Outcomes After Cervical Disc Arthroplasty Versus Stand-Alone Anterior Cervical Discectomy and Fusion: A Meta-Analysis.

STUDY DESIGN: Systemic review and meta-analysis. OBJECTIVES: To review and compare surgical outcomes for patients undergoing stand-alone anterior cervical discectomy and fusion (ACDF) versus cervical disc arthroplasty (CDA) for the treatment of cervical spine disease. METHODS: A systematic search was performed on PubMed, Medline, and the Cochrane Library. Comparative trials measuring outcomes of patients undergoing CDA and stand-alone ACDF for degenerative spine disease in the last 10 years were selected for inclusion. After data extraction and quality assessment, statistical analysis was performed with R software metafor package. The random-effects model was used if there was heterogeneity between studies; otherwise, the fixed-effects model was used. RESULTS: In total, 12 studies including 859 patients were selected for inclusion in the meta-analysis. Patients undergoing stand-alone ACDF had a statistically significant increase in postoperative segmental angles (mean difference 0.85° [95% confidence interval = 0.35° to 1.35°], P = .0008). Patients undergoing CDA had a decreased rate of developing adjacent segmental degeneration (risk ratio = 0.56 [95% confidence interval = -0.06 to 1.18], P = .0745). Neck Disability Index, Japanese Orthopedic Association score, Visual Analogue Scale of the arm and neck, as well as postoperative cervical angles were similar between the 2 treatments. CONCLUSIONS: When compared with CDA, stand-alone ACDF offers similar clinical outcomes for patients and leads to increased postoperative segmental angles. We encourage further blinded randomized trials to compare rates of adjacent segmental degeneration and other postoperative outcomes between these 2 treatments options.

Optogenetic Modulation for the Treatment of Traumatic Brain Injury.

Although research involving traumatic brain injury (TBI) has traditionally focused on the acute clinical manifestations, new studies provide evidence for chronic and progressive neurological sequelae associated with TBI, highlighting the risk of persistent, and sometimes life-long, consequences for affected patients. Several treatment modalities to date have demonstrated efficacy in experimental models. However, there is currently no effective treatment to improve neural structure repair and functional recovery of TBI patients. Optogenetics represents a potential molecular tool for neuromodulation and monitoring cellular activity with unprecedented spatial resolution and millisecond temporal precision. In this review, we discuss the conceptual background and preclinical evidence of optogenetics for neuromodulation, and translational applications for TBI treatment are considered.

Robotic-Assisted Spine Surgery: History, Efficacy, Cost, And Future Trends.

Robot-assisted spine surgery has recently emerged as a viable tool to enable less invasive and higher precision surgery. The first-ever spine robot, the SpineAssist (Mazor Robotics Ltd., Caesarea, Israel), gained FDA approval in 2004. With its ability to provide real-time intraoperative navigation and rigid stereotaxy, robotic-assisted surgery has the potential to increase accuracy while decreasing radiation exposure, complication rates, operative time, and recovery time. Currently, robotic assistance is mainly restricted to spinal fusion and instrumentation procedures, but recent studies have demonstrated its use in increasingly complex procedures such as spinal tumor resections and ablations, vertebroplasties, and deformity correction. However, robots do require high initial costs and training, and thus, require justification for their incorporation into common practice. In this review, we discuss the history of spinal robots along as well as currently available systems. We then examine the literature to evaluate accuracy, operative time, complications, radiation exposure, and costs - comparing robotic-assisted to traditional fluoroscopy-assisted freehand approaches. Finally, we consider future applications for robots in spine surgery.

Graft Materials and Biologics for Spinal Interbody Fusion.

Spinal fusion is the most widely performed procedure in spine surgery. It is the preferred treatment for a wide variety of pathologies including degenerative disc disease, spondylolisthesis, segmental instability, and deformity. Surgeons have the choice of fusing vertebrae by utilizing cages containing autografts, allografts, demineralized bone matrices (DBMs), or graft substitutes such as ceramic scaffolds. Autografts from the iliac spine are the most commonly used as they offer osteogenic, osteoinductive, and osteoconductive capabilities, all while avoiding immune system rejection. Allografts obtained from cadavers and living donors can also be advantageous as they lack the need for graft extraction from the patient. DBMs are acid-extracted organic allografts with osteoinductive properties. Ceramic grafts containing hydroxyapatite can be readily manufactured and are able to provide osteoinductive support while having a long shelf life. Further, bone-morphogenetic proteins (BMPs), mesenchymal stem cells (MSCs), synthetic peptides, and autologous growth factors are currently being optimized to assist in improving vertebral fusion. Genetic therapies utilizing viral transduction are also currently being devised. This review provides an overview of the advantages, disadvantages, and future directions of currently available graft materials. The current literature on growth factors, stem cells, and genetic therapy is also discussed.

Impact of skull density ratio on efficacy and safety of magnetic resonance-guided focused ultrasound treatment of essential tremor.

OBJECTIVE: Skull density ratio (SDR) assesses the transparency of the skull to ultrasound. Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy in essential tremor (ET) patients with a lower SDR may be less effective, and the risk for complications may be increased. To address these questions, the authors analyzed clinical outcomes of MRgFUS thalamotomy based on SDRs. METHODS: In 189 patients, 3 outcomes were correlated with SDRs. Efficacy was based on improvement in Clinical Rating Scale for Tremor (CRST) scores 1 year after MRgFUS. Procedural efficiency was determined by the ease of achieving a peak voxel temperature of 54°C. Safety was based on the rate of the most severe procedure-related adverse event. SDRs were categorized at thresholds of 0.45 and 0.40, selected based on published criteria. RESULTS: Of 189 patients, 53 (28%) had an SDR < 0.45 and 20 (11%) had an SDR < 0.40. There was no significant difference in improvement in CRST scores between those with an SDR ≥ 0.45 (58% ± 24%), 0.40 ≤ SDR < 0.45 (i.e., SDR ≥ 0.40 but < 0.45) (63% ± 27%), and SDR < 0.40 (49% ± 28%; p = 0.0744). Target temperature was achieved more often in those with an SDR ≥ 0.45 (p < 0.001). Rates of adverse events were lower in the groups with an SDR < 0.45 (p = 0.013), with no severe adverse events in these groups. CONCLUSIONS: MRgFUS treatment of ET can be effectively and safely performed in patients with an SDR < 0.45 and an SDR < 0.40, although the procedure is more efficient when SDR ≥ 0.45.

Anterior Techniques in Managing Cervical Disc Disease.

Surgical treatment may be indicated for select patients with cervical disc disease, whether it is cervical disc herniation or spondylosis due to degenerative changes, acute cervical injury due to trauma, or other underlying cervical pathology. Currently, there are various surgical techniques, including anterior, posterior, or combined approaches, in addition to new interventions being utilized in practice. Ideally, the surgical approach should be selected in consideration of each patient's clinical presentation, imaging findings, and overall medical comorbidities on an individual basis. But the unique advantages and disadvantages of each surgical technique often complicate the therapy choice in managing cervical disc diseases. Although anterior cervical discectomy and fusion (ACDF) is the most widely accepted procedure performed for both single and multi-level cervical disc diseases, there are multiple modifications to this technique. Surgeons have access to different types of plates, screws, and cages and can adopt newer advances in the field such as stand-alone and minimally invasive techniques when indicated. In short, no consensus exists in terms of a single approach that is preferred for all patients. This article aims to review the standard of care for management of cervical disc disease with a focus on the surgical techniques and, in particular, the anterior approach, exploring the various surgical options within this technique.

Embolization before stereotactic radiosurgery for the treatment of brain arteriovenous malformations.

Embolization is commonly used for the treatment of brain arteriovenous malformations (AVMs) prior to stereotactic radiosurgery (SRS). Due to mixed outcomes, however, its use remains controversial. This article is a review of recent studies assessing the efficacy of pre-radiosurgical embolization for brain AVMs. Articles published between 1990 and 2017 on the subject of pre-radiosurgical AVM embolization were retrieved from PubMed. A literature review was performed on the selected studies to compare obliteration, hemorrhage, and complication rates from groups treated with embolization prior to radiosurgery to those treated without embolization. Overall, the studies reviewed demonstrate mixed results on the efficacy of pre-radiosurgical AVM embolization. For large, complex AVMs, embolization prior to radiosurgery may have a role in carefully selected patients performed by experienced practitioners.

Formulation development of albumin based theragnostic nanoparticles as a potential delivery system for tumor targeting.

BACKGROUND: Generally, chemotherapeutic drugs attack on both normal and tumor cells non-specifically causing life threatening side effects, necessitating targeted drug delivery to tumors. PURPOSE: The purpose of this study is to formulate albumin-based nanoparticles for tumor targeted drug delivery and noninvasive diagnosis. METHODS: Albumin based nanoparticles (NPs) were developed as a potential tumor theragnostic agent by entrapping an anti cancer drug, doxorubicin and a near infrared dye, indocyanine green. Theragnostic nanoparticles were prepared using a well established coacervation/nanoprecipitation method followed by lyophilization. The formulation was optimized by varying process parameters using full factorial design of experiments. Release of dye and drug from NPs and physical state of the drug in NPs was studied using DSC. The NPs were injected into tumor bearing mice intravenously and imaged using a bio-imager. RESULTS: The optimized nanoparticle formulation had a particle size of 125.0 ± 1.8 nm, poly dispersity index of 0.180 ± 0.057 and zeta potential of -32.7 ± 0.9 mV. The release of dye and drug from the nanoparticles was determined to be quasi-fickian diffusion mediated. Differential scanning calorimetry (DSC) studies revealed the stability of drug in the NP. The in-vivo studies showed enhanced accumulation of the dye loaded NPs at the tumor site than the dye solution, thus allowing noninvasive tumor monitoring. CONCLUSION: These results project the newly proposed and evaluated nanoparticle formulation as a potential tumor targeting and imaging delivery system.