Orthopedic instrument, system and method for implanting an acetabular cup
An orthopedic instrument for installing a new reverse hip prosthesis, particularly the acetabular cup thereof, wherein the cup can be affixed to the pelvis with or without screws. The acetabular cup is releasably attached to the instrument and the instrument is used to position the cup in the pelvis. Optional screw guides are provided in the instrument in case the surgeon wishes to use screws to affix the cup to the pelvis.
1. An orthopedic instrument for implanting an acetabular cup having a surface for attachment to an acetabular socket in a pelvic bone and a concave surface having an acetabular cup stem affixed therein and projecting outwardly therefrom, the concave surface further comprising a circumferential groove located in proximity to a circumferential edge of the acetabular cup, the orthopedic instrument comprising
a handle comprising a shaft having an impactor head at a proximal end and an axially disposed first threaded annular portion at a distal end,
an acetabular impactor having a hemispherical head at a distal end and an axially disposed second threaded annular portion at a proximal end, the second threaded annular portion being screwed into the first threaded annular portion removably affixing the handle to the acetabular impactor,
the hemispherical head being configured to couple to the acetabular cup, the hemispherical head comprising an annular recess to receive the acetabular cup stem and retaining tabs configured to releasably engage the circumferential groove.
2. The orthopedic instrument of claim 1 , the acetabular cup further comprising at least one screw hole to accommodate a screw for attaching the acetabular cup to the pelvic bone, the acetabular impactor further comprising at least one channel configured as a drill guide.
3. The orthopedic instrument of claim 1 wherein the first threaded annular portion is internally threaded and the second threaded annular portion is externally threaded.
4. The orthopedic instrument of claim 1 wherein the first threded annular portion is externally threaded and the second threaded annular portion is internally threaded.
5. An orthopedic system for implanting an acetabular cup, the system comprising
an acetabular cup having a surface for attachment to an acetabular socket in a pelvic bone and a concave surface having an acetabular cup stem affixed therein and projecting outwardly therefrom, the concave surface further comprising a circumferential groove, said circumferential groove located in proximity to a circumferential edge of the acetabular cup, and
an orthopedic instrument comprising
a handle comprising a shaft having an impactor head at a proximal end and an axially disposed first threaded annular portion at a distal end,
an acetabular impactor having a hemispherical head at a distal end and an axially disposed second threaded annular portion at a proximal end, the second threaded annular portion being screwed into the first threaded annular portion removably affixing the handle to the acetabular impactor,
the hemispherical head being releasably coupled to the acetabular cup, the hemispherical head comprising an annular recess to receive the acetabular cup stem and retaining tabs configured to releasably engage the circumferential groove.
6. The orthopedic system of claim 5 , the acetabular cup further comprising at least one screw hole to accommodate a screw for attaching the acetabular cup to the pelvic bone, the acetabular impactor further comprising at least one channel configured as a drill guide.
7. A method of using an orthopedic instrument to implant an acetabular cup in a pelvic bone,
the acetabular cup having a surface for attachment to an acetabular socket in a pelvic bone and a concave surface having an acetabular cup stem affixed therein and projecting outwardly therefrom, the concave surface further comprising a circumferential groove, said circumferential groove located in proximity to a circumferential edge of the acetabular cup, and
the orthopedic instrument comprising
a handle comprising a shaft having an impactor head at a proximal end and an axially disposed first threaded annular portion at a distal end,
an acetabular impactor having a hemispherical head at a distal end and an axially disposed second threaded annular portion at a proximal end, the second threaded annular portion being screwed into the first threaded annular portion removably affixing the handle to the acetabular impactor,
the hemispherical head being configured to couple to the acetabular cup, the hemispherical head comprising an annular recess to receive the acetabular cup stem and retaining tabs configured to releasably engage the circumferential groove,
the method comprising releasably engaging the acetabular cup with the orthopedic instrument,
positioning the acetabular cup in the acetabular socket,
impacting the impactor head to affix the acetabular cup in the acetabular socket, and
releasing the orthopedic instrument from the acetabular cup.
8. A method of using an orthopedic instrument to implant an acetabular cup in a pelvic bone,
the acetabular cup having a surface for attachment to an acetabular socket in a pelvic bone, a concave surface having an acetabular cup stem affixed therein and projecting outwardly therefrom and at least one screw hole to accommodate a screw for attaching the acetabular cup to the pelvic bone, the concave surface further comprising a circumferential groove, said circumferential groove located in proximity to a circumferential edge of the acetabular cup, and
the orthopedic instrument comprising
a handle comprising a shaft having an impactor head at a proximal end and an axially disposed first threaded annular portion at a distal end,
an acetabular impactor having a hemispherical head at a distal end, an axially disposed second threaded annular portion at a proximal end and at least one channel configured as a drill guide, the second threaded annular portion being screwed into the first threaded annular portion removably affixing the handle to the acetabular impactor,
the hemispherical head being configured to couple to the acetabular cup, the hemispherical head comprising an annular recess to receive the acetabular cup stem and retaining tabs configured to releasably engage the circumferential groove,
the method comprising releasably engaging the acetabular cup with the orthopedic instrument,
positioning the acetabular cup in the acetabular socket,
impacting the impactor head to set the acetabular cup in the acetabular socket,
unscrewing the handle from the acetabular impactor,
drilling a screw hole in the pelvic bone using at least one channel configured as a drill guide,
passing a screw into the channel and threading the screw into the screw hole, and
releasing the orthopedic instrument from the acetabular cup.