Early acetabular cup migration is associated with long-term aseptic loosening: investigation of 1-year and 2-year radiostereometric analysis cohort migration thresholds against acetabular cup survivorship from two national registries
DOI:
https://doi.org/10.2340/17453674.2026.45784Keywords:
Arthroplasty, Hip, Implants, Radiostereometric Analysis, RSAAbstract
Background and purpose: 2-year proximal migration thresholds for acetabular cups used at primary total hip arthroplasty were first established in 2012 by matching radiostereometric analysis (RSA) measurements of cup migration with long-term survivorship from cohort studies. Subsequently, there have been new RSA studies reporting migration of contemporary cup designs whose survivorships are available from long-term registry data. The primary aim of this study was to re-evaluate the 2-year postoperative RSA migration thresholds and investigate whether thresholds at time points earlier than 2 years were possible.
Methods: The mean 6-month, 1-, and 2-year proximal migration of each RSA cohort was matched to the pooled 10-year proportion of acetabular cup revision due to aseptic loosening in the Australian Orthopaedic Association National Joint Replacement Registry and the Dutch Arthroplasty Registry in 2023. Revision rates were pooled according to these classifications using a random effects model.
Results: 164 implant-survival combinations (228,053 cups), involving 27 cup designs, were identified with RSA migration data to 2 years. At 1 year, mean cup migration of ≤ 0.1 mm was considered acceptable, while migration > 0.8 mm was unacceptable. The pooled proportions of acetabular cup revision in the acceptable, at-risk, and unacceptable threshold categories were 0.36% (95% confidence interval [CI] 0.26–0.47), 1.05% (CI 0.80–1.31), and 5.07% (CI 1.41–8.73) respectively. At 2 years, mean cup migration ≤ 0.2 mm was considered acceptable while mean migration > 1.0 mm had unacceptable survivorship. The pooled proportions of acetabular cup revision in the acceptable, at-risk, and unacceptable threshold categories were 0.55% (CI 0.48–0.62), 1.27% (CI 0.87–1.67), and 21.6% (CI 0.0–54.7), respectively, meaning that acetabular cups with high migration can be identified at both 1 and 2 years.
Conclusion: This study confirmed the existing 2-year migration thresholds and established a new threshold at 1 year. We found no association between continuous migration between 1 and 2 years and 10-year revision rates. The 1-year migration threshold is the earliest surrogate measure for assessing late loosening of the acetabular cup and may identify underperforming implants.
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Dunbar M, Ryd L. The power of registries and radiostereometric analysis (RSA). Acta Orthop 2025; 96: 11-12. doi: 10.2340/17453674.2024.41169. DOI: https://doi.org/10.2340/17453674.2024.41169
Nelissen R G, Pijls B G, Kärrholm J, Malchau H, Nieuwenhuijse M J, Valstar E R. RSA and registries: the quest for phased introduction of new implants. J Bone Joint Surg Am 2011; 93(Suppl 3): 62-5. doi: 10.2106/JBJS.K.00907. DOI: https://doi.org/10.2106/JBJS.K.00907
Pijls B G, Nelissen R G. The era of phased introduction of new implants. Bone Joint Res 2016; 5(6): 215-17. doi: 10.1302/2046-3758.56.2000653. DOI: https://doi.org/10.1302/2046-3758.56.2000653
Pijls B G, Nieuwenhuijse M J, Fiocco M, Plevier JW , Middeldorp S, Nelissen R G. Early proximal migration of cups is associated with late revision in THA: a systematic review and meta-analysis of 26 RSA studies and 49 survival studies. Acta Orthop 2012; 83(6): 583-91. doi: 10.3109/17453674.2012.745353. DOI: https://doi.org/10.3109/17453674.2012.745353
Malchau H, Bragdon C R, Muratoglu O K. The stepwise introduction of innovation into orthopedic surgery: the next level of dilemmas. J Arthroplasty 2011; 26(6): 825-31. doi: 10.1016/j.arth.2010.08.007. DOI: https://doi.org/10.1016/j.arth.2010.08.007
Kaptein B L, Pijls B, Koster L, Karrholm J, Hull M, Niesen A. Guideline for RSA and CT-RSA implant migration measurements: an update of standardizations and recommendations. Acta Orthop 2024; 95: 256-67. doi: 10.2340/17453674.2024.40709. DOI: https://doi.org/10.2340/17453674.2024.40709
Kärrholm J, Gill R H S, Valstar E R. The history and future of radiostereometric analysis. Clin Orthop Relat Res 2006; 448. doi: 10.1097/01.blo.0000224001.95141.fe. DOI: https://doi.org/10.1097/01.blo.0000224001.95141.fe
Cho C H, Pijls B G, Abrahams J M, Roerink A, Katembwe R, Baker A, et al. Migration patterns of acetabular cups: a systematic review and meta-analysis of RSA studies. Acta Orthop 2023; 94: 626-34. doi: 10.2340/17453674.2023.24580. DOI: https://doi.org/10.2340/17453674.2023.24580
LROI. Dutch Arthroplasty Register. LROI; 2023. Available from: https://www.lroi.nl/
AOANJRR. The Australian Orthopaedic Association National Joint Replacement Registry Adelaide South Australian Health and Medical Research Institute; 2023. Available from: https://aoanjrr.sahmri.com/
EU regulation 2017/745 of the European Parliament and the Council of 5 April 2017 on medical devices. Official Journal of the European Union 2023. WEBLINK??
Malak T T, Broomfield J A, Palmer A J, Hopewell S, Carr A, Brown C, et al. Surrogate markers of long-term outcome in primary total hip arthroplasty: a systematic review. Bone Joint Res 2016; 5(6): 206-14. doi: 10.1302/2046-3758.56.2000568. DOI: https://doi.org/10.1302/2046-3758.56.2000568
Van de Vusse S F, De Laat N N, Koster L A, Kaptein B L. The accuracy and precision of CT-RSA in arthroplasty: a systematic review and meta-analysis. Acta Orthop 2025; 96: 295-303. doi: 10.2340/17453674.2025.43334. DOI: https://doi.org/10.2340/17453674.2025.43900
Ryd L, Albrektsson B E, Carlsson L, Dansgård F, Herberts P, Lindstrand A, et al. Roentgen stereophotogrammetric analysis as a predictor of mechanical loosening of knee prostheses. J Bone Joint Surg Br 1995; 77(3): 377-83. doi: 10.1302/0301-620X.77B3.7744919. DOI: https://doi.org/10.1302/0301-620X.77B3.7744919
Kärrholm J, Borssén B, Löwenhielm G, Snorrason F. Does early micromotion of femoral stem prostheses matter? 4–7-year stereoradiographic follow-up of 84 cemented prostheses. J Bone Joint Surg Br 1994; 76(6): 912-17 .doi: 10.1302/0301-620X.76B6.7983118. DOI: https://doi.org/10.1302/0301-620X.76B6.7983118
Derbyshire B, Prescott R J, Porter M L. Notes on the use and interpretation of radiostereometric analysis. Acta Orthop 2009; 80(1): 124-30. doi: 10.1080/17453670902807474. DOI: https://doi.org/10.1080/17453670902807474
Puijk R, Singh J, Puijk R H, Laende E K, Plevier J W M, Nolte P A, et al. Evaluation and refinement of thresholds for early migration of total knee replacements as an estimator of late aseptic loosening: an updated systematic review of RSA and survival studies. Acta Orthop 2025; 96: 1-10. doi: 10.2340/17453674.2024.42574. DOI: https://doi.org/10.2340/17453674.2024.42574
Nieuwenhuijse M J, Valstar E R, Kaptein B L, Nelissen R G. Good diagnostic performance of early migration as a predictor of late aseptic loosening of acetabular cups: results from ten years of follow-up with Roentgen stereophotogrammetric analysis (RSA). J Bone Joint Surg Am 2012; 94(10): 874-80. doi: 10.2106/JBJS.K.00305. DOI: https://doi.org/10.2106/JBJS.K.00305
Kim Y S, Abrahams J M, Callary S A, De Ieso C, Costi K, Howie D W. Proximal translation of > 1 mm within the first two years of revision total hip arthroplasty correctly predicts whether or not an acetabular component is loose in 80% of cases: a case-control study with confirmed intra-operative outcomes. Bone Joint J 2017; 99-B(4): 465-74. doi: 10.1302/0301-620X.99B4.BJJ-2016-0805.R1. DOI: https://doi.org/10.1302/0301-620X.99B4.BJJ-2016-0805.R1
Abrahams J M, Kim Y S, Callary S A, De Ieso C, Costi K, Howie D W. The diagnostic performance of radiographic criteria to detect aseptic acetabular component loosening after revision total hip arthroplasty. Bone Joint J 2017; 99-B(4): 458-64. doi: 10.1302/0301-620X.99B4.BJJ-2016-0804.R1. DOI: https://doi.org/10.1302/0301-620X.99B4.BJJ-2016-0804.R1
Klerken T, Mohaddes M, Nemes S, Kärrholm J. High early migration of the revised acetabular component is a predictor of late cup loosening: 312 cup revisions followed with radiostereometric analysis for 2–20 years. Hip Int 2015; 25(5): 471-6. doi: 10.5301/hipint.5000246. DOI: https://doi.org/10.5301/hipint.5000246
Zhou Y, Wall C J, Stevens J, Fraval A, Lewis P L, McAuliffe M J. Data resource profile: the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Int J Epidemiol 2025; 54(4): dyaf078. doi: 10.1093/ije/dyaf078. DOI: https://doi.org/10.1093/ije/dyaf078
LROI. Completeness. The Dutch Arthroplasty Register; 2025. Available from: https://www.lroi.nl/jaarrapportage/data-quality/completeness/#Completeness-per-year
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Copyright (c) 2026 Chan Hee Cho, John M Abrahams, Lucian B Solomon, Thomas S Robertson, Christopher J Wall, Carl Holder, Liza N van Steenbergen, Bart G Pijls, Stuart A Callary
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