First experiences with a distractible titanium implant in ventral cervical disc surgery: report on 30 consecutive cases.

A new titanium implant for ventral cervical fusion after microsurgical discectomy via a conventional antero-lateral approach is presented. The implant consists of a ventral fixation plate and a distractible disc space graft whose extension can be changed by adjusting a set screw. Additional fixation is achieved by four monocortical spongiosa screws. Thirty patients (14 men, mean age 46.5 years; 16 women, mean age 46.8 years), in whom the implant was used, were the subjects of this investigation. Twenty-eight patients suffered from monosegmental cervical disc herniations (C4/5: n = 3; C5/6: n = 14; C6/7: n = 12; C7/T1: n = 1) and two patients showed traumatic discoligamental instability (C5/6: n = 1, C6/7: n = 1). The postoperative follow-up was at least 12 months (range 12-26 months, average 16.6 months). All patients underwent a clinical control including functional X-rays 6-8 weeks and again 10-14 months after surgery. All had benefitted from the procedure and the clinical results were comparable to other ventral cervical fusion techniques. We observed neither overdistraction or dislocation of the implant nor loosening or breaking of the screws. The advantages of the implant are: simple handling, controlled distraction of the intervertebral space and avoidance of a "second operation" to obtain an iliac crest bone graft for fusion.