Reply to the comments by Dr. Özer et al. on our article “Anatomic double-bundle ACL reconstruction with femoral cortical bone bridge support using hamstrings”

Abstract

Dear Editor, We would like to thank Dr. Ozer et al. for the comments regarding our article ‘‘Anatomic double-bundle ACL reconstruction with femoral cortical bone bridge support using hamstrings’’ [4]. We shall attempt to answer each of them in turn. We do, indeed, create the femoral tunnels using the outside-in technique via a small incision (1.5–2 cm) on the lateral femoral epicondyle, a procedure which in no way affects the posterior knee capsule. In our experience, neither the ACL technique outlined in the article, nor another that we used previously in which the femoral tunnels were also created via the outside-in technique [3] have led to any morbidity that could be attributed to the use of said method. The k-wires are inserted via the femoral lateral epicondyle, either at the same angle as the frontal plane of the femur or gently inclined from front to back, and in a slightly craniocaudal direction, entering the joint via the previously-located insertion points on the two ACL bundles (4–5 mm distal to the over the top position and posterior to the roof of the notch in the case of the AM bundle and 9–10 mm distal to the AM bundle and 4–5 mm anterior to the posterior margin of the articular cartilage of the lateral femoral condyle for its PL counterpart). We agree that chamfering the edges of the tunnels may reduce graft friction; however, we have never experienced any problems of this nature either. Though our earlier method [3] resolved the problem in question, one of our main concerns while developing our current technique was that the graft might be too short. We therefore measured the graft and calculated the length required for reconstruction (Table 1 shows that in all cases, the length used was more than sufficient). With regard to graft thickness, it is true that when hamstrings are used, one end of the graft is thinner than the other due to its tendofascial structure. The end in question, however, is the one whose length exceeds that required and will ultimately be cut in any case. As for the thickness of the AM bundle, we concur with other authors [1, 2, 5] that 6–7 mm is sufficient, especially if we take into account that we are performing an anatomical double-bundle reconstruction in which stability is guaranteed by both bundles. We also agree that the fixation screw used should be as long as possible; however, the longest available is 30 mm. The maximum length of the ones used in our technique (Biosteon, Stryker Endoscopy San Jose, CA) for diameters of less than 9 mm is 28 mm. Finally, we concur that increased fixation may be achieved by inserting a further screw in the PL tunnel.