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.

In some cases, in patients with high-risk bony morphology, an osteotomy might not be feasible. This can be the case in professional athletes during their active careers. Another example is a patient with a high posterior tibial slope who can already hyperextend the knee. In such a case, a slope-decreasing extension osteotomy would lead to even more hyperextension and should not be performed. A third example is a patient with a tomahawk- formed lateral condyle that cannot be addressed by an osteotomy. In such patients and in patients with generalized ligamentous laxity¹⁵, or chronic ACL injuries when the anterolateral complex may stretch over time¹⁶, an additional extraarticular stabilization may be an appropriate option to decrease rotatory instability and prevent ACL rerupture.

Different techniques of anterolateral stabilization have been described in the past, including the Lemaire technique¹⁷, the reconstruction of the anterolateral ligament¹⁸, or the MacIntosh¹⁹ procedure. Even if the specific indications for each technique are still unclear, each technique has certain advantages and disadvantages. A graft attached proximal to the lateral femoral epicondyle and running deep to the lateral collateral ligament, as in a Lemaire or MacIntosh procedure, will not result in excessive tightening or slackening during knee motion and may be preferable⁷. However, a chronic ACL injury with a stretched anterolateral complex may be sufficiently addressed with an anterolateral ligament reconstruction. Different fixation techniques for anterolateral stabilizations are on the market. The fixation can be conducted using screws, staples, or an anchor. If using a screw as femoral fixation, tunnel convergence of the femoral ACL tunnel and the anterolateral tunnel can be a pitfall and should be prevented.

Some may suggest that adding an anterolateral stabilization to all ACL reconstructions may be an option. However, the operation time is slightly prolonged, and some patients suffer from discomfort on the lateral side of the knee after undergoing an anterolateral stabilization. The anterolateral stabilization can lead to overconstraint of the lateral compartment with unclear clinical results in the long term⁶. The role of the self-healing capacity of the anterolateral complex has not been evaluated. A stretched anterolateral complex in chronic ACL insufficiency might contract as soon as the ACL is anatomically reconstructed.

In some cases, in patients with high-risk bony morphology, an osteotomy might not be feasible. This can be the case in professional athletes during their active careers. Another example is a patient with a high posterior tibial slope who can already hyperextend the knee. In such a case, a slope-decreasing extension osteotomy would lead to even more hyperextension and should not be performed. A third example is a patient with a tomahawk- formed lateral condyle that cannot be addressed by an osteotomy. In such patients and in patients with generalized ligamentous laxity¹⁵, or chronic ACL injuries when the anterolateral complex may stretch over time¹⁶, an additional extraarticular stabilization may be an appropriate option to decrease rotatory instability and prevent ACL rerupture.

Different techniques of anterolateral stabilization have been described in the past, including the Lemaire technique¹⁷, the reconstruction of the anterolateral ligament¹⁸, or the MacIntosh¹⁹ procedure. Even if the specific indications for each technique are still unclear, each technique has certain advantages and disadvantages. A graft attached proximal to the lateral femoral epicondyle and running deep to the lateral collateral ligament, as in a Lemaire or MacIntosh procedure, will not result in excessive tightening or slackening during knee motion and may be preferable⁷. However, a chronic ACL injury with a stretched anterolateral complex may be sufficiently addressed with an anterolateral ligament reconstruction. Different fixation techniques for anterolateral stabilizations are on the market. The fixation can be conducted using screws, staples, or an anchor. If using a screw as femoral fixation, tunnel convergence of the femoral ACL tunnel and the anterolateral tunnel can be a pitfall and should be prevented.

Some may suggest that adding an anterolateral stabilization to all ACL reconstructions may be an option. However, the operation time is slightly prolonged, and some patients suffer from discomfort on the lateral side of the knee after undergoing an anterolateral stabilization. The anterolateral stabilization can lead to overconstraint of the lateral compartment with unclear clinical results in the long term⁶. The role of the self-healing capacity of the anterolateral complex has not been evaluated. A stretched anterolateral complex in chronic ACL insufficiency might contract as soon as the ACL is anatomically reconstructed.