Study Finds No Difference Between Partial and Total Knee Replacement Outcomes

July 26, 2019

Partial knee replacement should be considered first over total knee replacement for patients with late-stage isolated medial compartment knee osteoarthritis, say researchers writing in The Lancet this month.

Partial knee replacement should be considered first over total knee replacement for patients with late-stage isolated medial compartment knee osteoarthritis, say researchers writing in The Lancet this month.

The effectiveness of the two procedures was compared side-by-side in a randomized controlled trial led by David Beard, of the University of Oxford, United Kingdom. Researchers found that both procedures were effective, have similar clinical outcomes and result in a similar incidence of complications and re-operations. However, during the five-year follow-up period of the trial, partial knee replacement procedures were found to be more cost-effective.

"Knee replacement is increasing in frequency and it has an associated substantial cost implication to any health-care provider. It is also essential that patients receive the most efficacious operation for this condition," the authors wrote.

This was a randomized controlled trial of 528 patients from 27 sites in the United Kingdom who had isolated osteoarthritis of the medial compartment of the knee. Half of the group was assigned to a partial knee surgery and half was assigned to received total knee replacement. They were followed for five years in which measures for patient-reported outcomes, re-operation or revision surgeries were recorded.

The operation time was similar for both groups: approximately 70 minutes, but the length of hospital differed. Patients receiving partial knee surgery stayed in hospital for 3.2 days as compared to 4.3 days for total knee replacement. Five years post-op patient completed a survey in which both groups reported superior outcomes as compared to their status at baseline with a patient satisfaction score of 82 percent for partial knee replacement and 77 percent for total knee replacement. But when asked "whether the patient’s knee was better before the operation," 95 percent of the partial knee replacement patients and 90 percent of the patients receiving total knee replacement reported satisfactory outcomes.

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At five years, researchers found no difference in the Oxford Knee Score (the measure used as the primary outcome) or other secondary outcome scores between the two groups.

Partial knee replacement was found to have better outcomes, lower cost surgeries and lower expenses for follow-up care.

"Before our study, and despite several cohort-based reports, knowledge of whether one operation type is superior, remained uncertain. Our five-year study has indicated that both total and partial knee replacement are beneficial interventions but, based on our combined clinical and cost-effectiveness data and provided the operation is performed by those with adequate experience, we recommend that partial knee replacement should be offered as the treatment of choice for late-stage isolated medial compartment osteoarthritis of the knee," the authors wrote.

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REFERENCE

David J Beard, Loretta J Davies, Jonathan A Cook, et al. "The clinical and cost-effectiveness of total versus partial knee replacement in patients with medial compartment osteoarthritis (TOPKAT): 5-year outcomes of a randomised controlled trial." The Lancet. July 17, 2019. DOI: 10.1177/0961203319861685