Knee implant standardization: an implant selection and cost reduction program.

The largest single unit cost in the hospital cost for total knee arthroplasty (TKA) is the cost of knee implants. We developed a knee implant standardization program to provide guidelines for knee implant selection and to reduce the cost of knee implants for hospitals. Patients are assigned to demand categories based on five criteria: age, weight, expected activity, general health, and bone stock. Implants are assigned to demand categories based on an implant's projected capacity to handle the patient's projected demand. The program was applied retrospectively to 127 knee replacement operations performed on 93 patients during 1992. If this program had been in place, 8.4% of what was actually spent on knee implants for these 127 patients would have been saved. If the most expensive implants allowed in each demand category had actually been used, the program would have saved our hospital 12.8% of the cost of knee implants for these patients. Potential savings were noted in higher demand categories I and II by reducing the use of expensive cementless, porous-coated implants. The greatest potential savings were noted in lower demand categories III and IV: 11% savings could have been realized in demand category III, and 27% savings could have been achieved in the cost of knee implants in demand category IV. Potential savings would have been realized in these lower demand categories because of the recommended use of an all-polyethylene tibial component in 38 of 92 patients. This knee implant standardization program has the potential to assist surgeons in selecting knee implants and reduce the cost of knee implants without compromising outcome following TKA.