The Outcomes of Patients With Neck Pain Following ACDF: A Comparison of Patients With Radiculopathy, Myelopathy, or Mixed Symptomatology.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The goal of the present study was to determine whether neck pain responds differently to anterior cervical discectomy and fusion (ACDF) between patients with cervical radiculopathy and/or cervical myelopathy. SUMMARY OF BACKGROUND DATA: Many patients who undergo ACDF because of radiculopathy/myelopathy also complain of neck pain. However, no studies have compared the response of significant neck pain to ACDF. METHODS: Patients undergoing one to three-level primary ACDF for radiculopathy and/or myelopathy with significant (Visual Analogue Scale [VAS] ≥ 3) neck pain and a minimum of 1-year follow-up were included. Based on preoperative symptoms patients were split into groups for analysis: radiculopathy (R group), myelopathy (M group), or both (MR group). Groups were compared for differences in Health Related Quality of Life outcomes: Physical Component Score-12, Mental Component Score (MCS)-12, Neck Disability Index, VAS neck, and VAS arm pain. RESULTS: Two hundred thirty-five patients met inclusion criteria. There were 117 patients in the R group, 53 in the M group, and 65 in the MR group. Preoperative VAS neck pain was found to be significantly higher in the R group versus M group (6.5 vs. 5.5; P = 0.046). Postoperatively, all cohorts experienced significant (P < 0.001) reduction in VAS neck pain, (ΔVAS neck; R group: -2.9, M: -2.5, MR: -2.5) with no significant differences between groups. However, myelopathic patients showed greater improvement in absolute MCS-12 scores (P = 0.011), RR (P = 0.006), and % minimum clinically important difference (P = 0.013) when compared with radiculopathy patients. This greater improvement remained following regression analysis (P = 0.025). CONCLUSION: Patients with substantial preoperative neck pain experienced significant reduction in their neck pain, disability, and physical function following ACDF, whether treated for radiculopathy or myelopathy. However, in this study, only myelopathy patients had significant improvements in their mental function as represented by MCS improvements. LEVEL OF EVIDENCE: 3.

The Impact of Multiple Comorbid Mental Health Disorders on Health-related Quality of Life Following ACDF.

STUDY DESIGN: Retrospective comparative study. OBJECTIVE: The goal was to determine whether comorbid depression and/or anxiety influence outcomes after anterior cervical discectomy and fusion (ACDF) for patients with degenerative cervical pathology. BACKGROUND DATA: The role preoperative mental health has on patient reported outcomes after ACDF surgery is not well understood. METHODS: Patients undergoing elective ACDF for degenerative cervical pathology were identified. Patients were grouped based on their preoperative mental health comorbidities, including patients with no history, depression, anxiety, and those with both depression and anxiety. All preoperative medical treatment for depression and/or anxiety was identified. Outcomes including Physical Component Score (PCS-12), Mental Component Score (MCS-12), Neck Disability Index (NDI), Visual Analogue Scale neck pain score (VAS Neck ), and Visual Analogue Scale arm pain score (VAS Arm) were compared between groups from baseline to postoperative measurements using multiple linear regression analysis-controlling for factors such as age, sex, and body mass index, etc. A P-value <0.05 was considered statistically significant. RESULTS: A total of 264 patients were included in the analysis, with an average age of 53 years and mean follow-up of 19.8 months (19.0-20.6). All patients with a diagnosis of depression or anxiety also reported medical treatment for the disease. The group with no depression or anxiety had significantly less baseline disability than the group with 2 mental health diagnoses, in MCS-12 (P=0.009), NDI (P<0.004), VAS Neck (P=0.003), and VAS Arm (P=0.001) scores. Linear regression analysis demonstrated that increasing occurrence of mental health disorders was not a significant predictor of change over time for any of the outcome measures included in the analysis. CONCLUSIONS: Despite more severe preoperative symptoms, patients with a preoperative mental health disorder(s) demonstrated significant improvement in postoperative outcomes after ACDF. No differences were identified in postoperative outcomes between each of the groups. LEVEL OF EVIDENCE: Level III.

Proton Pump Inhibitor Use Affects Pseudarthrosis Rates and Influences Patient-Reported Outcomes.

STUDY DESIGN: Retrospective cohort review. OBJECTIVES: Cervical pseudarthrosis is a frequent cause of need for revision anterior cervical discectomy and fusion (ACDF) and may lead to worse patient-reported outcomes. The effect of proton pump inhibitors on cervical fusion rates are unknown. The purpose of this study was to determine if patients taking PPIs have higher rates of nonunion after ACDF. METHODS: A retrospective cohort review was performed to compare patients who were taking PPIs preoperatively with those not taking PPIs prior to ACDF. Patients younger than 18 years of age, those with less than 1-year follow-up, and those undergoing surgery for trauma, tumor, infection, or revision were excluded. The rates of clinically diagnosed pseudarthrosis and radiographic pseudarthrosis were compared between PPI groups. Patient outcomes, pseudarthrosis rates, and revision rates were compared between PPI groups using either multiple linear or logistic regression analysis, controlling for demographic and operative variables. RESULTS: Out of 264 patients, 58 patients were in the PPI group and 206 were in the non-PPI group. A total of 23 (8.71%) patients were clinically diagnosed with pseudarthrosis with a significant difference between PPI and non-PPI groups (P = .009). Using multiple linear regression, PPI use was not found to significantly affect any patient-reported outcome measure. However, based on logistic regression, PPI use was found to increase the odds of clinically diagnosed pseudarthrosis (odds ratio 3.552, P = .014). Additionally, clinically diagnosed pseudarthrosis negatively influenced improvement in PCS-12 scores (P = .022). CONCLUSIONS: PPI use was found to be a significant predictor of clinically diagnosed pseudarthrosis following ACDF surgery. Furthermore, clinically diagnosed pseudarthrosis negatively influenced improvement in PCS-12 scores.

Does an Uninstrumented Level Increase the Rate of Revision Surgery in a Multilevel Posterior Cervical Decompression and Fusion?

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: The goal of this study is to determine if skipping a single level affects the revision rate for patients undergoing multilevel posterior cervical decompression and fusion (PCDF). SUMMARY OF BACKGROUND DATA: A multilevel PCDF is a common procedure for patients with cervical spondylotic myelopathy. With advanced pathology, it can be difficult to safely place screw instrumentation at every level increasing the risk of intraoperative and perioperative morbidity. It is unclear whether skipping a level during PCDF affects fusion and revision rates. PATIENTS AND METHODS: A cervical spine surgeries database at a single institution was used to identify patients who underwent ≥3 levels of PCDF. Inclusion criteria consisted of patients who had screws placed at every level or if they had a single level without screws bilaterally. Patients were excluded if the surgery was performed for tumor, trauma, or infection, and age below 18 years, or if there was <1 year of follow-up. RESULTS: A total of 157 patients met inclusion criteria, with 86 undergoing a PCDF with instrumentation at all levels and 71 that had a single uninstrumented level. Overall mean follow-up was 46.5±22.8 months. In patients with or without a skipped level, the revision rate was 25% and 26%, respectively (P<1.00). Univariate regression analysis demonstrated that proximal fixation level in the upper cervical region, having the fusion end at C7, prior surgery, and myelopathy were significant predictors of revision. Skipping a single level, however, was not predictive of revision. CONCLUSIONS: When performing a multilevel PCDF, there is no increase in the rate of revision surgery if a single level is uninstrumented. Conversely, other surgical factors, including the cranial and caudal levels, affect revision rates. In contrast to other reports, the C2 sagittal vertical axis did not affect reoperation rates. LEVEL OF EVIDENCE: Level IV.

The Effect of Oblique Magnetic Resonance Imaging on Surgical Decision Making for Patients Undergoing an Anterior Cervical Discectomy and Fusion for Cervical Radiculopathy.

BACKGROUND: The purpose of this study was to determine if oblique magnetic resonance imaging (MRI) sequences affect the surgical treatment recommendations for patients with cervical radiculopathy. METHODS: In this cohort study consecutive clinical cases of persistent cervical radiculopathy requiring surgical intervention were randomized, blinded, and reviewed by 6 surgeons. Initially each surgeon recommended treatment based on the history, physical examination, and axial, coronal and sagittal preoperative magnetic resonance (MR) images; when reviewing the cases the second time, the surgeons were provided oblique MR images. This entire process was then repeated after 2 months. Change in surgical recommendation, interobserver and intraobserver reliability and the average number of levels fused was determined. RESULTS: The addition of the oblique images resulted in the surgical recommendation being altered in 49.2% (59/120) of cases; however, the addition of oblique images did not substantially improve the interobserver reliability of the treatment recommendation (κ = .57 versus.57). Similarly, the overall intraobserver reliability using only traditional MRI sequences (κ = .64) was only slightly improved by the addition of oblique images (κ = .66). Lastly, the addition of oblique images did not change the average number of levels fused (traditional MRI = 1.38, oblique MRI = 1.41, P = .53), or the total number of 3-level fusions recommended (6 versus 6, P = 1.00). CONCLUSIONS: The additional oblique images resulted in a change to the surgical plan in almost 50% of cases; however, it had no substantial effect on the reliability of surgical decision making. Further studies are needed to see if this alteration in treatment affects clinical outcomes. LEVEL OF EVIDENCE: 3.

Incidence and Risk Factors for Pin Site Infection of Exposed Kirschner Wires Following Elective Forefoot Surgery.

BACKGROUND: Kirschner wires (K-wires) are commonly utilized for temporary metatarsal and phalangeal fixation following forefoot procedures. K-wires can remain in place for up to 6 weeks postoperatively and are at risk for complications. This study investigated the incidence of infectious complications of exposed K-wires after forefoot surgery and identifies risk factors for these complications. METHODS: A single-surgeon retrospective chart review of forefoot surgeries from 2007 to 2017 was undertaken. Inclusion criteria were adult patients (≥18 years) undergoing elective forefoot surgery with the use of exposed K-wires. Incidence of pin site infectious complication, defined as cellulitis, or pin site drainage and/or migration/loosening of the pin was noted. Patient demographic and perioperative data were analyzed, along with the number of K-wires placed per procedure. Mann-Whitney U and chi-square tests were performed to determine predictive factors related to pin site infection rates, with a multivariable model with significant factors subsequently performed. Two-thousand seventeen K-wires in 1237 patients were analyzed. RESULTS: There were 35 pin site infections for a rate of 1.74%. Combined forefoot procedures (507 pins in 229 patients) had a pin site infection rate of 4.93% (N = 25), followed by lesser metatarsal osteotomies (667 pins in 446 patients) at 1.05% (N = 7), then hammertoe corrections (694 pins in 421 patients) at 0.43% (N = 3), and no pin site infections with chevron osteotomies (149 pins in 141 patients). Male sex, body mass index (BMI), current smoker, and number of pins were significant risk factors (P ≤ .05). Additionally, there were 23 non-infection-related K-wire complications. No long-term sequelae were encountered based on any complications. CONCLUSION: K-wires are commonly used for temporary immobilization of the smaller bones of the forefoot following deformity correction. Male sex, BMI, current smoker, and number of pins were significant risk factors for pin site infection, with a higher rate of infection with 2 or more pins placed. LEVEL OF EVIDENCE: Level IV, case series.

Sarcopenia does not affect clinical outcomes following lumbar fusion.

Sarcopenia, defined as decreased skeletal muscle mass or function, has recently been found to have increased perioperative morbidity and mortality. The relationship between sarcopenia and clinical outcomes in patients undergoing lumbar fusion has not been examined. This study investigates whether sarcopenia affects fusion rates and outcomes following single-level lumbar decompression and fusion. A retrospective analysis was undertaken of 97 consecutive patients who underwent a single level lumbar fusion for degenerative spondylolisthesis. Demographics, perioperative data, and patient reported clinical outcomes were collected. Measurements of paraspinal muscle CSA were made using a standardized protocol at the level of the L3-4 disc space on a preoperative lumbar MRI. Univariate analysis was used to compare cohorts with regards to demographics, comorbidities, and clinical outcomes. Of 97 patients, 16 patients (15.8%) were in the sarcopenic cohort utilizing a threshold of 986.1 mm2/m2. Reoperation rates were not significantly different between the two groups (0% vs 3.6%, p = .451). The sarcopenia cohort had lower BMI (28.1 vs 31.8, p = .017) and less male patients (6.3% vs 55.6%, p < .001). Mean follow-up was 18.3 months. There was no significant difference in postoperative Oswestry Disability Index (ODI) (24.7 vs 23.2, p = .794) Short Form 12 Physical (38.0 vs. 40.4, p = .445) Mental scores (55.5 vs. 53.6, p = .503), or visual analog scale (VAS) back pain scores (3.4 vs. 3.3, p = .818). No significant difference was found with regards to outcomes when comparing sarcopenic to non-sarcopenic patients undergoing lumbar fusion. Sarcopenia does not impact the clinical success of lumbar fusion for degenerative spondylolisthesis.

The Total Cost to the Health Care System in Medicare and Medicaid Patients for the Treatment of Cervical Myelopathy.

INTRODUCTION: Cervical myelopathy is a common indication for spine surgery. Modern medicine demands high quality, cost-effective treatment. Most cost analyses fail to account for complication costs from nonoperative treatment. The purpose is to compare the total health care costs for operative versus nonoperative treatment of cervical myelopathy. METHODS: The Center for Medicare and Medicaid Services Carrier File from 2005 to 2012 was reviewed using the PearlDiver database, representing a 5% sampling of Medicare billings which diagnosed patients with cervical myelopathy by International Classification of Diseases 9 code. Patients were separated into operative and nonoperative cohorts, and the total health care expenditures per patient normalized to 2012 dollars were collected. RESULTS: A total of 3209 patients were included, and 1755 (55.87%) underwent surgery. A 6-year cost analysis performed on 309 patients over the age of 65 from 2006 undergoing surgery resulted in a nonsignificant increase in total health care expenditures ($166,192 vs. $153,556; P=0.45). Operative treatment had a net decrease in total health care costs following the first year of surgery. CONCLUSIONS: There is no significant difference in the total health care expenditures for operative versus nonoperative treatment of cervical myelopathy after 3 years. It is critical to understand that nonoperative treatment of this progressive disease leads to a substantial increase in total health care expenditures with increased risk of falls, injury, and further morbidity.

Dimensions of the Subaxial Lateral Mass: A Systematic Review of Anatomic (Morphometric) Measurement Studies.

STUDY DESIGN: This was a systematic review. OBJECTIVE: To review and synthesize information on subaxial lateral mass dimensions in order to determine the ideal starting point, trajectory, and size of a lateral mass screw. SUMMARY OF BACKGROUND DATA: The use of lateral mass instrumentation for posterior cervical decompression and fusion has become routine as these constructs have increased rigidity and fusion rates. METHODS: A systematic search of Medline and EMBASE was conducted. Studies that provided subaxial cervical lateral mass measurements, distance to the facet, vertebral artery and neuroforamen and facet angle made either directly (eg, cadaver specimen) or from patient imaging were considered for inclusion. Pooled estimates of mean dimensions were reported with corresponding 95% confidence intervals. Stratified analysis based on level, sex, imaging plane, source (cadaver or imaging), and measurement method was done. RESULTS: Of the 194 citations identified, 12 cadaver and 10 imaging studies were included. Pooled estimates for C3-C6 were generally consistent for lateral mass height (12.1 mm), width (12.0 mm), depth (10.8 mm), distance to the transverse foramen (11.8 mm), and distance to the nerve. C7 dimensions were most variable. Small sex-based differences in dimensions were noted for height (1.2 mm), width (1.3 mm), depth (0.43 mm), transverse foramen distance (0.9 mm), and nerve distance (0.3-0.8 mm). No firm conclusions regarding differences between measurements made on cadavers and those based on patient computed tomographic images are possible; findings were not consistent across dimensions. The overall strength of evidence is considered very low for all findings. CONCLUSIONS: Although estimates of height, width, and depth were generally consistent for C3-C6, C7 dimensions were variable. Small sex differences in dimensions may suggest that surgeons should use a slightly smaller screw in female patients. Firm conclusions regarding facet angulation, source of measurement, and method of measurement were not possible.

Severe Lumbar Disability Is Associated With Decreased Psoas Cross-Sectional Area in Degenerative Spondylolisthesis.

STUDY DESIGN: Retrospective cohort. OBJECTIVES: Alterations in lumbar paraspinal muscle cross-sectional area (CSA) may correlate with lumbar pathology. The purpose of this study was to compare paraspinal CSA in patients with degenerative spondylolisthesis and severe lumbar disability to those with mild or moderate lumbar disability, as determined by the Oswestry Disability Index (ODI). METHODS: We retrospectively reviewed the medical records of 101 patients undergoing lumbar fusion for degenerative spondylolisthesis. Patients were divided into ODI score ≤40 (mild/moderate disability, MMD) and ODI score >40 (severe disability, SD) groups. The total CSA of the psoas and paraspinal muscles were measured on preoperative magnetic resonance imaging (MRI). RESULTS: There were 37 patients in the SD group and 64 in the MMD group. Average age and body mass index were similar between groups. For the paraspinal muscles, we were unable to demonstrate any significant differences in total CSA between the groups. Psoas muscle CSA was significantly decreased in the SD group compared with the MMD group (1010.08 vs 1178.6 mm2, P = .041). Multivariate analysis found that psoas CSA in the upper quartile was significantly protective against severe disability (P = .013). CONCLUSIONS: We found that patients with severe lumbar disability had no significant differences in posterior lumbar paraspinal CSA when compared with those with mild/moderate disability. However, severely disabled patients had significantly decreased psoas CSA, and larger psoas CSA was strongly protective against severe disability, suggestive of a potential association with psoas atrophy and worsening severity of lumbar pathology.

Utilization of Time-driven Activity-based Costing to Determine the True Cost of a Single or 2-level Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: This is a prospective case series. OBJECTIVE: To determine the actual cost of performing 1- or 2-level anterior cervical discectomy and fusion (ACDF) using actual patient data and the time-driven activity-based cost methodology. SUMMARY OF BACKGROUND DATA: As health care shifts to use value-based reimbursement, it is imperative to determine the true cost of surgical procedures. Time-driven activity-based costing determines the cost of care by determining the actual resources used in each step of the care cycle. MATERIALS AND METHODS: In total, 30 patients who underwent a 1- or 2-level ACDF by 3 surgeons at a specialty hospital were prospectively enrolled. To build an accurate process map, a research assistant accompanied the patient to every step in the care cycle including the preoperative visit, the preadmission testing, the surgery, and the postoperative visits for the first 90 days. All resources utilized and the time spent with every member of the care team was recorded. RESULTS: In total, 27 patients were analyzed. Eleven patients underwent a single-level ACDF and 16 underwent a 2-level fusion. The total cost for the episode of care was $29,299±$5048. The overwhelming cost driver was the hospital disposable costs ($13,920±$6325) which includes every item used during the hospital stay. Intraoperative personnel costs including fees for the surgeon, resident/fellow, anesthesia, nursing, surgical technician, neuromonitoring, radiology technician and orderlies, accounted for the second largest cost at $6066±$1540. The total cost excluding hospital overhead and disposables was $9071±$1939. CONCLUSIONS: Reimbursement for a bundle of care surrounding a 1- or 2-level ACDF should be no less than $29,299 to cover the true costs of the care for the entire care cycle. However, this cost may not include the true cost of all capital expenditures, and therefore may underestimate the cost.

Descriptive Analysis of Associated Factors for Urgent Versus Nonurgent Inpatient Spine Transfers to a Tertiary Care Hospital.

Patients with spine-associated symptoms are transferred regularly to higher levels of care for operative intervention. It is unclear what factors lead to the transfer of patients with spine pathology to level I care facilities, and which transfers are indicated. All patients with isolated spinal pathology who were transferred from 2011 to 2015 were reviewed. Patients were divided into urgent transfers, defined as anyone who required operative intervention, and nonurgent transfers. Two hundred twenty-seven patients were transferred for isolated spinal pathology over 51 months; 109 (48.0%) patients required urgent intervention and 118 (52.0%) patients required nonurgent care. No significant differences were found between groups in terms of private insurance, age, sex, race, or Charlson comorbidity index. The urgent group was less likely to have a traumatic chief complaint (57.8% vs 78.0%, P = .001). More than half of all spine patients who were transferred to a tertiary care center required minimal intervention.

Preinjury Patient Characteristics and Postinjury Neurological Status Are Associated With Mortality Following Spinal Cord Injury.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: This study investigates the association between spinal cord injuries (SCI) and post-injury mortality. SUMMARY OF BACKGROUND DATA: SCIs) are severe conditions treated in the acute trauma setting. Owing to neurological deficits, unstable spinal columns, and associated injuries, these patients often have complex inpatient hospitalizations with significant morbidity and mortality. It is assumed that a high rate of postinjury mortality would follow such severe injuries; however, the effect of SCI and its treatment on predictors of longevity remain largely unknown. METHODS: Patients seen at a regional referral center for SCI were reviewed from a prospectively maintained database. Four hundred and twenty-six patients with SCI and varying degrees of injury between 2004 and 2009 were collected. Injury characteristics, including injury severity score, level of SCI, and type of SCI were retrieved. To determine independent predictors of 5-year mortality, a logistic regression using patient and injury characteristics at the time of presentation was performed. RESULTS: Average age was 47.4 years (range: 14-95), and 74.5% (318/426) were male. Half of the cohort sustained low-energy mechanisms of injury (220/426; 52.4%). The 30-day, 90-day, 1-year, 2-year, and 5-year mortality rates in the SCI cohort were 6.6% (28/426), 9.2% (39/426), 12.0% (51/426), 15.0% (64/426), and 17.8%, respectively (76/426). Logistic regression demonstrated that increasing age (B = 1.06, P < 0.001), increasing ICU length-of-stay (B = 1.06; P = 0.002), decreased motor score at presentation (B = 0.98; P = 0.004), and lack of surgical intervention (B = 0.38; P < 0.001) were independent predictors of mortality at 5 years. CONCLUSION: There is substantial mortality associated with SCI. A significant proportion of the mortalities occurred acutely after injury. Mortality was associated with neurological deficit and severity of injury, as well as with preinjury patient characteristics. To combat this high rate of death, efforts are needed to address the concomitant disease processes associated with neurological deficits. LEVEL OF EVIDENCE: 3.

Pulmonary embolism after total joint arthroplasty: cost and effectiveness of four treatment modalities.

Pulmonary embolism (PE) treatment relies on therapeutic anticoagulation and may be associated with severe complications. Inferior vena cava filters (IVCFs) are used as an alternative/adjunct to anticoagulation. In this study we evaluate 4 treatment protocols for clinical efficacy and cost. We reviewed over 27,000 total joint arthroplasty (TJA) patients. We retrospectively identified 294 patients with a documented, symptomatic PE within 90 days of surgery. All patients were treated with warfarin postoperatively. In addition, for the acute management, patients were divided into four treatment groups: (1) IVCF only, (2) IVCF with heparin, (3) heparin only and (4) no treatment. Complication rates, hospital stay and PE recurrence are reported. Among patients who received warfarin, IVCF was associated with fewer complications and lower overall hospital costs compared to the use of heparin for the treatment of PE after TJA.

Diagnosis of periprosthetic joint infection using synovial C-reactive protein.

The diagnosis of periprosthetic joint infection (PJI) is a considerable challenge. This study examines the quantification of C-reactive protein (CRP) in synovial fluid for diagnosis of PJI. Synovial fluid samples were collected prospectively from 63 patients undergoing revision or primary joint arthroplasty. All patients were divided into septic vs aseptic groups. There were 43 patients in the aseptic group and 20 patients in the septic group. There was a statistically significant difference in the mean synovial CRP between the septic cohort at 40 mg/L vs a mean of 2 mg/L for aseptic failure (P < .0001). The sensitivity was 85% with 95% specificity at a threshold of 9.5 mg/L. The area under the curve was 0.92. We believe that synovial CRP assay holds great promise as a diagnostic marker for PJI.

Physicians' ability to predict hospital length of stay for patients admitted to the hospital from the emergency department.

Accurate predictions of patient length of stay (LOS) in the hospital can effectively manage hospital resources and increase efficiency of patient care. A study was done to assess emergency medicine physicians' ability of predicting the LOS of patients who enter the hospital through the ER. Results indicate that EM physicians are relatively accurate with their pediatric patients than any other age groups. In addition, as actual hospital LOS increases, the prediction accuracy decreases. Possible reasons may be due increasing medical complications associated with increasing age and this may lead to overall longer stays. Other variables such as the admitted service of the patient are not statistically significant in predicting LOS in this study. Future studies should be done in order to determine other variables that may affect LOS predictions.

GLUT2 immunoreactivity in Gomori-positive astrocytes of the hypothalamus.

A specialized subtype of astrocyte, the Gomori-positive (GP) astrocyte, is unusually abundant and prominent in the arcuate nucleus of the hypothalamus. GP astrocytes possess cytoplasmic granules derived from degenerating mitochondria. GP granules are highly stained by Gomori's chrome alum hematoxylin stain, by the Perl's reaction for iron, or by toluidine blue. The source of the oxidative stress causing mitochondrial damage in GP astrocytes is uncertain, but such damage could arise from the oxidative metabolism of glucose transported into astrocytes by high-capacity GLUT2 glucose transporters. In accord with this hypothesis, the reported anatomical distribution of astrocytes staining positively for GLUT2 glucose transporters closely matches that of GP astrocytes. To examine whether or not these two staining procedures detect the same population of astrocytes, immunocytochemistry was performed on semithin sections to detect GLUT2 protein and sections were then stained with toluidine blue to detect GP granules. It was determined that GP astrocytes are frequently immunoreactive for the GLUT2 transporter protein. These data support the possibility that GP astrocytes may have an important influence upon the reactivity of the hypothalamus to glucose and that a specialized glucose metabolism may in part underlie the development of mitochondrial abnormalities in hypothalamic GP astrocytes.

The human cadaver in the age of biomedical informatics.

Major national and international critiques of the medical curriculum in the 1980s noted the following significant flaws: (1) over-reliance on learning by rote memory, (2) insufficient exercise in analysis and synthesis/conceptualization, and (3) failure to connect the basic and clinical aspects of training. It was argued that the invention of computers and related imaging techniques called to question the traditional instruction based on the faculty-centered didactic lecture. In the ensuing reform, which adopted case-based, small group, problem-based learning, time allotted to anatomical instruction was severely truncated. Many programs replaced dissection with prosections and computer-based learning. We argue that cadaver dissection is still necessary for (1) establishing the primacy of the patient, (2) apprehension of the multidimensional body, (3) touch-mediated perception of the cadaver/patient, (4) anatomical variability, (5) learning the basic language of medicine, (6) competence in diagnostic imaging, (7) cadaver/patient-centered computer-assisted learning, (8) peer group learning, (9) training for the medical specialties. Cadaver-based anatomical education is a prerequisite of optimal training for the use of biomedical informatics. When connected to dissection, medical informatics can expedite and enhance preparation for a patient-based medical profession. Actual dissection is equally necessary for acquisition of scientific skills and for a communicative, moral, ethical, and humanistic approach to patient care. Anat Rec (New Anat) 269:20-32, 2002.