No correlation between radiological and clinical outcome 1 year following cervical arthrodesis

Aim: To correlate clinical and radiological outcome following one- and two-level anterior cervical discectomy and fusion (ACDF) with stand-alone polyetheretherketone (PEEK) cages filled with demineralized bone matrix (DBM). Methods: We performed a retrospective review of a consecutive patient cohort with degenerative disc disease that underwent ACDF with stand-alone PEEK cages filled with demineralized bone matrix (DBM) between 2010 and 2013 with a minimum follow-up of 12 months. Changes in the operated segments were measured and compared to radiographs directly after surgery. Clinical outcome was evaluated by a physical examination, pain by visual analog scale (VAS) for arm and neck. Health-related quality of life was measured using the EuroQOL questionnaire (EQ-5D). Results: Of 282 consecutive cases, follow-up data were obtained from 194 (69%) cases. The median age at presentation was 54 years and 91 patients were male (46%). Ninety-eight and 96 patients had one- and two-level surgeries, respectively. Mean VAS pain was reduced from 5.2 ± 3.6 to 2.6 ± 2.4 (p < 0.001) and from 5.8 ± 3.3 to 2.1 ± 2.7 (p < 0.001) in the myelopathy and radiculopathy group, respectively. Fusion was achieved in 79 and 82% of segments in one- and two-level surgeries, respectively. Cervical alignment was better in 10 and 1%, similar in 68 and 76%, worse in 23 and 23% in one- and two-level surgeries, respectively. Subsidence was observed in 44 and 34% of segments in one- and two-level surgeries, respectively. Follow-up operations due to symptomatic adjacent disc disease or implant failure were needed in 13 (7%) and 15 (8%) of cases, respectively. Subsidence, adjacent disc disease, and cervical alignment all had no influence on the clinical outcome. Conclusions: The clinical outcome after ACDF with PEEK cages filled with demineralized bone matrix is highly satisfactory. Radiological signs of non-fusion, subsidence, and cervical alignment have no influence on clinical outcome.