The outcomes of 25 pediatric patients who underwent upper cervical or occipitocervical fusion at the authors' institution since 1983 were reviewed. At a mean age of 9 years, the patients presented with spinal instability that was associated with os odontoideum in 11 cases, rotatory subluxation in five cases, odontoid fracture in two cases, atlantooccipital dislocation in two cases, and congenital atlantoaxial instability in five patients, four of whom had Down's syndrome (trisomy 21). Ten children had abnormal findings on neurological examination preoperatively; however, nine experienced improvement or resolution of deficits as of their latest follow-up evaluation (mean 17 months). Fusion was achieved with the first operation in 21 of 25 patients; eventually it was attained in all but one. Four patients exhibited persistent spinal instability after an initial procedure. This was caused by erosion of a multistranded cable through the intact arch of C-2 in two cases, by pin site infection necessitating early halo removal in one case, and by slippage in a halo following a Gallie procedure, which was revised with a Brooks fusion in one case. This series, the largest yet published, shows that with appropriate surgical management, posterior upper cervical fusion in the pediatric population is highly successful. Careful attention to halo pin site care and caution in using multistranded cable in young patients may improve results.
David W. Lowry, Ian F. Pollack, Brent Clyde, A. Leland Albright and P. David Adelson
Douglas L. Brockmeyer, Julie E. York and Ronald I. Apfelbaum
Craniovertebral instability is a challenging problem in pediatric spinal surgery. Recently, C1-2 transarticular screw fixation in pediatric patients has been used to assist in the stabilization of the craniovertebral joint. Currently there are no data that define the anatomical suitability of this technique in the pediatric population. The authors report their experience in 32 pediatric patients in whom craniovertebral instability was treated by placement of C1-2 transarticular screws.
From March 1991 to October 1998, 32 patients 16 years of age or younger with atlantooccipital, or atlantoaxial instability, or both were evaluated at our institution. There were 22 boys and 10 girls. Their ages ranged from 4 to 16 years (mean age 10.2 years). The most common causes of instability were os odontoideum (12 patients) and ligamentous laxity (nine patients). Six patients had undergone a total of nine previous attempts at posterior fusion at outside institutions.
All patients underwent extensive preoperative radiological evaluation including thin cut (1-mm) computerized tomography scanning with multiplanar reconstruction to evaluate the C1-2 joint space anatomy. Of the 64 possible C1-2 joint spaces in 32 patients, 55 sides (86%) were considered suitable for transarticular screw placement preoperatively. In three patients the C1-2 joint space anatomy was considered unsuitable for screw placement bilaterally. In three patients the anatomy was considered inadequate on one side. Fifty-five C1-2 transarticular screws were subsequently placed, with no resulting neurological or vascular complications. We conclude that C1-2 transarticular screw fixation is technically possible in a large proportion of pediatric patients with craniovertebral instability.
Timothy Ryken and Arnold Menezes
Rheumatological complications have been described in up to 30% of patients being followed for inflammatory bowel disease. The majority of these complications occur as spondylitic changes in the lumbar spine. Erosive arthritic disease associated with inflammatory bowel disease occurs less frequently, but it can result in ligamentous laxity and joint instability. To highlight the potential significance of the process at the craniocervical junction, the authors describe the long-term follow-up care of a complicated case. A 56-year-old woman, with a long history of ulcerative colitis, presented with atlantoaxial instability and underwent a C1-3 fusion; however, the presence of significant occipitoatlantal instability was not recognized. This resulted in high cervicomedullary quadriplegia, requiring traction reduction and a combined anterior transoral decompressive-posterior occipitocervical fusion. The patient's neurological deficit completely resolved postoperatively.
Derek A. Taggard, Arnold H. Menezes and Timothy C. Ryken
Operative intervention for the treatment of instability at the craniovertebral junction in patients with Down's syndrome has become somewhat controversial because some authors have reported high surgery-related complication rates and suggested that the incidence of neurological abnormality associated with this abnormal motion may be low. In this report, the authors describe the clinical and radiographic findings in 33 patients treated at their institution. Common presenting symptoms included neck pain (14 patients), torticollis (12 patients), and myelopathy manifested as hyperreflexia (21 patients), or varying degrees of quadriparesis (11 patients). Four patients suffered acute neurological insults, two after receiving routine general anesthetics for minor surgical procedures and two other patients following minor falls. Atlantoaxial instability was the most common abnormality documented on radiography (22 patients). Atlantooccipital instability (15 patients) was also frequently observed and was coexistent with the presence of atlantoaxial luxations in 14 patients. A rotary component of the atlantoaxial luxation was present in 13 cases. In 17 patients bony anomalies were present, the most frequent of which was os odontoideum (10 patients). Twenty-four patients underwent operative intervention, and successful fusion was achieved in 23. In six of nine patients with basilar invagination, reduction was achieved with preoperative traction and thus avoided the need for ventral decompressive procedures. There were no cases of postoperative deterioration, and 22 patients made excellent or good recoveries. The results of this series highlight the clinicopathological phenomena of craniovertebral instability in patients with Down's syndrome and suggest that satisfactory outcomes can be achieved with a low rate of surgical morbidity.
Technical note and case series
Amory J. Fiore, Regis W. Haid, Gerald E. Rodts, Brian R. Subach, Praveen V. Mummaneni, Charles J. Riedel and Barry D. Birch
A variety of techniques may be used to achieve fixation of the upper cervical spine. Transarticular atlantoaxial screws, posterior interspinous cable and graft constructs, and interlaminar clamps have been used effectively to achieve atlantoaxial fixation. Various anatomical factors, however, may preclude the successful application of these techniques. These factors include aberrant vertebral artery anatomy, irreducible atlantoaxial subluxation, exaggerated cervicothoracic kyphosis, and the absence of the osseous substrate for fixation. In these cases, an alternative method of fixation must be performed. The authors present an alternative method to achieve fixation of the atlas in which lateral mass screws can be applied to atlantoaxial and occipitocervical fixation.
Between February 1998 and November 2001, eight patients who ranged in age from 16 to 74 years underwent posterior fixation for upper cervical instability. Diagnoses included C-2 metastastic disease in two patients, irreducible odontoid fractures in two patients, atlantoaxial subluxation in two patients, and transverse ligament synovial cyst in two patients. Various anatomical factors precluded transarticular atlantoaxial screw fixation in seven patients. One patient with a highly unstable spine due to a C-2 metastasis and pathological fracture underwent occipitocervical fusion.
Atlantocervical fixation was achieved in seven patients by using varying constructs incorporating C-1 lateral mass screws. Occipitocervical fixation was achieved in one patient by incorporating C-1 lateral mass screws as an additional fixation point. A total of 14 C-1 lateral mass screws were placed in eight patients. There were no intraoperative complications. In all patients rigid fixation was achieved as demonstrated on postoperative radiographs. One patient died on postoperative Day 9 of aspiration pneumonia. At a mean follow-up time of 7.4 months, rigid fixation was maintained in all patients.
Atlantal lateral mass screws can be used to provide a safe and efficacious means of achieving atlantoaxial fixation when anatomical constraints preclude the use of a more traditional procedure. Atlantal lateral mass screws may also be incorporated in occipitocervical constructs to provide additional fixation points which may prevent construct failure.
John K. Stokes, Alan T. Villavicencio, Paul C. Liu, Robert S. Bray and J. Patrick Johnson
Surgical treatment of atlantoaxial instability has evolved to include various posterior wiring techniques including Brooks, Gallie, and Sonntag fusions in which success rates range from 60 to 100%. The Magerl–Seemans technique in which C1–2 transarticular screws are placed results in fusion rates between 87 and 100%. This procedure is technically demanding and requires precise knowledge of the course of the vertebral arteries (VAs). The authors introduce a new C1–2 fixation procedure in which C-1 lateral mass and C-2 pedicle screws are placed that may have advantages over C1–2 transarticular screw constructs.
A standard posterior C1–2 exposure is obtained. Polyaxial C-2 pedicle screws and C-1 lateral mass screws are placed bilaterally. Rods are connected to the screws and secured using locking nuts. A cross-link is then placed. Fusion can be performed at the atlantoaxial joint by elevating the C-2 nerve root.
The technique for this procedure has been used in four cases of atlantoaxial instability at the author's institution. There have been no C-2 nerve root– or VA-related injuries. No cases of construct failure have been observed in the short-term follow up period.
Atlantoaxial lateral mass and axial pedicle screw fixation offers an alternative means of achieving atlantoaxial fusion. The technique is less demanding than that required for transarticular screw placement and may avoid the potential complication of VA injury. The cross-linked construct is theoretically stable in flexion, extension, and rotation. Laminectomy or fracture of the posterior elements does not preclude use of this fixation procedure.
Scott Y. Rahimi, E. Andrew Stevens, David John Yeh, Ann Marie Flannery, Haroon Fiaz Choudhri and Mark R. Lee
The atlantoaxial region has been extensively described as a spinal segment especially prone to injury in children. In this clinical review, the authors evaluate and summarize the management of 23 pediatric cases of atlantoaxial instability treated between March 1990 and October 2002. Four broad categories of atlantoaxial problems were observed—atlantoaxial rotatory subluxation in six patients, anterior–posterior atlantoaxial instability caused by ligamentous injury or congenital ligamentous laxity (10 patients), atlantoaxial fracture with or without dislocation (five patients), and atlantooccipital dislocation (two patients). Most cases (60.9%) were treated without surgical intervention, resulting in excellent outcomes; however, 21.7% of cases were treated with a cervical halo (mean patient age 72.6 months) alone for 3 months. Various techniques of surgical stabilization including transarticular screws with sublaminar wiring, trans-oral decompression with posterior plating, and laminectomy with Steinmann pin occipital–cervical fusion were used with good results. Both patients with atlantooccipital dislocation underwent immediate Locksley occipital–cervical fusion, with marked neurological improvement. Individualized case management must be based on clinical presentation, with internal fixation being the last resort.
John R. Vender, Andy J. Rekito, Steven J. Harrison and Dennis E. McDonnell
The past several decades have been the setting for a remarkable evolution of spinal instrumentation technology. The advancements that have been made have allowed previously complex disorders of the cervical spine, the atlantoaxial articulation, and the occipitocervical junction to be managed more effectively with direct methods of internal fixation and arthrodesis. This has resulted in improvements in patient outcomes and fusion success rates. The improved strength of instrumentation constructs allows minimal, if any, external bracing, obviating the need for a halo orthosis in many cases. In this paper the authors review key events that have occurred in neuroimaging, biomechanical testing, and the development of fusion and instrumentation constructs.
Daniel J. Hoh, Paul Khoueir and Michael Y. Wang
for atlantoaxial instability, which can also occur with AS and present a potential risk of neurologic injury with both intubation and surgery. F ig . 3. Illustration demonstrating the measurement of the CBA in severe cervical flexion deformity. Presurgical considerations include obtaining a thorough medical history, as these patients often times are high-risk surgical candidates. Patients with fixed thoracic deformities may have reduced pulmonary function, which presents greater morbidity with anesthesia and procedures performed in the prone position
Elias Dakwar, Jaypal Reddy, Fernando L. Vale and Juan S. Uribe
. Neurological symptoms can occur with cord or spinal nerve compression resulting from several complications of this spinal disease. Vertebral fractures can develop in patients with ankylosed spines with minimal or no traumatic injury. The most common fracture site is at the C5–6 interspace. 31 Clinically significant atlantoaxial subluxation can occur in up to 21% of patients with AS and can lead to spinal cord compression. 23 Cauda equina syndrome is a rare complication of longstanding AS; its pathogenesis is poorly understood and includes inflammation, arachnoiditis