Related Experiment Video
Updated: Jan 8, 2026
In Vitro Application of a Wireless Sensor in Flexion-Extension Gap Balance of Unicompartmental Knee Arthroplasty
Published on: May 5, 2023
In Silico Modeling Validation and Contact Pressure Distribution Comparison Analysis of Conventional and
Yeseop Park1, Katherine Elbert2, Jason Koh3
1Department of Orthopaedic Surgery, University of Illinois at Chicago, Chicago, Illinois.
Background:
Unicompartmental knee arthroplasty (UKA) improves recovery, but optimizing load remains challenging. This study measures tibiofemoral contact pressures after conventional and robotic UKA in cadavers and validates a finite element (FE) model against experimental data.
Methods:
Sixteen fresh-frozen cadaveric lower limbs underwent medial UKA with conventional cutting guides (n = 8) or CORI robotic assistance (n = 8). Medial (implanted) and lateral (native) compartment pressures were recorded from 0° to 90° using pressure film sensors. The FE model replicated and was validated against these measurements.
Results:
Medial compartment pressure decreased significantly from 1.864 MPa at 0° to 0.252 MPa at 90° (p < 0.05). The lateral compartment showed a similar significant decrease from 0.733 MPa to 0.320 MPa (p < 0.05). No significant differences were observed between conventional and robotic-assisted techniques (p > 0.05). The FE model demonstrated strong agreement with the measured data, with r2 values of 0.9994 (medial) and 0.9962 (lateral).
Conclusion:
Conventional and robotic-assisted UKA techniques demonstrated similar contact pressure profiles. However, increased force and area in the native lateral compartment may predispose to postoperative degeneration. The FE model reliably predicted contact behavior and may be especially useful in refining conventional UKA techniques.
Level Of Evidence:
Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.
