Multiplanar realignment for unstable Hangman's fracture with Posterior C2-3 fusion: A prospective series.

OBJECTIVE: There is lack of consensus on the preferred approach for unstable Hangman's fracture. The associated soft tissue injuries apart from apparent bony injury add to the complexity of dislocation and needs to be addressed. Here, we evaluated the clinico-radiological characteristics and outcome of patients managed by posterior C2-3 fusion.

PATIENTS & METHODS: Nine patients with unstable Hangman's fracture (type II and IIA) were prospectively studied. The displacement of fractured fragments and C2-3 dislocation was studied in multiple planes. C2 pars-pedicle screw was placed to bring fractured fragments together (lag effect), which was then fused with C3 lateral masses to achieve multiplanar realignment. Clinical outcome was assessed in terms of pain (VAS score) and neurological status after surgery. Patient's clinico-radiological status was followed up at regular intervals.

RESULTS: Pain was the predominant symptom (VAS: 8.1 ± 1.1). Only one had neurological deficit (ASIA- D). Mean VAS score improved significantly in postoperative period (1.2 ± 1.6). About two-third (66.7%) had atypical Hangman's. In six, fractured segments were malaligned in multiple planes. Axial rotation, lateral translation and superior translation (over-riding) of fragments were seen in 4, 4 and 3 patients respectively. Two had adjacent level injuries. Reduction and realignment of fractured fragments as well as C2-3 in multiple planes could be achieved in all. Follow-up varied from 6 to 22 months (mean, 12.8 ± 5.7). Bony fusion was evident in 9 to 12 months. Three patients showed mild curvature change in subaxial spine.

CONCLUSION: The fractures fragments may be dislocated in axial (rotation and lateral translation) apart from antero-posterior plane. It is important to study the radiology in various planes. Posterior C2-3 fusion is an effective way to achieve good realignment of bony fragments in all planes. It also addresses the instability resulting from soft tissue injury.