Quantifying the Relationship Between the Transverse Acetabular Ligament and the Radiographic Teardrop.

BACKGROUND: The transverse acetabular ligament (TAL) has been described as an anatomic landmark to guide in the positioning of the acetabular component during total hip arthroplasty. On plain films, the radiographic teardrop (RT) has similarly been used as a measure of appropriate cup positioning. The goal of this study is to quantify the distance and location between the anatomic TAL and RT landmarks to aid in the positioning of acetabular component. METHODS: Sixteen randomly selected cadaveric pelvises (eight males, eight females) underwent dissection. Radiographic markers were placed bilaterally at the anteromedial insertions of the TAL, and true anteroposterior pelvic radiographs of the cadavers were obtained. Distances between the markers and the lateral borders of the RT were measured. RESULTS: The mean distance between the anteromedial insertion of the TAL and the lateral border of the RT in the male specimens was 11.8 (99% confidence interval, 11.4-12.2) mm. In the female specimens, the TAL to RT distance was shorter, with a mean of 8.4 (99% CI, 7.2-9.6) mm. There was a statistically significant difference between male and female cadavers (P < .01). CONCLUSION: The distance between the RT and TAL differs between males and females. Understanding the distance between these anatomic and radiographic landmarks should aid surgeons in obtaining a more accurate degree of acetabular component medialization and can serve as a guide to minimize overmedialization in order to achieve more accurate and reproducible placement of acetabular components during a total hip arthroplasty.

Post-traumatic cervical spine epidural hematoma: Incidence and risk factors.

BACKGROUND: The incidence and risk factors for post-traumatic cervical epidural hematoma are not well described in the current literature. Our aim was to determine the incidence and associated risk factors for post-traumatic cervical spine epidural hematoma (SEH). METHODS: We performed a retrospective review of our institution's prospectively collected data submitted to the state trauma registry, using ICD-9 codes, for all patients activated as a trauma with cervical spine injuries, between the years 2010 and 2014. Patients with MRI available were classified based on the presence of cervical epidural hematoma (CEH) or no hematoma (NEH). For our second analysis, we classified patients with cord compression associated with an epidural hematoma (CC) and no cord compression (NCC). Potential risk factors evaluated included: INR, PTT, albumin and platelets levels, radiographic findings of Ankylosing Spondylitis (AS), and ISS. No conflicts of interest exist and/or funding was used for this study. RESULTS: 497 out of 1810 trauma activations met our inclusion criteria. 46 patients (2.5%) were found to have a post-traumatic cervical SEH (CEH). Of the CEH cohort, 76% were male, with 72% Caucasian, and a mean age of 55 years. 27 patients (5.4%) were found to have cervical cord compression at the level of the SEH. Of the CC arm, 78% were male, with 67% Caucasian, and a mean age of 56 years. A higher ISS and an elevated INR were found to be associated with epidural hematoma causing cord compression. CONCLUSIONS: An incidence of 2.5% is reported for post-traumatic cervical spine epidural hematoma. Of these, 59% had associated spinal cord compression. Patients with a higher ISS and elevated INR levels are at a higher risk for developing this potentially devastating.

Improvements in Neck and Arm Pain Following an Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: A retrospective analysis. OBJECTIVE: The aim of this study was to quantify improvements in Visual Analogue Scale (VAS) neck and arm pain, Neck Disability Index (NDI), and Short Form-12 (SF-12) Mental (MCS) and Physical (PCS) Composite scores following an anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: ACDF is evaluated with patient-reported outcomes. However, the extent to which these outcomes improve following ACDF remains poorly defined. METHODS: A surgical registry of patients who underwent primary, one- or two-level ACDF during 2013 to 2015 was reviewed. Comparisons of VAS neck and arm, NDI, and SF-12 MCS and PCS scores were performed using paired t tests from preoperative to each postoperative time point. Analysis of variance (ANOVA) was used to estimate the reduction in neck and arm pain over the first postoperative year. Subgroup analyses were performed for patients with predominant neck (pNP) or arm (pAP) pain, as well as for one- versus two-level ACDF. RESULTS: Eighty-nine patients were identified. VAS neck and arm, NDI, and SF-12 PCS improved from preoperative scores at all postoperative time points (P < 0.05 for each). Across the first postoperative year, patients reported a 2.7-point (44.2%) reduction in neck and a 3.1-point (54.0%) reduction in arm pain (P < 0.05 for each). Sixty-one patients with pNP and 28 patients with pAP reported reductions in neck and arm pain over the first 6 months and 12 weeks postoperatively, respectively (P < 0.05 for each). Patients who underwent one-level ACDFs experienced a 47.2% reduction in neck pain and 55.1% reduction in arm pain over the first postoperative year (P < 0.05 for each), while those undergoing two-level ACDF experienced 39.7% and 49.2% for neck and arm, respectively (P < 0.05 for each). CONCLUSION: This study suggests that patients experience significant improvements in neck and arm pain following ACDF regardless of presenting symptom. In addition, patients undergoing one-level ACDF report greater reductions in neck and arm pain than patients undergoing two-level fusion. LEVEL OF EVIDENCE: 4.

Closed Rupture of the Flexor Profundus Tendon of Ring Finger: Case Report and Treatment Recommendations.

Zone III midsubstance flexor tendon rupture without underlying pathology is rare. The most common mechanism of injury for a spontaneous rupture is forced extension of an actively flexed distal interphalangeal joint. We describe a patient who experienced closed midsubstance zone III rupture of the flexor digitorum profundus (FDP) tendon of the ring finger at the lumbrical origin in the palm while lifting a heavy object. On exploration, there was no evidence of underlying tendon pathology, and primary end-to-end repair of the FDP was possible. This case highlights the importance of correct preoperative clinical localization of the rupture level, as well as a suggested surgical plan in equivocal cases.

Comparison between cervical total disc replacement and anterior cervical discectomy and fusion of 1 to 2 levels from 2002 to 2009.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: To compare the perioperative patient characteristics, early postoperative outcomes, and costs between anterior cervical discectomy and fusion (ACDF) and cervical total disc replacement (TDR) in the United States. SUMMARY OF BACKGROUND DATA: Cervical TDR and ACDF are indicated to treat symptomatic cervical degenerative pathology. The epidemiology, complication rates, and the cost differences between the 2 surgical approaches are not well characterized. METHODS: Data from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project was queried from 2002 to 2009. Patients undergoing cervical TDR or ACDF of 1 to 2 levels were identified. Patient demographics, comorbidities, length of stay, costs, and the in-hospital complications were assessed. SPSS (version 20) was used for statistical analysis with χ test for categorical data and independent-samples t test for continuous data. A value of P ≤ 0.001 denoted statistical significance. Multinomial regression analysis was used to identify the independent risk for complications in the TDR cohort compared with the ACDF cohort. RESULTS: There were 141,230 ACDF cases of 1 to 2 levels and 1830 cervical TDR cases identified in the Nationwide Inpatient Sample database. The ACDF cohort was older and demonstrated a greater comorbidity burden than the TDR group (P < 0.001). The ACDF-treated patients demonstrated a significantly greater length of stay than the TDR group (P < 0.001). In contrast, there were no significant differences in the incidence of postoperative complications, mortality, or hospital costs between the surgical cohorts. Multinomial regression did not demonstrate significant differences in the risk for postoperative complications between the surgical techniques. CONCLUSION: The ACDF cohort was significantly older and demonstrated a greater comorbidity burden that likely contributed to the greater length of stay when than the TDR cohort. Both cohorts demonstrated comparable incidences of early postoperative complications and costs. There were no significant differences in the risks for postoperative complications between the surgical cohorts. Further studies are warranted to characterize the long-term complications, costs, and patient outcomes between the 2 surgical techniques. LEVEL OF EVIDENCE: 3.

Incidence, outcomes, and mortality of reintubation after anterior cervical fusion.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: To compare perioperative patient characteristics, hospital resource utilization, and early postoperative outcomes in patients requiring reintubation after anterior cervical fusion (ACF). SUMMARY OF BACKGROUND DATA: Airway compromise is a potential complication after anterior cervical surgery. Postsurgical soft-tissue edema or hematoma formation may be so severe that an unplanned reintubation may be required. The rate of reintubation after ACF and the effect on hospital outcomes remains unknown. METHODS: The Nationwide Inpatient Sample database was queried from 2002-2011. Patients undergoing elective ACF procedures for degenerative diagnoses were selected. Those who required an unplanned reintubation after ACF were identified. Patient demographics, comorbidities, length of stay, costs, number of levels fused, and mortality were analyzed. SPSS version 20 was used for statistical analysis and a P < 0.001 denoted statistical significance. RESULTS: A total of 262,425 patients underwent an elective ACF between 2002 and 2011 of which 1464 patients (5.6 per 1000 cases) required reintubation during their admission. The rate of reintubation was statistically greater for 3+-level fusions than the 1- to 2-level fusion cases. On average, patients requiring reintubation were older and had a greater number of comorbidities. These patients also incurred a significantly greater hospital stay and total hospital costs than unaffected patients. In addition, significant predictors for reintubation included 3+-level fusions, congestive heart failure, anemia, postoperative aspiration pneumonia, hematoma, thromboembolic events, and dysphagia. CONCLUSION: The reintubation rate after an elective ACF is 0.5%, and it increases to 1.6% after 3+-level fusions. Older patients with greater comorbidities are at an increased risk for reintubation. Given the greater LOS, costs and mortality associated with reintubation, it is imperative to identify patients at increased risk to help improve patient outcomes and decrease hospital resource utilization. LEVEL OF EVIDENCE: 4.

Cerebral vascular accidents after lumbar spine fusion.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To determine the impact of a cerebral vascular accident (CVA) after lumbar spinal fusion, a population-based database was analyzed to identify the incidence, potential risk factors, hospital resource utilization, and the early postoperative outcomes. SUMMARY OF BACKGROUND DATA: A lumbar fusion (LF) is an effective surgical procedure to treat lumbar degenerative pathology. Although rare, a CVA can be a catastrophic event after an LF. METHODS: The Nationwide Inpatient Sample database was queried from 2002-2011. Patients undergoing an elective anterior lumbar fusion, a posterior lumbar fusion, or a combined anterior-posterior lumbar fusion were separated into subcohorts. Patients with a documented postoperative CVA were identified. Patient demographics, comorbidities (Charlson Comorbidity Index), length of stay, costs, early postoperative outcomes, and mortality were assessed. Statistical analysis involved T tests, χ2 analysis, and binary logistic regression with P < 0.001 denoting significance. RESULTS: A total of 264,891 LFs were identified between 2002 and 2011 of which 340 (1.3 per 1000) developed a postoperative CVA. Patients with a CVA were significantly older and demonstrated a greater comorbidity burden (Charlson Comorbidity Index). Patients with a CVA incurred a significantly greater length of stay, total hospital costs ($41,454 vs. $25,885), and a greater mortality rate (73.7 vs. 0.8 per 1000 patients). Regression analysis demonstrated that age more than 65 years and a history of neurological disorders, paralysis, congestive heart failure, or electrolyte imbalance were associated with an increased risk of a postoperative CVA. CONCLUSION: Patients who developed a postoperative CVA demonstrated a significantly greater incidence of postoperative complications, mortality, and total hospital costs. This study highlights important associated risk factors (e.g., age more than 65, neurological disorders, congestive heart failure) that may enable surgeons to identify high-risk patients prior to surgery. Further studies are warranted to characterize these risk factors and to establish guidelines to mitigate the complications associated with a postoperative CVA. LEVEL OF EVIDENCE: 4.

Perioperative characteristics and outcomes of patients undergoing anterior cervical fusion in July: analysis of the "July effect".

STUDY DESIGN: Retrospective national database analysis. OBJECTIVE: A national population-based database was analyzed to characterize the "July effect" on the perioperative outcomes of anterior cervical fusions (ACFs). SUMMARY OF BACKGROUND DATA: Perception biases exist regarding the outcomes of cervical spine surgery based upon the month of admission. METHODS: The Nationwide Inpatient Sample database was queried from 2009-2011. Patients who underwent an ACF in teaching and nonteaching hospitals were identified and separated into cohorts. Patients who were admitted in July were then compared with non-July admissions in both cohorts. Demographics, Charlson Comorbidity Index, length of stay, costs, postoperative complications, and mortality were assessed. RESULTS: A total of 52,499 ACF cases were identified in the Nationwide Inpatient Sample of which 26,831 (51.2%) were performed in teaching hospitals and 25,668 (48.8) in nonteaching institutions. July admissions represented 6.8% and 7.4% of cases in the teaching and nonteaching hospital cohorts, respectively. Among July admissions, the teaching cohort incurred a longer hospitalization than the nonteaching cohort (P < 0.05). In contrast, no significant differences in mortality or total hospital costs were demonstrated. In teaching institutions, the in-hospital complications associated with July patients included deep vein thrombosis and surgical site infection (P < 0.05), but this did not reach significance in nonteaching hospitals. Postoperative dysphagia and deep vein thromboses were also significantly more prevalent among July admissions in teaching hospitals compared with nonteaching institutions. CONCLUSION: This national study demonstrated that the early resident academic year was associated with a greater length of stay among July patients in teaching hospitals. This study did not demonstrate an increase in mortality or total hospital costs among July patients in either hospital cohort. In teaching hospitals, ACF-treated patients in July were associated with a greater incidence of postoperative thromboses and surgical site infection. In addition, the incidence of dysphagia was significantly greater among July patients in teaching hospitals than nonteaching hospitals.

Comparison of revision surgeries for one- to two-level cervical TDR and ACDF from 2002 to 2011.

BACKGROUND CONTEXT: Cervical total disc replacement (TDR) and anterior cervical discectomy and fusion (ACDF) provide comparable outcomes for degenerative cervical pathology. However, revisions of these procedures are not well characterized. PURPOSE: The purpose of this study is to examine the rates, epidemiology, perioperative complications, and costs between the revision procedures and to compare these outcomes with those of primary cases. STUDY DESIGN: This study is a retrospective database analysis. PATIENT SAMPLE: A total of 3,792 revision and 183,430 primary cases from the Nationwide Inpatient Sample (NIS) database from 2002 to 2011 were included. OUTCOME MEASURES: Incidence of revision cases, patient demographics, length of stay (LOS), in-hospital costs, mortality, and perioperative complications. METHODS: Patients who underwent revision for either one- to two-level cervical TDR or ACDF were identified. SPSS v.20 was used for statistical analysis with χ(2) test for categorical data and independent sample t test for continuous data. The relative risk for perioperative complications with revisions was calculated in comparison with primary cases using a 95% confidence interval. An alpha level of less than 0.05 denoted statistical significance. RESULTS: There were 3,536 revision one- to two-level ACDFs and 256 revision cervical TDRs recorded in the NIS database from 2002 to 2011. The revision cervical TDR cohort demonstrated a significantly greater LOS (3.18 vs. 2.25, p<.001), cost ($16,998 vs. $15,222, p=.03), and incidence of perioperative wound infections (13.6 vs. 5.3 per 1,000, p<.001) compared with the ACDF revision cohort (p<.001). There were no differences in mortality between the revision surgical cohorts. Compared with primary cases, both revision cohorts demonstrated a significantly greater LOS and cost. Furthermore, patients who underwent revision demonstrated a greater incidence and risk for perioperative wound infections, hematomas, dysphagia, and neurologic complications relative to the primary procedures. CONCLUSIONS: This study demonstrated a significantly greater incidence of perioperative wound infection, LOS, and costs associated with a TDR revision compared with a revision ACDF. We propose that these differences are by virtue of the inherently more invasive nature of revising TDRs. In addition, compared with primary cases, revision procedures are associated with greater costs, LOS, and complications including wound infections, dysphagia, hematomas, and neurologic events. These additional risks must be considered before opting for a revision procedure.

Epidemiological trends in the utilization of bone morphogenetic protein in spinal fusions from 2002 to 2011.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: A nationwide population-based database was analyzed to assess the utilization trends of bone morphogenetic protein (BMP) in spine fusion surgery from 2002-2011. SUMMARY OF BACKGROUND DATA: The utilization of off-label BMP in spine procedures is not well characterized. The purpose of this study was to analyze a population-based database to characterize the national trends of BMP utilization in terms of incidence, demographics, costs, and mortality. METHODS: Data from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project was queried for each year from 2002-2011. Patients undergoing an anterior cervical fusion or posterior cervical fusion, anterior lumbar fusion or posterior lumbar fusion, or a posterior thoracic fusion were identified and separated into cohorts. The frequency of BMP utilization was assessed in each surgical cohort by year. Patient demographics, hospital parameters, costs, and mortality rates were assessed. RESULTS: The adjusted annual number of procedures with BMP increased from 1116 in 2002 to 79,294 in 2011 (P < 0.001), representing 26.9% of all spinal fusion procedures. The rate of BMP utilization within each surgical cohort also significantly increased during the 10-year period (P < 0.001). The posterior lumbar fusion cohort accounted for the majority of spinal fusions that used BMP, representing 76.8% of all spinal fusions between 2002 and 2011. The anterior lumbar fusion cohort was associated with the highest proportion of BMP utilization, peaking at 56.9% of all anterior lumbar interbody fusions in 2006. The trend of BMP utilization in the anterior cervical fusion cohort peaked in 2007 with 10.6% of cases and then declined to 6.4% in 2011. There was a statistically significant trend of older patients with increasing comorbidities receiving BMP during this period. Hospital costs (adjusted for inflation) significantly increased an average of $9560 from 2002-2010. There were no significant trends with regard to the length of hospitalization stay and mortality rates during this period. CONCLUSION: This nonconflicted study demonstrates that the utilization of BMP has dramatically increased from 2002-2011. Interestingly, off-label application of BMP accounts for the vast majority of BMP utilization. The increase in the total hospital costs is likely multifactorial; older patients with more comorbidities undergoing surgery as well as the increasing utilization of BMP are all likely contributory factors. The length of hospitalization stay and mortality rates did not increase during the 10-year period.

Current trends in demographics, practice, and in-hospital outcomes in cervical spine surgery: a national database analysis between 2002 and 2011.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: To investigate national trends of cervical spine surgical procedures from 2002 to 2011. SUMMARY OF BACKGROUND DATA: There is a paucity of literature assessing the current practice trends and outcomes of cervical spine surgery following the 2008 Food and Drug Administration public health notifications regarding bone morphogenetic protein (BMP) utilization in cervical spine surgical procedures. METHODS: The National Inpatient Sample database was accessed for each year across 2002 to 2011. Patients undergoing anterior cervical fusion, posterior cervical fusion, and posterior cervical decompression were identified. Patient and hospitalization parameters including demographics, BMP utilization, costs, early postoperative outcomes, and mortality were assessed for each surgical cohort. A Pearson correlation coefficient with a 95% confidence interval (P < 0.05) was used to analyze trends in patient and hospital outcome parameters during this 10-year period. RESULTS: A total of 307,188 cervical spine procedures were performed from 2002 to 2011. Both the anterior cervical fusion and posterior cervical fusion cohort demonstrated a statistically significant increase in the number of procedures performed over time (r = +0.9, P < 0.001). A significant uptrend in patient age (r = +1.0, P < 0.001) and comorbidity burden (r = +0.9, P < 0.001) was demonstrated during the studied decade. Overall, BMP utilization (r = +0.7, P = 0.02) also demonstrated a significant increase during this time period, but demonstrated a decline after peaking in 2007. The posterior cervical fusion cohort demonstrated the greatest comorbidity, length of stay, costs, and mortality. CONCLUSION: This study demonstrates that the number of cervical spine procedures has increased between 2002 and 2011, irrespective of the change in BMP utilization after the 2008 Food and Drug Administration warning. Despite an older patient population with greater comorbidities undergoing cervical spine surgeries, hospital length of stay and mortality has not significantly changed. However, we did note a significant increase in costs during this time period. These findings may be related to advances in surgical technology and instrumentation that may be associated with rising hospital costs.

Complications after lumbar spine surgery between teaching and nonteaching hospitals.

STUDY DESIGN: Retrospective national database analysis. OBJECTIVE: A national population-based database was analyzed to characterize the perioperative complications of lumbar spine procedures performed at teaching and nonteaching hospitals. SUMMARY OF BACKGROUND DATA: Perception biases exist regarding the complications of lumbar spine surgery based upon the hospital teaching environment. METHODS: Data from the Nationwide Inpatient Sample was queried from 2002-2011. Patients undergoing an anterior lumbar interbody fusion, posterior lumbar interbody fusion, anterior/posterior lumbar fusion, or lumbar decompression to treat lumbar degenerative pathology were identified and separated into cohorts based upon the teaching status of the hospital. Patient demographics, Charlson Comorbidity Index, length of stay, complications, mortality, and costs were assessed. RESULTS: A total of 658,616 lumbar procedures were identified from 2002-2011, of which 367,875 (55.9%) were performed at teaching hospitals. An older patient population comprised the teaching hospital cohort and demonstrated a greater comorbidity burden than the nonteaching group (Charlson Comorbidity Index 2.90 vs. 2.55; P < 0.001). In addition, the teaching hospital cohort was associated with a significantly greater number of multilevel fusion cases (P < 0.001) and incurred a greater mean length of stay (3.7 vs. 3.0 d; P < 0.001). Patients treated at teaching hospitals demonstrated a significantly greater incidence of postoperative pulmonary embolism, deep vein thrombosis, infection, and neurological complications than the nonteaching cohort (P < 0.001). Overall, there were no significant differences in the mean total hospital costs or mortality between the hospital cohorts. Regression analysis demonstrated that teaching status was not a significant predictor of mortality (OR, 1.02; confidence interval 0.8-1.2; P = 0.8). CONCLUSION: Patients treated in teaching hospitals for lumbar spine surgery incurred a longer hospitalization and a greater incidence of postoperative complications including pulmonary embolism, deep vein thrombosis, infection, and neurological events. These findings may be explained by an increased complexity of procedures performed at teaching hospitals along with an older and a more comorbid patient population. Despite these differences, the teaching status was not a significant predictor of in-hospital mortality after a lumbar spine surgery. LEVEL OF EVIDENCE: 3.

Prospective, randomized, controlled trial of silicate-substituted calcium phosphate versus rhBMP-2 in a minimally invasive transforaminal lumbar interbody fusion.

STUDY DESIGN: Prospective, randomized, controlled trial. OBJECTIVE: To compare arthrodesis rates between patients undergoing a primary single-level minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) with either Actifuse or recombinant human bone morphogenetic protein-2 (rhBMP-2). SUMMARY OF BACKGROUND DATA: Preclinical animal studies suggest that silicate-substituted calcium phosphate (Actifuse) bone graft substitute offers equivalent or an increased fusion rate compared with other graft enhancers/extenders and rhBMP-2. METHODS: Fifty-two patients undergoing a single-level unilateral MIS TLIF were evenly randomized into 2 cohorts as follows: the Actifuse cohort received Actifuse combined with 5 mL of bone marrow aspirate (n = 26; 50%), whereas the rhBMP cohort received 4.2 mg of rhBMP-2 (n = 26; 50%). A pre hoc G*Power analysis yielded a sample size of n = 26 that was determined through a 2-tailed distribution calculation. Computed tomographic analysis was performed at 6 months and 1 year postoperatively. Pre- and postoperative visual analogue scale scores were obtained to assess the clinical outcomes. Arthrodesis was determined by 2 separate, blinded orthopedic surgeons and a board certified radiologist. RESULTS: At 1-year follow-up, 65% (17/26) of the Actifuse cohort and 92% (24/26) of the rhBMP-2 cohort demonstrated a radiographical arthrodesis (P = 0.01). In both study cohorts, the 1-year postoperative visual analogue scale scores significantly improved (P < 0.001). Pseudarthrosis rates at 1 year were 35.0% (9/26) and 7.7% (2/26) for the Actifuse and rhBMP-2 groups, respectively (P = 0.01, OR = 6.35, 95% CI = 1.22-33.1). A greater reoperation rate was noted in the Actifuse cohort (35.0%, 9/26) compared with the BMP-2 cohort (7.7%, 2/26; P = 0.01). One patient with BMP-2 also experienced symptomatic neuroforaminal bone growth (3.8%, n = 1/26). CONCLUSION: Silicate-substituted calcium phosphate was associated with a significantly lower rate of arthrodesis than rhBMP-2 in a MIS TLIF. The patients with pseudarthrosis in both cohorts were all clinically symptomatic with an unimproved visual analogue scale score. Additional analysis of Actifuse and other graft enhancers/extenders are needed prior to the utilization for an MIS TLIF. LEVEL OF EVIDENCE: 2.

Incidence and risk factors for perioperative visual loss after spinal fusion.

BACKGROUND CONTEXT: Perioperative visual loss (POVL) is a rare but devastating complication that may follow spinal surgeries. The incidence of POVL after spinal fusion is not well characterized during the past decade. PURPOSE: A population-based database was analyzed to characterize the incidence and risk factors for POVL associated with spinal fusion surgery on a national level. STUDY DESIGN: This study consisted of a retrospective database analysis. PATIENT SAMPLE: A total of 541,485 patients from the Nationwide Inpatient Sample (NIS) database were included in the study. OUTCOME MEASURES: Study outcome measures included incidence of POVL, length of stay (LOS), in-hospital costs, mortality, and POVL risk factors. METHODS: Data from the NIS were obtained from 2002 to 2009. Patients undergoing spinal fusion for degenerative pathologies were identified. Patient demographics, comorbidities, LOS, costs, and mortality were assessed. Statistical analyses were conducted using an independent t test for discrete variables and the chi-square test for categorical data. Binomial logistic regression was used to identify independent predictors of POVL. A p value of less than or equal to .001 was used to denote statistical significance. No funds were received by any of the authors for production of this study. RESULTS: A total of 541,485 spinal fusions were identified in the United States from 2002 to 2009. The overall incidence of POVL was 1.9 events per 10,000 cases. Of patients who had POVL, 56.2% underwent surgery for a diagnosis of spinal deformity. Patients with POVL were significantly younger on average compared with unaffected patients (37.6 years vs. 52.4 years; p<.001). Length of stay and hospital costs doubled for patients with POVL (p<.001). Logistic regression analysis demonstrated that independent predictors of visual loss were deformity surgery (odds ratio [OR]=6.1), diabetes mellitus with end organ damage (OR=13.1), and paralysis (OR=6.0, p<.001). CONCLUSIONS: Our findings demonstrated an overall POVL incidence of 1.9 events per 10,000 spinal fusions. Patients undergoing thoracic fusion for deformity correction accounted for the majority of cases of POVL. Despite being a rare complication after spinal fusion, POVL is an adverse event that may not be entirely preventable. Patients undergoing long-segment fusions for deformity and those with certain risk factors should be counseled regarding the risks of POVL.

Incidence and risk factors for postoperative ileus following anterior, posterior, and circumferential lumbar fusion.

BACKGROUND CONTEXT: Postoperative ileus is a known complication of surgery. The incidence and risk factors for ileus after lumbar fusion surgery is not well characterized. PURPOSE: To determine rates of postoperative ileus, a population-based database was analyzed to identify incidence, mortality, and risk factors associated with anterior (ALF), posterior (PLF), and combined anterior/posterior (APLF) lumbar fusions. STUDY DESIGN: This was a retrospective database analysis. PATIENT SAMPLE: The sample consisted of 220,522 patients from the Nationwide Inpatient Sample (NIS) database. OUTCOME MEASURES: Outcome measures were incidence of postoperative ileus, length of stay (LOS), in-hospital costs, and mortality. METHODS: Data from the NIS were obtained from 2002 to 2009. Patients undergoing ALF, PLF, and APLF for degenerative pathologies were identified and the incidence of postoperative ileus was assessed. Patient demographics, Charlson comorbidity index (CCI), LOS, costs, and mortality were assessed. SPSS v.20 was used to detect statistical differences between groups and perform logistic regression analyses to identify independent predictors of postoperative ileus. A p value less than .001 denoted significance. RESULTS: A total of 220,522 lumbar fusions were identified in the United States from 2002 to 2009. There were 19,762 ALFs, 182,801 PLFs, and 17,959 APLFs. The incidence of postoperative ileus was increased in ALFs over PLFs (74.9 vs. 26.0 per 1,000; p<.001). Within PLF and APLF groups, CCI scores were increased in the presence of postoperative ileus (p<.001). Across cohorts, patients with postoperative ileus demonstrated greater LOS and costs (p<.001). PLF-treated patients with postoperative ileus demonstrated increased mortality (p<.001). Independent predictors of postoperative ileus included male gender, 3+ fusion levels, alcohol abuse, anemia, fluid/electrolyte disorders, and weight loss (p<.001). CONCLUSIONS: The results of our study demonstrate increased incidence of postoperative ileus associated with anterior approaches for lumbar fusion. Across cohorts, postoperative ileus was associated with increased LOS and costs. To determine the mortality and resource use associated with postoperative ileus, we recommend preoperatively identifying and treating modifiable risk factors, especially when an anterior approach is used.

Complications of spinal fusion with utilization of bone morphogenetic protein: a systematic review of the literature.

STUDY DESIGN: Systematic review. OBJECTIVE: A systematic review was performed to identify the types of complications and complication rates associated with the use of bone morphogenetic protein (BMP) in both anterior and posterior cervical and lumbar spine surgery. SUMMARY OF BACKGROUND DATA: There has been an increase in BMP use in various clinical situations typically in an "off-label" fashion. Associated with its use, however, have been reports of various complications. METHODS: A MEDLINE search was conducted. All articles involving complications after spine surgery in patients receiving BMP were included. Articles were excluded on the basis of the following criteria: Non-English manuscripts and nonhuman subjects. A total of 29 articles met the inclusion and exclusion criteria and were used in the analysis. For each complication identified, the incidence was calculated by pooling the subjects from the studies that reported the complication. χ tests were used to compare the incidence rates between those that had received BMP and the control groups. RESULTS: Of the 29 articles included, 7 reported complication rates in anterior cervical fusions, 3 in posterior cervical fusions, 4 in anterior lumbar interbody fusions (ALIF), 9 in posterior/transforaminal lumbar interbody fusions (PLIF/TLIF), and 6 in posterolateral lumbar fusions. Individual complication rates when BMP was used was in the range from 0.66% to 20.1% in anterior cervical fusions, 3.5% to 14.6% in posterior cervical fusions, 2.0% to 7.3% in ALIFs, 1.5% to 21.8% in PLIF/TLIFs, and 1.4% to 8.2% in posterolateral lumbar fusions. Pseudarthrosis rates were statistically significantly lower with the utilization of BMP in all procedures except for PLIF/TLIFs, which only approached significance (P = 0.07). The only individual complication that was statistically significantly greater with BMP utilization was retrograde ejaculation in ALIFs (7.3 vs. 2.3%; P = 0.03). The rate of dysphagia/swelling in anterior cervical fusions was greater with BMP (20.1 vs. 15.6%), however this only approached statistical significance (P = 0.07). CONCLUSION: The body of literature reports complication rates with BMP ranging from 0.66% to 21.8%. However, the only statistically significant adverse complication rate was retrograde ejaculation in the ALIF population (7.3%). Despite the increased awareness of complications associated with BMP, complication rates remain spine site specific and low. Thorough patient education should be done with the physician to make an informative use regarding BMP utilization in spinal surgery. LEVEL OF EVIDENCE: 3.

A perioperative cost analysis comparing single-level minimally invasive and open transforaminal lumbar interbody fusion.

BACKGROUND CONTEXT: Emerging literature suggests superior clinical short- and long-term outcomes of MIS (minimally invasive surgery) TLIFs (transforaminal lumbar interbody fusion) versus open fusions. Few studies to date have analyzed the cost differences between the two techniques and their relationship to acute clinical outcomes. PURPOSE: The purpose of the study was to determine the differences in hospitalization costs and payments for patients treated with primary single-level MIS versus open TLIF. The impact of clinical outcomes and their contribution to financial differences was explored as well. STUDY DESIGN/SETTING: This study was a nonrandomized, nonblinded prospective review. PATIENT SAMPLE: Sixty-six consecutive patients undergoing a single-level TLIF (open/MIS) were analyzed (33 open, 33 MIS). Patients in either cohort (MIS/open) were matched based on race, sex, age, smoking status, medical comorbidities (Charlson Comorbidity index), payer, and diagnosis. Every patient in the study had a diagnosis of either degenerative disc disease or spondylolisthesis and stenosis. OUTCOME MEASURES: Operative time (minutes), length of stay (LOS, days), estimated blood loss (EBL, mL), anesthesia time (minutes), Visual Analog Scale (VAS) scores, and hospital cost/payment amount were assessed. METHODS: The MIS and open TLIF groups were compared based on clinical outcomes measures and hospital cost/payment data using SPSS version 20.0 for statistical analysis. The two groups were compared using bivariate chi-squared analysis. Mann-Whitney tests were used for non-normal distributed data. Effect size estimate was calculated with the Cohen d statistic and the r statistic with a 95% confidence interval. RESULTS: Average surgical time was shorter for the MIS than the open TLIF group (115.8 minutes vs. 186.0 minutes respectively; p=.001). Length of stay was also reduced for the MIS versus the open group (2.3 days vs. 2.9 days, respectively; p=.018). Average anesthesia time and EBL were also lower in the MIS group (p<.001). VAS scores decreased for both groups, although these scores were significantly lower for the MIS group (p<.001). Financial analysis demonstrated lower total hospital direct costs (blood, imaging, implant, laboratory, pharmacy, physical therapy/occupational therapy/speech, room and board) in the MIS versus the open group ($19,512 vs. $23,550, p<.001). Implant costs were similar (p=.686) in both groups, although these accounted for about two-thirds of the hospital direct costs in the MIS cohort ($13,764) and half of these costs ($13,778) in the open group. Hospital payments were $6,248 higher for open TLIF patients compared with the MIS group (p=.267). CONCLUSIONS: MIS TLIF technique demonstrated significant reductions of operative time, LOS, anesthesia time, VAS scores, and EBL compared with the open technique. This reduction in perioperative parameters translated into lower total hospital costs over a 60-day perioperative period. Although hospital reimbursements appear higher in the open group over the MIS group, shorter surgical times and LOS days in the MIS technique provide opportunities for hospitals to reduce utilization of resources and to increase surgical case volume.

Incidence and mortality of perioperative cardiac events in cervical spine surgery.

STUDY DESIGN: Retrospective database analysis. OBJECTIVE: To determine the national incidence, mortality, and risk factors for perioperative cardiac complications associated with cervical spine surgery in the United States. SUMMARY OF BACKGROUND DATA: Perioperative myocardial infarctions and cardiac failure are leading causes of mortality in noncardiac surgery. The incidence of these complications has not been reported in cervical spine surgery. METHODS: Data from the Nationwide Inpatient Sample was obtained from 2002-2009. Patients undergoing anterior or posterior cervical fusion and posterior cervical decompression without fusion for degenerative etiologies were identified. Only elective admissions were included. Incidences of cardiac complications were identified and patient demographics, hospital costs, length of stay, and mortality were compared for each group. Logistic regression was used to identify independent predictors of cardiac complications. RESULTS: A total of 214,900 elective cervical spine procedures were identified in the United States from 2002-2009. Overall, there were 4.0 cardiac events per 1000 cases. For individual procedures, the incidence was 11.6 per 1000 posterior cervical fusions, 5.2 per 1000 posterior cervical decompressions, and 3.2 per 1000 anterior cervical fusions. Patients with cardiac events were statistically older with greater comorbidities (P < 0.0005). Across all cohorts, length of stay increased an additional 4.5 days, hospital costs increased $13,435, and mortality increased from 0.8 to 65.3 deaths per 1000 cases in the presence of a cardiac event (P < 0.0005). Logistic regression analysis demonstrated that independent predictors for cardiac events included age 65 years or more, multilevel fusions, acute blood-loss anemia, congestive heart failure, fluid/electrolyte disorders, and pulmonary circulation disorders. CONCLUSION: Our results demonstrate an overall incidence of 4.0 cardiac events per 1000 cervical spine surgical procedures. Older patients with greater comorbid risk factors, particularly cardiovascular diseases, were at significantly increased risk for cardiac complications. Due to the large impact cardiac events have on health care utilization and mortality, we recommend thorough risk stratification for older patients undergoing elective cervical spine procedures. LEVEL OF EVIDENCE: 3.

Incidence, risk factors, and mortality associated with aspiration in cervical spine surgery.

STUDY DESIGN: Retrospective national database analysis. OBJECTIVE: A population-based database was analyzed to characterize the incidence, mortality, and associated risk factors for aspiration pneumonia in cervical spine surgery. SUMMARY OF BACKGROUND DATA: Aspiration pneumonia represents a potentially fatal complication of any surgical procedure. The incidence of this complication is not well characterized after cervical spine surgery. METHODS: Data from the Nationwide Inpatient Sample was obtained from 2002-2009. Patients undergoing anterior cervical fusion, posterior cervical fusion, or posterior cervical decompression for radiculopathy and/or myelopathy were identified. Patient demographics, incidence of aspiration, costs, and mortalities were assessed. Statistical analysis was performed using Student t test for discrete variables and χ test for categorical data. Logistic regression was used to identify independent predictors for aspiration. RESULTS: A total of 202,694 patients were identified in the Nationwide Inpatient Sample from 2002 to 2009. Of these, 166,633 were anterior cervical fusions (82.2%), 13,298 were posterior cervical fusions (6.6%), and 22,764 were posterior cervical decompressions (11.2%). The overall incidence of aspiration was 5.3 events per 1000 cases. The greatest incidence was demonstrated in posterior cervical fusion-treated patients with 13.7 per 1000 cases, followed by posterior cervical decompressions with 6.4 per 1000 and anterior cervical fusions with 4.5 per 1000. Patients affected by aspiration were significantly older, more frequently male, and had greater comorbidities than unaffected patients (P < 0.001). Patients diagnosed with aspiration demonstrated significantly greater length of stay, costs, and mortality (P < 0.001). Logistic regression analysis demonstrated independent predictors of aspiration to include advanced age (≥65 yr), male sex, congestive heart failure, coagulopathy, neuropsychiatric disorders, and weight loss (P < 0.001). CONCLUSION: We demonstrated an overall incidence of 5.3 cases of aspiration per 1000 cervical procedures. Patients most commonly affected by aspiration were older males with greater comorbidity. Hospital courses complicated by aspiration had greater length of stay, costs, and mortality. Identification of patients with risk factors for aspiration may assist in early diagnosis and treatment to prevent further morbidity and mortality.

Outcomes of cervical spine surgery in teaching and non-teaching hospitals.

STUDY DESIGN: Retrospective national database analysis. OBJECTIVE: A national population-based database was analyzed to characterize cervical spine procedures performed at teaching and nonteaching hospitals with regards to patient demographics, clinical outcomes/complications, resource use, and costs. SUMMARY OF BACKGROUND DATA: There are mixed reports in the literature regarding the quality and costs of health care provided by teaching hospitals in the United States. However, outcomes of cervical spine surgery based upon teaching status remains largely unknown. METHODS.: Data from the Nationwide Inpatient Sample were obtained from 2002-2009. Patients undergoing elective anterior or posterior cervical fusion, or posterior cervical decompression (i.e., laminoforaminotomy, laminectomy, laminoplasty) for a diagnosis of cervical myelopathy and/or radiculopathy were identified and separated into 2 cohorts (teaching and nonteaching hospitals). Patient demographics, comorbidities, complications, length of hospitalization, costs, and mortality were compared for both groups. Regression analysis was performed to assess independent predictors of mortality. RESULTS: A total of 212,385 cervical procedures were identified from 2002-2009 in the United States, with 54.6% performed at teaching hospitals. More multilevel fusions and posterior approaches were performed in teaching hospitals (P < 0.0005). Patients treated in teaching hospitals trended toward male sex, increased costs, and hospitalizations. Overall, procedure-related complications and inhospital mortality were increased in teaching hospitals. Regression analysis revealed that significant predictors of mortality were age 65 years or more (odds ratio = 3.0) and multiple comorbidities. Teaching status was not a significant predictor of mortality (P = 0.07). CONCLUSION: Patients treated in teaching hospitals for cervical spine surgery demonstrated longer hospitalizations, increased costs, and mortality compared with patients treated in nonteaching hospitals. Incidences of postoperative complications were identified to be higher in teaching hospitals. Possible explanations for these findings are an increased complexity of procedures performed at teaching hospitals. Older age and presence of comorbidities were more significant predictors of inhospital mortality than teaching status. Future studies should identify long-term complications and costs beyond an inpatient setting to assess if differences extend beyond the perioperative period. LEVEL OF EVIDENCE: 4.