ISAKOS: 2019 Congress in Cancun, Mexico

2019 ISAKOS Biennial Congress ePoster #722


Can We Always Reproduce the Same Anatomical Femoral Tunnel Using Transportal Technique in Anterior Cruciate Ligament Reconstruction?: Variation of Femoral Tunnel Placement by Surgeon

Jai-Hyun Chung, MD, Seoul KOREA, REPUBLIC OF
Chong-Hyuk Choi, MD, PhD, Seoul KOREA, REPUBLIC OF
Jin-Young Jang, MD, Seoul KOREA, REPUBLIC OF
Sang-Woo Jeon, MD, Seoul KOREA, REPUBLIC OF
Kyung-Han Lim, MD, Yongsan City, Seoul KOREA, REPUBLIC OF

Yonsei University College of Medicine, Seoul, KOREA, REPUBLIC OF

FDA Status Not Applicable


Because of variation in each surgeon and inter-surgeon, it is necessary to make an effort to reduce variability and build an objective system for accurate femoral entry position using transportal technique in ACL reconstrucion



Anatomical reconstruction is known to be an effective way to reproduce the original ACL femoral insertion. Several studies have reported that the position of tunnel can be more anatomically made when using the transportal technique; therefore, anatomical reconstruction using transportal technique has been recently performed a lot in ACL reconstruction. However, when performing anatomical reconstruction, there is no precise guideline for knee flexion angle when performing femoral tunnel drilling, as well as a lack of objective guiding system for tunnel entry avoiding the destruction of posterior cortex. Therefore, there is a high possibility that portal entry is not located at the planned same position. The purpose of this study was to compare the femoral tunnel entry between two surgeons using the same surgical technique, and to figure out the variability of tunnel entry.


One hundred patients (100 knees), who underwent arthroscopic anatomical ACL reconstruction using transportal technique by two different orthopedic surgeons from 2010 to 2018, were included. For all patients, 3D computed tomography were taken after ACL reconstruction and reconstructed using Mimics program. Bernard's quadrant method was used to measure the femoral tunnel entry. Variability in one surgeon and the mean value between the two surgeons were compared using an independent two-sample t-test.

Although the mean value of relative depth of femoral tunnel from posterior wall (28.52% vs. 27.12%) and the relative height of femoral tunnel from Blumensaat line (24.51% vs. 26.09%) were not significantly different between two surgeons, the height difference from Blumensaat line (1.5%) was greater than the difference in depth from posterior wall (1.3%) (p <0.04). The range of measured values measured by standard deviation is quite wide, with the values from posterior wall to femoral tunnel in each surgeon being 28.52±5.11 vs. 27.12±3.92%, and those from Blumensaat line to femoral tunnel in each surgeon being 24.51±7.29 vs. 26.09±5.82%. These results show that the range of relative height of the femoral tunnel from inferior femoral condyle was greater. Although there was no significant difference in the mean value of femoral tunnel entry, variability in each surgeon was measured as being large.


Although anatomical femoral tunnel entry is located at the closest position to surgeon’s planning using transportal technique, variability is present in each surgeon in addition to inter-surgeon variability. Therefore, it is necessary to make an effort to reduce variability and build an objective system for accurate femoral entry position.