The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 16, 1990
Filed:
Jul. 17, 1989
Aaron A Hofmann, Salt Lake City, UT (US);
Joseph S Skraba, Austin, TX (US);
Intermedics Orthopedics, Inc., Austin, TX (US);
Abstract
A surgeon-assemblable asymmetric tibial prosthesis with a snap-in tibial insert for surface replacement of the proximal tibia. The tibial prosthesis, consisting of two parts, a baseplate and a right or left knee specific insert, is used in conjunction with prosthetic femoral and patellar components. Asymmetry is created by having the radius which describes the medial condyle slightly greater, preferably 1/8', than the radius describing the lateral surface. The baseplate exhibits symmetry about an anterior/posterior centerline, allowing it to be used on right or left proximal tibias by rotation of the component 180.degree. about the centerline. The insert is contoured to provide an anatomically correct surface which articulates with the condyles of the femoral prosthesis. The anatomic fit contributes to normal range of motion since there is less chance of lateral overhang to cause soft tissue impingement. The increased cortical rim contact permits direct load transfer to the stronger cortical bone. In the preferred embodiment, two fully threaded bond screws secure the baseplate to the tibial bone surface and four pegs project from the inferior baseplate surface into the areas of the strongest tibial cancellous bone to provide torsional stability and reduce shear stress at fixation interfaces.