2015 ISAKOS Biennial Congress ePoster #1281
Study on the Direction of Femoral Tunnel Movement in Anatomical Double-Bundled Anterior Cruciate Ligament Reconstruction
Masaki Yoda, MD, PhD, Anjo, Aichi JAPAN
Shigeo Takahashi, MD, PhD, Nagoya, Aichi JAPAN
Kazutoshi Kurokouchi, MD, PhD, Nagoya, Aichi JAPAN
Tadahiro Sakai, MD, PhD, Toyota, Aichi JAPAN
Hideki Yamamoto, MD, Nagoya, Aichi JAPAN
Ryuichiro Yamamoto, MD, PhD, Nagoya, Aichi JAPAN
Naoki Ishiguro, Prof., Nagoya, Aichi JAPAN
Mitsubishi Nagoya Hospital , Nagoya, Aichi, JAPAN
FDA Status Cleared
Summary: To reduce femoral tunnel enlargement after anatomical double-bundled ACL reconstruction, it is necessary at the time of reconstruction that the positions of the centers of both tunnels be prepared in the direction which assures that the t values by the quadrant method become as large as possible and that the distance between the two tunnels and that between the septa becomes as short as possible.
We investigated the movement directions of central femoral tunnel positions in anatomical double-bundled anterior cruciate ligament reconstruction compared with the early postoperative phase positions. We also examined the relationship between central femoral tunnel positions and femoral tunnel enlargement.
Among patients who underwent anatomical double-bundled anterior cruciate ligament reconstruction between August 2008 and August 2011, we investigated 117 (61 men and 56 women) with available 3-dimensional computed tomography (3D-CT) images taken in an early postoperative phase and 1+ years after reconstruction. The mean period between reconstruction and the last 3D-CT images was 20.5 (12–41) months, mean patient height was 167.1 cm, mean body weight was 62.4 kg, and mean age at the time of reconstruction was 25.9 years. The femoral tunnels for the anteromedial bundle (AMB) and posterolateral bundle (PLB) were both prepared using the far anteromedial portal technique, and tunnels were confirmed to be in the anatomical positions in all patients by early postoperative 3D-CT. Patients who had undergone combined ligament reconstruction or had fused tunnels or femoral posterior wall destruction were excluded. In the early postoperative phase and at the last 3D-CT imaging, the distance from behind the Blumensaat line (B line) on the central positions of the tunnels (t value) and that from the B line along the perpendicular line to the B line (h value) were calculated as percentages by the quadrant method. The distances between the centers of the tunnels, between the septa, and the tunnel areas were also measured. These measurements were statistically analyzed.
The positions of the tunnel centers (h value/t value) in the early postoperative phase were 24.6/19.1% for AMB and 51.9/30.7% for PLB, and those at the last imaging were 21.6/20.4% and 48.2/33.8%, respectively. Thus, h values of the central positions of both tunnels were significantly decreased, while t values were significantly increased. The distance between the tunnel centers at the last imaging was significantly increased compared with that in the early postoperative phase, and the distance between the septa at the last imaging was significantly decreased compared with that in the early postoperative phase. The enlargement rates of both tunnels correlated negatively with the t values in the early postoperative phase and positively with the distance between the tunnels and the distance between the septa in the early postoperative phase. The enlargement rates of the two tunnels correlated positively with the change in t-values; however, there was no correlation with the change in the h values.
In order to reduce femoral tunnel enlargement after anatomical double-bundled anterior cruciate ligament reconstruction, it is necessary at the time of reconstruction that the positions of the centers of both tunnels be prepared in the direction which assures that the t values become as large as possible within the anatomical range and that the distance between the two tunnels and that between the septa becomes as short as possible.