Health Sciences · Robert W. Jackson Arthroscopy
Two artifacts are likely related:
2025.JAC.299.1 – A plasticized specimen of a femoral condyle of the knee, likely from a cadaver. This specimen shows two threaded inserts that have been cemented into cavities drilled in the condyle. These are likely meant as fixture points for an experimental femoral component of a partial knee implant.
2025.JAC.299.2 – A plastic (probably high density polyethylene) component that is likely an experimental femoral component of a partial knee implant. This has two holes in either end corresponding to the threaded inserts in 2025.JAC.299.1 one of these holes contains a threaded plastic fastener. The other fastener is missing.
Accession Number: 2025.JAC.299.1-2
Alternative Name:
Plastic (likely HDPE), Casting Resin, Bone
Markings:
2025.JAC.299.1: Height = 5.3, Width = 3, Length = 2; 2025.JAC.299.1: Height = 2.5, Width = 4.3 , Length = 6.
No information has yet been found about these items, but, from their context within the collection, they may represent early experimental efforts towards the development of a partial knee replacement that was undertaken at the University of Toronto and Toronto General Hospital.
2025.JAC.299.2 is likely an incomplete example of a femoral component of a partial knee implant that was meant to be affixed to the knee using threaded fasteners.
2025.JAC.299.1 may represent an effort to study the effectiveness of cementing anchor points into the bone.
Both items are in good cosmetic condition. 2025.JAC.299.1 is incomplete as it is missing one of its plastic fasteners.
Associated Instruments:
Unknown. The project likely took place at the University of Toronto and Toronto General Hospital. It is unclear whether these were created in collaboration with a medical manufacturer.
Date of Manufacture: c. early 1970s.
This and other items related to the development of a partial knee replacement based on a MacIntosh plateau and a plastic femoral component were likely gathered by Dr. Robert W. Jackson during his time on staff at the Division of Orthopedic Surgery
The Robert W. Jackson Arthroscopy Collection was acquired by the University of Toronto from Dr. Jackson’s family on November 12th, 2020.
Robert W. Jackson, Frederick P. Dewar, David L. MacIntosh, John P. Kostuik, and Robin Black. US4034418A: Artificial knee joint. US Patent. Awarded July 12, 1977.
These items may be early prototypes that were part of an effort to develop a partial knee replacement that was undertaken at the University of Toronto and Toronto General Hospital. An implant was patented (see Jackson et al. 1977), however it was never brought to market. Artifact 2025.JAC.295.1-2 is an example of the patented implant. The threaded fasteners in this example are unrelated to the groove-type fastening system depicted in the 1977 implant.
This artifact may represent a step in the search for a reliable system for connecting the artificial surface to the femoral condyle. This system, using two plastic threaded fasteners to attach the prosthesis to sockets cemented into a femoral condyle, likely proved unsatisfactory.
Other explanations are possible. Dr. Jackson collected widely. These artifacts may be from another project entirely.