TY - JOUR
T1 - 5-year migration and inducible displacement of the uncemented LCS and ATTUNE rotating platform knee systems
T2 - a secondary report of a randomized controlled RSA trial
AU - Puijk, Raymond
AU - Koster, Lennard A.
AU - Pijls, Bart G.C.W.
AU - Singh, Jiwanjot
AU - Schager, Marjolein
AU - Kaptein, Bart L.
AU - Nolte, Peter A.
N1 - Publisher Copyright:
© 2025 The Author(s).
PY - 2025
Y1 - 2025
N2 - Background and purpose — Early migration of the uncemented cruciate-sacrificing rotating platform ATTUNE and Low Contact Stress (LCS) tibial components was classified as at-risk for aseptic loosening rates exceeding 6.5% at 15 years based on recent fixation-specific migration thresholds. In this secondary report of a randomized controlled trial (RCT) we aimed to evaluate whether the 5-year migration, inducible displacement, and the clinical outcome of the ATTUNE components were comparable to those of the LCS. Methods — Patients from the initial 2-year radiostereometric analysis (RSA) RCT were recruited for a 5-year follow-up. At 5 years, participants underwent 2 supine and 1 loaded RSA examination, clinical assessments, and questionnaires. Migration was analyzed using maximum total point motion (MTPM), translations, and rotations, focusing on 5-year migration, continuous migration (> 0.10 mm/year), and inducible displacement. Revisions, along with clinical and functional outcomes, were also evaluated. Results — At 5 years, 24 ATTUNE and 24 LCS implants were analyzed. The mean MTPM was similar for tibial components (ATTUNE 1.13mm [confidence interval (CI) 0.94–1.33]; LCS 1.24 mm [CI 1.05–1.46]) but significantly lower for the ATTUNE femoral component (1.14 mm [CI 0.92–1.39]) than LCS 1.87 mm [CI 1.57–2.21]). 2-to-5-year migration rates were comparable, but 11 ATTUNE and 7 LCS exceeded 0.10 mm MTPM/year, indicating a higher risk of loosening. Inducible displacement was similar, although 1 patient with a tibial ATTUNE showed excessive displacement (3.34 mm MTPM) with focal osteolysis but no symptoms. 1 revision 10 days post-surgery was performed for an ATTUNE insert spinout, resolved with an isolated insert exchange. Clinical and functional outcomes were comparable. Conclusion — At the 5-year follow-up, ATTUNE tibial components showed similar migration, while the femoral component migrated significantly less than the LCS, which mainly occurred during the first 2 years. 2-to-5-year migration rates, inducible displacement, and clinical and functional outcomes were comparable. These findings suggest a comparable long-term risk of aseptic loosening between the uncemented ATTUNE and LCS knee systems.
AB - Background and purpose — Early migration of the uncemented cruciate-sacrificing rotating platform ATTUNE and Low Contact Stress (LCS) tibial components was classified as at-risk for aseptic loosening rates exceeding 6.5% at 15 years based on recent fixation-specific migration thresholds. In this secondary report of a randomized controlled trial (RCT) we aimed to evaluate whether the 5-year migration, inducible displacement, and the clinical outcome of the ATTUNE components were comparable to those of the LCS. Methods — Patients from the initial 2-year radiostereometric analysis (RSA) RCT were recruited for a 5-year follow-up. At 5 years, participants underwent 2 supine and 1 loaded RSA examination, clinical assessments, and questionnaires. Migration was analyzed using maximum total point motion (MTPM), translations, and rotations, focusing on 5-year migration, continuous migration (> 0.10 mm/year), and inducible displacement. Revisions, along with clinical and functional outcomes, were also evaluated. Results — At 5 years, 24 ATTUNE and 24 LCS implants were analyzed. The mean MTPM was similar for tibial components (ATTUNE 1.13mm [confidence interval (CI) 0.94–1.33]; LCS 1.24 mm [CI 1.05–1.46]) but significantly lower for the ATTUNE femoral component (1.14 mm [CI 0.92–1.39]) than LCS 1.87 mm [CI 1.57–2.21]). 2-to-5-year migration rates were comparable, but 11 ATTUNE and 7 LCS exceeded 0.10 mm MTPM/year, indicating a higher risk of loosening. Inducible displacement was similar, although 1 patient with a tibial ATTUNE showed excessive displacement (3.34 mm MTPM) with focal osteolysis but no symptoms. 1 revision 10 days post-surgery was performed for an ATTUNE insert spinout, resolved with an isolated insert exchange. Clinical and functional outcomes were comparable. Conclusion — At the 5-year follow-up, ATTUNE tibial components showed similar migration, while the femoral component migrated significantly less than the LCS, which mainly occurred during the first 2 years. 2-to-5-year migration rates, inducible displacement, and clinical and functional outcomes were comparable. These findings suggest a comparable long-term risk of aseptic loosening between the uncemented ATTUNE and LCS knee systems.
KW - Arthroplasty
KW - Implants
KW - Knee
KW - Osteoarthrosis
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UR - http://www.scopus.com/inward/citedby.url?scp=85216124271&partnerID=8YFLogxK
U2 - 10.2340/17453674.2024.42744
DO - 10.2340/17453674.2024.42744
M3 - Article
AN - SCOPUS:85216124271
SN - 1745-3674
VL - 96
SP - 59
EP - 65
JO - Acta Orthopaedica
JF - Acta Orthopaedica
ER -