Intramedullary rod assembly for cement injection system
First Claim
1. An intramedullary rod assembly for fixation of abnormal bone such as fixation of impending pathological fracture as in bone areas involved with cancer, allografts fixation, augmentation of osteogenic skeleton, and the like, comprising an elongated hollow tubular rod member of medical grade metal of generally cylindrical form having an internal bore extending the length thereof from a distal end to a proximal end surrounded along its length by an outer wall, a threaded first coupling formation at the proximal end of the rod member to be coupled to a threaded coactive coupling formation of an insertion bar device for inserting the rod member into a recipient medullary canal and subsequently to a discharge tube of a cement injector gun device for injecting methylmethacrelate cement or the like into the bore of the rod member, the rod member having a plurality of sharp exterior protruding longitudinal edge formations along circumferentially spaced radial planes of the rod member spanning substantially the length thereof to extend into bone tissue and provide rotational stability for the rod, said outer wall having a plurality of axially and circumferentially spaced threaded apertures in the portions thereof intervening between said edge formations and threaded plug members removably mounted in said apertures for selective removal before inserting the rod member in recipient bone to leave certain of said apertures open for discharge of the cement into adjacent bone portions when the rod is fully implanted and the cement is injected into the bone of the rod member.
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Accused Products
Abstract
Apparatus and methods for intramedullary fixation of abnormal bone, such as a femur, wherein an axially elongated intramedullary rod is provided having outwardly projecting thin fins or elongated sharp edge formations at circumferentially spaced locations spanning substantially the length of the rod to provide rotational stability, and provided with a plurality of holes in each of the surface portions between pairs of the fins or edge formations, which are normally closed by screw plugs or plugged with methylmethacrelate plugs, but which may be removed selectively prior to rod insertion into the medullary canal to permit discharge of methylmethacrelate cement or the like into desired surrounding bone areas. A coupling formation such as a threaded coupling neck is provided at one end of the rod, to be assembled with a tube extending from a piston aided dispensing device similar to a caulking gun to force the low viscosity cement into the hollow interior bore of the rod and discharge through apertures where the plugs have been removed or holes are open in the rod.
527 Citations
23 Claims
- 1. An intramedullary rod assembly for fixation of abnormal bone such as fixation of impending pathological fracture as in bone areas involved with cancer, allografts fixation, augmentation of osteogenic skeleton, and the like, comprising an elongated hollow tubular rod member of medical grade metal of generally cylindrical form having an internal bore extending the length thereof from a distal end to a proximal end surrounded along its length by an outer wall, a threaded first coupling formation at the proximal end of the rod member to be coupled to a threaded coactive coupling formation of an insertion bar device for inserting the rod member into a recipient medullary canal and subsequently to a discharge tube of a cement injector gun device for injecting methylmethacrelate cement or the like into the bore of the rod member, the rod member having a plurality of sharp exterior protruding longitudinal edge formations along circumferentially spaced radial planes of the rod member spanning substantially the length thereof to extend into bone tissue and provide rotational stability for the rod, said outer wall having a plurality of axially and circumferentially spaced threaded apertures in the portions thereof intervening between said edge formations and threaded plug members removably mounted in said apertures for selective removal before inserting the rod member in recipient bone to leave certain of said apertures open for discharge of the cement into adjacent bone portions when the rod is fully implanted and the cement is injected into the bone of the rod member.
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23. A method for intramedullary rod fixation of abnormal bone such as fixation of impending pathological fracture as in bone areas involved with cancer, allograft fixation, augmentation of osteopenic skeleton, and the like, comprising the steps of forming an elongated insertion hole in a recipient medullary canal or the like of recipient bone, inserting an intramedullary rod therein having an elongated hollow tubular rod portion of medical grade metal of generally cylindrical form including an internal bore extending the length thereof from a distal end to a proximal end surrounded by an outer wall and having a threaded coupling formation at the proximal end of the rod member, the intramedullary rod also having a plurality of sharp exterior protruding rectalinear edge formations along circumferentially spaced radial planes of the like extending substantially the length thereof and having axially and circumferentially spaced threaded apertures in the intervening portions thereof between said rod formations normally closed by removable threaded plug members, removing plug members from selected ones of said threaded apertures prior to insertion of the rod member to leave open apertures at locations where it is desired to have methylmethacrelate cement or the like discharge from the bore of the rod member into adjacent bone tissue, coupling a cement injector gun device having a charge of cement and discharge assisted piston means to the coupling formation of the rod member, activating the discharge assisted piston means to force the methylmethcrelate cement or the like into the bore of the rod member for discharge outwardly thereof through the threaded apertures left open by removal of their associated plugs, and decoupling the cement injector gun device from the intramedullary rod.
Specification