Impact of subaxial cervical spine surgeries on patients' head-cervical spine mobility: measurement with CROM device.

OBJECTIVE

To quantitatively evaluate and compare postoperative head and cervical spine mobility (HCSM) following different subaxial cervical surgeries.

METHOD: A cohort of 147 patients who underwent one, two, or three levels of anterior cervical discectomy and fusion (ACDF1, ACDF2, ACDF3) or laminoplasty (LAMP) surgery was assessed. Six-direction active cervical range of motion (CROM) was measured with a CROM device. The HCSM retention rate (HCSM-RR) for each patient was calculated by comparing their CROM values against a previously established normative baseline dataset.

RESULTS

Postoperative reductions in both CROM and HCSM-RR were observed across all six movement directions, with the extent of decline varying by surgical group. In flexion/extension, ACDF1 showed the best preservation (85.4%/82.7%), whereas ACDF3 resulted in the most limited mobility (65.7%/62.9%). For lateral bending, ACDF1 demonstrated superior outcomes (85.1%/85.3%), with ACDF2 and LAMP showing intermediate and comparable results, and ACDF3 the poorest. In axial rotation, the HCSM-RR was significantly lower in the ACDF3 (75%) than in other groups (82%-91%). Among all directions, axial rotation retained the highest HCSM-RR, whereas extension exhibited the lowest.

CONCLUSIONS

Our findings indicate that different subaxial cervical spine surgeries result in significant variations in postoperative HCSM. ACDF1 preserved the most HCSM, while ACDF3 resulted in the greatest loss. ACDF2 and LAMP exhibited similar retention rates. Quantifying the expected postoperative HCSM differences among these surgeries can aid in preoperative physician-patient communication about potential surgical outcomes and long-term quality of life, particularly for patients requiring three-level subaxial cervical surgeries.