Standalone cage versus anchored cage for anterior cervical discectomy and fusion: a comparative analysis of clinical and radiological outcomes

Purpose The use of standalone cages (SAC) and anchored cages (AC) in anterior cervical discectomy and fusion surgery (ACDF) has shown advantage of reduced operative time and lower incidence of dysphagia. However, there is limited literature available comparing the clinical and radiological outcomes of SAC and AC. Methods We conducted a prospective study for patients undergoing ACDF for cervical radiculopathy or myelopathy. Patient were classified based on the cage used into SAC group and the AC group. Clinical outcomes were assessed using the modified Japanese Orthopedic Association (mJOA) for myelopathy and Neck Disability Index (NDI) and Visual Analogue Scale (VAS) for radiculopathy. Dysphagia was graded as per Bazaz score. Radiologically, global cervical lordosis, segmental lordosis, cage subsidence, and migration were assessed. Results We analyzed 31 patients in each group with a minimum two year follow-up. The mean VAS improved from 7.9 to 4.56, mean NDI score improved from 27.6 to 19.8, and mean mJOA improved from 10.8 to 11.7 which were statistically significant (p < 0.05); however, no significant difference was noted between the SAC and AC groups. Mean global lordosis improved from 14.4 to 20.3 degrees and mean segmental lordosis improved from 6 to 10.1 degrees at six months and plateaued to 6.9 degrees at final follow up without any significant difference between the groups. The subsidence was statistically more in 12.9% (4/31) in SAC than 6.4% (2/31) in AC. Conclusion AC showed of lower rates of subsidence while both SAC and AC had comparable clinical outcomes and radiological alignment outcomes.

Automated summary

The use of standalone cages (SAC) and anchored cages (AC) in anterior cervical discectomy and fusion surgery (ACDF) has advantages of reduced operative time and lower incidence of dysphagia. However, there is limited literature available comparing the clinical and radiological outcomes of SAC and AC. This study found that both SAC and AC had comparable clinical outcomes and radiological alignment outcomes, but AC showed lower rates of subsidence.