gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2015)

20.10. - 23.10.2015, Berlin

In-vivo kinematics of customized, individually made TKA compared to two off-the-shelf TKA during deep knee bend and chair rise

Meeting Abstract

  • Harold Cates - Tennessee Orthopaedic Clinics, Knoxville, United States
  • Mathew Anderle - University of Tennessee, Knoxville, United States
  • William Hamel - University of Tennessee, Knoxville, United States
  • presenting/speaker Adrija Sharma - University of Tennessee, Knoxville, United States
  • Bradley Meccia - University of Tennessee, Knoxville, United States
  • Richard Komistek - University of Tennessee, Knoxville, United States

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2015). Berlin, 20.-23.10.2015. Düsseldorf: German Medical Science GMS Publishing House; 2015. DocPO26-1290

doi: 10.3205/15dkou775, urn:nbn:de:0183-15dkou7759

Veröffentlicht: 5. Oktober 2015

© 2015 Cates et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objectives: This study was designed to determine in vivo kinematics of subjects having either a customized, individually made (CIM) posterior cruciate retaining (CR) implant or one of two Off-the-shelf (OTS) CR TKA while performing a deep knee bend (DKB) and during a chair-rise.

Methods: Sixty-five subjects, having either a CIM or one of two OTS CR TKA, implanted by the same surgeon, were assessed. Fifteen CIM TKA and 25 of each OTS TKA were evaluated. Fluoroscopic videos were captured while patients performed the DKB and chair-rise under mobile-fluoroscopic surveillance. Each video was digitized, corrected for distortion, and analyzed to determine kinematics using 2D to 3D image registration.

Results and Conclusion: During the DKB, subjects having a CIM TKA experienced -3.8 (-1.0 to -6.8) mm of lateral condyle posterior femoral rollback (PFR) compared to only -2.6 (2.4 to -9.7) mm and -0.7 (6.0 to -6.5) mm for subjects having OTS TKA I and II, respectively. Interestingly, all subjects having a CIM TKA experienced PFR of their lateral condyle while subjects having a OTS TKA experienced incidences of their lateral condyle moving in the anterior direction, opposite of the normal knee pattern. During the chair-rise activity, subjects having a CIM TKA experienced 5.7 (0.8 to 12.5) mm of condylar roll forward, compared to only 1.1 (-4.6 to 5.6) mm and 3.9 (-3.0 to 9.4) mm for subjects having traditional TKA I and II, respectively. Again, all subjects having a CIM TKA experienced a normal roll forward pattern of lateral condyle motion, while subjects having a traditional TKA experienced an incidence of posterior sliding of their lateral condyle, opposite to the normal knee. During a DKB, subjects having a CIM CR TKA achieved 107° of weight-bearing knee flexion, while subjects having a traditional CR TKA I and II achieved only 100° and 97°, respectively.

OTS knee implants are designed based on J-curves derived from anatomic averages which cannot match the natural J-curves of the individual patient or their natural condylar offsets. More recently, a customized, individually made implant has been designed based on the anatomical geometry for individual patients while correcting any underlying deformities (flattening, osteophytes, etc.). In this study, patients with both brands of OTS implants exhibited paradoxical anterior slide of the lateral condyle during DKB. Patients having CIM CR TKA achieve more normal-like kinematic patterns of their lateral condyle for both a deep knee bend and a chair rise with a rotation pattern similar to a normal, healthy knee.