Knee arthroplasty polycentric

Gunston decided to publish his experience with the Polycentric rather than patent the design. In 1969, at a Canadian orthopedic meeting, Gunston met Lowell Peterson from the Mayo Clinic (Rochester, MN). Subsequently, Peterson s colleague, Richard Bryan, traveled to Winnipeg in December 1969 to study the procedure and to further evaluate Gunston s clinical results (Bryan and Peterson 1979). 

Gunston freely shared his drawings with Bryan and Peterson, and after some design modifications, the first Polycentric TKA was performed at the Mayo Clinic by July 1970. The first 81 Polycentric knees at the Mayo Clinic were fabricated by the hospital (Bryan and Peterson 1979). However, until 1978, the vast majority of the 1938 Polycentric components implanted at the Mayo Clinic were manufactured by orthopedic companies, such as Howmedica (Rutherford, NJ). 

Instant centers of rotation during flexion of the natural knee joint. (Adapted from Gunston 1971.) 

The Polycentric design was further modified by researchers at Mayo in 1973 to provide wider UHMWPE tracks (Bloom and Bryan 1977). Additional refinements of the Polycentric design, such as the introduction of UHMWPE runners with variable height, were proposed by Cracchiolo (1973). A review by Peterson and associates in 1975 provides an instructive summary of fhe differ-enf fypes of Polycenfric knee components, which were available from implant companies such as Howmedica and DePuy at the time. 

The UHMWPE material used for Polycentric components was RCH 1000. Gunston sterilized the UHMWPE tibial components he personally manufactured using an autoclave. However, orthopedic companies like Howmedica, which fabricated most of the Polycentric components implanted during the 1970s, sterilized their UHMWPE components with gamma radiation and used air-permeable packaging. 

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Bryan R.S., L.F. Peterson, and J.J. Combs, Jr. 1973a. Polycentric knee arthroplasty. A review of 84 patients with more than one year follow-up. Clin Orthop 94 136-139. 

Cracchiolo A., III. 1973. Polycentric knee arthroplasty using tibial prosthetic units of a variable height. A preliminary report of design characteristics and a concept of clinical use. Clin Orthop 94 140-147. 

Gunston RH. 1971. Polycentric knee arthroplasty. Prosthetic simulation of normal knee movement. J Bone Joint Surg 53 272-277. 

Gunston RH., and R.I. MacKenzie. 1976. Gomplications of polycentric knee arthroplasty. Clin Orthop 120 11-17. 

Mallory T.H. 1973. The use of polycentric knee arthroplasty in the treatment of fracture deformities of the knee. Clin Orthop 97 114—116. 

Skolnick M.D., R.S. Bryan, and L.F. Peterson. 1975. Unicompartmental polycentric knee arthroplasty description and preliminary results. Clin Orthop 112 208-214. 

Polycentric Knee Arthroplasty Bicondylar Prostheses 7.8 Conclusion... 

Peterson LF, Bryan RS, Combs JJ Jr. Polycentric knee arthroplasty. CurrPract Orthop Surg 1975 6 2-10. 

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