Traumatic spondylolisthesis of the axis: treatment rationale based on the stability of the different fracture types

Thirty-nine consecutive patients, 22 male and 17 female with an average age of 37.6 years, with traumatic spondylolisthesis of the axis were reviewed. The cause of injury in 75% of the patients was a road traffic accident. Th e fractures were classified according to Effendi et al., the type II fractu res were further divided into three subgroups: flexion, extension and listh esis injuries. There were 10 type I (25.7%) and 29 type II fractures (74.4% ); of these, 12 (30.8%) were classified as flexion-type, 2 (5.1%) as extens ion-type and 15 (38.5%) as listhesis-type. We did not identify any case of type III injury. Overall, 43.5% of the patients had sustained a significant head or chest trauma, with the highest incidence for type II listhesis inj uries. Significant neurological deficits occurred in four patients (10.3%); in all four, the fracture was classified as a type II listhesis. All ten t ype I injuries were successfully treated with a cervical orthosis. Ten of t he 12 type II flexion injuries demonstrated significant angulation. Two wer e treated with internal stabilisation, in seven with a halo device and one with a minerva plaster of Paris (PoP). Healing was uneventful in all ten pa tients. For the remaining two stable type II flexion injuries, application of a hard collar was adequate, as was the case for the two stable type II e xtension injuries. Six of the 15 type II spondylolisthesis injuries underwe nt primary internal stabilisation, and healing was uneventful in all cases. In four (44.4%) of the nine injuries that were primarily treated with a ha lo device/minerva PoP, secondary operative stabilisation had to be performe d. The classification of Effendi et al. provides a complete description of the different fractures. However, further distinction of the type II injuri es regarding their stability is mandatory. Type II spondylolisthesis injuri es are unstable, with a high number of associated injuries, a great potenti al for neurological compromise and significant complications associated wit h non-operative treatment. The majority of type II extension and type II fl exion injuries can be successfully treated with nonrigid external immobilis ation.