Patients were grouped into a myelopathy group and a nonmyelopathy group based on diagnosis as assigned by the operating surgeon. MRIs were analyzed by one spine surgeon to identify the presence of cord signal, number of levels with cord compression (mm), and a calculated compression ratio score with cord compression and with compression ratio among patients with myelopathy. RESULTS: The prevalence of moderate LUTS in our patient sample was 40% (97 of 242; 95% confidence interval [CI], 34%-47%). The prevalence of severe LUTS in our patient sample was 8% (19 of 242; 95% CI, 5%-12%). Clinically relevant urinary bother was reported in 18% of patients (41 of 228; 95% CI, 13%-24%). After adjustment for age and sex, the odds of moderate-to-severe LUTS among patients with myelopathy was greater than that observed in patients without myelopathy (adjusted odds ratio, 2.0; p = 0.015). The prevalence of clinically relevant urinary bother was higher in patients with myelopathy (30% [26 of 88]) compared with those with no myelopathy (11% [15 of 140]; p < 0.001). With the numbers available, among patients with myelopathy, there was no difference in distribution of LUTS symptom severity or IPSS score according to cord signal presence (50% [23 of 46]) and absence (65% [31 of 48]; p = 0.153), number of levels with compression (70% [seven of 10 with four levels]; 59% [13 of 22 with three levels]; 51% [19 of 37] with two levels; and 60% [15 of 25] with one level; p = 0.730), millimeters of cord compression (r = 0.02; p = 0.854), or compression ratio (r = 0.09; p = 0.413). CONCLUSIONS: Nearly half of all patients undergoing elective cervical spine surgery had moderate-to-severe LUTS. This is more than double the prevalence that has been reported in a community-dwelling adult population. These symptoms can impair quality of life, lead to surgical complications (urinary retention or incontinence), and may be mistaken for cauda equina, prompting potentially unnecessary imaging and studies. Given that urinary bother is reported less frequently than LUTS, patients may be less likely to seek care for urinary symptoms before undergoing surgery. Therefore, it is important to increase provider awareness of the high prevalence of LUTS. LEVEL OF EVIDENCE: Level III, prognostic study.

Prevalence of Preoperative Lower Urinary Tract Symptoms in Patients Undergoing Elective Lumbar Spine Surgery.

STUDY DESIGN: Cross-sectional cohort study. OBJECTIVE: To determine the prevalence of moderate-to-severe lower urinary tract symptoms (LUTS) in patients undergoing elective lumbar spine surgery, and to describe associations between prevalence, severity of symptoms, demographic variables, and spine pathology. SUMMARY OF BACKGROUND DATA: The prevalence of LUTS is unknown in patients with lumbar spine disease. Furthermore, the extent of LUTS severity and the relationship between spine pathology and LUTS is not well documented. METHODS: We used the validated International Prostate Symptom Score (IPSS) to assess LUTS severity among elective lumbar spine surgery patients from October 2015 to April 2017 at a single academic institution. Moderate-to-severe LUTS was defined as IPSS score of 8 or more. The IPSS also includes a question to assess urinary bother, for which a score of 4 or more indicates clinically significant bother. Prevalence estimates and 95% confidence intervals were computed in the sample overall, and according to sex, age, and lumbar spine diagnosis. RESULTS: IPSS data were obtained from 373 patients (97% of those eligible) undergoing elective lumbar spine surgery. Moderate-to-severe urinary symptoms were reported by 46% of these patients, and by 51% of women and 42% of men. Prevalence of moderate-to-severe urinary symptoms increased with age, rising from 38% in patients younger than 40 years to 57% in patients 70 years or older. LUTS prevalence according to spondylolisthesis, stenosis, scoliosis, and herniated nucleus pulposus diagnostic groups were 51%, 50%, 50%, and 31%, respectively. Clinically significant urinary bother was reported by 14% overall, 10% of men, and 18% of women, and prevalence also increased with age. CONCLUSION: Moderate-to-severe LUTS were highly prevalent in this sample. Urinary symptoms are more prevalent with increasing age, in women, and in patients with stenosis, spondylolisthesis, and scoliosis. Proportionally, fewer patients reported clinically significant urinary bother, which may impact patient reporting and physician identification of urinary symptoms. LEVEL OF EVIDENCE: 3.

A scoring system to predict postoperative medical complications in high-risk patients undergoing elective thoracic and lumbar arthrodesis.

BACKGROUND CONTEXT: Various surgical factors affect the incidence of postoperative medical complications following elective spinal arthrodesis. Because of the inter-relatedness of these factors, it is difficult for clinicians to accurately risk-stratify individual patients. PURPOSE: Our goal was to develop a scoring system that predicts the rate of major medical complications in patients with significant preoperative medical comorbidities, as a function of the four perioperative parameters that are most closely associated with the invasiveness of the surgical intervention. STUDY DESIGN/SETTING: This study used level 2, Prognostic Retrospective Study. PATIENT SAMPLE: The patient sample consisted of 281 patients with American Society of Anesthesiologists (ASA) scores of 3-4 who underwent elective thoracic, lumbar, or thoracolumbar fusion surgeries from 2007 to 2011. OUTCOME MEASURES: Physiologic risk factors, number of levels fused, complications, operative time, intraoperative fluids, and estimate blood loss were the outcome measures of this study. METHODS: Risk factors were recorded, and patients who suffered major medical complications within the 30-day postoperative period were identified. We used chi-square tests to identify factors that affect the medical complication rate. These factors were ranked and scored by quartiles. The quartile scores were combined to form a single composite score. We determined the major medical complication rate for each composite score, and divided the cohort into quartiles again based on score. A Pearson linear regression analysis was used to compare the incidence of complications to the score. RESULTS: The number of fused levels, operative time, volume of intraoperative fluids, and estimated blood loss influenced the complication rate of patients with ASA scores of 3-4. The quartile ranking of each of the four predictive factors was added, and the sum became the composite score. This score predicted the complication rate in a linear fashion ranging from 7.6% for the lowest risk group to 34.7% for the highest group (r=0.998, p<.001). CONCLUSIONS: Taken together, the four factors, though not independent of one another, proved to be strongly predictive of the major medical complication rate. This score can be used to guide medical management of thoracic and lumbar spinal arthrodesis patients with preexisting medical comorbidities.

Effectiveness of Posterolateral Lumbar Fusion Varies with the Physical Properties of Demineralized Bone Matrix Strip.

STUDY DESIGN: A randomized, controlled animal study. PURPOSE: To investigate the effectiveness of fusion and new bone formation induced by demineralized bone matrix (DBM) strips with jelly strengths. OVERVIEW OF LITERATURE: The form of the DBM can make a difference to the outcome. The effect of different jelly strengths on the ability of DBM to form new bone is not known. METHODS: Forty-eight rabbits were randomized into a control group and two experimental groups. In the control group (group 1), 1.4 g of autologous iliac crest bone was placed bilaterally. In the experimental groups, a high jelly strength DBM-hyaluronic acid (HA)-gelatin strip (group 2) and a low jelly strength DBM-HA-gelatin strip (group 3) were used. The fusion was assessed with manual manipulation and radiographs. The volume of the fusion mass was determined from computed tomographic images. RESULTS: The fusion rates as determined by manual palpation were 37.5%, 93.8% and 50.0% in group 1, group 2, and group 3, respectively (p<0.05). By radiography, the fusion rate of High jelly strength DBM strip was statistically significantly greater than that of the other alternatives (p<0.05). The mean bone volume of the fusion mass as determined by computed tomography was 2,142.2±318.5 mm(3), 3,132.9±632.1 mm(3), and 2,741.5±380.4 mm(3) in group 1, group 2, and group 3, respectively (p<0.05). CONCLUSIONS: These results indicate that differences in the structural and mechanical properties of gelatin that are associated with jelly strength influenced cellular responses such as cell viability and bony tissue ingrowth, facilitating greater bone fusion around high jelly strength implants.

A clinical perspective on musculoskeletal infection treatment strategies and challenges.

Orthopaedic implants improve the quality of life of patients, but the risk of postoperative surgical site infection poses formidable challenges for clinicians. Future directions need to focus on prevention and treatment of infections associated with common arthroplasty procedures, such as the hip, knee, and shoulder, and nonarthroplasty procedures, including trauma, foot and ankle, and spine. Novel prevention methods, such as nanotechnology and the introduction of antibiotic-coated implants, may aid in the prevention and early treatment of periprosthetic joint infections with goals of improved eradication rates and maintaining patient mobility and satisfaction.

Prevalence of degenerative changes of the atlanto-axial joints.

BACKGROUND CONTEXT: Degeneration of the atlantodens and atlanto-axial joints is associated with cervical spine pain and may also be associated with an increased risk of dens fracture. However, there is paucity of literature describing the prevalence of specific degenerative changes in the atlantodens and atlanto-axial facet joints. PURPOSE: To document age-related degenerative changes of the cervical spine in a large cohort of patients. STUDY DESIGN/SETTING: This is a retrospective cohort study. PATIENT SAMPLE: Adult trauma patients were admitted to our Level 1 trauma center. OUTCOME MEASURES: Osteoarthritis of the atlantodens and atlanto-axial facet joints of the cervical spine and the presence of intraosseous cyst and calcific synovitis, as determined by computed tomography (CT) scans. METHODS: We conducted a retrospective study of 1,543 adult trauma patients who received a cervical spine CT scan. The anterior atlantodens joint interval was measured. The presence or absence of intraosseous cysts and calcific synovitis was recorded. Degeneration of the atlantodens and atlanto-axial facet joints at age intervals was quantified. RESULTS: The atlantodens interval narrowed linearly with age (R(2)=0.992, p<.001). The prevalence of intraosseous cysts increased exponentially with age from 4.2% to 37.4%, and calcific synovitis increased from 0% to 11.1%. Intraosseous cyst formation generally began in the second and third decades of life and synovitis in the fifth and sixth decades of life. Facet joints also demonstrated age-related changes; however, the rate of degenerative changes was lower than in the atlantodens joint. CONCLUSIONS: To our knowledge, this is the first study that documents specific changes of both atlantodens and atlanto-axial facet joints as a function of age in a large cohort of 1,543 patients. These changes increased exponentially with age and may contribute to pain and limitation in motion. In light of our findings and recent studies demonstrating the association between degeneration and dens fracture in elderly, cervical spine radiographs of elderly patients should be carefully assessed for these changes.