[Clinical and Radiological Results after Anterior Cervical Corpectomy with Cage Fusion - a Retrospective Comparison of PEEK vs. Titanium Cages].

Anterior cervical corpectomy and fusion (ACCF) has become a standard procedure for patients with spondylotic myelopathy due to multisegmental stenosis of the cervical canal. Beside the fusion technique using autogenous bone grafts, synthetic cages have been increasingly used in recent years. Published information on the clinical and radiological results of different cage materials for ACCF is still limited. The study presented here is the largest series to date reporting clinical and radiological outcomes and complication rates after one- to three-level ACCF using structural polyetheretherketone (PEEK) or titanium cages augmented by anterior plate-screw osteosynthesis. Retrospective comparative study on 126 patients after cage ACCF using modular PEEK (n = 101) or distractable titanium (n = 25) cages with a minimum follow-up of 6 months. The numbers of hardware failures and implant-related surgical revisions were determined. The rate of subsidence and fusion and the course of lordotic alignment (segmental and regional Cobb's angles) were analysed. Neck Disability Index (NDI) and European Myelopathy Score (EMS) were assessed. Significantly greater number of screw and cage complications were detected in the titanium cage group (36 vs. 7.9 % and 64 vs. 36.6 %, respectively). Non-significant trend to a higher rate of implant related revision rate in the titanium cage group (16 vs. 2.97 %). Significantly greater rate of grade I or II fusion in the PEEK cage group after 6 months (82 vs. 52 %). NDI, EMS and lordotic alignment improved significantly in both groups. There were neither significant differences between the two groups nor significant correlations between these clinico-radiological parameters and the cage material. Partial correlations performed with control of parameters showing inhomogenous distribution (patient age, fusion distance, rate of multilevel corpectomy and the rate of intraoperative segmental overdistraction) showed no significant correlations for any of the clinical or radiological outcome parameters and the complications or revisions to the cage material. Cages are a safe and effective alternative to autogenous bone graft for ACCF. A significant improvement in clinical and radiological parameters can be achieved with both titanium and PEEK implants. Significant differences between the two cage material groups or significant correlations of clinico-radiological outcome and cage material were not proven. Moreover there is no evidence in the literature for clinical advantages of one special cage material, to date. Therefore further prospective randomised evaluation of different fusion techniques in ACCF is still necessary.