| 摘要 |
The invention relates to an instrument designed for the preparation of the thoracic region liable to receive a thoracic vertebra pedicle hook, which instrument is composed of the handle 1, a first metal stem 2 ending at a hook foot 3 adaptable to the lower rim of the thoracic vertebra pedicle, a second stem 4 adequately jointed with the first at two points (at the centre, in proximity to the handles and at the bottom, in proximity to the cutting surface). The central portion of the second stem comprises a handle 5 which is smaller and thinner than the handle of the first steam and ends at a special -shaped cutting surface 6 which, due to the special construction of the joints, is liable to move so that: a) it reduces the handle's path required for the opening of the instrument; b) it acquires force for a given path of the handle and c) it avoids the formation of voluminous construction at the centre (at the region of handles). The two handles are mutually spaced apart due to the special return spring adapted to the smaller handle 8. Owning to the proper position of the joints, the cutting surface of the instrument is set at the opened position when the handles are spaced apart and vice versa. The advantage of the invention is that it safely, accurately and rapidly prepares the region whereto the thoracic vertebra pedicle hook will be adapted for retaining on the prepared region the spine in an absolute steady manner. |
