The purpose of this study was to propose a new classification based on the structural, anatomical and biomechanical properties of the odontoid process, to evaluate the outcome and to suggest the adequate treatment in relation to the specific fracture type. The files of 97 patients with odontoid process fractures admitted to our institution were reviewed. The external and internal anatomy of the axis has been studied. The fractures were classified according to the proposed new classification. The method was tested for reliability and validity. Mean follow-up was 14 years. Intraobserver and interobserver agreement was excellent with intraclass correlation coefficients at levels of 0.98 and 0.85 respectively. Four types of odontoid process fractures are distinguished; type A fractures are avulsion fractures involving the tip of the odontoid; type B fractures are fractures of the neck between the lower edge of the transverse ligament and the line connecting the medial corners of the upper articular facets of the axis; type C fractures involve the area between the previously mentioned line and the base of the odontoid process (type C1) or extend to the body of the axis (type C2); type D fractures are complex fractures involving more than one level of the odontoid process. Classification of odontoid process fractures has to be reconsidered as novel imaging technology has shown new patterns of fractures. Computed tomography scan with image reconstruction is mandatory. The analysis of the imaging data in the present study justifies the new classification.
Diving injuries are the cause of devastating trauma, primarily affecting the cervical spine. The younger male population is more often involved in such injuries. This study describes our experience on diving injuries treatment and offers a long follow-up. During a 31-year period (1970–2001) 20 patients, 19 male and one female have been admitted with cervical spine trauma following a diving injury. All admissions have been made between May and September. One patient was lost to follow-up. The mean age of the patients was 23 years (16–47). The lower cervical spine was involved in 13 patients; four patients had lesions in the middle and upper cervical spine, while one patient had combined lesions. The most commonly fractured vertebrae were C5 and C6. Fracture-dislocation was evident in 10 patients, while a teardrop fracture was diagnosed in six patients. Six patients were classified, as ASIA A upon admission and bladder control was absent in 12. Only four patients were treated surgically, two with iliac bone grafting alone, one with posterior plating and one with an anterior plate plus graft. The other patients with initial neurological deficit were treated conservatively, because of their rapid neurological improvement, their lesion being regarded as stable. Fourteen patients were treated conservatively with steroids and Crutchfield skull traction or halo vest, followed by the application of a Minerva or Philadelphia orthosis. The mean follow-up was 11 years (6 mo to 23.8 years). Four patients in the ASIA A category died in the first month of their hospitalization (two of cardiac arrest, one from pulmonary embolism and one from respiratory infection) and two remained unchanged. Six patients with ASIA B and C improved neurologically and one remained unchanged. Nine patients had developed urinary tract infection and two had respiratory infections. Two out of the four operated on developed superficial trauma infection. In conclusion, diving injuries of the cervical spine demonstrate a high mortality and morbidity rate. The initial neurological deficit may improve with appropriate conservative treatment. The indications for surgical management are post-traumatic instability and persistent or deteriorating neurologic deficit.