Objective To compare the effectiveness of a zero-profile three-dimensiaonal (3D)-printed microporous titanium alloy Cage and a conventional titanium plate combined with a polyether-ether-ketone (PEEK)-Cage in the treatment of single-segment cervical spondylotic myelopathy (CSM) by anterior cervical discectomy and fusion (ACDF). Methods The clinical data of 83 patients with single-segment CSM treated with ACDF between January 2022 and January 2023 were retrospectively analyzed, and they were divided into 3D-ZP group (35 cases, using zero-profile 3D-printed microporous titanium alloy Cage) and CP group (48 cases, using titanium plate in combination with PEEK-Cage). There was no significant difference in gender, age, disease duration, surgical intervertebral space, and preoperative Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) score, neck disability index (NDI), vertebral height at the fusion segment, Cobb angle, and other baseline data between the two groups (P>0.05). The operation time, intraoperative blood loss, hospital stay, complications, interbody fusion, and prosthesis subsidence were recorded and compared between the two groups. VAS score, NDI, and JOA score were used to evaluate the improvement of pain and function before operation, at 3 months after operation, and at last follow-up, and the vertebral height at the fusion segment and Cobb angle were measured by imaging. The degree of dysphagia was assessed by the Bazaz dysphagia scale at 1 week and at last follow-up. Results The operation was successfully completed in all the 83 patients. There was no significant difference in intraoperative blood loss and hospital stay between the two groups (P>0.05), but the operation time in the 3D-ZP group was significantly shorter than that in the CP group (P<0.05). Patients in both groups were followed up 24-35 months, with an average of 25.3 months, and there was no significant difference in the follow-up time between the two groups (P>0.05). The incidence and grade of dysphagia in CP group were significantly higher than those in 3D-ZP group at 1 week after operation and at last follow-up (P<0.05). There was no dysphagia in 3D-ZP group at last follow-up. There was no complication such as implant breakage or displacement in both groups. The intervertebral fusion rates of 3D-ZP group and CP group were 65.71% (23/35) and 60.42% (29/48) respectively at 3 months after operation, and there was no significant difference between the two groups [OR (95%CI)=1.256 (0.507, 3.109), P=0.622]. The JOA score, VAS score, and NDI significantly improved in the 3D-ZP group at 3 months and at last follow-up when compared with preoperative ones (P<0.05), but there was no significant difference between the two groups (P>0.05). There was no significant difference in the improvement rate of JOA between the two groups at last follow-up (P>0.05). At 3 months after operation and at last follow-up, the vertebral height at the fusion segment and Cobb angle significantly improved in both groups, and the two indexes in 3D-ZP group were significantly better than those in CP group (P<0.05). At last follow-up, the incidence of prosthesis subsidence in 3D-ZP group (8.57%) was significantly lower than that in CP group (29.16%) (P<0.05). ConclusionThe application of zero-profile 3D-printed Cage and titanium plate combined with PEEK-Cage in single-segment ACDF can both reconstruct the stability of cervical spine and achieve good effectiveness. Compared with the latter, the application of the former in ACDF can shorten the operation time, reduce the incidence of prosthesis subsidence, and reduce the incidence of dysphagia.
Objective To investigate correlation between preoperative C2 slope (C2S) and effectiveness at 2 years after short-segment anterior cervical discectomy and fusion (ACDF), with the aim of providing reliable indicators for predicting effectiveness. Methods One hundred and eighteen patients with cervical spondylotic myelopathy, who received short-segment ACDF between January 2018 and December 2022 and met the selection criteria, were enrolled in the study. There were 46 males and 72 females, aged from 26 to 80 years, with a mean age of 53.6 years. The operative duration was (127.6±33.46) minutes and the intraoperative blood loss was (34.75±30.40) mL. All patients were followed up 2 years. The pre- and post-operative Neck Disability Index (NDI), Japanese Orthopaedic Association (JOA) score, and visual analogue scale (VAS) score for pain were recorded. Based on the anteroposterior and lateral cervical X-ray films, the sagittal parameters of the cervical spine were measured [C2-C7 Cobb angle, C0-C2 Cobb angle, T1 slope, C2S, sagittal segmental angle (SSA) of the surgical segment, and average surgical disc height (ASDH) of the surgical segment]. Statistical analyses were performed to assess the differences in these indicators between pre- and post-operation, as well as the correlations between the preoperative C2S and the JOA score, NDI, and VAS score at 2 years after operation. The patients were allocated into group A (C2S >11.73°) and group B (C2S≤ 11.73°) according to the median value of the preoperative C2S (11.73°). The JOA score, NDI, and VAS score before operation and at 2 years after operation, as well as the differences between pre- and post-operative values (change values), were compared between the two groups. ResultsThe T1 slope, C2-C7 Cobb angle, C0-C2 Cobb angle, SSA, and ASDH at immediate after operation and JOA score, NDI, and VAS score at 2 years after operation significantly improved in 118 patients when compared with preoperative ones (P<0.05). Pearson correlation analysis showed that preoperative C2S was not correlated with JOA score and NDI at 2 years after operation (P>0.05), but negatively correlated with VAS score (P<0.05). There were 59 patients with preoperative C2S>11.73° (group A) and 59 with C2S≤11.73° (group B). There was no significant difference in preoperative JOA score, NDI, and VAS score between the two groups (P>0.05). There were significant differences in VAS score at 2 year after operation and the change value between the two groups (P<0.05); there was no significant difference in the JOA score and NDI (P>0.05). Conclusion Patients with cervical spondylotic myelopathy and a higher preoperative C2S exhibited superior long-term pain relief and effectiveness following short-segment ACDF.