Distraction apparatus
AssigneePrototech Company
InventorPer Helland
Life of this patent
Estimating the term…
Abstract
The invention relates to a distraction apparatus for holding a fracture during the healing process. The apparatus includes screws or pins for insertion into a bone at points proximal and distal relative to a fracture site, and a pair of springs which can be connected externally between the screws or pins at spaced positions thereon. The springs act as an extension spring and a compression spring respectively between the screws or pins. The invention is characterized in that the springs are connected at the spaced positions at such distances relative to the bone that the springs will exert moments of force in order to obtain a desired torque load at the fracture site.
Claims8
A distraction apparatus for holding a fracture during healing, including screws or pins (5-8) for insertion into a bone at points proximal and distal relative to a fracture site, and a pair of springs (3, 4) which can be connected between the screws or pins (5-8) at spaced positions thereon, which springs (3, 4) act as an extension spring and a compression spring respectively between the screws or pins (5-8),
- characterised in that the apparatus comprises a distal and a proximal frame element (2, 1) carrying the screws/pins (5-8),
- two adjustable coil springs (3, 4),
- each frame element (2, 1) having fixed receiving members for the ends of coil springs (3, 4),
- said coil springs (3, 4) being received in and coupled to the receiving members and thereby to the-frame elements (2, 1),
- the coil spring (4) closer to the bone when the apparatus is in use being the compression spring and being inclined relative to the bone and the other spring (3) in such a way that the compression spring (4) will have a greater distance from the bone proximally than distally, measured along the screws/pins (5-8), whereby aligning moments are created in the bone fracture.
Dependencies are inferred from the claim text.