Clinical and biomechanical outcome analysis of ACL reconstruction with or without Lateral Exta-articular Tenodesis

The anterior cruciate ligament (ACL) is a ligament located in the knee. The most important function of this ligament is to prevent tibial anterior translation, but it also has an important role in limiting internal rotation of the tibia. ACL rupture is a very common knee-injury that is often sustained during sports, especially in cutting and pivoting sports such as rugby, skiing, and football. A study performed in 2009 showed that about 80% of surgeries performed on knee ligaments concern the ACL and 65% of ACL injuries that were operated on occurred during sports.

ACL reconstruction (ACLR) is reported to produce good or excellent results in more than 90% of the patients and 85% achieved a good outcome in terms of activity bases measures. Despite these good results, there is a low number of patients that can return to the same level of sport they had before. Approximately 80% return to a type of sports participation, but only 44% could resume competitive sport. This shows that other factors than knee function are involved as regards to return to sport. According to a study of Lentz et al. (2014), function and return to sport is also influenced by the fear for re-injury, quadriceps weakness, lack of confidence and reduced IKDC score, despite low average pain ratings. These parameters should be assessed to help identify patients at risk for not returning to their usual sport activities.

To prevent these complaints of instability, anterolateral and rotational laxity, and high failure rate after ACLR, a new extra-articular technique is already taken under consideration for many years, namely the use of an additional lateral extra-articular tenodesis (LET) combined with the ACL reconstruction with an autograft. It has been demonstrated that the use of a LET has many advantages. Recent research by Getgood et al. (2020) shows that performing LET on top of ACLR in young patients who are at high risk of failure reduces the frequency of graft rupture and persistent rotatory laxity significantly 2 years postoperatively. Also the systematic review by Hewison et al. (2015) shows a significant reduction in pivot shift in favour of the combined procedure. Further a 20-year follow-up study by Zaffagnini et al. (2017) shows good control of laxity in patients with the addition of a LET, but the tenodesis had no influence on later occur of osteoarthritis. Herbst et. Al found that LET with ACL reconstruction restored stability in a combined ACL-injured and anterolateral structures injured knee.

The aim of this study is to investigate if the addition of a LET supports the biomechanical and functional outcome after ACLR.