Medial portal reaming may allow for the creation of a more anatomically positioned femoral tunnel during Anterior Cruciate Ligament (ACL) reconstruction. However, this technique also results in a shorter tunnel which may make fixation difficult. The purpose of this study is to determine the average length of a femoral tunnel created using a medial portal technique and to correlate this with patient gender, height and Body Mass Index (BMI).

Fifty-four consecutive patients underwent ACL reconstruction with a femoral tunnel created using a medial portal technique. The tunnels were created using a spade tip guide pin (Arthrex, Naples, FL) with the goal of creating the tunnel in the 2-2:30 o'clock position (left knee) or 9:30-10 o'clock position (right knee). The total osseous length of the femur (TOL) was measured using a depth gauge. Descriptive statistics of the TOL were calculated and bivariate correlation coefficients (Pearson r) were calculated to determine the relationship between TOL and patient height and weight.

The mean TOL was found to be 33.77 ± 5.27 mm (24-50 mm). TOL was found to correlate with patient height (r=0.32, r²=0.10, p=0.04) and was not correlated to weight (r=0.24, r²=0.06, p=0.15) or BMI (r=0.06, r²=0.004, p=0.7). Men had a greater TOL (34.91 ± 5.4) than women (32.13 ± 4.80) but this difference was not found to be statistically significant (p=0.10).

ACL reconstruction using a medial portal yields a mean total osseous length of 33.77 mm. This length is significantly correlated with patient height.

ACL reconstruction using a medial portal approach to femoral reaming can lead to tunnels as short as 24 mm. Patient height may be a useful clinical tool to indicate the potential for a short femoral tunnel.