gms | German Medical Science

Objective: The implantation of a spacer is common practice after anterior discectomy in cervical spine. PEEK cages are in favour due to their better radiological behaviour in postoperative MRI-scans but earned a bad reputation due to their low fusion rates. The question is, does filling the cage with demineralized bone matrix (DBM) enhance the fusion rate?

Method: We report two consecutive groups of patients suffering from cervical radiculopathy or mild myelopathy treated with single level PEEK Cage fusion with their 1- or 2-year follow-up completed. The implantation was performed in 68 cases with demineralized bone matrix (DBM) in the central hole of the cage and in 74 cases empty. At follow-up examination fusion was determined by either plain X-ray or CT scan in selected cases.

Results: After minimum follow-up of one year (mean 15 ± 4 month) in 46 cases of the DBM group (n=68) fusion occurred as bony bridging around the PEEK cage, in 17 cases the result was indifferent and 5 cases showed signs of non-union suspect of a pseudarthrosis. In the group with empty cages (n=74) 50 were fused, 20 indifferent and 4 were considered pseudarthrotic. There is no significant difference between the two groups (p=0.874 in Chi-square test).

Conclusions: The fusion rate of PEEK cages does not improve by adding demineralized bone matrix (DBM). The additional costs of DBM are not justified in monosegmental anterior cervical decompressive surgeries.