Tear-drop fracture of the axis is an avulsion of the anterior inferior angle of the C2 vertebrae. This injury occurred in 3,2% of all fractures of the axis in the Roy-Camille series (1). The strength of our case report is that it is about 2 patients both treated conservatively. The limitation is the short follow-up. This fracture differs from lower cervical spine fracture by its mechanism which is an extension for C2 while its flexion for the lower cervical spine (2). Road traffic are the most common circumstance in the study of Hu et al. (2). Neurological deficit is rare (3). Half of the tear-drop injury are associated with other level injuries which may be the cause of neurological deficit (1, 4). This type of fractures is usually stable since posterior elements are intact (5).
Diagnosis can be made with lateral radiography of the cervical spine (6). CT-scan is the ideal investigation. Lingering over indirect signs of instability should be made: widening of the interspinous distance at the site of injury, narrowing of the disc space resulting of the damage to the intervertebral disc, loss of parallelism due to subluxation of the facet joints as a result of disruption of their capsules, posterior displacement of the vertebral body (greater than 3 mm at the CT-scan (7)) which indicates disruption of the posterior longitudinal ligament and the presence of vertebral soft-tissue widening which is evidence of anterior longitudinal damage(5). MRI can be helpful for the diagnosing an unstable injury especially with high velocity trauma, neurological deficit and soft tissue swelling (5). In our cases, we did not explore patients with MRI since there was no neurological deficit or any sign of instability in the CT-scan. The treatment of tear-drop axis fracture is controversial. All authors agree that a neurological deficit is an indication of surgical treatment with decompression and fusion (2, 3, 6–9). Agrawal et al. (6), Korres et al. (9), Watanabe et al. (3), Hu et al. (2) and Boran et al. (5) chose to manage conservatively stable tear drop fractures of the axis. Ma et al. chose a surgical treatment with anterior reduction, discectomy, bone grafting and instrumentation for a huge tear-drop fracture of the axis (8). Vialle et al. treated a stable tear-drop fracture of the axis without neurological deficit with a posterior fusion (7). The authors argument was that there was medullary canal narrowing at the level of C2 without any anomaly of the C2-C3 intervertebral disc. The outcome of this fracture treated conservatively or surgically is usually good (2). In our cases, the conservative treatment lead to a good outcome for stable fractures with no neurological deficit. Both our patients were satisfied with the treatment they received and their outcome.