C2 Hangman's fracture treated with posterior cervical fixation with preservation of the semispinalis cervicis muscle: a case report.

Introduction and importance: Although posterior fixation is well established for unstable Hangman's fractures, constructs including C1 often sacrifice cervical rotation, and conventional exposure frequently injures the semispinalis cervicis (SSC). Given the SSC's essential role in cervical stability, techniques that preserve this muscle may substantially improve postoperative function. However, its preservation during C1-3 fixation has been rarely documented in the literature. Case presentation: A 30-year-old woman sustained a Levine-Edwards type I Hangman's fracture from a rollover motor-vehicle accident. Conservative management failed, and CT revealed persistent non-union with an 8-mm fracture gap. Posterior C1-3 fixation with deliberate SSC preservation was performed. The SSC was mobilized laterally without detachment from the C2 spinous process, enabling adequate exposure for screw placement with intraoperative 3D navigation. Postoperative imaging confirmed complete SSC preservation. One year later, after solid bony healing, implant removal was performed. The preserved SSC displayed minimal adhesions, and screw removal proceeded uneventfully. Following removal, the patient experienced significant improvement in cervical rotation and remained asymptomatic. Clinical discussion: This case demonstrates that SSC preservation is feasible, reproducible, and may meaningfully influence postoperative biomechanics. By minimizing paraspinal muscle damage, this technique may reduce axial symptoms and optimize motion recovery - limitations commonly associated with conventional posterior approaches. Conclusion: SSC-preserving posterior C1-3 fixation may represent a valuable modification for managing selected Hangman's fractures, offering potential functional advantages beyond standard techniques. Broader application and long-term evaluation are warranted.