2025 ISAKOS Biennial Congress ePoster
Safe Sawing Conditions to Prevent Popliteal Artery Injury in Various Distal Femoral Osteotomies: 3-dimensional Simulation Analysis
Junhee Cho, MD, Seoul KOREA, REPUBLIC OF
Se-Han Jung, MD, Seoul KOREA, REPUBLIC OF
Min Jung, MD, PhD, Seoul KOREA, REPUBLIC OF
Kwangho Chung, MD, Seoul KOREA, REPUBLIC OF
Hyun-Soo Moon, MD, PhD, Seoul KOREA, REPUBLIC OF
Sung-Hwan Kim, MD, PhD, Seoul KOREA, REPUBLIC OF
Severance hospital, Seoul, Seoul, KOREA, REPUBLIC OF
FDA Status Cleared
Summary
The safety margin when performing osteotomies in various DFO scenarios may vary. When performing DFO, it is essential to be aware of safety tips related to the course of the popliteal artery and the normal curvature of the femoral posterior cortex
ePosters will be available shortly before Congress
Abstract
Purpose
To determine the safe sawing angles in distal femoral osteotomy (DFO) to prevent the popliteal artery injury and to elucidate the artery’s course and the distances from key structures to the artery within the osteotomy plane.
Methods
Three-dimensional reconstructions of the popliteal artery and femur were created from computed tomography angiography scans of 27 patients with healthy popliteal arteries. To simulate medial closing wedge (MCW) and lateral closing wedge (LCW) DFO, after forming the osteotomy plane that passes the designated hinge point and primary cutting start point, the plane was rotated by 5° and 10° to create the 0°, 5°, and 10° osteotomy planes. The minimum distances to popliteal artery from posterior cortex and posterior cortical line (dPA-PC, dPA-PCL) were measured in each osteotomy plane. A distance of less than 10 mm was defined as ‘at-risk’, and an at-risk ratio was calculated for each condition. Frontal safe sawing index (FSSI), maximal safe sawing angles (MSSA), maximal safe osteotomy angles (MSOA) were analyzed to evaluate the safety margin.
Results
The FSSI was significantly higher in MCW-DFO than LCW-DFO across all osteotomy planes (P<0.001). In MCW-DFO, FSSI decreased with higher degree upper cuts (P<0.001), while in LCW-DFO, FSSI increased but not significantly (P=0.058). The average minimal distance to the popliteal artery from the posterior cortex ranged from 13 to 14 mm in all DFO simulations. Both MCW-DFO and LCW-DFO showed a decrease in dPA-PC with higher degree cuts (P<0.001), and dPA-PCL was consistently shorter than dPA-PC (P<0.001). The at-risk ratio of dPA-PCL was significantly higher than that of dPA-PC in all conditions, indicating the potential benefit of performing cuts along the normal curvature of the cortex than cutting straightly. The MSSA for MCW-DFO was around 5°, with no significant variation between osteotomy planes. LCW-DFO had a smaller safety margin compared to MCW-DFO when performing osteotomy with sawing, considering the 95% confidence interval of MSSAs. However, MSOA values were higher in LCW-DFO than MCW-DFO (P<0.001). The dPA-PC was correlated with height, weight, body mass index, and transepicodylar distance (P<0.05).
Conclusion
The safety margin when performing osteotomies in various DFO scenarios may vary. When performing DFO, it is essential to be aware of safety tips related to the course of the popliteal artery and the normal curvature of the femoral posterior cortex.
Level of Evidence: Level II, Controlled laboratory study