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Observational Study
. 2017 Sep 7;18(1):388.
doi: 10.1186/s12891-017-1750-7.

Hospital volume and the risk of revision in Oxford unicompartmental knee arthroplasty in the Nordic countries -an observational study of 14,496 cases

Mona Badawy  1 , Anne M Fenstad  2 , Christoffer A Bartz-Johannessen  2 , Kari Indrekvam  3   4 , Leif I Havelin  2   4 , Otto Robertsson  5   6 , Annette W-Dahl  5   6 , Antti Eskelinen  7 , Keijo Mäkelä  8 , Alma B Pedersen  9   10 , Henrik M Schrøder  11 , Ove Furnes  2   4
Affiliations
Observational Study

Hospital volume and the risk of revision in Oxford unicompartmental knee arthroplasty in the Nordic countries -an observational study of 14,496 cases

Mona Badawy et al. BMC Musculoskelet Disord. .

Abstract

Background: High procedure volume and dedication to unicompartmental knee arthroplasty (UKA) has been suggested to improve revision rates. This study aimed to quantify the annual hospital volume effect on revision risk in Oxfordu nicompartmental knee arthroplasty in the Nordic countries.

Methods: 14,496 cases of cemented medial Oxford III UKA were identified in 126 hospitals in the four countries included in the Nordic Arthroplasty Register Association (NARA) database from 2000 to 2012. Hospitals were divided by quartiles into 4 annual procedure volume groups (≤11, 12-23, 24-43 and ≥44). The outcome was revision risk after 2 and 10 years calculated using Kaplan Meier method. Multivariate Cox regression analysis was used to assess the Hazard Ratio (HR) of any revision due to specific reasons with 95% confidence intervals (CI).

Results: The implant survival was 80% at 10 years in the volume group ≤11 procedures per year compared to 83% in other volume groups. The HR adjusted for age category, sex, year of surgery and nation was 0.87 (95% CI: 0.76-0.99, p = 0.036) for the group 12-23 procedures per year, 0.78 (95% CI: 0.68-0.91, p = 0.002) for the group 24-43 procedures per year and 0.82 (95% CI: 0.70-0.94, p = 0.006) for the group ≥44 procedures per year compared to the low volume group. Log-rank test was p = 0.003. The risk of revision for unexplained pain was 40-50% higher in the low compared with other volume groups.

Conclusion: Low volume hospitals performing ≤11 Oxford III UKAs per year were associated with an increased risk of revision compared to higher volume hospitals, and unexplained pain as revision cause was more common in low volume hospitals.

Keywords: Arthroplasty; Knee; Osteoarthritis; Procedure volume; Revision causes; Unicompartmental.

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Conflict of interest statement

Ethics approval and consent to participate

Permission to the study was obtained from the Norwegian Data Protection Authority (reference number: 03/00058-20/CGN). Selection and transformation of the respective datasets and de-identification of the patients, including deletion of the national civil registration numbers, was performed within each national registry. Anonymous data were then merged into a common database, thus individuals are not possible to identify in the NARA database.

Ethical approval of the study was obtained through each national registry.

Consent for publication

This study was approved through each national registries own ethical process. Patients in Norway give individual written concent to participate. In Finland and Denmark it is mandatory to participate for all hospitalized patients and no consent is required for an approved National medical registry and in Sweden no written consent is needed, but the patient can opt to not participate.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
14,496 cemented medial Oxford III UKA from 2000 to 2012 were selected for inclusion in this study. Other diagnoses than osteoarthritis were excluded. Abbreviations: NARA = Nordic Arthroplasty Register Association, OA = osteoarthritis
Fig. 2
Fig. 2
Cox regression survival curve adjusted for age, sex, year of surgery and nation
See this image and copyright information in PMC

References

    1. Niinimaki T, Eskelinen A, Makela K, Ohtonen P, Puhto AP, Remes V. Unicompartmental knee arthroplasty survivorship is lower than TKA survivorship: a 27-year Finnish registry study. Clin Orthop Relat Res. 2014;472:1496–1501. doi: 10.1007/s11999-013-3347-2. - DOI - PMC - PubMed
    1. Australian Orthopaedic Association National Joint Replacement Registry Annual report. Online source: http://aoanjjr.sahmri.com.
    1. Swedish Knee Register Annual Report. Online source: http://www.myknee.se/en.
    1. Danish Knee Arthtoplasty Register Annual Report. Online source: http://kea.au.dk/en/ClinicalQuality/.
    1. Norwegian Arthroplasty Register Annual Report. Online source: http://www.nrlweb.ihelse.net/eng/.

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