Introduction

The ever evolving concept anatomical anterior cruciate ligament ( ACL ) reconstruction warrants the graft to mimic the native anatomy of ACL , including it's tibial footprint dimensions as closely as possible for better knee kinematics , the clinical results of which have not been validated unequivocally.
This study aims to elucidate the clinical implications of restoring larger percentage of native ACL tibial insertion area by using hamstring autograft of adequate diameter in terms of objective knee stability and functional outcomes .

Methods

Over period of 2 years , 201 patients with ACL insufficiency who underwent arthroscopic ACL reconstruction using hamstring graft were enrolled in our study. Preoperative MRI and intraoperatively arthroscopic ruler was used to measure the footprint dimensions and the percentage of native ACL footprint area restored was calculated using tables.
The patients were divided into two groups depending upon the percentage of native ACL tibial footprint area restored . Group A, comprising of patients in which more than 70 percent area restored and Group B in which less than 70 percent area was restored . Pre and Postoperatively, patients were assessed objectively for knee stability using KT1000 and subjectively using Lysholm and International Knee Documentation Committee scoring systems.

Results

At average of 1 year follow-up, mean IKDC scores at the end of 12 months for group A ( >70% footprint area restored ) and group B (= 70 % footprint area restored ) were 89.28±4.74 and 79.22± 4.98 respectively (p-value < 0.05). The mean Lysholm scores at the end 12 months for Group A and B were 93.68 ± 2.71 and 88.02±2.8 respectively.(p-value < 0.05). The mean KT1000 scores at the end of 12 months for group A (>70% footprint area restored) and group B (= 70 % footprint area restored) were 0.37±0.66 and 0.39 ± 0.53 respectively ( p-value > 0.05 )

Conclusions

The functional outcomes in terms of the IKDC and Lysholm scores were better when ACL reconstruction procedure was able to restore more than 70% of the native ACL tibial footprint size while there was no objective difference in the knee laxity between the two groups.

Key words: anatomic ACL reconstruction , ACL footprint, hamstring graft diameter , functional outcomes