OBJECTIVETo evaluate the clinical results of using end plate rings in preventing subsidence of titanium cage in anterior cervical corpectomy and fusion (ACCF) surgery.

METHODSThe clinical data of 71 patients with cervical spondylotic myelopathy underwent ACCF in single segment from February 2008 to February 2011 were retrospectively analyzed. There were 38 males and 33 females, aged from 39 to 74 years old with a mean of 53.8 years. Thirty-three were used end plate rings and thirty-eight were not used (end plate rings group and no end plate ring group, respectively). The Japanese Orthopaedic Association (JOA) score, Odom's scale, imaging data were used to evaluate the clinical effects. Imaging data including Cobb angle of fusion segment, intervertebral height of anterior border (Da) and posterior border (Dp), the mean intervertebral height (Dm).

RESULTSAll patients were followed up from 13 to 34 months with an average of 19.5 months. Between two groups, there was no significant difference in Cobb angle of fusion segment and the mean intervertebral height (Dm) before surgery and one week after surgery. Whereas, one year after surgery, the Cobb angle of end plate ring group was (9.4 ± 3.8) degrees, and contral group was (7.5 ± 3.9) degrees, which was significantly lower than that of end plate ring group. Meanwhile, the Dm of end plate ring group was (57.3 ± 2.2) mm, and no end ring group was (55.2 ± 2.6) mm which was significantly lower than that of end plate ring group. The subsidence in end plate ring group was 57.6%, and was 78.9% in no end plate ring group. There was no significant difference in JOA score before and after surgery between two groups. At 1 year after operation, 90.9% (30/33) got excellent or good results in end plate ring group, 89.5% (33/38) got excellent or good results in contral group.

CONCLUSIONThe use of end plate rings could not completely prevent the subsidence of titanium cage, however, which can decrease the occurrence rate of the subsidence and lessen its degree.