Lightning Podiums: Spinal Gumbo - 803A

Presented by: Y. Tian

Author(s):

Y. Tian(1), Y. Guo(2), C. Ma(3), W. Tian(3), J. Yue(4)

(1) Yale University, Orthopaedic Surgery, New Haven, CT, United States
(2) Yale University School of Medicine, New Haven, CT, United States
(3) Jishuitan Hospital, Orthopaedic Surgery, Beijing, China
(4) Yale University School of Medicine, Orthopaedic Surgery, New Haven, CT, United States

Abstract

Study Design: A retrospective review with minimum 10 year follow-up study evaluating the treatment of disabling single level cervical herniated disc patients utilizing cervical disc arthroplasty (CDA) and ACDF.

Objective: To determine the factors that are associated with clinical outcomes of cervical disc arthroplasty surgery with a minimum 10 year of follow up.

Methods: This is a retrospective study for patients who were operated on from 2003-2007. All the patients were followed up at least 10 years. Clinical outcome was measured using Neck Disability Index (NDI), Japanese Orthopedic Association score(JOA), and Odom's scale. All the clinical and radiographic factors were studied and collected preoperatively and at 10-year follow-up. Receiver operating characteristic (ROC) was employed to determine the cut-off value for factors that predict the clinical outcome. Complications in both groups were noted. Results-clinical: 72 patients underwent single level CDA with mean age of 45.9 years (range, 26-69 years; 27 females and 45 males). 39 patients underwent single level ACDF with mean age of 51.8 years (range, 26-73 years; 10 females, 29 males). Both CDA and ACDF surgery acquired satisfactory clinical outcome after 10 years of follow-up in term of JOA, NDI and Odom's score. CDA group has lower adjacent segment degeneration rate compared to ACDF group (upper segment: 31.1% vs 55.4%, P=0.028; lower segment: 30% vs 77.5%, P=0.015). Mean NDI was superior in the ACDF group than that in ADR group at 10-year follow-up (9.74% in ACDF group vs 15.5% in CDA group, P=0.0016). By spearman correlation assay, in the CDA group. higher preoperative posterior disc height index (PDHI) (posterior disc height relative to the length of its superior endplate) was associated with better NDI (P=0.013) and JOA (P=0.038) scores at 10-year follow-up. Interestingly, younger age is associate with better NDI score (P=0.0073) and JOA score (P=0.028) in ACDF group, but was not of clinical significance in the CDA group. Further receiver operating characteristic (ROC) gave an optimal cut off value 0.229 for preoperative PDHI in CDA group (sensitivity 65.12%, specificity 58.06%). In PDHI≥0.229 group, the mean NDI score at 10-year follow-up is significantly better than that in PDHI< 0.228 group (13.5% vs 18.7%, P=0.02). Results-radiographic: ROM at operated level was 8.14±5.56 vs 3.38±1.92 (P< 0.001). However, the overall ROM of cervical spine and sagittal vertical axis (SVA) at 10-year follow up were not significantly different from their pre-operative value. There was also no significant difference between CDA group and ACDF group for overall ROM of cervical spine and SVA at 10-year follow up.

Conclusion: Both CDA and ACDF surgery were shown to be effective treatment modalities for single segment cervical disc herniation with favorable clinical outcome at 10-year follow up. CDA group has lower adjacent segment degeneration rate compared to ACDF group. In CDA group, the improved disc heights and ROM at operated level were still well maintained at 10 years follow up. However, the overall ROM and sagittal alignment did not significantly change at 10 years follow up and between two groups. Higher preoperative posterior disc height index (PDHI) predicts better clinical outcome in patient who underwent CDA. For patient with PDHI≥0.229, ADR is treatment of choice.