2023 ISAKOS Biennial Congress ePoster
Lateral Unicompartmental Knee Arthroplasty (UKA) Showed a Lower Risk of Failure Compared to Medial Unicompartmental Knee Arthroplasty in the Register of Prosthetic Orthopedic Implants (RIPO)
Stefano Zaffagnini, MD, Prof., Bologna ITALY
Domenico Alesi, MD, Bologna ITALY
Barbara Bordini, Stat, Bologna ITALY
Stefano Fratini, MD, Bologna ITALY
Cristina Ancarani, Stat, Bologna ITALY
Piero Agostinone, MD, Bologna, Italy ITALY
Alberto Grassi, PhD, Bologna ITALY
Giulio Maria Marcheggiani Muccioli, MD, PhD, Associate Professor, Bologna ITALY
IRCCS Istituto Ortopedico Rizzoli, Bologna, ITALY
FDA Status Not Applicable
Summary
This registry study showed that lateral UKA is a safe procedure showing longer survivorship than medial UKAs (95.2% and 87.5% at 10 years, respectively)
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Abstract
Introduction
The present study aimed to investigate differences in survivorship between medial and lateral unicompartmental knee arthroplasty (UKA) by analyzing the data of an Italian regional registry. The hypothesis was that, according to recent literature, lateral implants have comparable survivorship with regard to the medial implants.
Materials And Methods
The Register of Orthopaedic Prosthetic Implants (RIPO) of Emilia-Romagna (Italy) database was searched for all UKAs between July 1, 2000, and December 31, 2019.
For both cohorts, subject demographics and reasons for revision were presented as a percentage of the total cohort. Kaplan-Meier survivorship analysis was performed using revision of any component as the endpoint and survival times of unrevised UKAs taken as the last observation date (December 31, 2019, or date of death).
Results
Patients living outside the region and symmetrical implants (which do not allow the compartment operated to be traced) were excluded. 5571 UKAs implanted on 5172 patients (5215 medial UKAs and 356 lateral UKAs) were included in the study.
The survivorship analysis revealed 13 failures out of 356 lateral UKAs (3.7%) at mean 6.3 years of follow up and 495 failures out of 5215 medial UKAs (9.5%) at mean 6.7 years of follow up. The medial UKAs had a significantly higher risk of failure, with a Hazard Ratio of 2.6 (CI 95% 1.6-4.8; p< .001), adjusted for age, gender, weight, and mobility of the insert. Both the groups revealed a good survival rate, with 95.2% of lateral implants and 87.5% of medial implants still in situ at 10 years of follow-up.
Conclusions
Lateral UKA is a safe procedure showing longer survivorship than medial UKAs (95.2% and 87.5% at 10 years, respectively) in the present study.