Spinal trauma, spondylolisthesis, spinal infections, tumors and tuberculosis need to be reconstructed posteriorly after resection
Optimized fracture design, the fracture groove is a 45°V-shaped structure, which will not reduce the strength of the nail arm and is easier to fracture after the operation. After the fracture, there is no tip at the fracture and will not irritate the soft tissue.
For poly-axial screws, the spherical ring is designed into a saddle shape, which can reduce deformation. The poly-axial screws and the central axis can be adjusted at 25 degrees, which is convenient for intraoperative adjustment. The diameter of the ball head of the poly-axial screw is increased, and the design of fine lines is added on the ball head to improve the friction.
The biggest improvement in design of M9-Ia is the screws body thread now is double-line variable pitch.
The root of the screw is a taper thread. From the starting point of the thread to the base, it is a tapered shape. From the starting point to the root, the inner diameter gradually increases. This makes the root strength of the pedicle screw stronger and avoids the screw break.
Compression nut thread negative angle design structure, the clearance fit accuracy is higher, the placement is safer and easier, and the risk of sliding teeth and spreading is also reduced.