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PubMed1989

Familial os odontoideum. Case report.

A familial asymptomatic os odontoideum with a Klippel-Feil type II fusion of C-2 and C-3 is reported. The pattern of inheritance within this family is consistent with that of autosomal dominance. The index case, a 16-year-old boy, was studied with plain cervical spine x-ray films, lateral cervical tomography in flexion and extension, fluoroscopic evaluation of the subluxation, and magnetic resonance (MR) imaging of the spine in flexion and extension. In spite of the subluxation noted on flexion and extension, there was no evidence of cord compression on MR imaging. The etiology and management of this condition are discussed.

Adolescent↗
PubMed1989

Foramen magnum syndrome from pseudogout of the atlanto-occipital ligament. Case report.

The authors report a case of progressive foramen magnum syndrome due to deposits of calcium pyrophosphate dihydrate crystals, which caused reactive hypertrophy in the posterior longitudinal ligament at C-1 and in the transverse ligament of the atlas in an 84-year-old woman. This is the first reported case of symptomatic pseudogout in this anatomic location. Rapid neurological recovery followed transoral decompression of the cervicomedullary junction.

Aged↗
PubMed1990

Occipitocervical fusion for reduction of traumatic periodontoid hypertrophic cicatrix. Case report.

Periodontoid hypertrophic cicatrix resulting from trauma, as demonstrated by magnetic resonance (MR) imaging, is essentially the same as that seen in rheumatoid arthritis. Recent reports suggest that, in rheumatoid arthritis, occipitocervical fusion without transoral decompression of the pannus is adequate for resolution of this anterior lesion. A case of traumatic periodontoid cicatrix is presented in which posterior fusion resulted in reduction of the anterior mass lesion, clearly demonstrated by MR imaging. The etiology of periodontoid hypertrophic scarring, both traumatic and rheumatoid, is discussed in light of MR findings, and treatment implications are considered.

Arthritis, Rheumatoid↗
PubMed1991

Vertical odontoid fracture. Case report.

A case of vertical odontoid fracture is presented in which a concomitant fracture of the skull indicated possible pathogenetic mechanisms. The radiological diagnosis and the management of this case are discussed.

Adolescent↗
PubMed1992

Childhood odontoid fractures evaluated with computerized tomography. Case report.

A case is presented that illustrates the use of computerized tomography for the evaluation of an odontoid fracture in a child. Such a "fracture" may actually represent a "synchondrotic slip" of the odontoid and C-2 vertebral body between the neural arches of C-2. Treatment should almost always be conservative. Complete healing of the injury is expected.

Child, Preschool↗
PubMed1993

Odontoid fractures in elderly patients.

This retrospective analysis describes the clinical characteristics, treatment, and outcome of 19 patients aged 80 years or older with odontoid fractures. The fractures were due to falls in 15 patients (78.9%) and were associated with motor-vehicle accidents in four. Type III fractures were seen in three patients and type II fractures in 16. No patient suffered a neurological injury associated with the fracture. Five patients (26.3%) died during hospitalization; factors contributing to their death included prolonged bed rest, associated injuries, and concomitant medical illnesses. The mean follow-up period in the remaining 14 patients was 28.8 months (range 5 to 72 months). Eight patients with a posterior displacement of 5 mm or less were treated with cervical immobilization, three of whom showed a stable non-union of the fracture site at follow-up review. One patient with 10-mm displacement refused operative treatment. Three of the patients without surgical treatment subsequently died from unrelated causes; all remaining patients resumed their routine activity. Five patients with displacement of 5 mm or greater and instability at the fracture site were treated with posterior cervical fusion of C1-2 using wire and autologous iliac bone grafts. In this group, no operative morbidity or mortality occurred and stable constructs developed in all patients; one patient died from an unrelated cause during the follow-up period and the other patients resumed their normal activity. Prolonged bed rest caused respiratory complications in two of six patients who survived initial hospitalization; two of three patients treated with rigid immobilization developed complications that required alternative treatments.

Aged↗
PubMed1993

Progressive myelopathy secondary to odontoid fractures: clinical, radiological, and surgical features.

Late-onset progressive myelopathy, years after odontoid fracture, is considered a rarity. Sixteen patients with diagnosis of their odontoid fractures delayed from four months to 45 years have been studied and treated. Three had forgotten about the injury and, in the rest, the significance had been minimized by their clinicians. Fifteen patients had characteristic C-2 nerve root pain and 10 had noted weak hands and walking difficulties. Fifteen patients had Type II fractures, which were mobile in 11; hypertrophic pseudoarthrosis was marked in two. In seven patients it was confirmed at surgery that all or part of the transverse ligament was interposed in the fracture. Transoral surgery, combined with a variety of posterior fusion techniques, has allowed cord decompression, an understanding of the pathomechanics, and sound posterior bone fusion with arrest of the myelopathic condition. Measurements of craniovertebral angles and cord cross-sectional area in this series revealed a rough correlation, but the most striking relationship was between length of delay in diagnosis and diminished cord area in both non-union and malunion, suggesting a progressive injury mechanism. It is proposed that late myelopathy following odontoid fracture may be more common than hitherto believed and should be considered in the evaluation of patients with cervical spondylosis. The condition may be progressive. Finally, non-union may be due to interposition of the transverse ligament.

Adolescent↗
PubMed1993

Neurogenic hypertension related to basilar impression. Case report.

The authors report the resolution of essential hypertension following transoral odontoidectomy and medullary decompression in a 39-year-old woman with basilar invagination. Current understanding of central regulation of the cardiovascular system is discussed and the pertinent neuroanatomy illustrated. Experimental and clinical evidence supporting the role of neurogenic mechanisms in the pathogenesis of hypertension is reviewed.

Adult↗
PubMed1995

Surgical management of atlantoaxial nonunions.

Sixteen patients referred for atlantoaxial fixation failures were treated surgically with revision procedures during the past decade. Of these 16 patients, atlantoaxial instability occurred because of rheumatoid arthritis in five, as odontoideum in seven, transverse ligament disruption in two, and odontoid fracture nonunion in two. The 16 individuals (10 men, six women; mean age 43.7 years; age range 20-77 years) had undergone a total of 20 C1-2 internal fixation procedures that failed. Surgical strategies for definitive revision of the nonunions in these 16 subjects included 10 rigid internal fixations with transarticular screws, three revised C1-2 fixations with autogenous bone struts and wire or cables, and three extended fixations with occipitocervical instrumentation. Autogenous grafts were used in all revisions. A postoperative halo brace was used in five individuals with osteoporotic bone; all patients wore a restrictive postoperative cervical orthosis. Postoperatively, 15 patients (94%) had a stable construct (mean follow up 35 months; range 12-79 months), which included 13 osseous unions and two stable fibrous unions. One patient had nonunion; he fractured his anterior C1-2 transarticular screws 2 years postoperatively. He had occipital radicular pain without myelopathy but refused further surgery. Atlantoaxial pseudarthroses were effectively treated by addressing the pathological, biomechanical, and technical reasons for failed fusion. Successful fusion after reoperation was improved by using autologous bone grafts, adequately controlling atlantoaxial motion (with rigid transarticular screws internally or externally with a halo vest), compressing the bone grafts between the arches of C-1 and C-2 with wire cables, meticulously preparing the fusion bed, and by optimizing the pharmacological and clinical parameters to promote bone healing.

Adult↗
PubMed1995

Cannulated screws for odontoid screw fixation and atlantoaxial transarticular screw fixation. Technical note.

Cannulated screw systems use thin Kirschner wires (K-wires) that have been drilled into the bone to direct screw trajectories accurately into small bone fragments. Use of the K-wires avoids overdrilling the pilot holes and allows fixation of adjacent bone fragments during screw insertion. Hollow tools and hollow screws are inserted into the bone over the K-wires. Cannulated screw fixation is useful in the cervical spine to stabilize odontoid fractures and to treat atlantoaxial instability. This report describes techniques for successful cannulated screw insertion and methods to minimize complications. Cannulated screws have several distinct advantages compared to noncannulated screws: 1) the K-wires guide the screw position into the bone; 2) the K-wire trajectory can be repositioned easily if the original trajectory was not ideal; 3) the K-wires allow continuous fixation of adjacent unstable bone fragments; and 4) the K-wires prevent migration of unstable bone fragments during screw insertion. Complications associated with the K-wire (breakage, repositioning, and advancement) can be minimized using precise operative techniques, a specialized tool system, and intraoperative fluoroscopic monitoring. A unique cannulated screw tool system was developed specifically for upper cervical fixation to allow percutaneous drilling using long tunneling devices, tissue sheaths, drill guides, and long K-wires. These tools allow delivery of cannulated fracture-fixation screws at a low angle to the spine through long soft-tissue trajectories. Cannulated screws have significant advantages compared to noncannulated screws for fixation of the unstable cervical spine.

Bone Screws↗
PubMed1996

Longitudinal atlantoaxial dislocation with type III odontoid fracture. Case report and review of the literature.

Odontoid fractures are a common traumatic upper cervical spine injury. Treatment of Type III odontoid fractures includes skeletal traction for realignment and halo vest immobilization. The authors report an unusual case of severe atlantoaxial ligamentous disruption accompanying a traumatic Type III odontoid fracture. Five pounds of skeletal traction was associated with marked neurological deterioration from unanticipated longitudinal instability. Radiographic findings were identified that were suggestive of extensive ligamentous disruption. Recommendations for individualized patient management are given in the context of related literature.

Adult↗
PubMed1997

Synovial cyst and degeneration of the transverse ligament: an unusual cause of high cervical myelopathy. Case report.

A case of cystic degeneration of the transverse ligament located posteriorly to the dens and causing compression to the lower medulla and upper cervical spinal cord is reported. The clinical, pathological, and radiological findings are described and compared to the literature to characterize this syndrome more fully. The advantages of a posterolateral surgical approach are stressed.

Aged↗
PubMed1997

Triple anterior screw fixation of an acute combination atlas-axis fracture. Case report.

The authors report the successful treatment of an acute combination atlas-axis fracture in an 85-year-old man using anterior odontoid and C1-2 transarticular facet screw fixation and a Philadelphia collar. Treatment with halo brace immobilization failed, and the patient experienced recurrent episodes of oxygen desaturation when placed partially prone for chest physiotherapy. If a posterior approach is not feasible, an anterior odontoid and C1-2 transarticular facet screw fixation can be considered as a salvage procedure for patients with acute combination atlas-axis fractures.

Aged↗
PubMed1997

Unilateral posterior atlantoaxial transarticular screw fixation.

Bilateral posterior C 1-2 transfacet screw placement with associated posterior bone graft wiring is the accepted treatment for patients with atlantoaxial instability. This technique was modified to treat 19 patients with atlantoaxial instability and unilateral anomalies that prevented placement of a screw across the C1-2 facet. In these cases, a single contralateral transarticular screw was placed in conjunction with interspinous bone graft wiring to avoid neural or vertebral artery injury and to provide C1-2 stability. Postoperatively, all 19 patients were placed in Philadelphia collars (mean immobilization 8 weeks, range 6-12 weeks). Unilateral C1-2 facet screw fixation was needed for the following reasons: a high-riding transverse foramen of the C-2 vertebra present in 13 patients (left side in eight, right side in five), poor screw purchase in two (left side in both), screw malposition in one (left side), severe degenerative arthritis in one (right side), neurofibroma in one (right side), and fracture of the C-1 lateral mass in one (left side). Six weeks postsurgery, one patient presented with a broken screw and required occipitocervical fusion with a Steinmann pin and wire cable from the occiput to C-3 to achieve solid fusion. Solid fusions were achieved in the other 18 patients (mean follow-up period 31 months, range 14-54 months); there was no delayed screw breakage, wire breakage, or spinal instability. There were no operative or postoperative neurological or vascular complications. The authors' experience demonstrates that unilateral C1-2 facet screw fixation with interspinous bone graft wiring is an excellent alternative in the treatment of atlantoaxial instability when bilateral screw fixation is contraindicated.

Adult↗
PubMed1997

Vertical translocation: the enigma of the disappearing atlantodens interval in patients with myelopathy and rheumatoid arthritis. Part I. Clinical, radiological, and neuropathological features.

This statistical comparison between patients with cervical myelopathy secondary to horizontal atlantoaxial subluxation and those with vertical translocation is designed to elucidate the mechanisms responsible for cranial settling and the effect of translocation on the development of spinal cord compression. In a 10-year study of a cohort of 256 patients, 186 suffered from myelopathy and 116 (62%) of these exhibited vertical translocation according to the Redlund-Johnell criteria. Vertical translocation occurred after a significantly longer period of disease than atlantoaxial subluxation (p < 0.001). Translocation was characterized clinically by a high cervical myelopathy with features of a cruciate paralysis present in 35% of individuals compared with 26% who exhibited horizontal atlantoaxial subluxation (p = 0.29), but there was a surprising paucity of cranial nerve problems. The patients with vertical translocation had a greater degree of neurological disability (p = 0.002) and poorer survival rates (p = 0.04). Radiologically, vertical translocation was secondary to lateral mass collapse and associated with a progressive decrease in the atlantodens interval ([ADI], r = 0.4; p < 0.001) and pannus (p = 0.003). Thirty percent of patients exhibited an ADI of less than 5 mm. This phenomenon has been termed pseudostabilization. The authors' studies emphasize that the ADI (frequently featured in the literature) is totally unreliable as an indicator of neuraxial compromise in the presence of vertical translocation.

Arthritis, Rheumatoid↗
PubMed1997

Vertical translocation. Part II. Outcomes after surgical treatment of rheumatoid cervical myelopathy.

This is a prospective observational study in 116 patients with rheumatoid arthritis and vertical translocation who underwent cervical spine surgery after developing symptomatic myelopathy. These patients, whose mean age was 62 years, had suffered from rheumatoid arthritis for almost 25 years. Surgery was performed via a combination of anterior (67 transoral decompressions) and posterior approaches. Surgical morbidity was recorded in 39% of patients, with a 30-day mortality rate of 10.3%, which was largely related to poor preoperative neurological grade. Neurological improvement of at least one Ranawat class was observed in 55 patients. Univariate analysis revealed the following clinical variables to be associated with a good neurological outcome (Ranawat class): younger age and good preoperative muscle power. Significant radiological variables included the degree of vertical translocation as measured by the Redlund-Johnell method and the preoperative spinal cord area. The degree of transgression in the foramen magnum did not significantly affect neurological outcome. Neither the anterior nor the posterior atlantodens interval predicted neurological recovery. Multiple logistic regression models were constructed based on the preliminary evidence of the authors' univariate analysis and these confirmed the importance of preoperative neurological function, spinal cord area, and the degree of vertical translocation in influencing the final neurological grade.

Age Factors↗
PubMed1998

Failure of transodontoid screw fixation. Case report.

Anterior odontoid screw fixation is being performed with increasing frequency and may currently be the treatment of choice for Type II and selected Type III odontoid fractures, because it is the only surgical fusion that preserves C1-2 motion. Typically patients are immobilized postoperatively in a simple cervical collar. The authors present a case of postoperative fracture of the anterior body of the axis secondary to screw dislocation 5 weeks after single anterior odontoid screw osteosynthesis. Possible reasons for this rare complication and its implications for the technique are discussed.

Adult↗