caa a22 4500 605456461 CHVBK 20210128100218.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s00167-015-3561-4 doi (NATIONALLICENCE)springer-10.1007/s00167-015-3561-4 Control of paradoxical kinematics in posterior cruciate-retaining total knee arthroplasty by increasing posterior femoral offset [Elektronische Daten] [J. Donadio, A. Pelissier, P. Boyer, P. Massin] Purpose: Balancing the posterior cruciate ligament (PCL) with posterior cruciate-retaining total knee replacement (PCR-TKR) aims to restore femoral rollback. In practice, paradoxical roll forward persists. The purpose of this study is to propose a technique for optimizing PCL tension. Because PCL function starts above 60° of flexion, we hypothesize that PCL balancing requires flexion gap tightening by oversizing the femoral component and increasing posterior condylar offset (PCO). Methods: PCR-TKR was performed in 21 osteoarthritis patients with a gap-balancing technique. The femoral component was oversized if more than a 5-mm posterior drawer existed after tibial component implantation. Kinematics was recorded intra-operatively in two steps with dedicated navigation software (Praxim, La Tronche, Isère, France): antero-posterior (AP) displacements of condylo-tibial contact points were observed in native and implanted knees, with each knee serving as its own control. The absence of paradoxical displacements was verified once the final implants were inserted. Results: Paradoxical medial condyle displacement (11mm) persisted in a single case. On average, posterior displacement of the medial condyle decreased from 9±9 to 1±6mm (p=0.001) and that of the lateral condyle from 16±14 to 6±6mm (p=0.006). In the 0°-30° flexion interval, posterior displacement was 2 times less than before implantation for the medial condyle (p=0.001), and 4 times less for the lateral condyle (p=0.004). The course of the lateral condyle decreased from 2±3 to 0±4mm in the 90°-120° flexion interval (p=0.046). Six-month flexion was 124°±17°. Conclusion: Femoral component oversizing allows us to control paradoxical forward displacements in 95% of cases. When balancing PCR prostheses, AP laxity should be taken into account. Increasing PCO appears to be a reliable technique for adjusting PCL balance. Thus, it may optimize extensor mechanism action and, subsequently, the functional results of PCR-TKR. Level of evidence: Diagnostic study, Level II. European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA), 2015 Posterior cruciate ligament nationallicence Cruciate-retaining prosthesis nationallicence Kinematics nationallicence Paradoxical displacement nationallicence Donadio J. Department of Orthopaedic Surgery, Hôpitaux Universitaires Paris Nord Val de Seine, 46 rue Henri Huchard, 75877, Paris Cedex 18, France aut Pelissier A. Department of Orthopaedic Surgery, Hôpitaux Universitaires Paris Nord Val de Seine, 46 rue Henri Huchard, 75877, Paris Cedex 18, France aut Boyer P. Department of Orthopaedic Surgery, Hôpitaux Universitaires Paris Nord Val de Seine, 46 rue Henri Huchard, 75877, Paris Cedex 18, France aut Massin P. Department of Orthopaedic Surgery, Hôpitaux Universitaires Paris Nord Val de Seine, 46 rue Henri Huchard, 75877, Paris Cedex 18, France aut Knee Surgery, Sports Traumatology, Arthroscopy Springer Berlin Heidelberg 23/6(2015-06-01), 1631-1637 0942-2056 23:6<1631 2015 23 167 https://doi.org/10.1007/s00167-015-3561-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00167-015-3561-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Donadio J. Department of Orthopaedic Surgery, Hôpitaux Universitaires Paris Nord Val de Seine, 46 rue Henri Huchard, 75877, Paris Cedex 18, France aut NATIONALLICENCE 700 1- Pelissier A. Department of Orthopaedic Surgery, Hôpitaux Universitaires Paris Nord Val de Seine, 46 rue Henri Huchard, 75877, Paris Cedex 18, France aut NATIONALLICENCE 700 1- Boyer P. Department of Orthopaedic Surgery, Hôpitaux Universitaires Paris Nord Val de Seine, 46 rue Henri Huchard, 75877, Paris Cedex 18, France aut NATIONALLICENCE 700 1- Massin P. Department of Orthopaedic Surgery, Hôpitaux Universitaires Paris Nord Val de Seine, 46 rue Henri Huchard, 75877, Paris Cedex 18, France aut NATIONALLICENCE 773 0- Knee Surgery, Sports Traumatology, Arthroscopy Springer Berlin Heidelberg 23/6(2015-06-01), 1631-1637 0942-2056 23:6<1631 2015 23 167