Evaluating stability of the craniovertebral junction after unilateral C1 lateral mass resection: implications for the direct lateral approach

OBJECTIVE The direct lateral approach is an alternative to the transoral or endonasal approaches to ventral epidural lesions at the lower craniocervical junction. In this study, the authors performed, to their knowledge, the first in vitro biomechanical evaluation of the craniovertebral junction after sequential unilateral C1 lateral mass resection. The authors hypothesized that partial resection of the lateral mass would not result in a significant increase in range of motion (ROM) and may not require internal stabilization. METHODS The authors performed multidirectional in vitro ROM testing using a robotic spine testing system on 8 fresh cadaveric specimens. We evaluated ROM in 3 primary movements (axial rotation [AR], flexion/extension [FE], and lateral bending [LB]) and 4 coupled movements (AR+E, AR+F, LB + left AR, and LB + right AR). Testing was performed in the intact state, after C1 hemilaminectomy, and after sequential 25%, 50%, 75%, and 100% C1 lateral mass resection. RESULTS There were no significant increases in occipital bone (Oc)–C1, C1–2, or Oc–C2 ROM after C1 hemilaminectomy and 25% lateral mass resection. After 50% resection, Oc–C1 AR ROM increased by 54.4% (p = 0.002), Oc LB ROM increased by 47.8% (p = 0.010), and Oc–C1 AR+E ROM increased by 65.8% (p < 0.001). Oc–C2 FE ROM increased by 7.2% (p = 0.016) after 50% resection; 75% and 100% lateral mass resection resulted in further increases in ROM. CONCLUSIONS In this cadaveric biomechanical study, the authors found that unilateral C1 hemilaminectomy and 25% resection of the C1 lateral mass did not result in significant biomechanical instability at the occipitocervical junction, and 50% resection led to significant increases in Oc–C2 ROM. This is the first biomechanical study of lateral mass resection, and future studies can serve to validate these findings.

C1-C2 Wiring With Timed Self-Obsolescence for Complex C2 Body Fracture

BACKGROUND AND IMPORTANCE Fractures of C2 are typically managed nonoperatively with good rates of healing. Management decisions are complicated, however, when there are additional fractures in the axis possibly leading to increased instability. Additionally, the techniques used for treating these unstable axis fractures can have either significant complications or permanent loss of range of motion. Here, we present a novel technique for the reduction and stabilization of complex C2 body fracture. CLINICAL PRESENTATION A 34-yr-old woman with a complex C2 body fracture, which included a right pars and left lateral mass fracture, presented after a water slide accident. It was felt that this fracture was both unstable and would not heal in an anatomically acceptable way so an open surgical reduction was needed. After consideration of more traditional fusion and osteosynthesis techniques, we chose to perform a C1-C2 internal stabilization with C1 sublaminar and C2 spinous process wiring. The patient was then instructed to wear a Miami J collar for 3 mo. CONCLUSION The outcome was favorable with good approximation and healing with preserved range of motion.

592 Surgical Management of Open Tibia Fractures at A Major Trauma Centre: A Review of Cases Over A One-Year Period

Introduction The BOAST/BAPRAS updated the open fracture guidelines in December 2017 to replace BOAST 4 Open fracture guidelines; the changes gave clearer recommendations for timing of surgery and recommendations for reducing infection rates. Method Our work retrospectively evaluates the surgical management of open tibia fractures at a Major Trauma Centre (MTC), over a one-year period in light of key standards (13,14 and 15 of the standards for open fractures). Results The vast majority of cases (93%) had definitive internal stabilization only when immediate soft tissue coverage was achievable. 90% of cases were not managed as ‘clean cases’ following the initial debridement. 50% of cases underwent definitive closure within 72 hours. The reasons for definitive closure beyond 72hours were: patients medically unwell (20%), multiple wound debridement’s (33%) and no medical or surgical reason was clearly stated (47%). Conclusions The implementation of a ‘clean surgery’ protocol following surgical debridement is essential in diminishing risk of recontamination and infection. Hence, this must be the gold standard and should be clearly documented in operation notes. The extent of availability of a joint Orthoplastic theatre list provides a key limiting step in definitive bony fixation and soft tissue coverage of open tibia fractures.

Masquelet technique for management of posttraumatic bone defect in a patient of chronic osteomyelitis of long bone

<p class="abstract">Masquelet technique, which is the use of a temporary cement spacer followed by staged bone grafting, is a treatment strategy for reconstruction of large, infected, bone defects. This paper describes a patient treated with this technique to successfully manage postinfective or posttraumatic osseous long bone defect. Sequestrectomy was done and the injured limb was stabilized and aligned with application of external fixator at the time of initial antibiotic cement spacer placement. After 6 weeks of proper antibiotic coverage, all antibiotics were stopped for next 2 weeks. Clinical evaluation and investigations were done to rule out any residual infection. Osseous consolidation was successfully achieved with staged bone grafting and internal stabilization of long bone defect.</p>

The USA and the Formation of South Sudan

The United States played a key role in South Sudanese independence, which was decided in a 2011 referendum, and provided diplomatic support and humanitarian aid. Prior to the outbreak of the civil war in 2013, the United States supported and advocated for the Sudan People’s Liberation Movement (SPLM), which became the new country’s government. Though largely taking a back seat in meditation efforts run by the Intergovernmental Authority for Development (IGAD) and neighboring countries in, its internal stabilization the United States and its international partners have an interest in ensuring a lasting settlement to the present conflict in South Sudan, addressing the humanitarian crisis caused by the civil war, and preventing destabilizing regional spillover.

Comparative ultrastructure of the radiolar crown in Sabellida (Annelida)

Three major clades of tube-dwelling annelids are grouped within Sabellida: Fabriciidae, Serpulidae and Sabellidae. The most characteristic feature of these animals is the often spectacularly colorful and flower-like radiolar crown. Holding up such delicate, feathery appendages in water currents requires some sort of internal stabilization. Each of the above-mentioned family-ranked groups has overcome this problem in a different way. Herein we describe the arrangement, composition and ultrastructure of radiolar tissues for fabriciids, sabellids and serpulids using transmission electron microscopy, histology and immunohistochemistry. Our sampling of 12 species spans most of the phylogenetic lineages across Sabellida and, from within Sabellidae, includes representatives of Myxicolinae, Sabellinae and the enigmatic sabellin Caobangia. We further characterize the ultrastructure of the chordoid cells that make up the supporting cellular axis in Sabellidae and discuss the evolution of radiolar tissues within Sabellida in light of the recently published phylogeny of the group.

Traumatic Atlantoaxial Dislocation with Type II Odontoid Fractures: A Case Report

BACKGROUND፡ Odontoid fracture frequently ensues after a cervical trauma, and most commonly at the junction between the dens and the body (type II odontoid fracture).CASE PRESENTATION: This report is focused on a 24-years-old male patient with right-sided hemiparesis, resulting from traumatic atlantoaxial dislocation with type II odontoid fracture. Cervical CT-scanning showed a spondylolisthesis of the C1-C2 complex with type II odontoid fracture, and the injury was treated using posterior reduction and internal stabilization. Therefore, hemiparesis was reduced, and during the follow-up period, our patients were disease-free.CONCLUSION: Early diagnosis and the appropriate management of atlantoaxial trauma is a possible approach towards preventing severe neurological deficits.

Measuring Wind Speed Using the Internal Stabilization System of a Quadrotor Drone

This article proposes a method of measuring wind speed using the data logged by the autopilot of a quadrotor drone. Theoretical equations from works on quadrotor control are utilized and supplemented to form the theoretical framework. Static thrust tests provide the necessary parameters for calculating wind estimates. Flight tests were conducted at a test site with laminar wind conditions with the quadrotor hovering next to a static 2D ultrasonic anemometer with wind speeds between 0–5 m/s. Horizontal wind estimates achieve exceptionally good results with root mean square error (RMSE) values between 0.26–0.29 m/s for wind speed, as well as between 4.1–4.9 for wind direction. The flexibility of this new method simplifies the process, decreases the cost, and adds new application areas for wind measurements.