From static X-rays to dynamic 3D tracking: A scoping review of cervical spine Imaging-Based motion assessment.

purposeAccurate evaluation of cervical spine motion is crucial for understanding pathologies, monitoring surgical outcomes, and assessing motion-preserving procedures such as cervical disc arthroplasty (CDA). Traditional flexion–extension radiographs are widely used but are limited in reproducibility, precision, and the depth of biomechanical information they provide. This scoping review maps current imaging-based modalities for cervical spine motion assessment, highlighting their measurable motion metrics, accuracy, and ideal clinical contexts.

methodsA literature search was conducted in PubMed using key terms addressing techniques of cervical spine motion analysis. Only peer-reviewed English-language studies involving human or cadaveric models and published between 1995 and 2025 were included. Citation chaining and hand-searching were performed to supplement the database search.

resultsSeventeen studies met inclusion criteria, spanning static radiography, AI-enhanced analysis, dynamic and model-based fluoroscopy, quasi-static MRI, ultrasound, and radiostereometric analysis (RSA). Across these modalities, dynamic fluoroscopy, model-based fluoroscopy and RSA demonstrated the highest precision for vertebral motion measurement. MRI and ultrasound provided radiation-free alternatives with added soft-tissue or portability benefits. AI-enhanced radiography improved measurement reproducibility over standard X-rays but lacked the multidimensional insight of dynamic modalities. Static radiographs remained the most accessible but offered the least detailed motion assessment. Collectively, these findings highlight a trade-off between measurement accuracy, radiation exposure, and clinical practicality.

conclusionCervical motion assessment technologies vary widely in accuracy, radiation exposure, and clinical applicability. While RSA and model-based fluoroscopy provide unparalleled precision, their clinical use is limited by cost, radiation, and infrastructure requirements. AI-enhanced radiography and dynamic fluoroscopy offer practical improvements over standard radiographs while MRI and ultrasound provide radiation-free alternatives for selected cases. Clinical use should align with the diagnostic question, patient context, and required motion metrics.