well as some filaments to the shoulder joint and the scapula 1 ( Fig. 1 ). Fig. 1. Anatomical dissection of the left suprascapular nerve, posterolateral aspect, a. Suprascapular nerve; b. suprascapular artery; c. transverse scapular ligament; d. supraspinatus muscle (divided); e. spine of scapula; f. infraspinatus muscle (divided). The trapezius muscle has been removed. Comparative Anatomy In order to understand the strange course of the suprascapular nerve it is necessary to refer to comparative anatomy. Each vertebrate limb includes not only
Suprascapular entrapment neuropathy
Lawrence J. Clein
The legendary contributions of Thomas Willis (1621–1675): the arterial circle and beyond
Setti S. Rengachary, Andrew Xavier, Sunil Manjila, Usha Smerdon, Brandon Parker, Suzan Hadwan, and Murali Guthikonda
the father of comparative anatomy and one of the earliest comparative neurologists. Willis was primarily a keen observer who carefully recorded what he observed and then he developed a hypothesis as to the cause of the condition. His interpretations of the diseases he observed in living patients and autopsies were accurate, and many of them unique from what had been reported in the past. Willis' conclusions on the physiology of the nervous system stemmed from his basic supposition that function could be determined by detailed observation of structure: …we have
The foramen lacerum: surgical anatomy and relevance for endoscopic endonasal approaches
Wei-Hsin Wang, Stefan Lieber, Roger Neves Mathias, Xicai Sun, Paul A. Gardner, Carl H. Snyderman, Eric W. Wang, and Juan C. Fernandez-Miranda
only represents the first and most basic step required for the exposure of the foramen lacerum. In this study we investigated the surgical anatomy of the foramen lacerum and its adjacent structures using cadaveric dissections and imaging studies, propose several key surgical landmarks, and demonstrate the surgical technique for its full exposure with illustrative cases. Methods Anatomical Dissection Ten lightly embalmed human head specimens were prepared for dissection by cannulation of the carotid arteries, vertebral arteries, and internal jugular veins and injected
A comprehensive biomechanical analysis of sacral alar iliac fixation: an in vitro human cadaveric model
Bryan W. Cunningham, Paul D. Sponseller, Ashley A. Murgatroyd, Jun Kikkawa, and P. Justin Tortolani
T he lumbosacral junction is one of the most challenging regions of the spine in which to obtain a successful arthrodesis. Difficult anatomy, weak bone, large lumbosacral loads, and cantilever pullout forces in this region are the primary reasons for instrumentation-related complications. Traditional systems for lumbosacral fixation include transpedicular screws, iliac screws, and Galveston rods, which anchor directly into the iliac wings. 1 , 3 , 5 , 6 , 18 , 28 The Galveston technique often requires complex, 3D rod contouring, with the risk of postoperative
Surgical assessment of the insula. Part 1: surgical anatomy and morphometric analysis of the transsylvian and transcortical approaches to the insula
Arnau Benet, Shawn L. Hervey-Jumper, Jose Juan González Sánchez, Michael T. Lawton, and Mitchel S. Berger
approach. Additionally, we studied the surgical anatomy related to each procedure along with the final surface exposure of the insula. Finally, we describe 2 skull surface reference points to infer the position of the insular zones. FIG. 1. Illustration of the concepts of insular exposure and surgical window and freedom. The left transsylvian approach to insular Zone I was conceptualized by the medical illustrator. The insular exposure (dotted shape) is the area over the insular cortex available through a surgical approach. The insular exposure is the amount of
Endoscopic anatomy of the fourth ventricle
Pierluigi Longatti, Alessandro Fiorindi, Alberto Feletti, Domenico D'Avella, and Andrea Martinuzzi
N euroendoscopic anatomy of the fourth ventricle has been reported infrequently in the literature, mainly based on laboratory experiences or, more rarely, in accounts of caudocranial suboccipital surgical approaches. 3 , 4 , 6 , 12 , 16 , 19 Even neurosurgeons familiar with flexible endoscopes have scarcely taken advantage of the extraordinary versatility of their instruments to achieve complete visual control of all the ventricular cavities. 7 Nonetheless, the transaqueductal approach to the fourth ventricle performed with flexible scopes has been
Flexion-distraction injuries of the thoracolumbar spine: open fusion versus percutaneous pedicle screw fixation
Andrew J. Grossbach, Nader S. Dahdaleh, Taylor J. Abel, Gregory D. Woods, Brian J. Dlouhy, and Patrick W. Hitchon
Flexion-distraction injuries occur due to distractive forces causing disruption of the posterior and middle spinal columns. These fractures classically consist of a fracture line through the posterior bony elements; involvement of the posterior ligamentous complex is, however, common. Surgical treatment is often required for these unstable injuries to avoid neurological deterioration and posttraumatic kyphosis, and the surgery traditionally consists of an open posterior approach with instrumented fusion. Percutaneous pedicle screw fixation for these injuries, with the goal of minimal tissue disruption and preservation of normal anatomy while achieving adequate stabilization, has recently been reported in the literature, but to date, a direct comparative study comparing open and percutaneous fixation has not been reported. The authors report their experience treating these fractures with both techniques and review the available literature.
Patients with flexion-distraction injury who were treated between May 2003 and March 2013 were prospectively followed. American Spinal Injury Association scores and degree of kyphotic angulation were recorded at admission, discharge, and follow-up. Data regarding intraoperative blood loss and operative time were obtained from a chart review. Patients treated with open versus minimally invasive procedures were compared.
The authors identified 39 patients who suffered flexion-distraction injuries and were treated at their institution during the specified period; one of these patients declined surgery. All had injury to the posterior ligamentous complex. Open surgical procedures with pedicle screw fixation and posterolateral fusion were performed in 27 patients, while 11 patients underwent minimally invasive pedicle screw placement. Overall, there was improvement in kyphotic angulation at the time of discharge as well as most recent follow-up in both the open surgery and minimally invasive surgery (MIS) groups. The authors found no significant difference in American Spinal Injury Association score or the degree of kyphotic angulation between the MIS and open surgery groups. There was a trend toward shorter operative time for the MIS group, and patients who underwent minimally invasive procedures had significantly less blood loss.
Minimally invasive percutaneous pedicle screw fixation appears to have similar efficacy in the treatment of flexion-distraction injuries and it allows for reduced blood loss and tissue damage compared with open surgical techniques. Therefore it should be considered as an option for the treatment of this type of injury.
Determining the best vertebra for measuring pelvic incidence and spinopelvic parameters in adult spinal deformity patients with transitional anatomy
Fares Ani, Themistocles S. Protopsaltis, Yesha Parekh, Khalid Odeh, Renaud Lafage, Justin S. Smith, Robert K. Eastlack, Lawrence Lenke, Frank Schwab, Gregory M. Mundis Jr., Munish C. Gupta, Eric O. Klineberg, Virginie Lafage, Robert Hart, Douglas Burton, Christopher P. Ames, Christopher I. Shaffrey, and Shay Bess
T he prevalence of a lumbosacral transitional vertebra (LSTV) in patients with surgical back pain ranges from 4% to 35.6%. LSTV consists of a range of transitional anatomy, with sacralization of L5 being more common than lumbarization of S1. 1 – 9 Sacralization of L5 can be further radiographically characterized based on the Castellvi classification system. Type I LSTV consists of a dysplastic L5 transverse process whose craniocaudal dimension is at least 19 mm. Type II involves an incomplete fusion between the transverse process and sacrum. Type III
2010 AANS Annual Meeting Philadelphia, Pennsylvania May 1–5, 2010
of Neurological Surgeons JNS.2010.113.2.1 Paper 608 Byron Cone Pevehouse MD Award Comparative Effectiveness Review of Alternate Strategies for Assessing Hypothalamic-Pituitary Axis Function after Microsurgical Resection of Pituitary Adenoma Nicholas F. Marko , MD , and Robert J. Weil , MD (Cleveland, OH) 8 2010 113 2 A404 A404 This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose. 2010 Introduction: Observational methods can be
Abstracts of the 2013 Annual Meeting of the AANS/CNS Section on Disorders of the Spine and Peripheral Nerves
Phoenix, Arizona • March 6–9, 2013
. 2013 Introduction: In attempt to address rising costs and clinical variability including the rate of imaging utilization and surgical referral, multidisciplinary care pathways for back pain have been implemented around the world, each with unique approaches to classification, triage, and provision of care. No comparative studies have been performed to determine efficacy. The Saskatchewan Spine Pathway (SSP) includes triage clinics staffed by specialized physiotherapists. During the early implementation of the SSP, these clinics screened a backlog of