Embedded Vittalium MacIntosh Knee Implant

Accession Number: 2025.JAC.294

Alternative Name:

Vitallium, unidentified resin or plastic.

Any markings on the Vitallium implant is obscured by the covering material.

Dimensions (cm): Height = 1.6, Width – 5, Length = 3.2;

Function:

This item is in good cosmetic condition. The outside surface of the cover appears to be hand finished and has various patterns and marks across its surface. There is a noticeable scratch near the centre of the flat surface.

Associated Instruments:

Manufacturer:

Date of Manufacture: c. 1960s to 1970s

The Robert W. Jackson Arthroscopy Collection was acquired by the University of Toronto from Dr. Jackson’s family on November 12th, 2020.

Duncan C. McKeever. (1960). Tibial Plateau Prosthesis. Clinical Orthopaedics, 18, 86-95.

David L. MacIntosh (1966). “Arthroplasty of the Knee in Rheumatoid Arthritis.” Journal of Bone and Joint Surgery, British Volume. 48-B, 179.

Theodore A. Potter (1969).  “Arthroplasty of the Knee With Tibial Metallic Implants of the McKeever and MacIntosh Design.” The Surgical Clinics of North America 49, no. 4 (1969): 903–15.
 
Neville R. M. Kay and H. Delgado Martins (1972)  “The MacIntosh Tibial Plateau Hemiprosthesis for the Rheumatoid Knee.” Journal of Bone and Joint Surgery. British Volume 54-B, no. 2: 256–62.

David L. MacIntosh and Gordon A. Hunter (1972) “The Use of the Hemiarthroplasty Prosthesis for Advanced Osteoarthritis and Rheumatoid Arthritis of the Knee.” Journal of Bone and Joint Surgery. British Volume 54-B, no. 2: 244–55.

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.

The MacIntosh Hemiarthroplasty (tibial plateau) was developed at the Toronto General Hospital (TGH) beginning in 1954. It is named for its inventor, orthopedic surgeon David L. MacIntosh (1914 – 2013)

The design emerged in 1954 with the installation of the modified acrylic knee surface replacement into a patient with severe valgus deformity of the knee due to arthritis. This acrylic knee prosthesis, developed by Kiae and Jansen of Copenhagen, had likely been brought back to TGH by surgeon W.R. Harris, who had recently visited Sweden as an ABC Travelling Fellow. MacIntosh reportedly inspected the prosthesis then cut it in half with a surgical saw before implanting it into the patient with successful results. (MacIntosh and Hunter 1972, 244).

Design and Materials

The MacIntosh implant was used primarily in vases of valgus and varus deformity in the knee due to osteoarthritis or rheumatoid arthritis. A shelf was cut into a typical condyle of the knee, and a prosthesis installed to provide a new bearing surface of the appropriate height for a damaged and collapsed surface in order to straighten the knee. In cases of severe rheumatoid arthritis, it was common to replace both condyles. The implant was available in three diameters and five thicknesses from 3 to 15 mm, with custom thicknesses available for special order from the manufacturer. 

The design evolved quickly in its early years. Early examples were made from acrylic like the Kiae and Jansen prosthesis. This was abandoned due to issues with that material experienced with artificial hips. Teflon and titanium were both tried, but these had suffered premature wear. After 1964, only Vitallium  was used. (See MacIntosh and Hunter 1972, 244). The MacIntosh implant was a cementless design that used a friction fit. It relied on its textured bottom surface to stay in place. This was due to the recent experience of the eventual breakdown of polymethyl methacrylate (PMMA) bone cement in hip implants leading to foreign body reaction, prosthetic loosening, and bone resorption and collapse.

This “embedded” example may have been part of this early developmental work, but it is not yet clear what purpose it served.

At some point, possibly in the late 1960s or early 1970s, developmental work began on a polyethylene femoral surface that could be used with a MacIntosh plateau implant. This is described in US Patent 4,034,418, granted on July 12, 1977.  Robert W. Jackson, who was the lead applicant on this patent, documented this work by collecting prototype material. This has been catalogued with his collection. While this work seems to have been extensive, resulting in manufactured prototypes and human trials, it did not result in a commercial product. Modern knee implants typically incorporate a metal femoral bearing surface operating against a polyethylene tibial liner. This developmental work reversed this arrangement and may not have been practical 

History and Significance

The MacIntosh knee plateau saw widespread use. Harvard-based surgeon Theodore Potter, writing in 1969, noted that thicknesses had become available “during the past 2 ½ years.” This may indicate that production began in the second half of the 1960s. (Potter 1969, 906). Kay and Delgado Martins noted that “… several hundred were distributed and used in the United Kingdom in 1970.” (Kay and Delgado Martins 1972, 262)

The MacIntosh implant was likely the second significant unicompartmental knee to be introduced to the market. In 1957, one year before MacIntosh Duncan C. McKeever of Valley Falls, Kansas had introduced his Vitallium tibial plateau prosthesis manufactured by Zimmer. This had a stem that fit into slots cut into the surface of the tibia. (McKeever 1960, 93; Potter 1969). It was available in a single diameter, but multiple thicknesses. Potter 1969 describes trials using both the MacIntosh and McKeever prostheses. 

This first generation of knee hemiarthroplasties were gradually abandoned in favour of more advanced hemiarthroplasties, such as the Oxford Knee, and more general use of full knee arthroplasties. However, some orthopaedic surgeons continued to use the MacIntosh knee plateau well into the late 20th century.