Usefulness of titanium mesh cage for posterior C1-C2 fixation in patients with atlantoaxial instability.

The aim of this study was to investigate the usefulness of titanium mesh cage as an interlaminar spacer combined with nitinol shape memory loop fixation in patients with atlantoaxial instability.From April 2009 to March 2017, among the patients with atlantoaxial instability, a total of 30 patients were treated by nitinol shape memory loop fixation combined with titanium mesh cage as a spacer. We retrospectively reviewed 30 enrolled patients. Successful fusion was determined as improvement of symptoms and radiologic findings of bone fusion. We also reviewed surgical complications, instrumentation failure, bony fusion rate, and posterior atlantodental interval (PADI).After surgery, the symptoms of all patients significantly improved. Successful fusion was documented throughout the follow-up period. Evidence of solid bridging bone was found, and no instability was seen on flexion-extension radiographs and callus formation on 3D cervical spine computed tomography (CT) 6 months postoperatively in all cases. No surgical complications were observed. No cases of instrumentation failure were observed. The mean PADI also improved significantly to 22.45 ±â€Š1.11 mm 6 months postoperatively compared with the preoperative value of 18.37 ±â€Š1.16 mm (P < .05).We obtained a good fusion rate by using titanium mesh cage spacer with nitinol shape memory alloy loop in patients with atlantoaxial instability. This technique can help surgeons in avoiding vertebral artery injury and reducing bleeding and operation time. Therefore, we suggest that titanium mesh cage spacer combined with nitinol shape memory alloy loop can be a good substitute of autograft for C1-C2 fusion in treating atlantoaxial instabilities.

Cervical Intradural Disc Herniation Causing Progressive Quadriparesis After Spinal Manipulation Therapy: A Case Report and Literature Review.

Cervical intradural disc herniation (IDH) is an extremely rare condition, comprising only 0.27% of all disc herniations. Three percent of IDHs occur in the cervical, 5% in the thoracic, and over 92% in the lumbar spinal canal. There have been a total of 31 cervical IDHs reported in the literature. The pathogenesis and imaging characteristics of IDH are not fully understood. A preoperative diagnosis is key to facilitating prompt intradural exploration in patients with ambivalent findings, as well as in preventing reoperation. The purpose of reporting our case is to remind clinicians to consider the possibility of cervical IDH during spinal manipulation therapy in patient with chronic neck pain.The patient signed informed consent for publication of this case report and any accompanying image. The ethical approval of this study was waived by the ethics committee of Chonbuk National University Hospital, because this study was case report and the number of patients was <3.A 32-year-old man was transferred our emergency department with progressive quadriparesis. He had no history of trauma, but had received physical therapy with spinal manipulation for chronic neck pain over the course of a month. The day prior, he had noticed neck pain and tingling in the bilateral upper and lower extremities during the manipulation procedure. The following day, he presented with bilateral weakness of all 4 extremities, which rendered him unable to walk. Neurological examination demonstrated a positive Hoffmann sign and ankle clonus bilaterally, hypoesthesia below the C5 dermatome, 3/5 strength in the bilateral upper extremities, and 2/5 strength in the lower extremities. This motor weakness was progressive, and he further complained of voiding difficulty.Urgent magnetic resonance imaging (MRI) of the cervical spine revealed large, central disc herniations at C4-C5 and C5-C6 that caused severe spinal cord compression and surrounding edema. We performed C4-C5-C6 anterior cervical discectomy and fusion.The patient's limb weakness improved rapidly within 1 day postoperatively, and he was discharged 4 weeks later. At his 12-month follow-up, the patient had recovered nearly full muscle power.We presented an extremely rare case of cervical IDH causing progressive quadriparesis after excessive spinal manipulation therapy. The presence of a "halo" and "Y-sign" were useful MRI markers for cervical IDH in this case.