Publication:

Preoperative prediction of length of the femoral tunnel in single bundle anterior cruciate ligament reconstruction in knee MRI

Background This study aims to find the correlation between the length of the femoral tunnel and morphological parameters of the knee in the magnetic resonance imaging (MRI) before anatomical single-bundle anterior cruciate ligament (ACL) reconstruction and if these variables can be used for preoperative prediction.

Methods A prospective study of 30 patients undergoing ACL reconstruction by the same surgeon. Anthropometric measurements (weight, height, BMI) and knee morphological parameters were assessed using MRI. These included anteroposterior (AP) knee length, trans-epicondylar length, axial notch area, notch outlet length, posterior condyle length, notch width index (NWI), Blumensaat's line length, and lateral wall of the notch dimensions. Intraoperative femoral tunnel length was measured and correlated with these parameters.

Results A strong positive correlation was found between patient height and femoral tunnel length (r=0.797, p<0.001). Significant positive correlations were also observed between femoral tunnel length and both AP length of the knee (r=0.355, p=0.04) and trans-epicondylar length (r=0.377, p=0.040). Interestingly, a moderate negative correlation was found between BMI and femoral tunnel length (r=-0.425, p=0.019).

Conclusions Patient height, AP knee length and trans-epicondylar length could be helpful predictors of femoral tunnel length in preoperative planning for in single-bundle ACL reconstruction.