Consecutive case series and literature review. To describe the utility of 3-dimensional computed tomographic angiography (3D CTA) for evaluating vertebral artery (VA) anomalies before surgery. Recent advances in instrumentation surgery at the craniovertebral junction (CVJ) enable us to perform rigid internal fixation. However, the risk of VA injury as a complication of the surgery has become a major problem. Thus, the importance of preoperative evaluation of the VA course has been emphasized. Cases of 100 consecutive patients who underwent CVJ instrumentation surgery since July 1998 were analyzed. Occipitocervical/thoracic or C1-C2 posterior fusion was performed for atlantoaxial subluxation (AAS) in 59 patients and cervical fixation including C2 was required for middle-to-lower cervical lesions in 41 patients. Twenty-seven patients with AAS had a congenital skeletal anomaly (CSA) at the CVJ including os odontoideum and occipitalization of C1 (AAS-CSA[+] group). Anomalous VAs at the extra- and intraosseous regions were evaluated by 3D CTA. No neurovascular injury occurred during surgery. Abnormal courses of the VA at the extraosseous region were detected in 10 cases: 2 had fenestration and 8 had a persistent first intersegmental artery. All 10 cases were in the AAS-CSA(+) group. A high-riding VA was detected in 31 cases. Fourteen out of the 31 cases were in the AAS-CSA(+) group, indicating 51.9% of the AAS-CSA(+) group had high-riding VA. In the AAS-CSA(+) group, a C1-C2 transarticular screw and C2 pedicle screw were actually inserted in 58% and 31% of the planned insertions, respectively. The present findings suggest that the frequency of an abnormal VA at the extra- and intraosseous regions is increased when patients have AAS and CSA at the CVJ. Using preoperative 3D CTA, we can precisely identify anomalous VAs and thereby reduce the risk of their intraoperative injury.

This retrospective study was conducted to investigate the clinical outcomes of several surgical procedures for thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL). To evaluate the effect of myelopathy treatment and safety of posterior decompression with instrumented fusion. Many different surgical procedures have been used for the treatment of thoracic OPLL. However, the possibility of postoperative paraplegia remains a major risk, and consistent protocols and procedures for surgical treatment of thoracic OPLL have also not been established. A total of 51 patients who underwent surgery for thoracic OPLL were classified into 3 groups: (1) posterior decompression group (18 patients), which included 12 who underwent laminectomy and 6 who underwent cervicothoracic laminoplasty; (2) OPLL extirpation group (16 patients), which included 4 who underwent anterior decompression through thoracotomy and 12 who underwent anterior decompression through the posterior approach; and (3) posterior decompression and fusion group (17 patients), all of whom underwent laminectomy with posterior instrumented fusion. In each group, the Japanese Orthopedic Association score was used to evaluate thoracic myelopathy, and the recovery rate calculated 1 year after surgery and at final examination. Mean recovery rate at final follow-up was 41.9% in the posterior decompression group, 62.1% in the OPLL extirpation group, and 59.3% in the posterior decompression and fusion group. Postoperative paralysis occurred in 3 patients in the posterior decompression group and in 3 in the OPLL extirpation group. In the OPLL extirpation group, leakage of cerebrospinal fluid occurred in 8 patients and hydrothorax in 2. Late neurologic deterioration occurred in 7 patients in the posterior decompression group. There were no cases of postoperative paralysis or late neurologic deterioration in the posterior decompression and fusion group. A considerable degree of neurologic recovery was obtained by posterior decompression with instrumented fusion, despite the anterior impingement of the spinal cord by OPLL remaining. In addition, the rate of postoperative complications was extremely low with this procedure. We recommend that 1-stage posterior decompression and instrumented fusion be selected for patients in whom the spinal cord is severely damaged before surgery and/or when extirpation of OPLL is associated with increased risk.

The aim of this study was to evaluate whether transplantation of Schwann cells derived from bone marrow stromal cells (BMSC-SCs) promotes axonal regeneration and functional recovery in completely transected spinal cord in adult rats. Bone marrow stromal cells (BMSCs) were induced to differentiate into Schwann cells in vitro. A 4-mm segment of rat spinal cord was removed completely at the T7 level. An ultra-filtration membrane tube, filled with a mixture of Matrigel (MG) and BMSC-SCs (BMSC-SC group) or Matrigel alone (MG group), was grafted into the gap. In the BMSC-SC group, the number of neurofilament- and tyrosine hydroxylase-immunoreactive nerve fibers was significantly higher compared to the MG group, although 5-hydroxytryptamine- or calcitonin gene-related peptide-immunoreactive fibers were rarely detectable in both groups. In the BMSC-SC group, significant recovery of the hindlimb function was recognized, which was abolished by retransection of the graft 6 weeks after transplantation. These results demonstrate that transplantation of BMSC-SCs promotes axonal regeneration of lesioned spinal cord, resulting in recovery of hindlimb function in rats. Transplantation of BMSC-SCs is a potentially useful treatment for spinal cord injury.

Granulocyte colony-stimulating factor (G-CSF) is a protein that stimulates differentiation, proliferation, and survival of granulocytic lineage cells

Loosening of screws is a common problem in orthopedic and maxillofacial surgery. Modifying the implant surface to improve the mechanical strength of screws has been tried and reported. We developed screws coated with fibroblast growth factor-2 (FGF-2)−apatite composite layers. We then showed, in a percutaneous external fixation model, that this composite layer had the ability to hold and release FGF-2 slowly, thereby reducing the risk of pin tract infection of the percutaneous external fixation. The objective of the current study was to clarify the effect of FGF-2−apatite composite layers on titanium screws on bone formation around the screw. We analyzed samples of previously performed animal experiments. The screws were coated with FGF-2−apatite composite layers by immersing them in supersaturated calcium phosphate solutions containing FGF-2. Then, the uncoated, apatite-coated, and FGF-2−apatite composite layer-coated screws were implanted percutaneously in rabbits. Finally, using inflammation-free histological sections, we histomorphometrically assessed them for the presence of bone formation. Weibull plot analysis was then applied to the data. On average, screws coated with FGF-2−apatite composite layers showed a significantly higher bone apposition rate than the uncoated or apatite-coated screws. Although the difference in the average bone apposition rate was small, the FGF-2−apatite composite layers produced a significant, marked reduction in the incidence of impaired bone formation around the screw compared with the incidence in the absence of FGF-2 (uncoated and apatite-coated screws). The probability of resulting in a bone apposition rate equal to or less than 63.75%, for example, is 3.5 × 10-4 for screws coated with the FGF-2−apatite composite layers versus 0.05 for screws in the absence of FGF-2. FGF-2-apatite composite layer coating significantly reduced the risk of impaired bone apposition to the screw. Thus, it is feasible to use titanium screws coated with FGF-2−apatite composite layers as internal fixation screws to decrease the risk of loosening.