New Knee Replacement Devices Boost Early Revision Surgery

Patients who undergo the first 15 operations to place a new total knee arthroplasty (TKA) device are more likely to need early revision surgery than patients who were fitted with a prosthesis previously used in the hospital.

Researchers at the National Institute for Health and Welfare (THL; Helsinki, Finland) examined the risk of early revision surgery following the introduction of a new endoprosthesis model for TKA by studying data from the Finnish Arthroplasty Register to identify centers that had performed TKA replacement operations for primary osteoarthritis (OA) between 1998 and 2004. Of the 23,707 patients who underwent the surgical procedure, 22,551 were followed up for five years. The researchers excluded longer follow up from the analysis as subsequent revisions might result from wear rather than early technical failures.

The researchers found that the introduction of an endoprosthesis model in a hospital put the first patients at greater risk of revision surgery. The effect was substantial for the first 15 patients operated on with the new model, who were at 48% greater risk than patients having undergone an operation to implant a conventional endoprosthesis were. Overall, the likelihood of needing revision surgery was greatest during the first two years after the TKA procedure. The learning curve smoothed quickly, however, with no increased risk after the first 15 operations with the new model. The study was published early online on December 9, 2011, in Clinical Orthopaedics and Related Research.

“Patients should be informed if there is a plan to introduce a new model and offered the option to choose a conventional endoprosthesis instead,” concluded lead author Mikko Peltola, PhD, and colleagues of the THL Centre for Health and Social Economics (CHESS). “Although introducing potentially better endoprosthesis models is important, there is a need for managed uptake of new technology.”

TKA is an established treatment for patients with severe OA of the knee. There are numerous brands and models of endoprostheses available, and new models continue to emerge as a result of a combination of new technology, marketing efforts, and the increasing number of patients requiring the surgery. Hospital staff makes important decisions when choosing the implants and instruments they use, and these decisions carry consequences for patients' health.

Related Links:
[Finland] National Institute for Health and Welfare