Noncontiguous anterior decompression and fusion for multilevel cervical spondylotic myelopathy: a prospective randomized control clinical study

Abstract

Anterior decompression and fusion is an established procedure in surgical treatment for multilevel cervical spondylotic myelopathy (MCSM). However, contiguous corpectomies and fusion (CCF) often induce postoperative complications such as nonunion, graft subsidence, and loss of lordotic alignment. As an alternative, noncontiguous corpectomies or one-level corpectomy plus adjacent-level discectomy with retention of an intervening body has been developed recently. In this study, we prospectively compared noncontiguous anterior decompression and fusion (NADF) and CCF for MCSM in terms of surgical invasiveness, clinical and radiographic outcomes, and complications. From January 2005 to June 2007, 105 patients with MCSM were randomized to NADF group (n = 55) and CCF group (n = 50), and followed up for average 31.5 months (range 24-48 months). Average operative time and blood loss decreased significantly in the NADF group as compared with those in the CCF group (p < 0.05 and <0.001, respectively). For VAS, within 3 months postoperatively, there was no significant difference between the two groups. But at 6 months after surgery and final follow-up, VAS improved significantly in NADF group than that in CCF group (p < 0.05). No significant difference of JOA score was observed between the two groups at every collection time. In NADF group, all 55 cases obtained fusion at 1 year after operation (average 5.1 months). In CCF group, 48 cases achieved fusion 1 year postoperatively, but the other 2 cases were performed posterior stabilization and achieved fusion 6 months later. The differences of cervical lordosis between two groups were insignificant at the same follow-up time. But the loss of lordosis and height of fusion segments in 6 months postoperatively and final follow-up were significantly more in CFF group than in NADF group (p < 0.001). Complications were similar in both groups. But in CCF group three cases needed reoperation, one case with extradural hematoma was immediately re-operated after anterior decompression and two cases mentioned above were performed posterior stabilization at 1 year postoperatively. In conclusion, in the patients with MCSM, without developmental stenosis and continuous or combined ossification of posterior longitudinal ligaments, NADF and CCF showed an identical effect of decompression. In terms of surgical time, blood loss, VAS, fusion rate and cervical alignment, NADF was superior compared with CCF.

Fig. 1

In multilevel cervical spondylotic myelopathy with three discs involved that should be decompressed (a), one-level corpectomy plus adjacent-level discectomy with retention of an intervening body can be performed (b). If four level discs need to be decompressed (c), two noncontiguous copectomies can be done with reservation of the middle vertebral body (d)

Fig. 2

Preoperative sagittal T2-weighted image showed that the spinal cord compressed by C4/5,5/6,6/7 disc. In the level of C4/5 and C5/6, spinal cord compressed more severely than in C6/7 (1). Corpectomy of C5 and discectomy of C6/7 were performed with C6 body preserved (2 and 3)

Fig. 3

Preoperative sagittal T2-weighted image showed that the spinal cord compressed by four levels from C3/4 to C6/7 (1). Postoperative sagittal CT construction showed that corpectomies of C4 and C6 were performed and C5 body was reserved intact (2). Postoperative sagittal T2-weighted image showed that the spinal cord decompressed completely (3)