A three-dimensional computed tomography study to determine the ideal method for fluoroscopically-guided bone marrow aspiration from the iliac crest.

Bone marrow aspiration (BMA) through the iliac crest is potentially unsafe due to the vicinity of neurovascular structures in the greater sciatic notch. Our objective was to investigate the safety of a recently described BMA technique, specifically a trajectory from the posterior superior iliac spine (PSIS) to the anterior inferior iliac spine (AIIS). We conducted a chart review of 260 patients, analyzing three-dimensional reconstructed computed tomography images of the pelvis and sacrum to validate that this new approach offers a wide safety margin from the greater sciatic notch. Analysis of three-dimensional computed tomography scans demonstrated that the PSIS to AIIS trajectory never crossed the greater sciatic notch. The trajectory was noted to be at least one cm away from the greater sciatic notch in all measurements. The new trajectory entered the PSIS at 25.29 ± 4.34° (left side) and 24.93 ± 4.15° (right side) cephalad from the transverse plane, and 24.58 ± 4.99° (left side) and 24.56 ± 4.67° (right side) lateral from the mid-sagittal plane. The area of bone marrow encountered with the new approach was approximately 22.5 cm2. Utilizing the same CT scans, the trajectory from the traditional approach crossed the greater sciatic notch in all scans, highlighting the potential for violating the greater sciatic notch boundary and damaging important neurovascular structures. Statistically significant sex-related differences were identified in needle trajectory angles for both approaches. We conclude that based on this three-dimensional computed tomography study, a trajectory from the PSIS to the AIIS for BMA may offer a wide safety margin from the greater sciatic notch.

Peri-procedural Management of Implanted Spinal Cord Stimulators in Patients Undergoing Radiofrequency Ablation: A Case Report and Manufacturer-Specific Recommendations.

INTRODUCTION: Radiofrequency ablation (RFA) and spinal cord stimulation (SCS) are 2 common modalities used in management of various pain conditions. RFA generates heat and an electromagnetic field that can theoretically interfere with the functionality and longevity of the SCS device. This is problematic for patients who need RFA and have previously undergone implantation of an SCS device. CASE DESCRIPTION: We present a case highlighting the safe use of bipolar RFA in a patient who had previously undergone implantation of a cervical SCS device. DISCUSSION: We also present device-specific industry guidelines and recommendations for performing RFA in patients following SCS device implantation.

Office-Based Mesenchymal Stem Cell Therapy for the Treatment of Musculoskeletal Disease: A Systematic Review of Recent Human Studies.

BACKGROUND: The use of mesenchymal stem cells (MSCs) in clinical applications for the treatment of musculoskeletal disease is steadily increasing in office-based practice. The so-called "first generation" of MSCs is defined as autologous stem cells that have undergone minimal manipulation and are used for a homologous purpose. Systematic reviews of the clinical trials completed to date of such MSCs enable practitioners to better understand what is currently known about the outcomes and side effects of such treatments. STUDY DESIGN: A systematic review of human clinical studies of office-based MSC therapy for the treatment of painful degenerative musculoskeletal conditions. METHODS: A search of the Ovid MEDLINE, EMBASE, and Scopus databases was conducted from 2006 through September 2016. Seven hundred sixty-one records were identified from database searching, and two records from reference review of included papers. Studies with human subjects that evaluated treatment of musculoskeletal disease with minimally manipulated MSCs were included. RESULTS: Eight studies were included in this review based on selection criteria. A total of 941 patients were included, 841 of whom received cellular products, and no significant adverse events were reported. Symptomatology generally improved, though no differences were seen over controls where present. CONCLUSION: Support in the literature is strongest for the use of bone marrow aspirate concentrate (BMAC) injections for the treatment of knee pain, but applications of the use of BMAC and peripheral blood-derived MSCs for the treatment of hip pain, tendon pain, and disc pain have all been reported. Further research is required, with large randomized controlled trials.

Transient receptor potential vanilloid 1 agonists modulate hippocampal CA1 LTP via the GABAergic system.

Transient receptor potential vanilloid 1 (TRPV1) was shown to modulate hippocampal CA1 pyramidal cell synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD). Synaptic plasticity is the cellular mechanism thought to mediate declarative learning and memory in the hippocampus. Although TRPV1 is involved in modulating hippocampal plasticity, it has yet to be determined how TRPV1 mediates its effects. Using field electrophysiology in hippocampal CA1 stratum radiatum we investigated how TRPV1 agonists modulate LTP, low frequency stimulation-induced LTD, and (RS)-3,5-dihydroxyphenylglycine (DHPG)-induced LTD. First we confirmed that TRPV1 agonists induce enhancement of CA1 pyramidal cell LTP in the absence the GABA(A) receptor antagonist picrotoxin. Because it was recently determined that TRPV1 mediates a novel form of LTD in CA1 inhibitory GABAergic interneurons, which can disinhibit CA1 pyramidal cells, we used picrotoxin to block the effect of the GABAergic circuitry on CA1 LTP. When using picrotoxin, the TRPV1 agonist-induced enhancement of CA1 LTP was eliminated suggesting that the GABAergic circuitry is required for TRPV1 agonist mediated increases. Regarding LTD, in contrast to previously reported data, we did not see TRPV1 agonist-mediated effect on low frequency-induced stimulus LTD. However, during DHPG-induced LTD, TRPV1 was involved in the acute, but not the long-term depression phase of this plasticity. In summary, our findings support TRPV1 agonist involvement in hippocampal synaptic plasticity, including its enhancement of CA1 LTP. We demonstrate that the enhancement mediated by TRPV1 agonists requires GABA input to pyramidal cells thus providing a mechanism for how TRPV1 agonists modulate hippocampal synaptic plasticity.