Reply to the Letter to the Editor: Does Combined Intra- and Extraarticular ACL Reconstruction Improve Function and Stability? A Meta-analysis

We would like to thank Dr. Tashman for his interest in our article, and for raising interesting questions concerning the combined ACL reconstruction technique.

Regarding the potentially damaging increased forces on cartilage, it is impossible to confirm the association of an additional extraarticular procedure with osteoarthritis (OA) with the present data. There are studies addressing both this correlation and its absence [4, 6]. A long-term study correlated the OA with medial meniscectomy, but not with the additional extraarticular procedure. There was no associated lateral OA, and the medial OA was related to medial meniscectomy in a study including 54 patients with 11 years followup [4]. Nevertheless, studies correlating the extraarticular procedure with OA of the lateral compartment [6] can also be found. Therefore, we agree that this topic requires further clarification regarding biomechanical aspects to elucidate whether the addition of the extraarticular procedure contributes to an overconstrained knee.

The assessment of different extraarticular techniques, and their varying degrees of rotation for graft fixation, are needed in order to determine if there is any overtightening in internal rotation. Due to the evolution of these graft procedures, randomized clinical studies examining the current techniques are also needed. However, the present meta-analysis did not find an association of OA with the addition of an extraarticular procedure at 2 to 7 years followup (Fig. 1). Even so, we do agree that longer-term followup studies are needed; confounding factors such as meniscal and chondral lesions should be excluded in order to determine the extent of overconstraining the joint after combined ACL reconstruction.

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As mentioned, further studies are necessary to determine the possible clinical benefits of extraarticular procedures when performing ACL reconstructions. However, the important finding of reduced laxity added by the combined extraarticular procedure leads to the current question: What are the most-appropriate indications for an additional extraarticular procedure? Certainly it is not indicated for all ACL lesions, but it has its place in some situations. Identifying those indications should be the motivation for adding an additional procedure that might indeed further constrain AP laxity and internal rotation. As suggested by Dr. Baumfeld [2], further randomized trials comparing current anatomic ACL reconstruction techniques with and without an anterolateral ligament reconstruction are required to determine whether the procedure is worthwhile, in light of its added surgical time and risk. Perhaps the best way to reconcile Dr. Baumfeld’s call for randomized trials with Dr. Tashman’s concerns about extra-articular procedures would be to focus on his idea that extra-articular procedures should not be used “routinely,” to identify those knees that might really benefit from the additional procedure, and then to compare anatomic ACL reconstructions with extra-articular procedures in only these situations. Based on our meta-analysis and recent relevant work [7, 8, 9], we believe those indications might include in knees at particular risk for failure, perhaps those with a Grade 3 pivot shift, those with chronic ACL lesions, and those presenting with a positive pivot shift after ACL reconstruction and undergoing revision as supported by recent studies. Additional indications could include (with some discretion and discussion needed in each case) high-level athletes, athletes who participate in pivoting sports, knees with a lateral femoral notch sign, those presenting with a Segond fracture, and revision procedures using intraarticular allograft material [5, 7, 8, 9]. We believe that extraarticular additional procedures are only used in specific situations, rather than routinely.

We believe that ACL lesions and relesions, due to their great myriad of clinical presentations, should not be treated with standard isolated intraarticular reconstruction for every case. But our present data do not show any clear association between the combined procedure and the development of OA at followup of 1 to 7 years.