Efficacy and Safety of Lag Screw Fixation in Unstable Hangman's Fractures: A Systematic Review and Meta-analysis

Hangman's fracture, caused by high-energy hyperextension with axial loading trauma, remains challenging to manage. Unstable types (IIa and III) can be treated by a variety of surgical options. Lag-screw fixation has recently gained attention owing to its compatibility with navigation, minimally invasive instrumentation, and lower surgical morbidity.

A systematic review and meta-analysis of surgical efficacy and safety of lag screw fixation was undertaken. Nine studies, which included a total of 128 patients, assessed outcomes of lag screw fixation, including neck range of motion, intervertebral angle (C2-C3), postoperative pain (visual analog scale), intraoperative parameters, and complications.

Significant improvements were observed in pooled range of motion (extension: 6.28°, flexion: 5.13°) and correction of the C2 to C3 angle by -3.54° (P < 0.001) vs baseline. Pain decreased across early and late timepoints, although heterogeneity reflects variable follow-up and unreported analgesic/analgesia protocols. Reported complications were low in the included series.

C2 transpedicular lag-screw fixation restores alignment and preserves motion with low reported complications in available case series. Larger comparative trials are needed to define its role relative to fusion techniques.

Direct osteosynthesis of unstable hangman's fractures via lag-screw fixation offers a viable motion-preserving alternative to C2-C3 fusion. By avoiding fusion, this technique maintains physiological cervical biomechanics and reduces the risk of adjacent segment disease. However, clinicians must carefully weigh these benefits against the technical demands of screw placement and the current lack of high-level comparative evidence.