Transarticular Fixation with a Bioabsorptive Screw for Cervical Spondylolisthesis

Abstract

Patients with cervical instability and intramedullary signal intensity changes on preoperative magnetic resonance imaging scans may benefit from not only cervical decompression but also from fusion surgery. Transarticular screw (TAS) fixation is a useful technique for posterior fixation. We first report treating a patient with cervical spondylosis and instability by cervical laminoplasty with TAS fixation using a bioabsorptive screw. A 66-year-old woman who had undergone surgery for carcinoma of the tongue via the anterior approach experienced cervical myelopathy. Radiologic findings showed severe cervical canal stenosis with myelomalacia and spondylolisthesis at C4/C5 with instability. We performed laminoplasty of C3 to C7 and TAS fixation of C4/C5 using a bioabsorptive poly-L-lactide screw that contained hydroxyapatite. Her postoperative course was uneventful, and at 1 year after treatment we confirmed C4/C5 fusion. Our method has advantages over metal instrumentation. The treated area can be evaluated with the use of magnetic resonance imaging, and the space left after screw absorption is filled by newly formed bone. Because our screw contains hydroxyapatite, it is osteoconductive. This may increase the fusion rate and induce substitution with new bone. To our knowledge this is the first patient treated by cervical posterior TAS fixation via the use of a bioabsorptive screw. Our method is safe and economical and free of the complications elicited by the use of metal parts. TAS fixation with a bioabsorptive screw may be appropriate for one fixation in patients without severe instability.