Implantation of an empty polyetheretherketone cage in anterior cervical discectomy and fusion: a prospective randomised controlled study with 2 years follow-up.

PURPOSE: To compare the clinical outcomes, radiographic results and fusion rate of ACDF between empty PEEK cages and PEEK cages packed with ß-tricalcium phosphate. METHODS: Forty-five patients were prospectively enrolled with cervical degenerative disc disease who requiring ACDF with a PEEK cage. 23 patients were randomised to the study group (empty cages) and 22 patients were in the control group (cages filled with ß-tricalcium phosphate). Both patient groups were fixed with a cervical locking plate. A CT scan was performed 12 months postoperatively and 24 months if not confirmed fused at 12 months to evaluate the status of fusion. Clinical status was evaluated using the Japanese Orthopaedic Association (JOA) score, the Oswestry Disability Index (ODI) and the Visual Analogue Scale (VAS). RESULTS: 46 levels (97.88%) in the study group and 44 levels (97.77%) in the control group were confirmed as fused at 24 months. There was no significant difference between the fusion rates observed in the study and control groups (p = 0.82). There was no significant difference in JOA, ODI, or VAS scores at 24 months follow-up. The results showed that the members of the non-fusion group tended to be older than the individuals in the fusion group at 12 months, but was not significant in statistics. CONCLUSIONS: Similar fusion rates and clinical outcomes were achieved when using ACDF with PEEK cages and instrumentation, regardless of whether the cage was filled with bone substitute at 24 months follow-up. Fusion rates improved over time and are comparable between both groups. These slides can be retrieved under Electronic Supplementary material.

Atypical mycobacterial spondylitis as a challenging differential diagnosis to metastatic disease of the spine: a case report.

Disseminated Mycobacterium avium complex (MAC) infection is rarely seen in patients without acquired immune deficiency syndrome. A disseminated MAC infection presenting with symptoms that mimic tumor metastasis had not previously been reported. Few disseminated MAC infections have been reported, and all image patterns in these cases indicated destructive lesions. We present a case involving a tumor-like disseminated MAC infection with spondylitis in a 68-year-old man whose symptoms started with severe lower back pain and fever. Treatment for malignancy was performed initially but soon stopped after tissue proving MAC infection. Symptoms then improved dramatically after a four-drug combined anti-nontuberculous mycobacteria treatment.

Are intravertebral vacuum phenomena benign lesions?

We retrospectively reviewed plain radiographs from patients with four different diseases that can cause vertebral collapse: osteoporotic vertebral collapse, spinal infection, spinal metastasis, and multiple myeloma. The objective of the study was to find the percentages of intravertebral vacuum phenomena and vertebral collapse rates in the four groups. The vacuum phenomenon is often observed in osteoporotic compression fractures. However, these phenomena are rarely seen in spinal infection and malignant lesions. Whether the vacuum phenomenon is a benign indicator is not known. We retrospectively reviewed plain radiographs from four groups of patients, including 328 osteoporotic vertebral collapse patients, 317 spinal infection patients, 302 spinal metastasis patients, and 325 multiple myeloma patients. The pattern and occurrence rates of intravertebral vacuum phenomena and vertebral body collapse were analyzed. The occurrence rate of intravertebral vacuum phenomena in patients with osteoporotic vertebral collapse was approximately 18.9%. Only one case of intravertebral vacuum phenomena was observed in patients with spinal infection. Vacuum phenomena were not observed in patients with spinal metastasis. The occurrence rate of intravertebral vacuum phenomena in patients with multiple myeloma was 6.4%. The patterns of intravertebral vacuum phenomena were also analyzed. Intravertebral vacuum phenomena are common in patients with osteoporotic vertebral collapse. Most cases of intravertebral vacuum phenomena are of a benign nature. Moreover, intravertebral vacuum phenomena occur extremely rarely in patients with spinal infection. Such phenomena are also found in patients with multiple myeloma.

Progressive growth of arachnoid cysts with cauda equina syndrome after lumbar spine surgery.

Intradural arachnoid cysts are a rare cause of spinal cord compression. In symptomatic cases neuropathic pain, gait disturbance, and paraparesis or quadriparesis are often present. Postoperative arachnoid cysts have rarely been reported. We describe a 56-year-old male who developed progressively enlarging arachnoid cysts with cauda equina syndrome and vertebral body erosion after lumbar surgery. The clinical presentation of the patient, the possible mechanisms of cyst formation, and the management of the disease are discussed with regard to previous literature.