[Clinicopathological features and gene phenotypes of benign metastasizing leiomyoma]

Objective: To study the clinicopathological features, immunophenotypes and MED12 gene status in benign metastasizing leiomyoma (BML). Methods: Nine cases of BML diagnosed at the Affiliated Hospital of Qingdao University from 2012 to 2018 were collected, and the radiologic and histologic features were analyzed. The protein expression of leiomyosarcoma-related driver genes, including RB1, PTEN,ATRX,p16,p53, as well as ER,PR,CD34,FH, and Ki-67 were detected using immunohistochemistry, and the mutation status of MED12 gene exon 2 was detected by Sanger sequencing. Results: All the nine patients with BML were female, and the age range was 48 to 64 years (median 55 years). All patients had history of uterine fibroids. The morphologic features of BML were similar to a benign uterine leiomyoma and did not exhibit malignant characteristics. All cases were positive for ER and PR, and negative for CD34. In addition, RB1, PTEN, ATRX, and FH were positive in all cases (wild type), while p16 showed a focally positive pattern. P53 positive index was less than 5% (wild type), and Ki-67 positive index was less than 1%. Sanger sequencing was done in six BML samples; one sample harbored a nonsense mutation c. 142_144delinsTAA (p.Glu48Ter), and another exhibited a synonymy mutation (c.192C>T, p.Phe64=)and one missense mutation c.196C>T (p.Pro66Ser). Conclusions: The present study suggests that BML is a unique leiomyoma entity that is pathologically and genetically different from leiomyosarcomas and conventional uterine leiomyomas. Evaluating the genetic phenotype of BML, especially the expression of leiomyosarcoma-related driver genes protein and MED12 gene status, may be helpful in understanding the pathogenesis of BML and in its differentiation from leiomyosarcoma.

The impact of obesity on perioperative complications in patients undergoing anterior lumbar interbody fusion

OBJECTIVE

Anterior approaches to the lumbar spine provide wide exposure that facilitates placement of large grafts with high fusion rates. There are limited data on the effects of obesity on perioperative complications.

METHODS

Data from consecutive patients undergoing anterior lumbar interbody fusion (ALIF) from 2007 to 2016 at a single academic center were analyzed. The primary outcome was any perioperative complication. Complications were divided into those occurring intraoperatively and those occurring postoperatively. Multivariate logistic regression was used to assess the association of obesity and other variables with these complications. An estimation table was used to identify a body mass index (BMI) threshold associated with increased risk of postoperative complication.

RESULTS

A total of 938 patients were identified, and the mean age was 57 years; 511 were females (54.5%). The mean BMI was 28.7 kg/m2, with 354 (37.7%) patients classified as obese (BMI ≥ 30 kg/m2). Forty patients (4.3%) underwent a lateral transthoracic approach, while the remaining 898 (95.7%) underwent a transabdominal retroperitoneal approach. Among patients undergoing transabdominal retroperitoneal ALIF, complication rates were higher for obese patients than for nonobese patients (37.0% vs 28.7%, p = 0.010), a difference that was driven primarily by postoperative complications (36.1% vs 26.0%, p = 0.001) rather than intraoperative complications (3.2% vs 4.3%, p = 0.416). Obese patients had higher rates of ileus (11.7% vs 7.2%, p = 0.020), wound complications (11.4% vs 3.4%, p < 0.001), and urinary tract infections (UTI) (5.0% vs 2.5%, p = 0.049). In a multivariate model, age, obesity, and number of ALIF levels fused were associated with an increased risk of postoperative complication. An estimation table including 19 candidate cut-points, odds ratios, and adjusted p values found a BMI ≥ 31 kg/m2 to have the highest association with postoperative complication (p = 0.012).

CONCLUSIONS

Obesity is associated with increased postoperative complications in ALIF, including ileus, wound complications, and UTI. ALIF is a safe and effective procedure. However, patients with a BMI ≥ 31 kg/m2 should be counseled on their increased risks and warrant careful preoperative medical optimization and close monitoring in the postoperative setting.

Outcomes and Quality of Life Improvement After Multilevel Spinal Fusion in Elderly Patients

STUDY DESIGN

Retrospective case series.

OBJECTIVES

Both the rate and complexity of spine surgeries in elderly patients has increased. This study reports the outcomes of multilevel spine fusion in elderly patients and provides evidence on the appropriateness of complex surgery in elderly patients.

METHODS

We identified 101 patients older than70 years who had ≥5 levels of fusion. Demographic, medical, and surgical data, and change between preoperative and >500 days postoperative health survey scores were collected. Health surveys were visual analogue scale (VAS), EuroQoL 5 Dimensions (EQ-5D), Oswestry Disability Index (ODI), Scoliosis Research Society questionnaire (SRS-30), and Short Form health survey (SF-12) (physical composite score [PCS] and mental composite score [MCS]). Minimal clinically important differences (MCIDs) were defined for each survey.

RESULTS

Complications included dural tears (19%), intensive care unit admission (48%), revision surgery within 2 to 5 years (24%), and death within 2 to 5 years (16%). The percentage of patients who reported an improvement in health-related quality of life (HRQOL) of at least an MCID was: VAS Back 69%; EQ-5D 41%; ODI 58%; SRS-30 45%; SF-12 PCS 44%; and SF-12 MCS 48%. Improvement after a primary surgery, as compared with a revision, was on average 13 points higher in ODI (P = .007). Patients who developed a surgical complication averaged an improvement 11 points lower on ODI (P = .042). Patients were more likely to find improvement in their health if they had a lower American Society of Anesthesiologists or Charlson Comorbidity Index score or a higher metabolic equivalent score.

CONCLUSIONS

In multilevel surgery in patients older than 70 years, complications are common, and on average 77% of patients attain some improvement, with 51% reaching an MCID. Physiological status is a stronger predictor of outcomes than chronological age.

Cost Analysis of Single-Level Lumbar Fusions

STUDY DESIGN

Cost analysis of a retrospectively identified cohort of patients who had undergone primary single-level lumbar fusion at a single institution's orthopedic or neurosurgery department.

OBJECTIVE

The purpose of this article is to analyze the determinants of direct costs for single-level lumbar fusions and identify potential areas for cost reduction.

METHODS

Adult patients who underwent primary single-level lumbar fusion from fiscal years 2008 to 2012 were identified via administrative and departmental databases and were eligible for inclusion. Patients were excluded if they underwent multiple surgeries, had previous surgery at the same anatomic region, underwent corpectomy, kyphectomy, disc replacement, surgery for tumor or infection, or had incomplete cost data. Demographic data, surgical data, and direct cost data in the categories of supplies, services, room and care, and pharmacy, was collected for each patient.

RESULTS

The cohort included 532 patients. Direct costs ranged from $8286 to $73 727 (median = $21 781; mean = $22 890 ± $6323). Surgical approach was an important determinant of cost. The mean direct cost was highest for the circumferential approach and lowest for posterior instrumented spinal fusions without an interbody cage. The difference in mean direct cost between transforaminal lumbar interbody fusions, anterior lumbar interbody fusions, and lateral transpsoas fusions was not statistically significant. Surgical supplies accounted for 44% of direct costs. Spinal implants were the primary component of supply costs (84.9%). Services accounted for 38% of direct costs and were highly dependent on operative time. Comorbidities were an important contributor to variance in the cost of care as evidenced by high variance in pharmacy costs and length of stay related to their management.

CONCLUSION

The costs of spinal surgeries are highly variable. Important cost drivers in our analysis included surgical approach, implants, operating room time, and length of hospital stay. Areas of high cost and high variance offer potential targets for cost savings and quality improvements.

Asymmetric Pedicle Subtraction Osteotomy for Adult Spinal Deformity with Coronal Imbalance: Complications, Radiographic and Surgical Outcomes

BACKGROUND

Asymmetric pedicle subtraction osteotomy (APSO) can be utilized for adult spinal deformity (ASD) with fixed coronal plane imbalance. There are few reports investigating outcomes following APSO and no series that include multiple revision cases.

OBJECTIVE

To detail our surgical technique and experience with APSO.

METHODS

All thoracolumbar ASD cases with a component of fixed, coronal plane deformity who underwent APSO from 2004 to 2016 at one institution were retrospectively reviewed. Preoperative and latest follow-up radiographic parameters and data on surgical outcomes and complications were obtained.

RESULTS

Fourteen patients underwent APSO with mean follow-up of 37-mo. Ten (71.4%) were revision cases. APSO involved a mean 12-levels (range 7-25) and were associated with 3.0 L blood loss (range 1.2-4.5) and 457-min of operative time (range 283-540). Surgical complications were observed in 64.3%, including durotomy (35.7%), pleural injury (14.3%), persistent neurologic deficit (14.3%), rod fracture (7.1%), and painful iliac bolt requiring removal (7.1%). Medical complications were observed in 14.3%, comprising urosepsis and 2 cases of pneumonia. Two 90-d readmissions (14.3%) and 5 reoperations (4 patients, 28.6%) occurred. Mean thoracolumbar curve and coronal vertical axis improved from 31.5 to 16.4 degrees and 7.8 to 2.9 cm, respectively. PI-LL mismatch, mean sagittal vertical axis, and pelvic tilt improved from 40.0 to 27.9-degrees, 10.7 to 3.5-cm, and 34.4 to 28.3-degrees, respectively.

CONCLUSION

The APSO, in both a revision and non-revision ASD population, provides excellent restoration of coronal balance-in addition to sagittal and pelvic parameters. Employment of APSO must be balanced with the associated surgical complication rate (64.3%).

Local Application of Vancomycin in Spine Surgery Does Not Result in Increased Vancomycin-Resistant Bacteria-10-Year Data

STUDY DESIGN

Case-control study.

OBJECTIVES

To analyze the microbial flora in surgical spine infections and their antibiotic resistance patterns across time and determine the correlation between vancomycin application in the wound and vancomycin-resistant microbes.

SUMMARY OF BACKGROUND DATA

Prior studies show a reduction in surgical site infections with intrawound vancomycin placement. No data are available on the potential negative effects of this intervention, in particular, whether there would be a resultant increase in vancomycin-resistant organisms or bacterial resistance profiles.

METHODS

All culture-positive surgical site infections at a single institution were analyzed from 2007 to 2017. Each bacterium was assessed independently for resistance patterns. The two-tailed Fisher exact test was used to determine the correlation between vancomycin application and the presence of vancomycin-resistant bacteria, polymicrobial infections, or gram-negative bacterial infections.

RESULTS

One hundred and eight bacteria were isolated from 113 surgical site infections from 2007 to 2017. The most common organisms were staphylococcus with varying resistance patterns and Escherichia coli. Vancomycin-resistant Enterococcus faecium was isolated in three infections. Out of the 4,878 surgical cases from 2011 to 2017, vancomycin was placed in 48.3%, and no vancomycin in 51.7%. There were 33 infections (1.4%) in the vancomycin group and 20 infections (0.8%) in the no-vancomycin group (χ² = 0.0521). There was no correlation between vancomycin application in the wound and vancomycin-resistant microbes (χ² = 0.2334) and polymicrobial infections (χ² = 0.1328). There was an increased rate of gram-negative organisms in infections after vancomycin application in the wound versus no vancomycin (χ² = 0.0254).

CONCLUSIONS

Topical vancomycin within the surgical site is not correlated with vancomycin-resistant bacteria. However, there was an increased incidence of gram-negative organisms in infections after vancomycin application in the wound versus no vancomycin. Continued surveillance with prospectively collected randomized data is necessary to better understand bacterial evolution against current antimicrobial techniques.

LEVEL OF EVIDENCE

Level III.

Short-Term Outcomes of Staged Versus Same-Day Surgery for Adult Spinal Deformity Correction

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Assess differences between staged (≤3 days) and same-day surgery in perioperative factors, radiographic measures, and complications.

SUMMARY OF BACKGROUND DATA

Surgical adult spinal deformity correction may require combined anterior and posterior approaches. To modulate risk, some surgeons perform surgery that is expected to be longer and/or more complex in two stages. Prior studies comparing staged (≥7 days) and same-day surgery demonstrated mixed results and none have examined results with shorter staging intervals.

METHODS

Retrospective review of adults undergoing combined anterior/posterior approaches for spinal deformity over a 3-year period at a single institution (n=92). Univariate differences between staged and same-day surgery were assessed with chi-squared, Fisher exact, and Mann-Whitney U tests. Generalized estimating equations assessed whether differences in perioperative outcomes between groups remained after adjusting for differences in demographic and surgical characteristics.

RESULTS

In univariate analyses, staged surgery was associated with a length of stay (LOS) 3 days longer than same-day surgery (9.2 vs. 6.3 days, p < .001), and greater operative time, blood loss, transfusion requirement, and days in intensive care unit (p < .001 for each). Staged surgery had a higher rate of thrombotic events (p = .011) but did not differ in readmission rates or other complications. Radiographically, improvements in Cobb angle (average 13° vs. 17°, p = .028), lumbar lordosis (average 14° vs. 23°, p = .019), and PI-LL mismatch (average 10° vs. 2° p = .018) were greater for staged surgery, likely related to more extensive use of osteotomies in the staged group. After risk adjustment, taking into account the procedural specifics including longer fusion constructs and greater number of osteotomies, LOS no longer differed between staged and same-day surgery; however, the total operative time was 98 minutes longer for staged surgery (p < .001). Differences in blood loss between groups was accounted for by differences in operative time and patient and surgical characteristics.

CONCLUSIONS

Although univariate analysis of our results were in accordance with previously published works, multivariate analysis allowing individual case risk adjustment revealed that LOS was not significantly increased in the staged group as reported in previous studies. There was no difference in infection rates as previously described but an increase in thrombotic events was observed.

LEVEL OF EVIDENCE

Level III.

Reliability of radiological measurements of type 2 odontoid fracture

BACKGROUND CONTEXT

It is recognized that radiological parameters of type 2 dens fractures, including displacement and angulation, are predictive of treatment outcomes and are used to guide surgical decision-making. The reproducibility of such measurements, therefore, is of critical importance. Past literature has shown poor interobserver reliability for both displacement and angulation measurements of type 2 dens fractures. Since such studies however, various advancements of radiological review systems and measurement tools have evolved to potentially improve such measurements.

PURPOSE

To re-examine the inter-rater reliability of measuring displacement and angulation of type 2 dens fractures using modern radiological review systems. Besides quantitative measurements, the reliability of raters in identifying diagnostic classifications based on translational and angulational displacement was also examined.

STUDY DESIGN

Radiographic measurement reliability and agreement study.

PATIENT SAMPLE

Thirty-seven patients seen at a single institution between 2002 and 2017 with primary diagnosis of acute type 2 dens fracture with complete computed tomography (CT) imaging.

OUTCOME MEASURES

Radiological measurements included displacement and angulation. Diagnostic classifications based on consensus-based clinical cutoff points were also recorded.

METHODS

Measurements were performed by five surgeons with varying years of experience in spine surgery using the hospital's electronic medical record radiological measuring tools. The radiological measurements included displacement and angulation. Diagnostic classifications based on consensus-based clinical cutoff points were also recorded. Each rater received a graphic demonstration of the measurement methods, but had the autonomy to select a best cut from the sagittal CT to measure. All raters were blinded to patient information.

RESULTS

Measurements for displacement and angulation among the five raters demonstrated "excellent" reliability. Intra-rater reliability was also "excellent" in measuring displacement and angulation. The reliability of diagnostic classification of displacement (above vs. below 5 mm), was found to be "very good" among the raters. The reliability of diagnostic classification of angulation (above vs. below 11°) demonstrated "good" reliability.

CONCLUSIONS

Advancement of radiological review systems, including review tools and embedded image processing software, has facilitated more reliable measurements for type 2 odontoid fractures.

[Association of platelet/lymphocyte ratio and neutrophil/lymphocyte ratio with protein-energy wasting in maintenance hemodialysis patients]

Objective: To explore the association of platelet/lymphocyte ratio (PLR) and neutrophil/lymphocyte ratio (NLR) with protein energy wasting (PEW) in maintenance hemodialysis (MHD) patients. Methods: A multicenter cross-sectional study was conducted in eleven hemodialysis centers of Guizhou province from June to August, 2017. Clinical data, physical parameters, body composition data and laboratory values of MHD patients were collected. PLR and NLR were calculated according to routine blood test. All patients were divided into four groups (Q1-Q4) according to the median and quartile of PLR and NLR. Multivariate logistic regression models were applied to analyze the relationships between PLR, NLR and PEW. The comparison of predictive power of PLR and NLR for PEW was evaluated by receiver operating characteristic curve (ROC). Results: A total of 936 MHD patients were enrolled (519 males, 417 females), with a mean age of (55.6±15.6) years. The prevalence of PEW was 46.2% (432/936). Multivariate logistic regression analysis showed that patients in group PLR Q3 and Q4 were 2.07 (95%CI: 1.03-4.13, P=0.014) and 2.73 (95%CI: 1.58-4.74, P<0.001) times more likely to have PEW, compared with those in group PLR Q1 in unadjusted models. PLR was significantly associated with the development of PEW after adjusting age, sex, history of hypertension, diabetes and hemoglobin. Patients in Group PLR Q3 and Q4 were 2.82 times (95%CI: 1.42-5.60, P=0.003) and 2.93 times (95%CI: 1.50-5.73, P=0.002) times more likely to have PEW than those in Group PLR Q1. The ROC showed that only PLR can predict the development of PEW with a diagnostic threshold of 144.09 [area under curve (AUC)=0.61, 95%CI: 0.56-0.66, P<0.001], with a sensitivity and specificity of 61% and 58%, respectively, while the AUC of NLR is 0.55 (P=0.091). Conclusion: For MHD patients, only PLR could be a relevent factor of PEW and it showed the predictive power of PEW rather than NLR.

Lumbar epidural steroid injections for herniation and stenosis: incidence and risk factors of subsequent surgery

BACKGROUND CONTEXT

Lumbosacral epidural steroid injections (ESIs) have increased dramatically despite a narrowing of the clinical indications for use. One potential indication is to avoid or delay surgery, yet little information exists regarding surgery rates after ESI.

PURPOSE

The purpose of this research was to determine the proportion of patients having surgery after lumbar ESI for disc herniation or stenosis and to identify the timing and factors associated with this progression.

STUDY DESIGN/SETTING

This study was a retrospective review of nationally representative administrative claims data from the Truven Health MarketScan databases from 2007 to 2014.

PATIENT SAMPLE

The study cohort was comprised of 179,025 patients (54±15 years, 48% women) having lumbar ESIs for diagnoses of stenosis and/or herniation.

OUTCOME MEASURES

The primary outcome measure was the time from ESI to surgery.

METHODS

Inclusion criteria were ESI for stenosis and/or herniation, age ≥18 years, and health plan enrollment for 1 year before ESI to screen for exclusions. Patients were followed longitudinally until they progressed to surgery or had a lapse in enrollment, at which time they were censored. Rates of surgery were assessed with the Kaplan-Meier survival curves. Demographic and treatment factors associated with surgery were assessed with multivariable Cox proportional hazard models. No external funding was procured for this research and the authors' conflicts of interest are not pertinent to the present work.

RESULTS

Within 6 months, 12.5% of ESI patients underwent lumbar surgery. By 1 year, 16.9% had surgery, and by 5 years, 26.1% had surgery. Patients with herniation had surgery at rates of up to five-fold to seven-fold higher, with the highest rates of surgery in younger patients and those with both herniation and stenosis. Other concomitant spine diagnoses, male sex, previous tobacco use, and residence a rural areas or regions other than the Northeastern United States were associated with higher surgery rates. Medical comorbidities (previous treatment for drug use, congestive heart failure, obesity, chronic obstructive pulmonary disease, hypercholesterolemia, and other cardiac complications) were associated with lower surgery rates.

CONCLUSIONS

In the long term, more than one out of every four patients undergoing ESI for lumbar herniation or stenosis subsequently had surgery, and nearly one of six had surgery within the first year. After adjusting for other patient demographics and comorbidities, patients with herniation were more likely have surgery than those with stenosis. The improved understanding of the progression from lumbar ESI to surgery will help to better inform discussions regarding the value of ESI and aid in the shared decision-making process.

[Association of low serum parathyroid hormone with protein-energy wasting in maintenance hemodialysis patients]

Objective: To examine the relationship between low serum parathyroid hormone (PTH) and protein-energy wasting (PEW) in patients who underwent maintenance hemodialysis (MHD) treatment. Methods: A cross-sectional study was conducted in MHD patients between June 2015 and August 2017 in 11 MHD centers from Guizhou province. Body composition and physical parameters were measured, clinical data and other related laboratory values were collected according to the medical record system. Participants were assigned to low serum PTH group (PTH<150 ng/L), target PTH group (150 ng/L≤ PTH ≤300 ng/L) and high serum PTH group (PTH>300 ng/L). Multivariate logistic regression analysis was used to analyze the relationship between low serum PTH and risk of PEW, which was diagnosed according to the diagnostic criteria recommened by the International Society of Renal Nutrition and Metabolism (ISRNM). Results: A total of 873 MHD patients (488 males and 385 females) were included in the final analysis, with a mean age of 55.0 (44.0, 67.0) years and a mean hemodialysis duration of 31.0(17.0, 54.0) months. In unadjusted model, low serum PTH group was associated with PEW (OR=2.12, 95% CI: 1.26-3.54, P=0.004), when compared with high serum PTH group. After adjustment for age and sex, low serum PTH group was still significantly associated with PEW (OR=2.09, 95% CI: 1.23-3.52, P=0.006). Further adjustment for diabetes and hypertension, the correlation between low serum PTH group and PEW was still significant (OR=2.02, 95% CI: 1.04-3.90, P=0.037). However, the correlation was not observed in target PTH group and high serum PTH group. Conclusion: Low serum PTH was associated with risk of PEW, regardless of age, sex, history of diabetes and hypertension, and thus it might be a promising indicator of PEW in MHD patients.

The comprehensive anatomical spinal osteotomy and anterior column realignment classification

OBJECTIVE

Spinal osteotomies and anterior column realignment (ACR) are procedures that allow preservation or restoration of spine lordosis. Variations of these techniques enable different degrees of segmental, regional, and global sagittal realignment. The authors propose a comprehensive anatomical classification system for ACR and its variants based on the level of technical complexity and invasiveness. This serves as a common language and platform to standardize clinical and radiographic outcomes for the utilization of ACR.

METHODS

The proposed classification is based on 6 anatomical grades of ACR, including anterior longitudinal ligament (ALL) release, with varying degrees of posterior column release or osteotomies. Additionally, a surgical approach (anterior, lateral, or posterior) was added. Reliability of the classification was evaluated by an analysis of 16 clinical cases, rated twice by 14 different spine surgeons, and calculation of Fleiss kappa coefficients.

RESULTS

The 6 grades of ACR are as follows: grade A, ALL release with hyperlordotic cage, intact posterior elements; grade 1 (ACR + Schwab grade 1), additional resection of the inferior facet and joint capsule; grade 2 (ACR + Schwab grade 2), additional resection of both superior and inferior facets, interspinous ligament, ligamentum flavum, lamina, and spinous process; grade 3 (ACR + Schwab grade 3), additional adjacent-level 3-column osteotomy including pedicle subtraction osteotomy; grade 4 (ACR + Schwab grade 4), 2-level distal 3-column osteotomy including pedicle subtraction osteotomy and disc space resection; and grade 5 (ACR + Schwab grade 5), complete or partial removal of a vertebral body and both adjacent discs with or without posterior element resection. Intraobserver and interobserver reliability were 97% and 98%, respectively, across the 14-reviewer cohort.

CONCLUSIONS

The proposed anatomical realignment classification provides a consistent description of the various posterior and anterior column release/osteotomies. This reliability study confirmed that the classification is consistent and reproducible across a diverse group of spine surgeons.

[Interventional treatment of symptomatic intracranial in-stent restenosis]

Objective: To assess the feasibility and safety of interventional treatment of symptomatic intracranial in-stent restenosis (SISR). Methods: Clinical data of 21 patients with SISR who underwent interventional treatment in the General Hospital of the PLA Rocket Force from January 2012 to May 2018 were retrospectively analyzed. Perioperative complications, angiographic and clinical follow-up results were recorded. Results: The success rate of treatment was 100%, including 21 lesions of SISR (7 at the V4 segment of the vertebral artery, 7 at the basilar artery, 5 at the M1 segment of middle cerebral artery, 2 at the internal carotid artery). The residual stenosis rate was preoperative 84±7, postoperative 30±14 respectively. Balloon angioplasty and stent implantation were performed in 10 patients (48.6%) and 11 patients (52.4%), respectively. After treatment, 1 patient experienced perforating event without neurological sequelae. Of the 11 patients (52.4%) completed angiography follow-up, 3 (3/11, 27.3%) ocurred restenosis and 1 was retreated. During clinical follow-up, 1 patients received intravenous thrombolysis for the symptom of acute cerebral infarction in territory of stenting artery, in-stent restenosis or occlusion was not demonstrated by emergency cerebral angiography. Conclusion: Interventional treatment of SISR is feasible and safe, however, further studies need to warrant the long-term effects.

Does timing of transplantation of neural stem cells following spinal cord injury affect outcomes in an animal model?

Background

We previously reported that functional recovery of rats with spinal cord contusions can occur after acute transplantation of neural stem cells distal to the site of injury. To investigate the effects of timing of administration of human neural stem cell (hNSC) distal to the site of spinal cord injury on functional outcomes in an animal model.

Methods

Thirty-six adult female Long-Evans hooded rats were randomized into three experimental and three control groups with six animals in each group. The T10 level was exposed via posterior laminectomy, and a moderate spinal cord contusion was induced by the Multicenter Animal Spinal Cord Injury Study Impactor (MASCIS, W.M. Keck Center for Collaborative Neuroscience, Piscataway, NJ, USA). The animals received either an intrathecal injection of hNSCs or control media through a separate distal laminotomy immediately, one week or four weeks after the induced spinal cord injury. Observers were blinded to the interventions. Functional assessment was measured immediately after injury and weekly using the Basso, Beattie, Bresnahan (BBB) locomotor rating score.

Results

A statistically significant functional improvement was seen in all three time groups when compared to their controls (acute, mean 9.2 vs. 4.5, P=0.016; subacute, mean 11.1 vs. 6.8, P=0.042; chronic, mean 11.3 vs. 5.8, P=0.035). Although there was no significant difference in the final BBB scores comparing the groups that received hNSCs, the group which achieved the greatest improvement from the time of cell injection was the subacute group (+10.3) and was significantly greater than the chronic group (+5.1, P=0.02).

Conclusions

The distal intrathecal transplantation of hNSCs into the contused spinal cord of a rat led to significant functional recovery of the spinal cord when injected in the acute, subacute and chronic phases of spinal cord injury (SCI), although the greatest gains appeared to be in the subacute timing group.

[Application of the descending branch of the lateral circumflex femoral artery in the coronary artery bypass grafting operation]

Objective: To investigate the technical method for harvesting and application of the descending branch of the lateral circumflex femoral artery (DBLCFA) in the coronary artery bypass grafting (CABG) operation. Methods: Between December 2016 and April 2017, 19 patients were arranged to use DBLCFA and got CT angiography (CTA) of pelvic and femoral arteries pre-operative at Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College. Finally, DBLCFA was harvested in 16 patients (including 2 female patients, with a mean age of (47.4±8.5) years) through the anterior thigh incision (13 cases on the left side, 3 cases on the right side). The CABG operations were performed under the cardiopulmonary bypass support (in 10 cases) or under the beating heart condition (in 6 cases), and the DBLCFA conduit was used combining with bilateral internal thoracic artery (in 12 cases), radial artery (in 7 cases) and saphenpous vein (in 3 cases). Results: Due to anatomical variations such as short length and anomalous branch, or due to silent atherosclerosis stenosis of femoral artery, DBLCFA in 3 patients was considered inappropriate for use and was not harvested after CTA examination. In another 16 patients, DBLCFA was safely and quickly harvested and successfully used. On average, 3.4±0.6 anastomosis was built up in CBAG, no adverse effects were exhibited. The length of the harvested DBLCFA was (10.3±1.8) cm, with average lumen diameter of (1.9±0.5) mm. DBLCFA was used as free graft in 15 patients (7 to the first diagonal branch, 6 to the ramus intermedius branch, 1 to the left anterior descending branch and 1 to the second obtuse marginal branch). In 1 patient, the DBLCFA was firstly implanted end-to-side to the internal thoracic artery as a "Y" type composite graft, and then anastomosed to the third obtuse marginal branch. Conclusions: The descending branch of the lateral circumflex femoral artery is an option conduit in CABG. It can be harvested easily and safely. However, pre-operative CTA examination is necessary to exclude the variation and appropriate strategy for graft establishment should be considered during the operation.

Graft Subsidence and Revision Rates Following Anterior Cervical Corpectomy: A Clinical Study Comparing Different Interbody Cages

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To assess the subsidence and revision rates associated with different interbody cages following anterior cervical corpectomy and reconstruction.

SUMMARY OF BACKGROUND DATA

Different interbody cages are currently used for surgical reconstruction of the anterior and middle columns of the spine following anterior cervical corpectomy. However, subsidence and delayed union/nonunion associated with allograft and cage reconstruction are common complications, which may require revision with instrumentation.

MATERIALS AND METHODS

We reviewed the cases of 75 patients who underwent cervical corpectomy and compared the radiographic graft subsidence and revision rates for fibula allograft, titanium mesh cage, titanium expandable cage, and carbon fiber cages. Subsidence was calculated by comparing the immediate postoperative lateral x-ray films to those obtained during follow-up visits.

RESULTS

The average graft subsidence was 3 mm and revision rate was 25% for fibula allograft versus 2.9 mm and 11.1%, 2.9 mm and 18.8% for titanium mesh cages and titanium expandable cages, respectively. The average graft subsidence for carbon fiber cages was 0.7 mm with no revision surgery in this subset.

CONCLUSIONS

Our findings suggest that subsidence and revision rates following anterior corpectomy and interbody fusion could be minimized with the use of a carbon fiber cage.

Predicting complication risk in spine surgery: a prospective analysis of a novel risk assessment tool

OBJECTIVE The ability to assess the risk of adverse events based on known patient factors and comorbidities would provide more effective preoperative risk stratification. Present risk assessment in spine surgery is limited. An adverse event prediction tool was developed to predict the risk of complications after spine surgery and tested on a prospective patient cohort. METHODS The spinal Risk Assessment Tool (RAT), a novel instrument for the assessment of risk for patients undergoing spine surgery that was developed based on an administrative claims database, was prospectively applied to 246 patients undergoing 257 spinal procedures over a 3-month period. Prospectively collected data were used to compare the RAT to the Charlson Comorbidity Index (CCI) and the American College of Surgeons National Surgery Quality Improvement Program (ACS NSQIP) Surgical Risk Calculator. Study end point was occurrence and type of complication after spine surgery. RESULTS The authors identified 69 patients (73 procedures) who experienced a complication over the prospective study period. Cardiac complications were most common (10.2%). Receiver operating characteristic (ROC) curves were calculated to compare complication outcomes using the different assessment tools. Area under the curve (AUC) analysis showed comparable predictive accuracy between the RAT and the ACS NSQIP calculator (0.670 [95% CI 0.60-0.74] in RAT, 0.669 [95% CI 0.60-0.74] in NSQIP). The CCI was not accurate in predicting complication occurrence (0.55 [95% CI 0.48-0.62]). The RAT produced mean probabilities of 34.6% for patients who had a complication and 24% for patients who did not (p = 0.0003). The generated predicted values were stratified into low, medium, and high rates. For the RAT, the predicted complication rate was 10.1% in the low-risk group (observed rate 12.8%), 21.9% in the medium-risk group (observed 31.8%), and 49.7% in the high-risk group (observed 41.2%). The ACS NSQIP calculator consistently produced complication predictions that underestimated complication occurrence: 3.4% in the low-risk group (observed 12.6%), 5.9% in the medium-risk group (observed 34.5%), and 12.5% in the high-risk group (observed 38.8%). The RAT was more accurate than the ACS NSQIP calculator (p = 0.0018). CONCLUSIONS While the RAT and ACS NSQIP calculator were both able to identify patients more likely to experience complications following spine surgery, both have substantial room for improvement. Risk stratification is feasible in spine surgery procedures; currently used measures have low accuracy.

Current Evidence Regarding Diagnostic Imaging Methods for Pediatric Lumbar Spondylolysis: A Report From the Scoliosis Research Society Evidence-Based Medicine Committee

BACKGROUND

Spondylolysis is common among the pediatric population, yet no formal systematic literature review regarding diagnostic imaging has been performed. The Scoliosis Research Society (SRS) requested an assessment of the current state of peer reviewed evidence regarding pediatric spondylolysis.

METHODS

Literature was searched professionally and citations retrieved. Abstracts were reviewed and analyzed by the SRS Evidence-Based Medicine Committee. Level I studies were considered to provide Good Evidence for the clinical question. Level II or III studies were considered Fair Evidence. Level IV studies were considered Poor Evidence. From 947 abstracts, 383 full texts reviewed. Best available evidence for the questions of diagnostic methods was provided by 27 studies: no Level I sensitivity/specificity studies, five Level II and two Level III evidence, and 19 Level IV evidence.

RESULTS

Pain with hyperextension in athletes is the most widely reported finding in history and physical examination. Plain radiography is considered a first-line diagnostic test for suspected spondylolysis, but validation evidence is lacking. There is consistent Level II and III evidence that pars defects are detected by advanced imaging in 32% to 44% of adolescents with spondylolysis based on history and physical. Level III evidence that single-photon emission computed tomography (SPECT) is superior to planar bone scan and plain radiographs but limited by high rates of false-positive and false-negative results and by high radiation dose. Computed tomography (CT) is considered the gold standard and most accurate modality for detecting the bony defect and assessment of osseous healing but exposes the pediatric patient to ionizing radiation. Magnetic resonance imaging (MRI) is reported to be as accurate as CT and useful in detecting early stress reactions of the pars without a fracture.

CONCLUSION

Plain radiographs are widely used as screening tools for pediatric spondylolysis. CT scan is considered the gold standard but exposes the patient to a significant amount of ionizing radiation. Evidence is fair and promising that MRI is comparable to CT.

Adult Lumbar Scoliosis: Nonsurgical Versus Surgical Management

Adult spinal deformity has become an increasingly recognized condition, with a 32% incidence in the adult population and a 68% incidence in the elderly population. Often, patients with adult spinal deformity are initially offered nonsurgical treatment for their symptoms despite the lack of data to support its efficacy because of the high complication rate associated with surgical treatment in this age group. Determining which patients would benefit the most from nonsurgical versus surgical treatment remains a challenge. Limited evidence exists to support guidelines on the most effective way to treat patients with adult spinal deformity. Treatment decisions for patients with adult spinal deformity often rely on individual surgeon experience and patient preferences.

ISSLS PRIZE IN BASIC SCIENCE 2017: Intervertebral disc/bone marrow cross-talk with Modic changes

STUDY DESIGN

Cross-sectional cohort analysis of patients with Modic Changes (MC).

OBJECTIVE

Our goal was to characterize the molecular and cellular features of MC bone marrow and adjacent discs. We hypothesized that MC associate with biologic cross-talk between discs and bone marrow, the presence of which may have both diagnostic and therapeutic implications.

BACKGROUND DATA

MC are vertebral bone marrow lesions that can be a diagnostic indicator for discogenic low back pain. Yet, the pathobiology of MC is largely unknown.

METHODS

Patients with Modic type 1 or 2 changes (MC1, MC2) undergoing at least 2-level lumbar interbody fusion with one surgical level having MC and one without MC (control level). Two discs (MC, control) and two bone marrow aspirates (MC, control) were collected per patient. Marrow cellularity was analyzed using flow cytometry. Myelopoietic differentiation potential of bone marrow cells was quantified to gauge marrow function, as was the relative gene expression profiles of the marrow and disc cells. Disc/bone marrow cross-talk was assessed by comparing MC disc/bone marrow features relative to unaffected levels.

RESULTS

Thirteen MC1 and eleven MC2 patients were included. We observed pro-osteoclastic changes in MC2 discs, an inflammatory dysmyelopoiesis with fibrogenic changes in MC1 and MC2 marrow, and up-regulation of neurotrophic receptors in MC1 and MC2 bone marrow and discs.

CONCLUSION

Our data reveal a fibrogenic and pro-inflammatory cross-talk between MC bone marrow and adjacent discs. This provides insight into the pain generator at MC levels and informs novel therapeutic targets for treatment of MC-associated LBP.

Does Transforaminal Lumbar Interbody Fusion Have Advantages over Posterolateral Lumbar Fusion for Degenerative Spondylolisthesis?

Study Design Retrospective cohort study. Objective To compare the clinical and radiographic outcomes of transforaminal lumbar interbody fusion (TLIF) and posterolateral lumbar fusion (PLF) in the treatment of degenerative spondylolisthesis. Methods This study compared 24 patients undergoing TLIF and 32 patients undergoing PLF with instrumentation. The clinical outcomes were assessed by visual analog scale (VAS) for low back pain and leg pain, physical component summary (PCS) of the 12-item Short-Form Health Survey, and the Oswestry Disability Index (ODI). Radiographic parameters included slippage of the vertebra, local disk lordosis, the anterior and posterior disk height, lumbar lordosis, and pelvic parameters. Results The improvement of VAS of leg pain was significantly greater in TLIF than in PLF unilaterally (3.4 versus 1.0; p = 0.02). The improvement of VAS of low back pain was significantly greater in TLIF than in PLF (3.8 versus 2.2; p = 0.02). However, there was no significant difference in improvement of ODI or PCS between TLIF and PLF. Reduction of slippage and the postoperative disk height was significantly greater in TLIF than in PLF. There was no significant difference in local disk lordosis, lumbar lordosis, or pelvic parameters. The fusion rate was 96% in TLIF and 84% in PLF (p = 0.3). There was no significant difference in fusion rate, estimated blood loss, adjacent segmental degeneration, or complication rate. Conclusions TLIF was superior to PLF in reduction of slippage and restoring disk height and might provide better improvement of leg pain. However, the health-related outcomes were not significantly different between the two procedures.

Long fusion from sacrum to thoracic spine for adult spinal deformity with sagittal imbalance: upper versus lower thoracic spine as site of upper instrumented vertebra

OBJECT

Despite increasing numbers of patients with adult spinal deformity, it is unclear how to select the optimal upper instrumented vertebra (UIV) in long fusion surgery for these patients. The purpose of this study was to compare the use of vertebrae in the upper thoracic (UT) versus lower thoracic (LT) spine as the upper instrumented vertebra in long fusion surgery for adult spinal deformity.

METHODS

Patients who underwent fusion from the sacrum to the thoracic spine for adult spinal deformity with sagittal imbalance at a single medical center were studied. The patients with a sagittal vertical axis (SVA) ≥ 40 mm who had radiographs and completed the 12-item Short-Form Health Survey (SF-12) preoperatively and at final follow-up (≥ 2 years postoperatively) were included.

RESULTS

Eighty patients (mean age of 61.1 ± 10.9 years; 69 women and 11 men) met the inclusion criteria. There were 31 patients in the UT group and 49 patients in the LT group. The mean follow-up period was 3.6 ± 1.6 years. The physical component summary (PCS) score of the SF-12 significantly improved from the preoperative assessment to final follow-up in each group (UT, 34 to 41; LT, 29 to 37; p = 0.001). This improvement reached the minimum clinically important difference in both groups. There was no significant difference in PCS score improvement between the 2 groups (p = 0.8). The UT group had significantly greater preoperative lumbar lordosis (28° vs 18°, p = 0.03) and greater thoracic kyphosis (36° vs 18°, p = 0.001). After surgery, there was no significant difference in lumbar lordosis or thoracic kyphosis. The UT group had significantly greater postoperative cervicothoracic kyphosis (20° vs 11°, p = 0.009). The UT group tended to maintain a smaller positive SVA (51 vs 73 mm, p = 0.08) and smaller T-1 spinopelvic inclination (-2.6° vs 0.6°, p = 0.06). The LT group tended to have more proximal junctional kyphosis (PJK), although the difference did not reach statistical significance. Radiographic PJK was 32% in the UT group and 41% in the LT group (p = 0.4). Surgical PJK was 6.4% in the UT group and 10% in the LT group (p = 0.6).

CONCLUSIONS

Both the UT and LT groups demonstrated significant improvement in clinical and radiographic outcomes. A significant difference was not observed in improvement of clinical outcomes between the 2 groups.