2015 ISAKOS Biennial Congress ePoster #1301

The Location of Femoral Tunnel Center with Different Femoral Footprint Guide Systems in Single Bundle ACL Reconstruction

Young-Jin Seo, MD, PhD, Hwaseong, Gyeonggi KOREA, REPUBLIC OF
Si-Young Song, MD, Hwaseong, Gyeonggi KOREA, REPUBLIC OF
Yon-Sik Yoo, MD, PhD, Hwaseong-Si, Gyeonggi-do KOREA, REPUBLIC OF
Myoung-Soo Cha, MD, Hwaseong, Gyeonggi KOREA, REPUBLIC OF
Yoon-Sang Kim, PhD, Cheonan, Chungcheongnam-do KOREA, REPUBLIC OF
Joon-Ho Koh, MS, Cheon An KOREA, REPUBLIC OF
Seong-Wook Jang, PhD, Cheonan, Chungcheongnam-do KOREA, REPUBLIC OF
Jong Min Kim, MD, Incheon KOREA, REPUBLIC OF

Hallym University Medical Center, Dongtan, Hwaseong, KOREA

FDA Status Not Applicable

Summary: standard offset guide system with a proper offset can provide the center of the femoral tunnel close to the anatomic center

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Abstract:

Introduction

To compare the center of the femoral tunnel which was drilled with a standard femoral tunnel guide versus a free-hand technique. Even though the femoral tuunel which was created with the help of the standard offset guide was reported to be placed in the anteromedial bundle oriented position, we hypothesized that the guide with a proper offset could place the tunnel more close to the anatomic center of the footprint compared to the tunnel with the freehand technique.

Methods

The study population included 32 cases who underwent anatomical single bundle ACL reconstruction and were able to take CT evaluation postoperatively. The author made an effort to place the femoral tunnel at the center of the femoral footprint using a transportal technique in all cases. The center of the femoral tunnel of 15 cases were marked using a microfracture awl without a help of a guide instrument (group I) and the femoral tunnel of the other 17 cases were established by use of a standard 6 or 7 mm offset femoral guide (group II). The doubled tibialis anterior allograft of 8 mm diameter was used as a graft in all cases. The diameter of the femoral reamer was also set to be 8 mm corresponding to the graft diameter. The DICOM file obtained from postoperative CT images was imported to a special software program (Rapidform 2006 INUS, Korea). The images of the medial femoral condyle was removed via the top of the incondylar notch roof in the sagittal plane to clearly visularize the lateral wall of the intercondylar notch. The center of the femoral tunnel of both groups were compared according to the quadrant method. The reference point of the femoral tunnel’s center was calculated based on the previous study. The statistical approach was done using SPSS.

Results

The center of the femoral tunnel in group I was calculated to be 40.6 ± 11.6 % in deep-shallow position of the quadrand method on the reconstructed 3D images. In group II, the location of the femoral tunnel was measured to be 29.2 ± 6.1 % in deep-shallow position, showing a significant difference between two groups (P = 0.024). The high-low position of the femoral tunnel according to the quadrand method on the reconstructed 3D images exhibited 44.3 ± 6.1 % in group I and 30.7 ± 7.1 % in group II with a significant difference (P =0.017).

Conclusions

Coordinates of the previous cadaveric study is very similar to the tunnel center in group II. The center of the femoral tunnel established by use of the free-hand technique (group I) exhibited a significantly shallower tunnel placement compared to that drilled with help of the offset guide (group II) confirming our hypothesis.