A Clinical Evaluation Of Zero-profile Intervertebral Fusion System For Single-level Anterior Cervical Discectomy And Fusion Procedures

Objective:To compare radiologic and clinical outcomes,using a Zero-Profile Intervertebral Fusion System versus an anterior cervical plate and spacer construct for single-level anterior cervical discectomy and fusion(ACDF)procedures.Methods:This study included 48 patients with cervical spondylosis requiring ACDF at a single level at C3-C7.And these patients have been treated from January 2016 to January 2017.Twenty-three patients underwent single-level ACDF with Zero-P intervertebral fusion system,and another 25 patients had common cages implanted with an anterior titanium plate.The clinical outcomes were evaluated using the Japanese Orthopaedic Association(JOA)score and the visual analog scale(VAS)score before and after operation.The cervical Cobb angle and intervertebral disk height were measured on anteroposterior and lateral X-rays after surgery,at 2 days,1 and 6 months,and at last follow-up to assess fusion rate and restoring of cervical lordosis.According to Pitzan's criteria to evaluate the intervertebral fusion status.Incidence of postoperative dysphagia was monitored according to Bazaz dysphagia index.Results:A significant difference between groups in operative time(58.76±8.45 minutes,67.30±8.48minutes)and estimated blood loss(46.49±9.05 mL,65.34±6.76 mL)was found(P<0.05).Mean JOA scores improved significantly and the VAS scores decreased correspondently from preoperative to last follow-up in both groups(P<0.05).But no significant differences between groups in the JOA scores and the VAS scores.The cervical Cobb angle had a significant correction when compared with that before the operation in both groups(P<0.05).But the maintenance of Cobb angle in the Zero-P group was better than that in the cage with plate group(P<0.05).The incidence of dysphagia in the Zero-P group was lower compared with that in the cage with plate group,and the symptom duration was much shorter.Conclusion:Anterior cervical discectomy and fusion with Zero-P resulted in similar clinical and radiologic outcomes as compared with plate and spacers and may help minimize postoperative dysphagia.An improvement in maintenance of the cervical angle might be expected if the titanium alloy plate in Zero P is positioned well.