Background Female patients undergoing arthroscopic anterior cruciate ligament reconstruction with hamstring tendon graft developed increased post-operative laxity compared to male and female patients who had been reconstructed using patellar tendon graft.

Hypothesis Supplementary tibial fixation in female patients will reduce laxity.

Study Design Prospective, randomized, double-blinded clinical trial.

Methods Fifty-six female patients divided into two groups (standard tibial fixation versus supplementary staple fixation) were followed for 2 years.

Results After 2 years the mean side-to-side difference utilizing KT-1000 arthrometer manual maximum measurements was 1.8 mm (standard group) and 1.1 mm (staple group) (p=0.05). A Grade 0 Lachman test was present in 63% of the standard group and 86% of the staple group (p=0.04). Kneeling pain was experienced by 7% of the standard group and 29% of the staple group (p=0.05).

Conclusions Supplementary tibial fixation in female patients undergoing ACL reconstruction with hamstring tendon graft and interference screw fixation with a single screw size significantly improves laxity measurements and clinical stability assessment 2 years postoperatively. However, this is at the cost of increased kneeling pain.