Comparison of a Stand-Alone Anchored Spacer Versus Plate-Cage Construct in the Treatment of Two Noncontiguous Levels of Cervical Spondylosis: A Preliminary Investigation

The application of stand-alone anchored spacer (SAAS) in anterior cervical discectomy and fusion (ACDF) has been proven to be safe and effective to treat cervical spondylosis. Skip-level ACDF with SAAS, fusing only the involved levels without anterior plates, may be the optimal treatment. The aim of the study was to compare the clinical outcomes, radiologic results of SAAS, and plate-cage construct in the treatment of 2 noncontiguous levels of cervical spondylosis.A total of 65 patients with 2 noncontiguous levels of cervical spondylosis were included in the retrospective review of prospective collected data. The clinical and radiologic outcomes were assessed with the Japanese Orthopaedic Association score, Neck Disability Index, cervical alignment, and range of motion and disc height of intermediate segment, respectively. All the aforementioned parameters were compared before and after surgery in the respective group, which also were compared between the 2 groups. Complications also were recorded, and correlations between the surgical outcome and various factors were analyzed.No significant differences existed in clinical results between the 2 groups (P > 0.05). In addition, no statistical significance was observed in fusion rate, cervical alignment, and range of motion and disc height of intermediate segment, dysphagia, and hoarseness (P > 0.05). Preoperative Japanese Orthopaedic Association score and high-intensity signal in T2-weighted images were important predictors for surgical outcome.Skip-level ACDF with SAAS is a safe and effective treatment of 2 noncontiguous levels of cervical spondylosis without obvious contraindications, which can keep the IS intact, and have a low impact on the IS.