Impact of Nordic Arthroplasty Register Association (NARA) collaboration on demographics, methods and revision rates in knee arthroplasty: a register-based study from NARA 2000–2017

Tero Irmola; Ville Ponkilainen; Keijo T Mäkelä; Otto Robertsson; Annette W-Dahl; Ove Furnes; Anne M Fenstad; Alma B Pedersen; Henrik M Schrøder; Mika J Niemeläinen; Antti Eskelinen

doi:10.2340/17453674.2022.5256

Authors

Tero Irmola Coxa Hospital for Joint Replacement, and Faculty of Medicine and Health Technologies, University of Tampere, Tampere, Finland https://orcid.org/0000-0002-1785-5174
Ville Ponkilainen Department of Orthopaedics and Traumatology, Central Finland Hospital Nova, Jyväskylä, Finland https://orcid.org/0000-0002-5026-4560
Keijo T Mäkelä Finnish Arthroplasty Register, National Institute for Health and Welfare, Helsinki, Finland; Department of Orthopaedics and Traumatology, Turku University Hospital, and University of Turku, Turku, Finland
Otto Robertsson The Swedish Knee Arthroplasty Register, Department of Orthopedics, Skane University Hospital, Lund, Sweden, and Department of Clinical Sciences, Orthopedics, Lund University, Sweden https://orcid.org/0000-0002-8915-9792
Annette W-Dahl The Swedish Knee Arthroplasty Register, Department of Orthopedics, Skane University Hospital, Lund, Sweden, and Department of Clinical Sciences, Orthopedics, Lund University, Sweden https://orcid.org/0000-0003-4053-7358
Ove Furnes The Norwegian Arthroplasty Register, Department of Orthopaedic Surgery, Haukeland University Hospital, Bergen, Norway; Department of Clinical Medicine, University of Bergen, Bergen, Norway https://orcid.org/0000-0001-8223-2515
Anne M Fenstad The Norwegian Arthroplasty Register, Department of Orthopaedic Surgery, Haukeland University Hospital, Bergen, Norway https://orcid.org/0000-0002-6429-0153
Alma B Pedersen Department of Clinical Epidemiology, Aarhus University Hospital, Denmark, and the Danish Knee Arthroplasty Registry https://orcid.org/0000-0002-3288-9401
Henrik M Schrøder Department of Orthopaedic Surgery, Naestved Hospital, Denmark, and the Danish Knee Arthroplasty Register
Mika J Niemeläinen Coxa Hospital for Joint Replacement, and Faculty of Medicine and Health Technologies, University of Tampere, Tampere, Finland https://orcid.org/0000-0002-9438-111X
Antti Eskelinen Coxa Hospital for Joint Replacement, and Faculty of Medicine and Health Technologies, University of Tampere, Tampere, Finland https://orcid.org/0000-0003-0302-0253

DOI:

https://doi.org/10.2340/17453674.2022.5256

Keywords:

Incidence of knee arthroplasty, knee implants, Knee osteoarthritis, knee replacement, primary arthroplasty, register study

Abstract

Background and purpose: We have previously observed differences in treatment and outcome of knee arthroplasties in the Nordic countries. To evaluate the impact of Nordic collaboration in the last 15 years we aimed to compare patient demographics, methods, and revision rates in primary knee arthroplasties among the 4 Nordic countries.
Patients and methods: We included 535,051 primary knee arthroplasties reported 2000–2017 from the Nordic Arthroplasty Register Association (NARA) database. Kaplan–Meier analysis (KM) and restricted mean survival time (RMST) analysis were used to evaluate the cumulative revision rate (CRR) and RMST estimates with 95% confidence intervals (CI) and to compare countries in relation to risk of revision for any reason.
Results: After 2010, the increase in incidence of knee arthroplasty plateaued in Sweden and Denmark but continued to increase in Finland and Norway. In 2017 the incidence was highest in Finland with 226 per 105 person-years, while it was less than 150 per 105 in the 3 other Nordic countries. In total knee arthroplasties performed for osteoarthritis (OA), overall CRR at 15 years for revision due to any reason was higher in Denmark (CRR 9.6%, 95% CI 9.2−10), Norway (CRR 9.1%, CI 8.7−9.5), and Finland (CRR 7.0%, CI 6.8−7.3) compared with Sweden (CRR 6.6%, CI 6.4−6.8). There were differences among the countries in use of implant brand and type, fixation, patellar component, and use of unicompartmental knee arthroplasty.
Interpretation: We evinced a slowing growth of incidence of knee arthroplasties in the Nordic countries after 2010 with Finland having the highest incidence. We also noted substantial differences among the 4 Nordic countries, with Sweden having a lower risk of revision than the other countries. No impact of NARA could be demonstrated and CRR did not improve over time.