KSSTA - 2026-06-16 - Journal Article; Review
Unicompartmental knee arthroplasty is associated with greater patient preference but higher revision rates than total knee arthroplasty in the same patient: A systematic review and meta-analysis.
Elsheikh R, Burgert N, Kievit A, de Leeuw PAJ, Hirschmann MT, Dahmen J
Topics
Key Takeaway
In patients with a contralateral TKA, UKA achieves 7.4° greater ROM and 2.7x higher patient preference but carries a 5x higher revision risk (OR 0.2) compared to the contralateral TKA.
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Summary
This systematic review and meta-analysis evaluated UKA outcomes in patients who had a contralateral TKA, using the TKA as an intra-patient comparator for ROM, PROMs, survivorship, and preference. UKA produced 7.4° greater postoperative ROM (p<0.001) and was preferred by patients (OR 2.7, p=0.044), but TKA showed greater KSS improvement (MD 2.4, p=0.013) and significantly lower revision risk (OR 0.2, p=0.017). Forgotten Joint Score was statistically equivalent between procedures (MD 2.9, p=0.243).
Key Limitation
The underlying studies are predominantly retrospective with small sample sizes, and revision rate data likely reflect heterogeneous follow-up durations, making the OR for revision risk difficult to interpret without time-to-event analysis.
Original Abstract
PURPOSE
Despite the high prevalence of isolated knee compartment disease, unicompartmental knee arthroplasty (UKA) is often avoided in patients with a contralateral total knee arthroplasty (TKA). The present study aimed to evaluate the impact of a contralateral TKA on functional outcomes, patient preference and long-term survivorship following UKA.
METHODS
A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines. PubMed, Embase, Scopus and Cochrane Central Library were systematically searched for studies evaluating UKA in patients with a contralateral TKA. The primary outcome was post-operative range of motion (ROM). Secondary outcomes included patient-reported outcome measures (PROMs), implant survivorship, complications and patient preference.
RESULTS
Fourteen studies comprising 575 patients were included in the analysis. Compared with contralateral TKA, UKA achieved significantly greater post-operative ROM (MD = 7.4°, p < 0.001) and a higher improvement from baseline (∆ROM MD = 2.7°, 95% confidence interval [CI] = 0.02-5.56; p = 0.049). Although post-operative Knee Society Score (KSS) did not differ between UKA and TKA (p = 0.142), improvement in KSS was significantly greater following TKA (MD = 2.4, 95% CI = 0.65-4.18; p = 0.013). Forgotten Joint Score was comparable between procedures (MD = 2.9, 95% CI = -4.82 to 10.76; p = 0.243). UKA was associated with a higher revision risk (odds ratio [OR] = 0.2, 95% CI = 0.09-0.69; p = 0.017), while patient preference significantly favoured UKA (OR = 2.7, 95% CI = 1.03-7.35; p = 0.044).
CONCLUSION
In patients with a contralateral TKA, UKA provides greater ROM, comparable joint forgettability and higher patient preference, but carries a higher revision risk. UKA should not be automatically withheld in this population, provided that patients are carefully selected and counselled about the risks. Prospective studies are needed to guide patient selection and optimize outcomes in hybrid bilateral knee arthroplasty.
LEVEL OF EVIDENCE
Level III.