Modular humeral prosthesis for reconstruction of the humerus

Abstract

The invention is directed to a modular humeral prosthesis for implantation into a humerus of a patient. The prosthesis includes a proximal humeral component having a platform disposed on an upper end. A tapered projection is disposed on the platform. A cup-shaped fracture cap having a tapered opening with generally the same shape as the tapered projection is removably disposable on the tapered projection. The fracture cap is shaped so as to allow for space between the cap and the glenoid of a patient into whom the prosthesis is to be implanted and thereby allow the bones of the patient's humeral head to be reconstructed by reassembling and securing the bone fragments about the fracture cap. The prosthesis further includes a humeral head having a tapered opening which may be disposed on the proximal humeral component. The humeral head is interchangeable with the fracture cap. The prosthetic humeral head may be inserted into the patient's glenoid to replace the patient's natural humeral head in fracture cases where the natural humeral head is not viable, in arthritis cases where cartilage is degenerated, or where head fracture reconstruction is attempted but fails. The fracture cap and humeral head are both modular so as to allow caps and heads of differing sizes to be disposed on the proximal humeral component. The prosthesis also includes a modular distal stem extension which may be secured and locked on the distal end of the proximal humeral component. The distal stem extension allows the overall length of the prosthesis to be selectively increased, thereby allowing the prosthesis to be fitted to patient's having humeral shafts of differing sizes.