Conversion of UKA to TKA using identical standard implants-How does it compare to primary UKA, primary TKA and revision TKA?

Christian B Scheele ^1,2, Matthias F Pietschmann ³, Thomas C Wagner ³

⁰Department of Orthopedics and Trauma Surgery, Musculoskeletal University Center Munich (MUM), University Hospital, Großhadern Campus, Ludwig Maximilians University, Marchioninistr. 15, Munich, 81377, Germany. christian.b.scheele@googlemail.com.

Arthroplasty (london, England) +

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September 2, 2024

View abstract on PubMed

Summary

Unicompartmental knee arthroplasty (UKA) offers superior outcomes compared to total knee arthroplasty (TKA). Conversion of UKA to TKA maintains functional results, while revision TKA leads to poorer outcomes.

Area Of Science

Orthopedic Surgery
Biomedical Engineering
Reconstructive Surgery

Background

Unicompartmental knee arthroplasty (UKA) is effective for anteromedial knee osteoarthritis, but has higher revision rates than total knee arthroplasty (TKA).
Comparing UKA, TKA, converted UKA, and revised TKA is crucial for clinical decision-making.

Purpose Of The Study

To compare functional outcomes and patient satisfaction across UKA, TKA, UKA converted to TKA, and revised TKA.
To evaluate the efficacy of using identical standard implants for UKA to TKA conversions.
To provide data supporting informed clinical choices in knee arthroplasty.

Main Methods

Retrospective analysis of 116 UKA, 77 TKA, 28 converted UKA, and 21 revised TKA patients.
Mean follow-up of four years.
Assessment of patient-reported outcome measures (PROMs) including Oxford Knee Score, UCLA score, KSS score, modified WOMAC-Score, patient satisfaction, and return to daily activities, work, and sports.

Main Results

UKA demonstrated the highest patient satisfaction and significantly better scores than TKA, converted UKA, and revised TKA.
Converted UKA showed no significant inferiority to primary TKA in any assessed score.
Converted UKA yielded significantly better revision outcomes than revised TKA in two specific scores.

Conclusions

Patients undergoing UKA conversion to TKA with identical implants did not experience significantly worse functional outcomes.
UKA is an effective therapeutic option with outcomes superior to primary TKA, emphasizing bone-sparing benefits.
Revision TKA is associated with poorer functional outcomes compared to both primary UKA and TKA.

Keywords:

Functional results Patient satisfaction Revision arthroplasty TKA UKA