Does an ACL injury require additional peripheral stabilization? The rise of individualized ACL reconstruction

By: Daniel Günther, MD, PD, MHBA
Department of Orthopaedic Surgery, Trauma Surgery, and Sports Medicine,
Cologne Merheim Medical Center, Witten/Herdecke University, Germany

Reconstruction of the anterior cruciate ligament (ACL) is among the most frequent surgeries in orthopedics. After ACL rupture, it is important to treat anterior tibial translation instability and antero-lateral rotatory instability of the knee. Despite improved clinical and kinematic outcomes after anatomic ACL reconstruction, a subset of patients continues to exhibit persistent rotatory knee instability, as demonstrated by a positive pivot-shift phenomenon, or experiences a rerupture of the ACL^1,2.

Maybe such patients would have profited from an additional anterolateral extraarticular stabilization at the time of ACL reconstruction?

The indications and techniques of anterolateral stabilization have been a hot topic over the last decade. Initially, the discussion was inspired mainly by personal opinions rather than clear indications. The anatomy was rediscovered³, and a consensus statement⁴ conceptualized the experiences of the orthopedic community, giving rise to multiple biomechanical and clinical studies^5-9.

To date, it is known that many different factors contribute to rotatory instability of the knee, such as injuries to the menisci¹⁰, injuries to the periphery, or malaligned bone morphology¹¹ including an increased posterior tibial slope¹², a tomahawk-formed lateral femoral condyle¹³, and valgus or varus malalignment¹⁴.

It is important to address those risk factors surgically whenever possible. A meniscal root tear, a symptomatic medial meniscus ramp lesion, or a common meniscus tear should be fixed at the time of ACL reconstruction. An increased posterior tibial slope and/or a valgus or varus malalignment can be addressed with an osteotomy. There is ongoing debate about whether such osteotomies should be performed exclusively in revision ACL surgery or even in primary cases. Clear indications, such as the threshold of malalignment to perform an osteotomy in ACL surgery, must be further defined.

The indications for an antero-lateral stabilization must be further defined: The ACL graft choice might lead to persistent knee laxity. A prospective clinical trial showed that an anterolateral stabilization leads to clinically relevant reduction in graft rupture and persistent rotatory laxity at 2 years after ACL reconstruction using a hamstring tendon graft⁹. It will be interesting to see the results of an ongoing trial using the quadriceps tendon for ACL reconstruction, since the quadriceps tendon is biomechanically stiffer than the hamstring tendon.

It is important to mention that an anterolateral stabilization should not be a substitute for nonanatomic ACL tunnel placement. A high femoral ACL tunnel, like created in the past using a transtibial approach, may lead to sufficient anterior tibial translation stability, but not to sufficient rotatory stability of the knee.

In summary, ACL surgery has become increasingly more individualized, including different ACL graft options like the quadriceps, hamstring, patella, or peroneus longus tendons, osteotomies to address bony malalignment, specific techniques to address meniscus injuries like meniscus root or ramp repair, and the stabilization of the periphery including antero-lateral stabilization techniques.

A proficient sports surgeon aiming for optimized patient outcomes must include all these techniques in his or her “construction kit.” ACL surgery has improved tremendously during the last decade, but it has also become much more complex.

In the past, teaching younger surgeons the skills required to perform complex operations was mainly performed in the operating room by the senior surgeon assisting with parts of the operation. However, it is beneficial to increase the skill level of younger surgeons before entering the operation room to perform complex individualized surgeries. Like a pilot proving his or her skills in a flight simulator, a surgeon should perform well in a simulated setting before treating real patients. For this reason, cadaver courses to practice such techniques in a calm and professional atmosphere are crucial. AO Sports creates such a learning experience, and all ambitious sports surgeons can profit from experienced instructors and incredible course formats. I highly recommend the AO Sports courses to learn and improve techniques in individualized ACL reconstruction.

The indications for an antero-lateral stabilization must be further defined: The ACL graft choice might lead to persistent knee laxity. A prospective clinical trial showed that an anterolateral stabilization leads to clinically relevant reduction in graft rupture and persistent rotatory laxity at 2 years after ACL reconstruction using a hamstring tendon graft⁹. It will be interesting to see the results of an ongoing trial using the quadriceps tendon for ACL reconstruction, since the quadriceps tendon is biomechanically stiffer than the hamstring tendon.

It is important to mention that an anterolateral stabilization should not be a substitute for nonanatomic ACL tunnel placement. A high femoral ACL tunnel, like created in the past using a transtibial approach, may lead to sufficient anterior tibial translation stability, but not to sufficient rotatory stability of the knee.

In summary, ACL surgery has become increasingly more individualized, including different ACL graft options like the quadriceps, hamstring, patella, or peroneus longus tendons, osteotomies to address bony malalignment, specific techniques to address meniscus injuries like meniscus root or ramp repair, and the stabilization of the periphery including antero-lateral stabilization techniques.

A proficient sports surgeon aiming for optimized patient outcomes must include all these techniques in his or her “construction kit.” ACL surgery has improved tremendously during the last decade, but it has also become much more complex.

In the past, teaching younger surgeons the skills required to perform complex operations was mainly performed in the operating room by the senior surgeon assisting with parts of the operation. However, it is beneficial to increase the skill level of younger surgeons before entering the operation room to perform complex individualized surgeries. Like a pilot proving his or her skills in a flight simulator, a surgeon should perform well in a simulated setting before treating real patients. For this reason, cadaver courses to practice such techniques in a calm and professional atmosphere are crucial. AO Sports creates such a learning experience, and all ambitious sports surgeons can profit from experienced instructors and incredible course formats. I highly recommend the AO Sports courses to learn and improve techniques in individualized ACL reconstruction.