부산대학교 도서관

The studies in this thesis analyze femoral fixation of a hamstring graft for reconstruction of the anterior cruciate ligament (ACL). So far, the concept of isometry has been predominant when making the tunnel, in such a way that what was sought after was the graft having the same tension in all degrees of knee flexion. For this, the tunnel was located high and deep in the lateral femoral condyle. In recent years, the location of this tunnel has varied in the search for a more anatomic location for it (lower and more superficial). In recent years, one of the most used methods of fixation at the femoral level to fix this graft has been a system like the Cross-Pin (Stryker). It was originally designed for the realization of the tunnel in a non-anatomical location. However, the use of this system with an anatomical location was being done without studies that affirmed its safety with respect to the posterolateral structures of the knee. The first working hypothesis was that the use of the Cross-Pin fixation system, when a femoral tunnel was done in its anatomic location, endangered the posterolateral structures of the knee. In order to do it, a study with 10 human cadaver knees was conceived in which an ACL reconstruction was performed via arthroscopy. Subsequently, the knee was dissected and the distance from the Cross-Pin to various anatomical structures in the posterolateral region of the knee and the different bone structures was precisely measured. It was possible to objectify that this variation in the surgical technique jeopardized the posterolateral knee structures, primarily the lateral collateral ligament and the tendon of the popliteus muscle. The second study was aimed at introducing a change in the surgical technique that decreased this risk. It was hypothesized that if a tunnel longer than 30 mm (recommendation of the surgical technique) were made, the risk of damaging these structures would be less. A work, via arthroscopy, with 22 human cadaver knees divided into two groups was also designed. The knees in the first group had a tunnel of 30 mm in length done. On the other hand, the tunnel was as long as the condyle permitted in the second group. The knees were dissected and the measurements were performed as in the previous work. The conclusion was that the hamstring graft fixation from the anteromedial portal with a 30 mm femoral tunnel presents a higher risk of injury of the posterolateral structures of the knee. The femoral tunnel should be drilled as long as possible. Finally, a third study in which 2 guides for the initiation of femoral tunnel were compared was designed. The classical offset guide was compared to the newly designed BullsEye (Linvatec) guide. Fourteen paired human knees were used for it. Each of the 2 knees from the same donor was assigned to a group: the tunnel was made with one guide in the first group and the other guide with the other group. At the same time, whether the degree of flexion might be related to a greater length of the femoral tunnel was also compared. It was concluded that the BullsEye guide is more accurate in situating the femoral tunnel of the ACL in an anatomical position. In addition, the tunnels drilled with the 5 mm-offset guide produced shorter tunnels and had a greater risk of a rupture of the posterior wall of the tunnel. On the other hand, it might be concluded that the degree of knee flexion was unrelated to the length of the tunnel regardless of the guide used.