Anterior Lumbar Interbody Implants: Importance of the Interdevice Distance

Object. The implantation of interbody fusion cages allows for the restoration of disc height and the enlargement of the neuroforaminal space. The purpose of this study was to compare the extent of subsidence occurring after conventional cage placement compared to a novel wider cage placement technique. Methods. This study is a retrospective evaluation of radiographs of patients who underwent stand-alone single level anterior lumbar interbody fusion with lordotic titanium cages and rhBMP-2. Fifty-three patients were evaluated: 39 patients had wide cage placement (6 mm interdevice distance) and 14 had narrow cage placement (2 mm interdevice distance). Anterior and posterior intervertebral disc space heights were measured post-operatively and at follow-up imaging. Results. The decrease in anterior intervertebral disc space height was 2.05 mm versus 3.92 mm (P < .005) and 1.08 mm versus 3.06 mm in posterior disc space height for the wide cage placement and the narrow cage placement respectively. The proportion of patients with subsidence greater than 2 mm was 41.0% in the wide cage patients and 85.7% for the narrow cage patients (P < .005). Conclusions. The wider cage placement significantly reduced the amount of subsidence while allowing for a greater exposed surface area for interbody fusion

The Use of a Dehydrated Amnion/Chorion Membrane Allograft in Patients Who Subsequently Undergo Reexploration after Posterior Lumbar Instrumentation

Background Context. Products that can reduce development of epidural fibrosis may reduce risk for ongoing pain associated with development of scar tissue and make subsequent epidural reexploration easier. Purpose. To evaluate the use of dehydrated human amnion/chorion membrane (dHACM) on the formation of soft tissue scarring in the epidural space. Study Design. Case series. Patient Sample. Five patients having transforaminal lumbar interbody lumbar fusion (TLIF) with posterior instrumentation and implantation of dHACM in the epidural space and subsequent epidural reexploration. Outcome Measures. Degree of scar tissue adjacent to the epidural space at reexploration. Intraoperative and postoperative complications related to dHACM and patient reported outcomes. Methods. The degree of scar tissue adjacent to the epidural space was assessed during the reexploration surgery. Patients’ outcomes were collected using standard validated questionnaires. Results. Four of 5 cases had easily detachable tissue during epidural reexploration. Angiolipoma of 10% was noted in 1 case and 5% in 2 cases. Significant improvements in patient reported outcomes were observed. No intraoperative or postoperative complications occurred. Conclusions. Our findings suggest that dHACM implant during TLIF may have favorable effects on epidural fibrosis and is well tolerated. Further studies with larger cohorts are required to prove our results

Pathology Case Study: Seizures

This is a case study presented by the University of Pittsburgh Department of Pathology in which a 7-year-old girl is experiencing episodic seizures. Visitors are given both the microscopic and gross descriptions, including neuroimaging results, and are given the opportunity to diagnose the patient. This is an excellent resource for students in the health sciences to familiarize themselves with using patient history and laboratory results to diagnose disease. It is also a helpful site for educators to use to introduce or test student learning in neuropathology. [ASC

Simvastatin protects bladder and renal functions following spinal cord injury in rats

<p>Abstract</p> <p>Background</p> <p>Urinary bladder and renal dysfunction are secondary events associated with spinal cord injury (SCI) in humans. These secondary events not only compromise quality of life but also delay overall recovery from SCI pathophysiology. Furthermore, in experimental models the effects of SCI therapy on bladder and renal functions are generally not evaluated. In this study, we tested whether simvastatin improves bladder and renal functions in a rat model of experimental SCI.</p> <p>Methods</p> <p>SCI was induced by controlled contusion of T9-T10 in adult female rats. Simvastatin (5 mg/Kg body weight) was administered at two hours after SCI and repeated every 24 hours until the end point. Simvastatin-treated SCI animals (simvastatin group) were compared with vehicle-treated SCI animals (vehicle group) in terms of the Basso Beattie Bresnahan score, tissue morphology, cell death, and bladder/renal functions.</p> <p>Results</p> <p>The urinary bladder of vehicle animals showed a 4.3-fold increase in size and a 9-fold increase in wet weight compared to sham animals. Following SCI, the urine to plasma osmolality ratio increased initially but decreased 1 week after SCI. Hematoxylin and eosin staining of bladder tissue showed transitional epithelial hyperplasia, degeneration of lamina propria, and enlargement of tunica adventia in addition to detrusor muscle hypertrophy. Rats treated with simvastatin for 14 days displayed remarkable recovery by showing decreased bladder size and maintenance of a normal urine/plasma osmolality ratio, in addition to improved locomotion. The muscularis layer of the bladder also regained its compact nature in simvastatin animals. Moreover, SCI-induced renal caspase-3 activity was significantly decreased in the simvastatin group indicating the ability of simvastatin to reduce the renal tubular apoptosis.</p> <p>Conclusion</p> <p>Post-injury administration of simvastatin ameliorates bladder and renal dysfunction associated with SCI in rats.</p

Vascular Regeneration in a Basal Chordate Is Due to the Presence of Immobile, Bi-Functional Cells

The source of tissue turnover during homeostasis or following injury is usually due to proliferation of a small number of resident, lineage-restricted stem cells that have the ability to amplify and differentiate into mature cell types. We are studying vascular regeneration in a chordate model organism, Botryllus schlosseri, and have previously found that following surgical ablation of the extracorporeal vasculature, new tissue will regenerate in a VEGF-dependent process within 48 hrs. Here we use a novel vascular cell lineage tracing methodology to assess regeneration in parabiosed individuals and demonstrate that the source of regenerated vasculature is due to the proliferation of pre-existing vascular resident cells and not a mobile progenitor. We also show that these cells are bi-potential, and can reversibly adopt two fates, that of the newly forming vessels or the differentiated vascular tissue at the terminus of the vasculature, known as ampullae. In addition, we show that pre-existing vascular resident cells differentially express progenitor and differentiated cell markers including the Botryllus homologs of CD133, VEGFR-2, and Cadherin during the regenerative process