Nine (5%) patients (6 men and 3 women) had sustained a multi- ple fracture of the axis. Mean patient age was 48 years. The cause of injury was a motor vehi-.
■ Feature Article
S P OT L I G H T O N
spine Multiple Fractures of the Axis DEMETRIOS S. KORRES, MD, DSC; PANAYIOTIS J. PAPAGELOPOULOS, MD, DSC; ANDREAS F. MAVROGENIS, MD; GEORGE S. SAPKAS, MD, DSC; ANTONIOS PATSINEVELOS, MD; PETROS KYRIAZOPOULOS, MD; DEMETRIOS EVANGELOPOULOS, MD
abstract Multiple fractures of the axis are not common lesions. A retrospective study was performed to identify the different fracture patterns and to analyze the incidence of these injuries and their long-term behavior. The medical records of 674 consecutive patients with fractures of the cervical spine were reviewed. Nine (1%) of 674 patients (6 men and 3 women) had multiple fractures of the axis. Mean patient age was 48 years. The most common lesion was a combination of traumatic spondylolisthesis with either an odontoid process or a teardrop fracture of the axis body. All patients were treated conservatively with an excellent or good outcome at mean 12-year follow-up (range: 2-18 years). Computed tomography was the imaging modality of choice for the correct diagnosis of these rare lesions.
ue to the anatomical and functional peculiarities, the axis vertebra always provokes great interest. Its position in the upper cervical spine and articulation with the atlas and third cervical vertebra represents an area of transition, contributing to a unique biomechanical behavior. Forces acting with different vectors may create specific lesions classified in respect to the injured anatomical area. In this way, isolated fractures of the dens (a), fractures of the posterior arch (b), fractures of the body (c), fractures of the articular masses (d), and fractures of the transverse processes (e) can be distinguished. Combinations of these fractures are rarely reported in the literature,1 but data focusing on the entire spectrum of this entity
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and particularly to the behavior of these lesions in the long-term are still lacking. Missed and overlooked lesions may lead to incorrect diagnosis and management, and subsequent instability or deformity. The complexity of these lesions and the presence of stable or unstable lesions requires a careful clinical approach and a modified treatment option.
MATERIALS AND METHODS From January 1970 to December 2002, 674 patients were admitted to the authors’ institution with cervical spine injury. Fractures of the axis were diagnosed in 172 (25%) patients. Nine (5%) patients (6 men and 3 women) had sustained a multiple fracture of the axis. Mean patient age was 48 years.
The cause of injury was a motor vehicle accident in five patients and a fall from a height in the remaining four. In the former group, mean patient age was 38 years, and in the latter 62 years. Four of nine patients had a second associated fracture to the spine or to the skeleton. Two patients presented with neurological deficits, which were due to a second level injury. All patients were treated conservatively with skeletal or Glisson type traction in bed for 2-6 weeks, followed by immobilization with a Minerva or halo vest. Radiographic evaluation included plain radiographs and computed tomography (CT). Computed tomography has been performed routinely since 1980. Magnetic resonance imaging (MRI) has been performed routinely during the past 5 years in all patients with spine trauma. Six (7%) of 90 dens fractures were diagnosed in a multiple level injury of the axis; 3 were associated with traumatic spondylolisthesis, 2 with a lateral articular mass fracture, and 1 with an axis body fracture and traumatic spondylolisthesis. Seven (10%) of 69 cases of traumatic spondylolisthesis were associated with a From the First Department of Orthopedics, Athens University Medical School, Athens, Greece. Reprint requests: Demetrios S. Korres, MD, 10 Heyden St, GR-10434 Athens, Greece.
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second fracture in the axis. In 1 case, a combined injury of both the dens and the axis body was detected. In 3 cases, this lesion was associated with a teardrop fracture of the axis body, and in the remaining 3 cases it was associated with a dens fracture. Fractures of the body or other anatomical area of the axis included in multiple injuries were found in 6 (26%) of 23 cases. In 2 patients, a fracture of the lateral mass was associated to a dens fracture. A teardrop fracture of the axis body was diagnosed in association to traumatic spondylolisthesis in 3 cases, and, as
2 Figure 2: CT shows the tear drop fracture (*) and the variant of the traumatic spondylolisthesis (arrow) of the axis.
already mentioned, in 1 case a fracture of the body was associated with an odontoid process fracture and a traumatic spondylolisthesis of the C-2 vertebra. Average follow-up of all nine patients was 12 years (range: 2-18 years). Clinical examination and full radiographic evaluation including anteroposterior, lateral, openmouth views, and dynamic radiographs in flexion and extension were performed.
1 Figure 1: Plain lateral radiograph of the cervical spine shows multiple fractures of the axis (tear-drop fracture of the body, traumatic spondylolisthesis, and fractured dense at its base), and fracture of the C6 vertebra.
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CASE REPORT A 44-year-old man presented with a cervical spine injury after a heavy item fell on his head
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■ Feature Article
mity of the axis vertebral body was seen in seven patients. These deformities were attributed to the initial teardrop fracture, whereas deformities of the dens were related to a posterior or lateral shift or an increased angulation of the dens fracture.
DISCUSSION
3A
3B
Figure 3: Lateral dynamic views of the cervical spine in flexion (A) and extension (B) 3.5 years after the injury show no instability.
at work. The patient was unconscious for a few minutes. On admission, he was alert, well-orientated, and reported neck pain. No neurological deficits were noted at the initial clinical examination. Standard radiographs revealed a fracture of the C-6 vertebra (Figure 1). Computed tomography showed multiple fractures of the axis, which were a teardrop fracture of the body, traumatic spondylolisthesis, and a fracture at the base of the odontoid process (Figure 2). The patient was treated conservatively in Gardner type bed traction for 3 weeks, and with halo vest immobilization for 2.5 months. Standard radiographs showed consolidation of all fractures, and dynamic radiographs showed that stability was obtained. At latest follow-up, 3.5 years after the injury, the patient is doing well with no neck pain, but has a slight reduction in the range of motion at C1-C2 (Figure 3).
RESULTS At latest follow-up, all nine patients underwent a clinical and radiographic examination. Three patients were symptom-free. Six patients had restricted cervi-
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cal spine range of motion, but only two of these patients had mild neck pain; both patients had sustained fractures of the articular masses, and secondary arthritic changes were detected at the affected C1C2 joint.
...fractures of the axis are considered to be the most common lesions of the cervical spine, accounting for approximately 26% of all cervical spine fractures. Two patients with American Spinal Injury Association D and C scores at admission recovered fully, and none of the neurologically intact patients showed a deterioration of their neurological status. Plain radiographs confirmed fracture healing in all nine patients. Residual defor-
The occipito-atlanto-axial joint complex is a transitional area vulnerable to injury due to its anatomical position. The presence of unique ligamentous structures provides the best conditions for protection and stability at the upper cervical spine. However, fractures of the axis are considered to be the most common lesions of the cervical spine, accounting for approximately 26% of all cervical spine fractures. These fractures are clinically and therapeutically challenging because of their anatomical characteristics.2 The variety of C-2 fractures is a result of its unique anatomy and biomechanical characteristics. The architecture of the axis, the distribution and strength of the bone trabeculae, and the proportion and location of cortical bone, in addition to the magnitude of the applied force and the position of the axis at the time of injury, lead to unique mechanical properties responsible for the specific patterns of cervical traumatic lesions. Different forces are responsible for different fracture patterns.3 The direction of the applied injury force and the internal structure of the axis in relation to the age of the patient play an important role in the creation of the different fracture patterns.4 Fractures of the C-2 vertebra are divided into five types, with the following frequency, as detected in our series: a) fractures of the odontoid process (49%); b) fractures of the vertebral arch (37%); c) fractures of the vertebral body (11%); d) isolated fractures of the lateral mass (2%); and e) miscellaneous fractures (ie, of the spinous process, the laminas, etc) (19%). Fractures of the dens, the vertebral body, and traumatic spondylolisthesis of the axis are divided into subgroups, making these injuries even more complex.5-8 However, combinations of the above fracture patterns
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What is already known on this topic ■ Forces acting on the upper cervical spine with different vectors may create specific injuries of the axis such as isolated fractures of the dens, posterior arch, vertebral body, articular masses, or transverse process. ■ Multiple fractures of the axis are rare. Data focusing on the entire spectrum of this entity, and particularly the behavior of these lesions in the long-term, are still lacking.
What this article adds
REFERENCES
■ The most common multiple injuries of the axis are two simultaneous fractures: a fracture of the dens associated with traumatic spondylolisthesis or a fracture of the articular mass. ■ Three simultaneous fractures of the axis (a fracture of the dens associated with a fracture of the vertebral body and traumatic spondylolisthesis) seem to be a unique injury. ■ Computed tomography is essential to reveal occult injuries of the axis. Multidectorrow CT is important for evaluation of multiple fractures of the axis. ■ The management of multiple fractures of the axis depends on the type and stability of these injuries and the neurological status of the patient. ■ In most cases, conservative treatment is effective. Operative treatment is indicated in cases of severe instability associated with neurological deterioration.
are common (5%),9 as they are probably the result of a single force or multiple forces acting simultaneously. Multiple injuries of the axis, although reported in certain series,10 are seldom reported in the literature as a separated entity. The diagnosis of such injuries is obtained by a careful history and complete clinical and radiographic investigation. A high degree of suspicion and knowledge of this injury pattern is also of importance. The clinical presentation is similar to that of an isolated lesion in the cervical spine (ie, restricted and painful motion, wreck neck), and less often, neurological deficits may be present. Radiographic evaluation should include plain lateral and “open-mouth” views of the cervical spine. Computed tomography is essential to reveal occult bone lesions. In these cases, the necessity for evaluation with a multidetector-row CT, which permits acquisition with ⭐1-mm thin slice width, is important.11 The most common lesions (confirmed by our series) are two simultaneous fractures of the axis, particularly dens fractures and traumatic spondylolisthesis,6,12,13 a fracture of the dens associated with a frac-
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managed conservatively. Skeletal traction followed by the application of a halo vest until bony fusion is achieved is the treatment of choice. Operative treatment is indicated in cases of severe instability associated with deteriorated neurological status.
ture of the articular mass of the axis,14 or other combinations.10 The occurrence of three simultaneous fractures of the axis reported in our series and detected only with CT seems rare. To our knowledge, this combination is not reported in the literature (Figure 2). The management of multiple lesions of the axis depends on the type and stability of the lesions and the neurological status of the patient. The presence of two fractures, even stable in their isolated form, may affect the stability of the cervical spine. Gleizes et al12 recommend conservative treatment in two stable injuries, eg, in a type I or III dens fracture combined with a type I traumatic spondylolisthesis. They recommend surgical treatment in an unstable fracture, as in a dens fracture type II and a type I traumatic spondylolisthesis. In the current series, all patients were treated conservatively with skeletal or Glisson traction followed by the use of external support (four poster or sternooccipital-mandibular-immobilizer brace) for 3 months. In the most recent cases, a halo vest was used. The results were excellent or good with no late complications. Multiple fractures of the axis can be
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T, Roidis N, CA, Lyritis G. axis studied in Orthop. 2004;
5. Anderson LD, d’Alonzo RT. Fractures of the odontoid process of the axis. J Bone Joint Surg Am. 1974; 56:1663-1774. 6. Roy-Camille R, Bleunie JF, Saillant G, Judet T. Fractures de l’ odontoide associées à une fractures des pedicules de l’ axis. Rev Chir Orthop. 1979; 65:387-391. 7. Effendi B, Roy D, Cornish B, Dussault RG, Laurin CA. Fractures of the ring of the axis. A classification based on the analysis of 131 cases. J Bone Joint Surg Br. 1981; 63:319327. 8. Benzel EC, Hart BL, Ball PA, Baldwin NG, Orrison WW, Espinosa M. Fractures of the C2 vertebral body. J Neurosurg. 1994; 81:206212. 9. Korres DS. The Cervical Spine—Traumatology, Pathology. Athens, Greece: Litsas; 1999. 10. Burke JT, Harris JH Jr. Acute injuries of the axis vertebra. Skeletal Radiol. 1989; 18:335346. 11. Li AE, Fishman EK. Cervical spine trauma: evaluation by multidetector CT and threedimensional volume rendering. Emergency Radiology. 2003; 10:34-39. 12. Gleizes V, Jacquot FP, Signoret F, Feron JM. Combined injuries in the upper cervical spine: clinical and epidemiological data over a 14year period. Eur Spine J. 2000; 9:386-392. 13. Daum W, Archer CR. Fracture of the odontoid associated with pedicle fracture of the axis: a previously undescribed entity. J Trauma. 1977; 17:381-386. 14. Signoret F, Feron JM, Bonfait H, Patel A. Fractured odontoid with fractured superior articular process of the axis. Report of three cases. J Bone Joint Surg Br. 1986; 68:182184.
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