Clinical and radiological results comparison of allograft and polyetheretherketone cage for one to two-level anterior cervical discectomy and fusion: A CONSORT-compliant article.

Background: Recently, many kinds of cages for cervical fusion have been developed to avoid the related complications caused by tricortical iliac crest graft. The existing literature has reported the excellent clinical efficacy and superior fusion rate. However, various types of cages have their own disadvantages. Which bone graft material is the best choice for cage with the fewest complications? At present, there is still no conclusion. Methods: By reviewing patients with 1 to 2-level cervical degenerative disease in our hospital with a novel cage made of allograft or polyetheretherketone (PEEK), we evaluated the efficacy and reliability of the new cage in anterior cervical discectomy and fusion (ACDF). From 2015 to 2016, a prospective review of 58 and 49 consecutive cases with spondylotic radiculopathy or myelopathy undergoing ACDF using allograft (group A) and PEEK (group B) cage were performed. The follow-up ranged from 12 to 40 months. Intraoperative index, clinical outcome and complications were recorded. Radiographs evaluated segmental and overall cervical lordosis, the height of the intervertebral space, interbody height ratio (IHR), cage positioning, and fusion state. Results: A total of 134 cages were implanted. Compared to preoperatively, the visual analog scale (VAS) and neck disability index (NDI) were reduced postoperatively without any change during the subsequent follow-up in both groups. There was no migration or extrusion of the cages at the latest follow-up. There were 2 and 4 patients suffering dysphagia respectively. In both groups, the intervertebral height, IHR, segmental and overall cervical lordosis were significantly greater than pre-operation (P<.05) and were maintained at the last follow-up, but were not statistically significant (P>.05). The allograft group achieved a fusion rate of 100% (58/58) according to CT scans at 3 months post-operation, while PEEK group was 91.8% (45/49), which reached 95.9% (47/49) at 6 months and 100% at 12 months. In addition, the fusion state was maintained in all patients at the last follow-up. Conclusion: Our data showed that the new allograft cage is superior to the PEEK cage in providing a high fusion rate and fewer complications after 1-level and 2-level ACDF procedures. It may represent an excellent alternative to other cages.