Five-year outcome of stand-alone fusion using carbon cages in cervical disc arthrosis

From January 1, 2001 to December 31, 2003, in the Neurosurgery Department of Rome University o "Sapienza," 167 patients underwent anterior surgery for cervical spondylodiscoarthrosis. The levels treated by the anterior stand-alone technique were: C3-C4 (11%), C4-C5 (19%), C5-C6 (40%), and C6-C7 (30%). All patients underwent left anterior presternocleidomastoid-precarotid approach, microdiscectomy, and interbody fusion using a carbon fiber cage filled with hydroxyapatite. All patients were discharged within 48 h after surgery with cervical orthosis. In one case, a hematoma of the surgical site occurred within 12 h of surgery; for this reason the patient underwent surgical revision and was discharged 4 days later. All patients have worn cervical orthosis for a mean period of 7 weeks and underwent radiological follow-up with cervical RX at 1 and 3 months after surgery. All patients underwent follow-up from 54 to 90 months after surgery, and all of them underwent cervical RX, cervical CT scans for the estimate of fusion, and evaluation of neurological status using VAS and NDI. Of 167 patients, 132 were cooperative for this study, 18 were non-cooperative, and 17 died. The estimation of fusion made by cervical CT scans with sagittal reconstruction showed complete osteointegration of the cage in 115 patients (87.1%), while it showed pseudoarthrosis in 17 patients (12.9%). In 24 patients, we observed adjacent segment degeneration, and 13 of these underwent new surgical procedures in this institute or in another hospital. Clinical evaluation with VAS and NDI showed a good outcome, with poorest benefit in patients over 60 years. The clinical analysis showed a good fusion rate in according with literature, 13% of non-fusion rate without clinical evidence and 20% of ASDegeneration but only 10% had required new surgery. We also observed that patients over 60 years of age had less satisfactory outcome, probably related with the evolution of pathophysiological degeneration of the cervical spine. In the opinion, pseudoarthrosis is caused by malpositioning of the carbon fiber cage.