cannot be said about the pediatric counterpart. Primarily because of a lack of human pediatric cadaveric tissue, but also because of the relatively small number of treated patients, this is a significantly understudied area in spinal biomechanics. This fact is especially true of the most complex region of the pediatric spine: the craniocervical junction (CCJ). This region includes the bony elements of the occiput, atlas (C-1), and axis (C-2), as well as the supporting ligamentous and soft-tissue structures. Our current biomechanical knowledge is based mostly on
Rinchen Phuntsok, Marcus D. Mazur, Benjamin J. Ellis, Vijay M. Ravindra and Douglas L. Brockmeyer
Gmaan Alzhrani, Yair M. Gozal, Ilyas Eli, Walavan Sivakumar, Amol Raheja, Douglas L. Brockmeyer and William T. Couldwell
contralateral side contributes to suboptimal resection. Given the complexity of the anatomical relationships between the occipital bone, atlas, axis, and surrounding ligaments and musculature of the craniocervical junction (CCJ), lesions located in the ventral aspect of the CCJ represent a surgical challenge. The surgical corridor for lesions located in the clivus and ventral aspect of the CCJ has evolved over time from ventral-based approaches (transoral, transfacial, and frontal transbasal) 6 , 25 , 28 to posterolateral-based approaches (far lateral and extreme lateral
Rinchen Phuntsok, Benjamin J. Ellis, Michael R. Herron, Chase W. Provost, Andrew T. Dailey and Douglas L. Brockmeyer
responsible for OA (Oc–C1) and AA (C1–2) joint stability. In this study, we aim to shed light on this important subject by using the finite element (FE) method (FEM). Many previous studies have investigated the biomechanical contribution of various ligamentous structures on craniocervical junction (CCJ) stability. 31 , 35 , 36 , 38 Most of these studies have used cadaveric material, employing a process of sequential weakening or removal of stabilizing structures, to arrive at their conclusions. 5 , 7 Unfortunately, this paradigm creates an experimental condition in which
Rinchen Phuntsok, Chase W. Provost, Andrew T. Dailey, Douglas L. Brockmeyer and Benjamin J. Ellis
T he craniocervical junction (CCJ) is a complex, highly mobile region of the cervical spine. Its motion is facilitated by the occipitoatlantal (OA) and the atlantoaxial (AA) joints, which are stabilized by several osteoligamentous structures. These structures include the transverse ligament (TL), tectorial membrane (TM), alar ligaments (ALs), OA capsular ligaments (OACLs), and AA capsular ligaments (AACLs). In a previous study using finite element (FE) modeling techniques, we found that the OACLs play a significant role stabilizing the OA joint (C0–C1). 17 In
Douglas L. Brockmeyer, Andrew Jea, Alan R. Cohen and Arnold H. Menezes
Atlas the baleful: he knows the depths of all the seas, and he, no other, guards the tall pillars that keep the sky and earth apart. — Homer, “The Odyssey” This issue of Neurosurgical Focus is devoted to one of the most fascinating topics in neurosurgery: the craniocervical junction (CCJ). Like Atlas, the mythological Titan who held up the celestial spheres, the structures that make up the CCJ are responsible for support and protection of the critical cervicomedullary structures within. As shown by the wide variety of topics presented in this issue
Marcus D. Mazur, Vijay M. Ravindra and Douglas L. Brockmeyer
dysplasia (SED) or Down syndrome. In other cases, patients are symptomatic from medullary or spinal cord compression and present with myelopathy and/or bulbar findings. A standard biomechanical axiom states that to achieve the torsional rigidity necessary to facilitate fusion at the craniocervical junction (CCJ), it is necessary to have bilateral fixation. This concept has been passed down over many years, and has been examined in a small number of biomechanical studies that have evaluated atlantoaxial fixation. 13 , 14 In certain circumstances, such as when bone is
Wayne M. Gluf and Douglas L. Brockmeyer
Object. In this, the second of two articles regarding C1–2 transarticular screw fixation, the authors discuss their surgical experience in treating patients 16 years of age and younger, detailing the rate of fusion, complication avoidance, and lessons learned in the pediatric population.
Methods. The authors retrospectively reviewed 67 consecutive patients (23 girls and 44 boys) younger than 16 years of age in whom at least one C1–2 transarticular screw fixation procedure was performed. A total of 127 transarticular screws were placed in these 67 patients whose mean age at time of surgery was 9 years (range 1.7–16 years). The indications for surgery were trauma in 24 patients, os odontoideum in 22 patients, and congenital anomaly in 17 patients. Forty-four patients underwent atlantoaxial fusion and 23 patients underwent occipitocervical fusion. Two of the 67 patients underwent halo therapy postoperatively.
All patients were followed for a minimum of 3 months. In all 67 patients successful fusion was achieved.Complications occurred in seven patients (10.4%), including two vertebral artery injuries.
Conclusions. The use of C1–2 transarticular screw fixation, combined with appropriate atlantoaxial and craniovertebral bone/graft constructs, resulted in a 100% fusion rate in a large consecutive series of pediatric patients. The risks of C1–2 transarticular screw fixation can be minimized in this population by undertaking careful patient selection and meticulous preoperative planning.
Michael Karsy, Neal Moores, Faizi Siddiqi, Douglas L. Brockmeyer and Robert J. Bollo
cases of BSSMO for odontoidectomy have been reported in adult patients with juvenile rheumatoid arthritis, 13 Klippel-Feil syndrome, and congenital occipitocervical instability, 37 BSSMO has not been previously reported as a method to improve anterior access to the subaxial cervical spine in young children with cervical chin-on-chest deformities. Herein, we describe our surgical technique and present 5 pediatric cases with long-term follow-up, in which BSSMO was used to provide enhanced surgical access to the craniocervical junction and subaxial cervical spine
Epidural venous engorgement resulting in progressive cervical myelopathy from shunt-related intracranial hypotension
Case report and review of the literature
James K. Liu, Oren N. Gottfried and Douglas L. Brockmeyer
the cervical spine revealed myelomalacia with atrophy of the upper cervical spinal cord in association with engorgement of the epidural veins in the anterior epidural space, which was most prominent at C-1 and C-2, causing a mass effect on the cervical cord ( Fig. 2 ). The patient’s cervical alignment was normal and there was no evidence of a herniated disc. Both CT angiography ( Fig. 3 ) and cerebral angiography ( Fig. 4 ) revealed a markedly engorged dilated anterior epidural venous plexus within the spinal canal at the craniocervical junction and upper cervical
Douglas L. Brockmeyer, Meghan M. Brockmeyer and Taryn Bragg
craniovertebral junction . Neurosurgery 66 : 3 Suppl 2 – 6 , 2010 10 Menezes AH : Craniocervical developmental anatomy and its implications . Childs Nerv Syst 24 : 1109 – 1122 , 2008 11 Menezes AH , Traynelis VC : Anatomy and biomechanics of normal craniovertebral junction (a) and biomechanics of stabilization (b) . Childs Nerv Syst 24 : 1091 – 1100 , 2008 12 Menezes AH , Vogel TW : Specific entities affecting the craniocervical region: syndromes affecting the craniocervical junction . Childs Nerv Syst 24 : 1155 – 1163 , 2008 13 Muthu SK