title: Transarticular fixation with a bioabsorptive screw for cervical spondylolisthesis.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors: Department of Neurosurgery, Chiba Hokuso Hospital, Nippon Medical School, Chiba, Japan. Electronic address: kyongson@nms.ac.jp.
authors: Kyongsong
authors: K
authors: Kim
authors: Department of Neurosurgery, Kushiro Rosai Hospital, Hokkaido, Japan.
authors: Toyohiko
authors: T
authors: Isu
authors: Department of Neurosurgery, Chiba Hokuso Hospital, Nippon Medical School, Chiba, Japan.
authors: Tomoko
authors: T
authors: Omura
authors: Department of Neurosurgery, Shin-Midori General Hospital, Kanagawa, Japan.
authors: Daijiro
authors: D
authors: Morimoto
authors: Department of Neurosurgery, Chiba Hokuso Hospital, Nippon Medical School, Chiba, Japan.
authors: Shiro
authors: S
authors: Kobayashi
authors: Department of Neurosurgery, Nippon Medical School, Tokyo, Japan.
authors: Akira
authors: A
authors: Teramoto
mesh_terms: D020341:Absorbable Implants; D000368:Aged; D001863:Bone Screws; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000601:surgery; D011859:Radiography; D013117:Spinal Cord Compression / Q000000981:diagnostic imaging / Q000601:surgery; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods*; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000601:surgery*
keywords: Bioabsorptive screw; Cervical; Cervical compression myelopathy; Laminoplasty; Posterior fixation