Double D key locking prosthesis
AssigneeHammill Manuf. Co.
InventorsRobert L. Doubler, John E. Hammill
Life of this patent
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Abstract
A modular prosthesis has an intramedullary rod element which is to be inserted in a bone. The rod has a shaped proximal portion which is telescoped into one end of a bore in the trochanter element. The mating surfaces of the shaped rod and the trochanter bore form a rotationally immovable connection. A neck element is telescoped into the other end of the trochanter bore. The neck and the trochanter have mating surfaces with mating recesses. A key lock element is inserted into the mating recesses to prevent rotational movement between the neck and the trochanter. All the elements are secured together by a bolt through the neck, trochanter and rod.
Claims10
A modular prosthesis to be used in hip replacement comprising:
- an intramedullary rod having a distal end adapted for insertion into the intramedullary canal of the femur and a tapered proximal end, said tapered proximal end having a smaller circumference than said distal end, said tapered proximal end having the smallest circumference at said proximal end, said proximal end having a screw threaded blind bore along a longitudinal axis of said intramedullary rod,
- a trochanter having a narrow distal end and a larger proximal end with a shaped through bore from said distal end to said proximal end, said circumference of said trochanter bore and said circumference of said proximal end of said intramedullary rod adapted to telescope together forming a rotationally secure connection, said larger proximal end of said trochanter having a recess,
- a neck having an extension on the distal end adapted to be inserted into the proximal end of said through bore of said trochanter, said distal end of said neck having a planar surface including a blind bore, said extension on said distal end of said neck and said proximal end of said through bore in said trochanter adapted to telescope together to form a rotationally adjustable connection,
- a key lock adapted to be inserted in said recess in said trochanter and said blind bore in said neck to fix said rotationally adjustable connection, said neck having a through bore, said proximal end of said through bore having a countersunk bore, said distal end of said through bore formed as said extension and adapted to telescope over the proximal end of said intramedullary rod, and
- a screw threaded bolt adapted to be disposed in said countersunk bore and threadably engaged with said screw threads in said proximal end of said intramedullary rod forming a locked integral prosthesis.
A modular hip prosthesis kit comprising a plurality of different sized intramedullary rods, trochanters, necks, various angled key locks, and bolts, said plurality of intramedullary rods, trochanters, necks, various angled key locks and bolts being adapted for interchangeable assembly to form a particular hip prosthesis with specific characteristics, said specific characteristics including a longitudinal axis and an anteversion angle, said angle fixed by selection of one of said various angled key locks, said one of said various angled key locks adapted to secure one of said plurality of trochanters with one of said plurality of necks in a specific horizontal angle.
Dependencies are inferred from the claim text.