Comparing the Immune Response to PEEK as an Implant Material with and without P-15 Peptide as Bone Graft Material in a Rabbit Long Bone Model.

P-15 is a 15-amino-acid-long biomimetic peptide widely demonstrated to enhance osteogenesis in vivo. Despite the prevalence of polyether-ether-ketone (PEEK) in interbody device manufacturing, a growing body of evidence suggests it may produce an unfavorable immune response. The purpose of this preliminary study was to characterize the immune response and new bone growth surrounding PEEK implants with and without a P-15 peptide-based osteobiologic.

One- and 2-year outcomes of lumbar facet arthroplasty versus spinal fusion in young (<65 years) and old (≥65 years) patients for the treatment of degenerative spondylolisthesis and stenosis.

Background: Facet arthroplasty, an alternative to lumbar fusion, offers stabilization and preserves range of motion. This subanalysis of the TOPS IDE trial (FDA #G160168) compared facet arthroplasty, using the TOPS device, with a standard single-level transforaminal lumbar interbody fusion (TLIF) in patients stratified by age (<65 and ≥65 years) with symptomatic grade 1 degenerative spondylolisthesis with moderate to severe spinal stenosis at L2-5.

Methods: Patient-reported outcomes (PROMS), including Oswestry disability index (ODI), visual analog pain scales (VAS), and Zurich claudication questionnaires (ZCQ), were assessed at baseline and multiple postoperative timepoints.

Description of the local hemodynamic environment in intracranial aneurysm wall subdivisions.

Intracranial aneurysms (IAs) pose severe health risks influenced by hemodynamics. This study focuses on the intricate characterization of hemodynamic conditions within the IA walls and their influence on bleb development, aiming to enhance understanding of aneurysm stability and the risk of rupture. The methods emphasized utilizing a comprehensive dataset of 359 IAs and 213 IA blebs from 268 patients to reconstruct patient-specific vascular models, analyzing blood flow using finite element methods to solve the unsteady Navier-Stokes equations, the segmentation of aneurysm wall subregions and the hemodynamic metrics wall shear stress (WSS), its metrics, and the critical points in WSS fields were computed and analyzed across different aneurysm subregions defined by saccular, streamwise, and topographical divisions.

The Osteogenic Peptide P-15 for Bone Regeneration: A Narrative Review of the Evidence for a Mechanism of Action.

Bone regeneration is a complex multicellular process involving the recruitment and attachment of osteoprogenitors and their subsequent differentiation into osteoblasts that deposit extracellular matrixes. There is a growing demand for synthetic bone graft materials that can be used to augment these processes to enhance the healing of bone defects resulting from trauma, disease or surgery. P-15 is a small synthetic peptide that is identical in sequence to the cell-binding domain of type I collagen and has been extensively demonstrated in vitro and in vivo to enhance the adhesion, differentiation and proliferation of stem cells involved in bone formation.

Distribution of rupture sites and blebs on intracranial aneurysm walls suggests distinct rupture patterns in ACom and MCA aneurysms.

The mechanisms behind intracranial aneurysm formation and rupture are not fully understood, with factors such as location, patient demographics, and hemodynamics playing a role. Additionally, the significance of anatomical features like blebs in ruptures is debated. This highlights the necessity for comprehensive research that combines patient-specific risk factors with a detailed analysis of local hemodynamic characteristics at bleb and rupture sites.

Comapping Cellular Content and Extracellular Matrix with Hemodynamics in Intact Arterial Tissues Using Scanning Immunofluorescent Multiphoton Microscopy.

Deviation of blood flow from an optimal range is known to be associated with the initiation and progression of vascular pathologies. Important open questions remain about how the abnormal flow drives specific wall changes in pathologies such as cerebral aneurysms where the flow is highly heterogeneous and complex. This knowledge gap precludes the clinical use of readily available flow data to predict outcomes and improve treatment of these diseases.

Surgical Posture with Microscopic Versus Exoscopic Visualization in Anterior Cervical Procedures.

Background: Surgeons sustain deviated postures during procedures even with the use of loupes or an operative microscope. The surgical exoscope is a new intraoperative visualization technology designed to improve surgical ergonomics; however, no objective data exist to say that surgeon posture is significantly improved. This study aimed to quantify the difference in posture during standard anterior cervical spine procedures performed with the aid of an operative microscope versus an exoscope.

An Immunologic and Biomechanical Comparison of Polyether Ether Ketone-Zeolite and Polyether Ether Ketone Interbody Fusion Devices.

Study Design: A laboratory study comparing polyether ether ketone (PEEK)-zeolite and PEEK spinal implants in an ovine model.

Objective: This study challenges a conventional spinal implant material, PEEK, to PEEK-zeolite using a nonplated cervical ovine model.

Summary Of Background Data: Although widely used for spinal implants due to its material properties, PEEK is hydrophobic, resulting in poor osseointegration, and elicits a mild nonspecific foreign body response.

Real-time vessel segmentation and reconstruction for virtual fixtures for an active handheld microneurosurgical instrument.

Purpose: Complications related to vascular damage such as intra-operative bleeding may be avoided during neurosurgical procedures such as petroclival meningioma surgery. To address this and improve the patient's safety, we designed a real-time blood vessel avoidance strategy that enables operation on deformable tissue during petroclival meningioma surgery using Micron, a handheld surgical robotic tool.

Methods: We integrated real-time intra-operative blood vessel segmentation of brain vasculature using deep learning, with a 3D reconstruction algorithm to obtain the vessel point cloud in real time.

Prediction of bleb formation in intracranial aneurysms using machine learning models based on aneurysm hemodynamics, geometry, location, and patient population.

Background: Bleb presence in intracranial aneurysms (IAs) is a known indication of instability and vulnerability.

Objective: To develop and evaluate predictive models of bleb development in IAs based on hemodynamics, geometry, anatomical location, and patient population.

Methods: Cross-sectional data (one time point) of 2395 IAs were used for training bleb formation models using machine learning (random forest, support vector machine, logistic regression, k-nearest neighbor, and bagging).

Case Series of Skull Base Meningioma Resection in the Octogenarian Population.

 The geriatric population is the fastest growing segment of the American population, and octogenarians are increasingly seen by neurosurgeons for relatively common lesions such as meningiomas. Unfortunately, providers do not have clear data to guide decision-making regarding these lesions, particularly if they involve the skull base. Current research in outcomes among the elderly looks at a wide range of ages, often anyone older than 65.

Hemodynamics in aneurysm blebs with different wall characteristics.

Background: Blebs are important secondary structures of intracranial aneurysms associated with increased rupture risk and can affect local wall stress and hemodynamics. Mechanisms of bleb development and evolution are not clearly understood. We investigate the relationship between blebs with different wall characteristics and local hemodynamics and rupture sites.

Blebs in intracranial aneurysms: prevalence and general characteristics.

Background: Blebs are rupture risk factors in intracranial aneurysms (IAs), but their prevalence, distribution, and associations with clinical factors as well as their causes and effects on aneurysm vulnerability remain unclear.

Methods: A total of 122 blebs in 270 IAs selected for surgery were studied using patient-specific vascular reconstructions from 3D angiographic images. Bleb geometry, location on the aneurysm, and frequency of occurrence in aneurysms at different locations were analyzed.

Biomechanics of Posterior Dynamic Fusion Systems in the Lumbar Spine: Implications for Stabilization With Improved Arthrodesis.

Study Design: A comparative biomechanical human cadaveric spine study of a dynamic fusion rod and a traditional titanium rod.

Objective: The purpose of this study was to measure and compare the biomechanical metrics associated with a dynamic fusion device, Isobar TTL Evolution, and a rigid rod.

Summary Of Background Data: Dynamic fusion rods may enhance arthrodesis compared with a rigid rod.

Prevalence of tethered spinal cord in infants with VACTERL.

Object: The term VACTERL represents a nonrandom association of birth defects including vertebral malformations, anal atresia, cardiac anomalies, tracheoesophageal fistulas (TEFs), renal anomalies, and limb malformations. Clinical experience and a few published case series suggest that a tethered spinal cord (TSC) occurs commonly in children with VACTERL, but to date, no study has defined the prevalence of TSC in patients with VACTERL. Such information would guide decisions about the appropriateness of screening spinal imaging.