Changing the ACL Reconstruction Algorithm from Transtibial Technique with Hamstring to Independent Tunnels Technique with Patellar Tendon is Associated with a more Physiological Knee Laxity but this is not Reflected in Dramatically Improved Perceptions of Life Quality and Activity Levels at 5-to-10 year follow-up

Introduction:
Activity level at 5-to-10 years after ACL reconstruction represent a multifactorial process. The surgical technique is only one factor among others such as preinjury activity levels, lifestyle modifications and changes in family status, and others not necessarily related to the knee injury. The purpose of this study was to test whether changing the surgical algorithm from transtibial drilling technique using hamstring to independent tunnels technique using patellar tendon result not only in a more physiological knee laxity but also in higher activity levels and improved perceptions of life quality at this follow-up.

Materials and Methods:
Transtibial ACL reconstructions using autologous hamstring tendons performed between 2004 and 2010 were compared to independent tunnels ACL reconstructions using autologous bone-patellar-tendon-bone performed between 2011 and 2016. Inclusion criteria were: age 18-35 years, male sex, sports trauma, 5-10 years follow-up. Exclusion criteria were: contra-lateral ACL tear, revision ACL reconstruction during follow-up, and concomitant lower limb surgery. Outcome measures were compared between the groups.

Results:
There were eligible and available 55 patients in the transtibial hamstring and 35 patients in the independent tunnels patellar tendon group (comment: data collection of the patellar tendon group is estimated to include finally over 50 patients once all patients are invited to the follow-up test in the next 2-3 months). At follow-up, KT-1000 was 2.8±2.3 vs. 1.6±1.8 (p<0.05), high grade pivot shift (2+ or higher) was recorded in 35% vs. 6% of the cases (p<0.01). Marx score was 6±5 in both groups, KOOS-ADL 94±9 vs. 94±8, IKDC-subjective 82±13 vs. 87±12, KOOS-sports 74±20 vs. 77±15, and KOOS- QOL 58±24 vs. 63±21 (p>0.05 for all comparisons).

Conclusions:
Changing the ACLR algorithm from transtibial technique with hamstring tendons to independent tunnels technique with bone-patellar tendon-bone clearly results in a more physiological knee laxity and decreased proportion of high-grade pivot shift at 5-to-10 year follow-up. However, at this follow-up frame, both groups show similar Marx activity scores, "Excellent" KOOS-ADL, and favorable IKDC-subjective, KOOS-sports and KOOS-QOL scores without dramatic advantage to the independent tunnels bone-patellar tendon technique.