gms | German Medical Science

Objective: This is a prospective, randomized and controlled study, approved by the local ethical committee of Saarland (Germany), N° 209/06.

Anterior cervical discectomy and fusion including plate fixation is an accepted technique for treatment of symptomatic degenerative disc disease. Plate fixation has been introduced to improve stability, reduce pseudarthosis rate and improve clinical result. To date Titanium is the material of choice for plate creation because of its stability and biocompatibility. However, there are some disadvantages as stress shielding, screw dislocation and imaging artefact. Bioresorbable plates were developed and thought to solve this problem. We have already introduced the compatibility of one-level ACDF with bioresorable plates.

The aim of this current study was to compare clinical results, segmental motility and MRI compatibility of a cervical spine segments that were treated either with bioresorbable or with titanium plates in two level ACDF.

Methods: 20 Patients with two level cervical radiculopathy and/or myelopathy scheduled for surgery were randomized to anterior discectomy and fusion (ACDF) with bisegmental bioresorbable plates (10 patients, study group) or bisegmental titanium plates (10 patients, control group). Radiostereometric Analysis (RSA) was performed immediately postoperative, after 6 and 12 months. Functional x-ray was done after 6 and 12 months postoperatively. MRI of the cervical spine was done immediately postoperative and after 12 months to assess postoperative changes, as effusion, haematoma and swelling. Follow-up examinations were done using the Visual Analogue Scale (VAS) with regard to arm pain and Neck Disability Index (NDI).

Results: Three-dimensional analysis of segmental motion (left-right, cranio-caudal, and posterior-anterior) did not reveal any statistical difference between both groups at any examination time postoperatively (p>0.05). Fusion rate and speed evaluated on RSA of the operated cervical spine segments were similar in both groups. MRI of cervical spine did not show any pathology, especially haematoma or infection. The VAS and NDI did not differ between both groups after 6 months (p>0.05).

One patient of the bioresorbable group showed loss of lordosis of the cervical spine.

Conclusions: Anterior plate fixation using a bisegmental bioresorbable plate has the same fusion progress and stability as when using a titanium plate-screw system. During the study no complications, like soft tissue inflammation, swelling, or infection were seen.