an oval or round well-corticated ossicle of variable size, found in the expected position of the odontoid process. Current opinion considers os odontoideum to represent the result of prior, often unrecognised, trauma. Atlanto-axial instability occurs in 83% of cases of os odontoideum. Therefore, when an os odontoideum is noted, flexion/extension radiographs should be obtained to exclude instability.
An ossicle formed as a consequence of type 2 fractures at the junction of the odontoid process with the body of the axis. Presence of an os odontoideum may lead to nonunion owing to fracture displacement or angulation.
42 year old male. Onset of incoordination of gait and global weakness of arms following a minor whiplash type injury 1 week ago.
No recollection of previous trauma.
Neck pain and occipital headache.
Grade 5/5 power all muscle groups in legs.
Hyper-reflexia, Clonus +ve, Babinski sign +ve.
Hoffman test +ve
showed a non-union of type II odontoid peg (Images will be uploaded soon). Well corticated fracture margins.
There is a small fresh haematoma behind the odontoid.
OS-Odontoideum (non-union of type II Odontoid peg fracture) associated with a new injury.
Posterior C1/2 stabilisation using Transarticular screws, C1/2 sublaminar cables, Tricortical iliac crest bone graft as Gallie Fusion.
Patient positioned prone. Odontoid peg fracture carefully reduced with cervical spine in traction and dynamic fluoroscopy, reduced to anatomical alignment. Midline Posterior approach. C1 posterior ring undersurface decorticated. C2 posterior elements exposed. C2/1 Transarticulr screws under partially direct vision and partially fluoroscopy. Stable fixation achieved. Sublaminar wire carefully introduced under C1 and around C2 Spinous process. Tricortical iliac crest bone graft harvested from posterior iliac crest and cut to size. Graft fixed in C1/2 space with cable.
Post Op Follow Up
Patient has returned to work and is functioning well.
Neurological examination reveals significant improvement in power, proprioception and gait.
Please note that each case is considered individually and not all patients have the same result from surgical intervention. We do not guarantee this type of recovery in every patient and in fact some patients may not improve from surgery. You should discuss your problem with your own doctor and consider carefully all the treatment options before considering surgery. You should be aware of all serious risks of surgery before undergoing intervention.