Acta Orthopaedica - 2026-03-05 - Journal Article
Associations between hospital characteristics, volume, and reasons for revision: a cohort study of 48,029 unicompartmental knee arthroplasties with 3,397 revisions from the Dutch Arthroplasty Register.
De Raadt HWH, Koenraadt-van Oost I, Nijs A, Spekenbrink-Spooren A, Elmans L, Van Geenen RCI
Topics
Key Takeaway
High-volume UKA centers (≥80 procedures/year) had significantly lower revision rates, with loosening, OA progression, malalignment, and pain all less frequent compared to low-volume centers (≤24/year) across 48,029 procedures.
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Summary
Using the Dutch Arthroplasty Register (2007–2022), this study examined whether annual hospital UKA volume and hospital type predict revision risk and revision etiology across four volume tiers and four hospital categories. High-volume hospitals (≥80/year) and top clinical teaching hospitals had significantly lower revision rates (P<0.001), and cementless fixation outperformed cemented fixation. Revision reasons including loosening, OA progression, malalignment, and pain were all less prevalent at high-volume centers, and malalignment was disproportionately registered as the revision reason when cases were referred from outside institutions.
Key Limitation
Confounding by case mix and patient selection criteria across hospital types cannot be fully adjusted in a registry model, meaning higher-volume academic centers may selectively treat more favorable UKA candidates, partially explaining their lower revision rates.
Original Abstract
BACKGROUND AND PURPOSE
It remains debated whether high annual hospital volumes for unicompartmental knee arthroplasty (UKA) are associated with a low risk of revision, and what explanations may underlie this relationship. We aimed to analyze the association between specific hospital characteristics defined as volume, type, and referral for revision, and frequency and reasons for UKA revision.
METHODS
Data from primary UKAs (2007-2022) and their revisions were extracted from the Dutch Arthroplasty Register. Hospitals were categorized by type; academic, top clinical teaching, private, or other general hospitals. Hospitals were grouped by annual UKA volume: ≤24, 25-39, 40-79, and ≥80 procedures. Multiple linear regression assessed the relationship between the number of revisions with hospital volume and type, adjusted for confounders. Chi-squared tests were used to test for differences in revision reasons based on volume and referrals.
RESULTS
48,029 primary UKAs and 3,397 revisions were included. High-volume and top clinical teaching hospitals had a significantly lower risk of revision following primary UKA (P < 0.001). Cementless implants had a lower risk compared with cemented implants. Revision reasons varied by hospital volume and whether revision occurred after referral (P < 0.001). Loosening, progression of osteoarthritis, malalignment, and pain were less common in the highest volume hospitals. If revision occurred after referral, malalignment was more frequently registered as the reason for revision.
CONCLUSION
High-volume and top clinical teaching hospitals were associated with lower risk of revision following primary UKA. Differences in revision reasons, with fewer cases of loosening, progression of osteoarthritis, malalignment, and pain, may explain the lower risk of revision at higher volume hospitals.