Spencer Summers

Neuropathic pain-induced depressive-like behavior and hippocampal neurogenesis and plasticity are dependent on TNFR1 signaling.

Patients suffering from neuropathic pain have a higher incidence of mood disorders such as depression. Increased expression of tumor necrosis factor (TNF) has been reported in neuropathic pain and depressive-like conditions and most of the pro-inflammatory effects of TNF are mediated by the TNF receptor 1 (TNFR1). Here we sought to investigate: (1) the occurrence of depressive-like behavior in chronic neuropathic pain and the associated forms of hippocampal plasticity, and (2) the involvement of TNFR1-mediated TNF signaling as a possible regulator of such events. Neuropathic pain was induced by chronic constriction injury of the sciatic nerve in wild-type and TNFR1(-/-) mice. Anhedonia, weight loss and physical state were measured as symptoms of depression. Hippocampal neurogenesis, neuroplasticity, myelin remodeling and TNF/TNFRs expression were analyzed by immunohistochemical analysis and western blot assay. We found that neuropathic pain resulted in the development of depressive symptoms in a time dependent manner and was associated with profound hippocampal alterations such as impaired neurogenesis, reduced expression of neuroplasticity markers and myelin proteins. The onset of depressive-like behavior also coincided with increased hippocampal levels of TNF, and decreased expression of TNF receptor 2 (TNFR2), which were all fully restored after mice spontaneously recovered from pain. Notably, TNFR1(-/-) mice did not develop depressive-like symptoms after injury, nor were there changes in hippocampal neurogenesis and plasticity. Our data show that neuropathic pain induces a cluster of depressive-like symptoms and profound hippocampal plasticity that are dependent on TNF signaling through TNFR1.

Intraosseous schwannomas involving the sacrum: Characteristic imaging findings and review of the literature

Background and purpose Sacral intraosseous schwannomas represent a rare subset of schwannomas. The existing literature detailing the radiographic appearance of intraosseous schwannomas is limited. The aim of this study is to formally characterize the radiological appearance of sacral intraosseous schwannomas to differentiate them from other lytic lesions. Materials and methods Imaging studies of 13 pathologically proven intraosseous schwannomas were reviewed from multiple institutions by fellowship-trained radiologists. A PubMed search was performed and identified four papers pertaining to the imaging characteristics of sacral intraosseous schwannomas. The results of these papers were compared to findings from our cases. Results All tumors had heterogeneous signals and were predominately solid but cystic components with fluid-fluid levels were present. The tumors caused a mass effect but none infiltrated the surrounding soft tissues. Post-contrast T1-weighted images revealed heterogeneous enhancement in all 13 tumors and four possessed non-enhancing cysts. A literature review identified 16 other cases of sacral intraosseous schwannomas forming a total of 29 cases examined. Conclusions Sacral intraosseous schwannomas should be considered in the differential diagnosis for both radiologists and pathologists when dealing with large expansile, lytic lesions, with well-defined sclerotic margins involving the sacrum. This is particularly important in middle-aged adults presenting with pathology centered around S2-3.

Albumin, Prealbumin, and Transferrin May Be Predictive of Wound Complications following Total Knee Arthroplasty

&NA; Nutritional status has become increasingly important in optimizing surgical outcomes and preventing postoperative infection and wound complications. However, currently, there is a paucity in the orthopaedics literature investigating the relationship between nutritional status and wound complications following total knee arthroplasty (TKA). Therefore, the purpose of this study was to determine the prevalence of (1) postoperative infections, (2) wound complications, (3) concomitant infection with wound (CoIW) complication, and (4) infection followed by wound complication by using (1) albumin, (2) prealbumin, and (3) transferrin levels as indicators of nutritional status. These four different outcome measures were chosen as they are encountered commonly in daily clinical practice. A retrospective review of a national private payer database for patients who underwent TKA with postoperative infections and wound complications stratified by preoperative serum albumin (normal: 3.5‐5 g/dL), prealbumin (normal: 16‐35 mg/dL), and transferrin levels (normal: 200‐360 mg/dL) between 2007 and 2015 was conducted. Patients were identified by Current Procedural Terminology (CPT), International Classification of Disease, ninth revision (ICD‐9) codes, and Logical Observation Identifiers Names and Codes (LOINC). Linear regression was performed to evaluate changes over times. Yearly rates of infection, as well as a correlation and odds ratio analysis of nutritional laboratory values to postoperative complications, were also performed. Our query returned a total of 161,625 TKAs, of which 11,047 (7%) had postoperative wound complications, 18,403 (11%) had infections, 6,296 (34%) had CoIW, and 4,877 (4%) patients with infection developed wound complications. Albumin was the most commonly ordered laboratory test when assessing complications (96%). Wound complications, infections, CoIW, and infection with wound complications after were higher in those below the normal range: albumin <3.5 g/dL (9, 14, 6, and 5%), prealbumin <15 mg/dL (20, 23, 13, and 12%), and transferrin <200 mg/dL (12, 17, 6, and 6%). Preoperative albumin, prealbumin, and transferrin values falling below the normal range represented an increased risk for postoperative complications. Those patients who were in the normal range, however, did not have an increased risk. Therefore, our results suggest that preoperative nutritional optimization can play an important role in reducing the risk for postoperative complications.

Operative Trends in the Treatment of Hip Fractures and the Role of Arthroplasty

Introduction: There is a projected exponential increase in the number of hip fractures in the United States. Trends in patient demographics and the role of total hip arthroplasty (THA) and its associated outcomes following hip fractures surgery have not been well studied. Methods: Patients with proximal femur fractures between 1990 and 2007 were identified in the National Hospital Discharge Survey database. Demographics, comorbidities, perioperative complications, and discharge status for patients undergoing THA, hemiarthroplasty, or internal fixation were examined. Multivariable regression was performed to determine independent risk factors for perioperative complications. Results: Between 1990 and 2007, there was a statistically significant increase in patient age, adverse events, medical comorbidities, surgical complications, medical complications, and nonroutine discharge across all surgical treatment modalities. In the same time period, the utilization of THA for all fracture types decreased significantly. Discussion: Total hip arthroplasty was found to be an independent risk factor for perioperative complications. Orthopedic surgeons should be aware that the hip fracture population continues to get older, with more medical comorbidities and are at higher risk for perioperative complications. Conclusion: Total hip arthroplasty is associated with a higher rate of perioperative complications in the hip fracture population.

Volatile Hypertension Following Anterior Cervical Discectomy and Fusion

Case:A sixty-one-year-old man underwent anterior cervical discectomy and fusion (ACDF) from C4 to C7 for the treatment of cervical spondylosis. Postoperatively, the patient experienced paroxysmal surges in blood pressure with associated diaphoresis and anxiety that were difficult to control. He had additional episodes after discharge, requiring a second hospital admission. He was ultimately diagnosed with baroreflex failure syndrome and was managed with a three-drug regimen. He gradually improved and was symptom-free at seven months. Conclusion:Baroreflex failure syndrome should be considered in the setting of volatile hypertension following ACDF. Prompt recognition of this condition can lead to early referral to a specialist and may reduce patient morbidity.

Poster 335 Inter-Rater Reliability and Precision of Measurements of the Piriformis Muscle Using Ultrasound: An Observational Cross Sectional Study

Conclusion: Viscosupplementation injections to the knee joint appear to be effective in those with osteoarthritis. Most appear to be effective by injection #2 of 3 in a series. Any sub-groups, i.e. those with post-traumatic osteoarthritis, may need to be further stratified in future studies. However, positive predictive factors in reducing VNS scores may include ligamentous involvement moreso than meniscal tear.