Anterior Cruciate Ligament Reconstruction Using a Ribbon-Like Graft With a C-Shaped Tibial Bone Tunnel.
ABSTRACT: According to recent anatomic studies, the anterior cruciate ligament (ACL) appears to be a flat, "ribbon-like" structure, with a thin, oval-shaped insertion on the femur and a C-shaped tibial insertion. According to this anatomy, we describe an ACL-reconstruction technique that aims to approximate this natural anatomy. The basic principle of this technique is not to use conventional round tunnels but create tunnel shapes that resemble more closely the original ACL insertion sites. Using either a rectangular quadriceps tendon graft or a "flat" hamstring graft may not only provide a biomechanical advantage with increased rotational stability but also improve bone-tendon healing due to increased bone-tendon contact and decreased diffusion length. Creating a C-shaped tibial tunnel also avoids laceration of the anterior horn of the lateral meniscus, which is frequently harmed during conventional tibial tunnel drilling.
Project description:Conventional single-bundle anterior cruciate ligament (ACL) reconstruction cannot improve the rotational stability of the knee. Traditional double-bundle ACL reconstruction requires is demanding, complex, time- and implant consuming, and associated with a high incidence of complications. Double-bundle ACL reconstruction using a free quadriceps tendon autograft through 3 independent tunnels provides some advantage, but the antegrade graft passage, tibial tunnel confluence, and graft site morbidity represent disadvantages. This Technical Note describes a modification of double-bundle ACL reconstruction using the hamstring tendon autograft through a single branched tibial tunnel and a single femoral tunnel using 2 interference screws (Arthrex, Naples, FL). The gracilis tendon autograft is passed through tibial tunnel stem to the posterolateral tibial tunnel branch to the posterolateral position in the femoral tunnel. The semitendinosus tendon autograft is passed through the tibial tunnel stem to the anteromedial tibial tunnel branch to the anteromedial position in the femoral tunnel. Both grafts are fixed by 2 interference screws: 1 at the femoral tunnel and 1 at the tibial tunnel stem with the knee at 20° flexion.
Project description:We present a technique for anterior cruciate ligament (ACL) reconstruction using hamstring tendon autograft with preserved tibial insertions. The tendons, harvested with an open-ended tendon stripper while their tibial insertions are preserved, are looped around to prepare a quadrupled graft. The femoral tunnel is drilled independently through a transportal technique, whereas the tibial tunnel is drilled in a standard manner. The length of the quadrupled graft and loop of the RetroButton is adjusted so that it matches the calculated length of both tunnels and the intra-articular part of the proposed ACL graft. After the RetroButton is flipped, the graft is manually tensioned with maximal stretch on the free end, which is then sutured to the other end with preserved insertions. We propose that preserving the insertions is more biological and may provide better proprioception. The technique eliminates the need for a tibial-side fixation device, thus reducing the cost of surgery. Furthermore, tibial-side fixation of the free graft is the weakest link in the overall stiffness of the reconstructed ACL, and this technique circumvents this problem. Postoperative mechanical stability and functional outcome with this technique need to be explored and compared with those of ACL reconstruction using free hamstring autograft.
Project description:Allograft healing (ligamentization) after reconstruction of the anterior cruciate ligament (ACL) is dependent on multiple factors, including tissue processing, host biologic environment, and biomechanical stressors. Magnetic resonance imaging (MRI) can be used to assess graft maturation after ACL reconstruction.A significant difference will exist in the MRI analysis between 2 distinct allograft constructs. Specifically, the MRI signal-to-noise quotient (SNQ) value will be smaller in quadrupled hamstring tendon (HT) allografts compared with doubled tibialis anterior (TA) allografts due to the difference in graft geometry (surface area-to-volume ratio).Cohort study; Level of evidence, 2.Prospectively collected data from a subset of patients who participated in a randomized controlled trial at a single center from July 2010 to April 2012 were reviewed. Patients underwent ACL reconstruction using either HT or TA allografts. Six months postoperatively, 32 patients underwent noncontrast MRI to assess ligamentization. The SNQ was calculated for the allograft using sagittal noncontrast T2-weighted MRI as follows: SNQ = (Sgraft - Sqaudriceps )/Sbackgroud . Graft properties including sagittal and coronal angle as well as tibial and femoral tunnel location were measured. All participants completed validated patient-reported outcome measures preoperatively and at 2 years postoperatively.The mean MRI SNQ for the HT and TA allografts was 2.56 ± 2.41 and 3.15 ± 3.38, respectively (P = .57). For the entire group, there was a significant correlation between MRI SNQ and both sagittal graft angle (P = .02) and sagittal tibial tunnel position (P < .001). We did not find a significant correlation between the tibial tunnel location in the coronal plane, coronal graft angle, or location of the femoral tunnel and the MRI SNQ.Allograft ligamentization 6 months postoperatively, as assessed by MRI, is dependent on position of the tibial tunnel in the sagittal plane as well as sagittal graft orientation. We did not detect a difference in graft maturation at 6 months between the tibialis anterior and hamstring tendon allografts. This is the only study to our knowledge that directly compares quadrupled HT allografts and doubled TA allografts using postoperative MRI.
Project description:Many techniques have been described for anterior cruciate ligament (ACL) reconstruction in skeletally immature patients, including extra-articular, complete or partial transphyseal, and physeal-sparing techniques. An all-epiphyseal technique places the tendon and its tunnels and fixation all within the child's epiphysis, leaving the growth plates untouched. We describe an all-epiphyseal quadruple-hamstring ACL reconstruction using a split tibial tunnel. The split tibial tunnels drop the tunnel size down to 4.5 to 5.5 mm from 7 to 8 mm because only half the total graft diameter passes through each of the split tunnels. This increases the safety margin for keeping the tunnel within the tibial epiphysis, in addition to avoiding damage into the growth plate. The bone bridge between the 2 tunnels serves as a solid low-profile fixation post. Femoral graft fixation is achieved with an interference screw, which allows precise tensioning and low-profile fixation entirely within the femoral tunnel. By placing the graft at the native ACL's anatomic attachment points without spanning or violating the growth plates at any step of the procedure, an all-epiphyseal ACL reconstruction with a split tibial tunnel theoretically minimizes the risk of growth disturbance in an ACL-deficient child.
Project description:Combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries are the most common type of combined ligamentous injury of the knee. The optimal treatment for these combined injuries is controversial. Combined ACL and MCL-posterior oblique ligament (POL) reconstruction avoids late anteromedial rotatory instability and chronic valgus instability of the knee and decreases the increased stress on the ACL graft. Graft choice (hamstring tendon autograft, quadriceps bone-patellar tendon-bone autograft, or Achilles tendon allograft) and anatomic restoration of the medial and posteromedial corner of the knee are challenges of this combined reconstruction. This article describes a technique that allows combined ACL and MCL-POL reconstruction. The hamstring tendons from the contralateral limb are tripled and used as the ACL graft. The gracilis tendon from the ipsilateral limb is doubled and used as the MCL-POL graft. The semitendinosus tendon of the ipsilateral limb is preserved. After ACL reconstruction, the MCL-POL graft is suspended on the ACL graft at the distal end of the tibial tunnel and the graft limbs are used for open reconstruction of the MCL and POL. Three interference screws (Arthrex, Naples, FL) and 1 metal staple are used for graft fixation of this combined reconstruction.
Project description:Background/objective:The purpose of the study was to evaluate the change in orientation of the reconstructed ACL with the change in position of the interference screw in the tibial tunnel. Method:It was a retrospective review of Magnetic Resonance Imaging (MRI) in which 51 normal and 61 MRI of patients who had undergone ACL reconstruction at our institute were evaluated. Postoperative ACL reconstruction group MRI studies were obtained and evaluated by two sports medicine fellows independently to assess the position of interference screw, distance of the graft from the anterior cortex of tibia and inclination of the graft. The data was collected and compared with MRI data of normal ACL patients. Results:There were total 61 patients with ACL reconstruction. 32 patients had anterior screw placement and 29 patients had posterior screw placement in the tibial tunnel. The distance of the graft from the anterior cortex was 39.18% in ACL intact group, 50.35% in anterior screw group and 41.64% in posterior screw group. The inclination angle was 44.49? in intact group, 49.69° and 42.20° in anterior and posterior screw group respectively. The difference between intact group and anterior screw group was statistically significant. Conclusion:Posterior position of interference screw in tibial tunnel increases graft obliquity than anterior position and decreases its distance from the anterior tibial cortex. This increased graft obliquity and distance from the anterior tibial cortex is similar to the native ACL.
Project description:Anterior cruciate ligament (ACL) reconstruction with preservation of either the remnant or the tibial stump is performed with the hope of improving the vascularization and proprioceptive function of the graft. Remnant preservation is technically difficult because it hinders the visualization of the intra-articular tunnel site. Taking a cue from the concept of tibial stump preservation, we have modified our ACL reconstruction technique to preserve a sleeve of the soft tissue and ACL stump attached to the femoral condyle, in addition to tibial stump preservation, while still allowing adequate visualization of the femoral ACL insertion site. We describe our modification in this article and hypothesize that this should further improve graft vascularization and ligamentization.
Project description:Preservation of the anterior cruciate ligament (ACL) remnant during ACL reconstruction has the advantages of improved vascularity and synovial encircling of the graft tendon. We describe a technique called single-anteromedial bundle biological augmentation (SAMBBA) using complete preservation of the ACL remnant, as well as preservation of the semitendinosus tibial insertion, that uses standard portals and equipment.
Project description:Cadaveric and clinical biomechanical studies show improved kinematic restoration using double-bundle anterior cruciate ligament (ACL) reconstruction techniques. These have been criticized in the past for being technically challenging. We present a novel 3-socket approach for anatomic "all-inside" double-bundle reconstruction using a single hamstring tendon fashioned to create a trifurcate graft: the TriLink technique. The semitendinosus alone is harvested, quadrupled, and attached to 3 suspensory fixation devices in a Y-shaped configuration, creating a 4-stranded tibial limb and 2 double-stranded femoral limbs. A medial viewing/lateral working arthroscopic approach is adopted using specifically designed instrumentation. Anatomic placement of the 2 femoral tunnels is performed by a validated direct measurement technique. A single mid-bundle position is used on the tibia. Both femoral and tibial sockets are created in a retrograde manner using outside-to-in drilling. This is a simplified operative technique for anatomic double-bundle ACL reconstruction that maximizes bone preservation. The TriLink construct replicates the 2 bundles of the ACL, conferring native functional anisometry and improving femoral footprint coverage while avoiding the complexities and pitfalls of double-tibial tunnel techniques. Preservation of the gracilis reduces the morbidity of hamstring harvest and allows greater flexibility in graft choice in cases requiring multiligament reconstruction.
Project description:The planar topography of the anterior cruciate ligament (ACL) insertion was investigated and correlated to the use of the double-bundle/double tibial tunnel ACL reconstruction technique within the ACL tibial insertion area. The anteroposterior and mediolateral length of the tibial ACL attachment and the distances of the tibial insertion area from the anterior and posterior tibial borders were measured and the stability of the joint was tested using the double-bundle/double tibial tunnel ACL reconstruction technique. The anteroposterior length, 19.54 mm in men and 17.36 mm in women, of the ACL insertion, averaged approximately 40% of the total intercondylar anteroposterior dimension of the plateau. This broad distribution of insertion fibres ensures ligament tension and hence joint stability. The reported anteroposterior broad insertion of ACL fibres to the tibia is not sufficiently reproduced by the use of one or more bundles having a common tibial tunnel for the ACL reconstruction. In our view, this might be better achieved with two different bundles, with separate tunnels, and independent tensioning in different knee angles. This technique might achieve better results in human knee stability as opposed to other reported techniques.