Atlantoaxial Stabilization Using C1 and C2 Laminar Screw Fixation

We describe the use of a C1 laminar screw in combination with a C2 laminar screw as a salvage technique to treat two patients, one with persistent first intersegmental artery and the other with vertebral artery occlusion after cervical spine fracture. The combined use of C1 and C2 laminar screws allows for good fixation of the atlantoaxial joint with a lower risk of vertebral artery injury; therefore, it can be an alternative surgical procedure for patients with congenital or traumatic anomalous vertebral artery

Curettage and external fixation for displaced pathological fracture through non-ossifying fibroma in the radius: A case report

Non-ossifying fibromas are extremely rare in the upper extremity, such as those in the radius and humerus. The treatment of completely displaced fractures following non-ossifying fibromas in the radius has not been reported. We present the case of a pathological fracture caused by a non-ossifying fibroma in the radius treated using external fixation. The patient was a 10-year-old girl who presented to our hospital with right forearm pain after an accidental fall. She had no remarkable medical history. Radiographs and computed tomography showed a pathological fracture through osteolytic lesions with sclerotic rims in the diaphysis of the radius, suggesting a pathological fracture through a non-ossifying fibroma in the radius. We performed tumor curettage and external fixation due to marked fracture displacement. Histological findings were compatible with those of non-ossifying fibroma. Six months post-surgery, there were no limitations in the range of motion of supination and pronation of the forearm, and radiographs confirmed a bone union. Although non-ossifying fibromas in the radius are rare, cases with large lesions can cause pathological fractures after minor trauma. This case suggests that curettage and external fixation are beneficial, especially if early surgery is required due to unacceptable displacement and when there is no time for a biopsy to rule out malignancy

Regeneration across a partial defect in rat sciatic nerve encased in a silicone chamber

Forty-four rat sciatic nerves with partial defects were repaired with a silicone chamber. Each partial defect was created by resecting a 10 mm segment from the tibial fascicle leaving the peroneal fascicle intact. The proximal and the distal stumps of the tibial fascicle together with the intact peroneal fascicle were encased in a single silicone chamber. After seven days a fibrin matrix had surrounded the peroneal fascicle and spanned the defect between the tibial stumps. This matrix was later invaded by non-neuronal cells and regenerating axons. Non-myelinated nerve fibres had almost regenerated across the defect by 16 days. The tetanic force of the gastrocnemius muscle 120 days after repair showed 80% recovery, which was no different from that of partial defects repaired with conventional nerve grafts. The results suggest that the silicone chamber technique could be applicable to the treatment of partially transected nerve trunks

Effects of gradual bone lengthening on the rabbit tibial nerve

Little is known about the effect of gradual bone lengthening on peripheral nerves. In the present study, an external fixation device was applied to the rabbit tibia, which was then divided. After seven days, the tibia was subjected to 0.7 mm/day callus distraction for periods of up to one month. The tibial nerve was fixed in glutaraldehyde and plastic sections were cut in longitudinal and transverse planes for light and electron microscopy. Light microscopy showed a 64% increase in the gap length at the node of Ranvier in myelinated axons from the experimental side compared with the control side. The cross-sectional area of the non-myelinated axons was not altered significantly. We conclude that gradual stretching of the nerve elongates the nerve fibres at least at the region of the nodes, perhaps a point of least resistance. Diameters of fibres seem to be held more constant during the lengthening procedure