A comparison of anterior cervical discectomy and corpectomy in patients with multilevel cervical spondylotic myelopathy

Abstract

Background: The optimal surgical approach for multilevel cervical spondylotic myelopathy (CSM) has not been defined, and the relative merits of multilevel anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy (2-level or skip 1-level corpectomy) and fusion (ACCF) remain controversial. However, few comparative studies have been conducted on these two surgical approaches.

Methods: This study retrospectively reviewed the case histories of 120 patients that underwent surgical treatment for 3- or 4-level CSM from July 2003 to June 2008. One hundred and twenty patients (81 male and 39 female) of mean age 58.3±9.8 years (37-78) were included. The study compared perioperative parameters (blood loss, operation times), complications [surgery-related complications (CSF, hoarseness, epidural hematoma, C5-palsy, dysphagia), instrumentation and graft related complications (dislodgement, subsidence)], clinical parameters [Japanese Orthopedic Association (JOA) scores, Neck Dysfunciton Index (NDI) scores], and radiologic parameters (segmental lordosis, fusion rate).

Results: At a minimum of 2-year follow-up, both ACDF and ACCF groups demonstrated a significant increase in the JOA scores (preoperatively 9.25±1.9 and 8.86±1.9, postoperatively 13.86±1.6 and 13.27±1.8, respectively), segmental lordosis (preoperatively 9.79±3.4 and 9.54±3.0, postoperatively 17.75±2.6 and 14.49±2.5, respectively) and NDI scores (preoperatively 12.56±3.0 and 12.21±3.4, postoperatively 3.44±1.7 and 5.68±2.6, respectively). Six patients (2 dislodgement, 4 subsidence) in ACCF group had instrumentation and graft related-complications and they had no obvious neurological symptoms without a second operation. Blood loss (102.81±51.3 and 149.05±74, respectively, P=0.000), NDI scores (P=0.000), and instrumentation and graft related-complications (P=0.032) were significantly lower in the ACDF group, whereas operation time (138.07±30.9 and 125.08±26.4, respectively, P=0.021) and segmental lordosis (P=0.000) were significantly greater in the ACDF group. Other parameters were not significantly different in the two groups.

Conclusions: Surgical managements of 3- or 4-level CSM by ACDF or ACCF showed no significant differences in terms of achieved clinical symptom improvements, with the exception of better postoperative NDI scores in ACDF. In addition, ACDF is better than ACCF in terms of blood loss, lordotic curvature improvement and instrumentation and graft related-complication rates, with the exception of operation times.

Fig. 1

The segmental lordosis was calculated by measuring the angle between the superior endplate of the upper most involved vertebra and the inferior endplate of the lower most involved vertebra at preoperation (a) and postoperation (b) on lateral radiographs

Fig. 2

A 58-year-old male developed numbness and weakness in his four extremities for 2 years, together with unbalance gait for 2 months. Preoperative radiographs showed that the sagittal alignment of the cervical spine was kyphotic (a–d). He was performed with skip 1-level ACCF without surgery related-complications. After operation, his JOA scores improved from 9 preoperation to 13 postoperation. Postoperative lateral and flexion–extension cervical radiographs showed that the cervical kyphosis was corrected and the graft was fused (e–h)

Fig. 3

A 64-year-old male developed numbness in his two hands and weakness in his four extremities for 3 years, which progressively worsened in 1 month. Preoperative imaging studies showed that the spinal cord compressed at C3/4, C4/5, C5/6, C6/7 (a–d). He was performed with 4-level ACDF without surgery related-complications. After operation, his JOA scores improved from 9 preoperation to 14 postoperation. Postoperative lateral and flexion–extension cervical radiographs showed that the cervical lordosis was improved and the graft got bony fusion (e, f)