Comparison of titanium and polyetheretherketone (PEEK) cages in the surgical treatment of multilevel cervical spondylotic myelopathy: a prospective, randomized, control study with over 7-year follow-up

Abstract

Purpose: Anterior cervical discectomy and fusion (ACDF) with titanium- or polyetheretherketone (PEEK)-cage reconstruction is widely used in the treatment of cervical spondylotic myelopathy (CSM). This study was to compare outcomes of titanium and PEEK cages in the treatment of multilevel CSM.

Methods: Between November 2002 and December 2004, a total of 80 patients with 3-level CSM were randomized in a 1:1 ratio to titanium group and PEEK group. The overall follow-up period of the patients ranged from 86 to 116 months (average 99.7 months). Clinical and radiological results were compared between titanium group and PEEK group.

Results: At the final follow-up, the clinical outcomes including JOA score, NDI score, and the excellent and good rates of clinical outcomes in the PEEK group were better than those in the titanium group. More loss of the Cobb angles and the intervertebral height was observed in the titanium group, resulting in the radiological parameters in the titanium group becoming inferior to the PEEK group at the final follow-up. Cage subsidence rates were 34.5 and 5.4% in the titanium and PEEK groups, respectively. Fusion was observed in all patients of two groups at the final follow-up. Two patients presented with cage dislocation without clinical symptoms in the titanium group.

Conclusions: In surgical treatment of multilevel CSM, PEEK cage is superior to titanium cage in maintenance of intervertebral height and cervical lordosis, resulting in better clinical outcomes in the long-term follow-up.

Figures

Fig. 1

Flowchart of the study comparing the titanium cage and PEEK cage

Fig. 2

a Preoperative Cobb angle of operated segments (segmental Cobb, α); Preoperative Cobb angle of C2–C7 (C2–C7 Cobb, β). b Postoperative Cobb angle of operated segments (segmental Cobb, α); Postoperative Cobb angle of C2–C7 (C2–C7 Cobb, β)

Fig. 3

Measurement of intervertebral height of the involved segments (anterior height of intervertebral space: AH = a–b–c; posterior height of intervertebral space: AH = a′–b′–c′)

Fig. 4

Cage subsidence could be seen in the titanium group (a) and PEEK group (b)

Fig. 5

Loss of sagittal lordosis of the cervical spine due to cage subsidence in the titanium group: a radiograph before operation, b radiograph immediately after operation, c radiograph at the final follow-up

Fig. 6

Dislocation of titanium cage