Fracture of the spinal vertebral is very common orthopedic problem especially for the elderly mainly because of a decreased bone mass and a change in bone structure which eventually make the bones become progressively porous, brittle and fragile. Bones weakened by osteoporosis or by malignant processes account for a large proportion of vertebral fractures. Most of such fractures, that can be fixed using an orthopedic tool, occur as a result of trauma and are due to the weakened structure of the bone through loss of bone calcium and associated alteration of bony support or through frank replacement of bony tissue by malignant cells.

A mechanical bone tamping device is an orthopedic tool which is used for osteoporotic repair. This orthopedic tool includes a pair of arms mounted on a spreading mechanism such as a screw jack. The mechanism in this orthopedic tool is introduced into a tiny hole in a vertebra through a cannula. The orthopedic tool is then operated to spread the arms apart, forming a cavity, which may be filled with cement to fortify the vertebra.
Present orthopedic tools designed to inject bone cement into the vertebra weakened by disease generally utilize two types of orthopedic tool processes. The first orthopedic tool process involves simply injecting liquid bone cement into the interstices of the bone under pressure. However, the problem with this orthopedic tool process is that it requires the bone cement to be in a relatively liquid state to allow it to fill the interstices of the bone. Because venous channels within the bone communicate with epidural veins in the spinal canal and with veins in the general vasculature, numerous complications have arisen from this orthopedic tool injection process whereby bone cement has inadvertently entered to the spinal canal causing paralysis from compressing the spinal cord or, alternately, cement has entered the general venous system, causing death by pulmonary embolism. Obviously, these consequences of injecting bone cement under pressure into the interstices or trabeculae of vertebral bodies using an orthopedic tool are unacceptable. A second and safer orthopedic tool method has been developed to strengthen osteoporotic or malignant vertebral fractures. This orthopedic tool process involves placing a balloon into the intervertebral body and inflating it so that a cavity is formed in the weakened bone. This cavity can then be filled with a more viscous form of bone cement using an orthopedic tool, thereby reducing the risk of embolism to the spinal canal or lungs as is seen with high pressure less viscous orthopedic tool injection. The problem with this orthopedic tool technique is that the balloons used to create the cavity within the bone frequently break when spicules of bone puncture them or because they expand along the path of least resistance forming an unusual or asymmetrical cavity which inhibits or compromises the ideal placement of the cement support for stabilization of the weakened vertebrae using an orthopedic tool. A more desirable orthopedic tool placement system is required to allow placement of bone cement in the exact position required by the treating surgeon and in a manner that acceptably lessens the risk of bone cement migration or embolism.
To achieve this greater safety and efficacy, a mechanical orthopedic tool for creating a cavity within the soft bone is used. This form of cavity creation using an orthopedic tool is much more controllable than with balloon inflation orthopedic tool process because it does not depend on the elastic properties of a balloon wall expanding along the path of least resistance to create a cavity, whereas the dimensions of a balloon created cavity are largely beyond the control of the surgeon and more or less dependent upon the extent of disruption of the architecture of the pathologic bone.
Compressing soft bone outward forms a cavity, much as one might form a cavity in moist snow by inserting a hand, fingers extended, and then closing it to form a fist. To produce the cavity by purely mechanical action using an orthopedic tool, a screw jack or other expanding mechanism is employed to compress or tamp the surrounding weakened bone. This orthopedic tool mechanism, when operated, forces the arms apart, thereby directly compressing or tamping the soft bone.
When a screw jack mechanism of an orthopedic tool is employed to form the cavity, the exact dimensions of the cavity as well as the placement of the cavity can be controlled by the orthopedic surgeon. The screw jack mechanism of an orthopedic tool affords a more direct, exquisitely controllable and safer means by which cavities can be formed for bone cement stabilization of vertebrae weakened or fractured by benign or malignant disease conditions.