Sign in Subscribe
CAT scans

Dynamic Computed Tomography Enables In Vivo Assessment of Patellofemoral and Tibiofemoral Kinematics Before and After Total Knee Arthroplasty

Strategic Insights

— 1 min read

Investigators at Radboud University Nijmegen Medical Center in Nijmegen, Netherlands, have developed and evaluated a dynamic computed tomography (CT) protocol for assessing patellofemoral (PF) and tibiofemoral (TF) kinematics before and after total knee arthroplasty (TKA). The research, supported by Smith and Nephew, aimed to quantify postoperative kinematic changes in a pilot study. The findings suggest that dynamic CT enables in vivo assessment of PF and TF kinematics before and after TKA, with potential as a research tool.

Key Takeaways:

  • The study involved 10 patients (mean age, 65 +/- 8 years; 6 men) who underwent dynamic CT scans preoperatively and at 1-year follow-up during active flexion-extension-flexion.
  • Postoperatively, the patella showed increased flexion (median difference: 0.9 degrees-3.9 degrees), medial proximal tip rotation (median difference: 1.5 degrees-6.0 degrees), lateral tilt (median difference: 2.7 degrees-5.5 degrees), and lateral shift (median difference: -1.5 to -2.8 mm).
  • The medial and lateral femoral condyles translated 2-4 mm anterior-posteriorly during knee flexion.
  • Interoperator agreement for patellar registration ranged from good to excellent across all parameters (ICC = 0.85-1.00).
  • Further automation is needed to investigate relationships between these kinematic patterns and patient outcomes in larger-scale studies.
  • The research has been peer-reviewed and published in the journal Knee Surgery, Sports Traumatology, Arthroscopy.

Statistics:

  • 10 patients were analysed across a shared flexion range of 14 degrees-55 degrees.
  • Postoperative patellar flexion increased by 0.9 degrees-3.9 degrees.
  • Medial proximal tip rotation increased by 1.5 degrees-6.0 degrees postoperatively.
  • Lateral tilt increased by 2.7 degrees-5.5 degrees postoperatively.
  • Lateral shift decreased by -1.5 to -2.8 mm postoperatively.
  • The medial and lateral femoral condyles translated 2-4 mm anterior-posteriorly during knee flexion.

Sources:

  • NewsRx. Reports from Radboud University Nijmegen Medical Center Provide New Insights into Arthroplasty (Dynamic Computed Tomography Assessment of Patellofemoral and Tibiofemoral Kinematics Before and After Total Knee Arthroplasty: a Pilot Study). Medical Devices & Surgical Technology Week. November 2, 2025; p 1386.
  • Dynamic Computed Tomography Assessment of Patellofemoral and Tibiofemoral Kinematics Before and After Total Knee Arthroplasty: a Pilot Study. Knee Surgery, Sports Traumatology, Arthroscopy, 2025.

Read more