Anterior cruciate ligament reconstruction, can an anatomic femoral tunnel be achieved with the trans-tibial technique? Cadaveric study (original) (raw)
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Orthopedics, 2012
Incorrect bone tunnel position, particularly on the femoral side, is a frequent cause of failed anterior cruciate ligament reconstruction. Several studies have reported that drilling the femoral tunnel through the anteromedial portal allows a more anatomical placement on the lateral femoral condyle and higher knee stability than does transtibial reconstruction. In the current study, the femoral tunnel was drilled with transtibial (n56) and anteromedial (n56) portal techniques in 12 cadaveric knees. With appropriate landmarks inserted into bone tunnels, the direction and length of the tunnels were determined on anteroposterior and lateral radiographs. Knee stability was evaluated with a KT1000 arthrometer (MEDmetric Corporation, San Diego, California) and pivot shift test, comparing the pre-and postoperative values of both techniques. Finally, all knees were dissected to enhance vision of the insertion of the reconstructed ligament. The anteromedial portal technique led to better placement of the femoral tunnel in the coronal and sagittal planes, with higher knee stability according to the pivot shift test but not the KT1000 arthrometer. Anatomical and clinical results reported in the literature on transtibial and anteromedial portal techniques are controversial, but most of studies report better results with the anteromedial portal technique, especially regarding rotational stability. The current cadaveric study showed that the anteromedial portal technique provided better tunnel placement on the lateral femoral condyle in the coronal and sagittal planes, with an improvement in the rotational stability of the knee.
The American Journal of Sports Medicine, 2012
Background: Tunnels created for reconstruction of a torn anterior cruciate ligament (ACL) are critical determinants of joint stability and clinical outcomes. There is limited objective evidence on the ability of transtibial (TT), anteromedial (AM) portal, and outside-in (OI) operative techniques in creating anatomic tunnels. Hypothesis: (1) Tibial tunnel–independent techniques can create tunnels more accurately at the anatomic ACL footprint center than the TT technique, and (2) femoral tunnel exit location of the OI and TT techniques on the lateral cortex will be significantly further away from the lateral epicondyle than the femoral tunnel exit location of the AM portal technique. Study Design: Controlled laboratory study. Methods: Eight cadaveric knee specimens with a mean age of 56 years were used in this study. A digitizing system was used to record points along the outlines of the ACL insertion area and apertures of tunnels created by the TT, AM portal, and OI techniques. The f...
The Knee, 2008
The aim of this cadaveric study was to compare the transtibial versus the anteromedial portal with respect to the anatomic femoral positioning of the ACL attachment. Ten fresh frozen cadaveric knees were included in our study. A standard arthroscopy was performed and the normal ACL was partially cut through with arthroscopic scissors leaving a small footprint of 2 mm at the anatomical insertion area on the lateral femoral condyle. The femoral tunnel was drilled through the tibial tunnel and subsequently through the anteromedial portal. Using a probe with standard magnification, we measured the distances of the two femoral tunnels from the margin of ACL footprint arthroscopically. The femurs were then dissected and we measured the distances of the two tunnels from the posterior part of the lateral femoral condyle. The median arthroscopically measured distance of the centers of transtibial femoral tunnel and of the femoral tunnel through the anteromedial portal from the margin of the femoral ACL footprint were 6.20 mm and 2.80 mm respectively. The difference was statistically significant. After femoral dissection the median distance of the centers of the transtibial femoral tunnel and the femoral tunnel performed through the anteromedial portal from the border of the articular surface at the lateral femoral condyle was 6.10 mm and 5.25 mm respectively (p b 0.001). Both measurements showed that ACL reconstruction technique through the anteromedial portal is more accurate compared to the transtibial technique.
Knee Surgery, Sports Traumatology, Arthroscopy, 2014
As anterior cruciate ligament anatomy and kinematics become better understood, a more anatomic approach to ACL reconstruction is increasingly being pursued. 5 ACL deficiency has consistently been demonstrated to give rise to increased anterior translation, medial translation, and internal rotation of the tibia during various loading maneuvers. Knee kinematics and stability have been shown to markedly improve following ACL reconstruction with restoration of native ACL insertion sites and ligament orientation. ACL reconstructive procedures that fail to alleviate knee instability post-operatively often lead to a predictively higher risk for osteoarthritis of the knee, failure to return to previous level of play, and poor subjective and objective knee outcome scores. Although an understanding of ACL biomechanics and knee kinematics has significantly improved in recent decades, optimal surgical technique in ACL reconstruction remains uncertain; to date, no ACL reconstruction procedure has been shown to exactly replicate the biomechanics of the native ACL. 9, 13, 22 Small variations in femoral tunnel positioning can drastically change ACL length, tensioning patterns as well as alter ACL force vectors and joint kinematics. Grafts placed higher on the femoral wall in ACL reconstruction-a less coronally oblique orientation-less effectively opposes rotatory loads as compared with grafts placed lower on the femoral wall. 18 Decreased sagittal plane obliquity has also been implicated, largely because such an orientation incompletely resists anterior translational loads as compared with the native ACL. 1, 3, 6, 17 Regardless of which ACL reconstruction technique is utilized, a growing body of literature supports the notion that a more anatomic reconstruction better restores knee kinematics than non-anatomic reconstructions. The modified transtibial endoscopic single bundle ACL reconstruction has been demonstrated to have equal efficacy in improving knee joint biomechanical stability as ACL reconstructions performed via an anteromedial portal technique and an outside-in technique. The most limiting aspect of this technique is the reliance of femoral tunnel positioning on tibial tunnel orientation and position; because the femoral tunnel is drilled through the tibial tunnel, the tibial tunnel represents a potentially unforgiving linear constraint to instrumenting the femur. The ideal scenario for transtibial reconstruction is one where the tibial tunnel is collinear with a line connecting the centers of both femoral and tibial ACL insertions. Such geometry has been shown to be impractical, however. As noted by Heming et al, a guide pin drilled through the center of both insertions will consistently exit the tibia within millimeters of the joint line. 15 A tibial tunnel created with this proximal of a starting point likely would compromise tibial graft fixation and create significant graft-tunnel mismatch problems if a bone-tendon-bone graft was employed. If a more distal, traditional tibial starting position is employed instead, the resultant tunnel will be less aligned with the native ligament and will result in less-than-anatomic femoral tunnel positioning. In a previous cadaveric study, we noted that tibial and femoral tunnels can be created in a highly anatomic manner using a transtibial technique but requires a fairly proximal, carefully chosen tibial starting position. 20 In that study, however, an 11mm tibial reamer was utilized in + Tunnels were reamed with guide centered on Tibial-Articular ACL Footprint with no subsequent Femoral reaming ++ Tunnels were reamed with guide centered on Femoral-Articular ACL Footprint with subsequent Femoral reaming
Arthroscopy Techniques, 2017
Tunnel malposition is one of the most common technical reasons for anterior cruciate ligament reconstruction failure. Small changes in tunnel placement can result in significant differences in outcome. More anatomic placement of the tunnels can lead to greater knee stability and a more accurate reproduction of native knee kinematics. This Technical Note describes 2 tibial tunneleindependent methods to obtain anatomic femoral tunnel placement. The all-inside anteromedial portal technique requires only minimal surgical incisions but allows precise femoral tunnel placement. However, hyperflexion of the knee is required, adequate surgical assistance is necessary, and this technique may be susceptible to graft-tunnel mismatch. The outside-in technique may be more beneficial in obese patients, skeletally immature patients, or revision cases. On the downside, it does require an additional 2-cm surgical incision. This article also provides surgical pearls to fine-tune tibial tunnel placement. A lthough anterior cruciate ligament (ACL) reconstructions can fail for a variety of reasons, the most common technical error is incorrect tunnel placement, with the femoral tunnel more commonly misplaced than the tibial tunnel. 1-3 In fact, even small changes in tunnel placement have been shown to significantly affect knee kinematics after ACL reconstruction. 4 Epidemiologic data from the Multicenter ACL Revision Study (MARS) showed that 80% of failed ACL reconstructions were at least partially due to femoral tunnel malposition and 37% due to incorrect tibial tunnel placement. 3
Joints, 2017
Purpose The purpose of this study was to investigate, through three-dimensional computed tomography (3D-CT), the accuracy of femoral tunnel positioning in patients undergoing anterior cruciate ligament (ACL) reconstruction, comparing transtibial (TT) and anteromedial (AM) techniques. Methods We evaluated postoperative 3D-CT scans of 26 patients treated with ACL reconstruction with hamstrings autograft using a low accessory AM portal technique and 26 treated with the TT technique. The position of the femoral tunnel center was measured with the quadrant method. Results Using quadrant method on CT scans, femoral tunnels were measured at a mean of 32.2 and 28.1% from the proximal condylar surface (parallel to Blumensaat line) and at a mean of 31.2 and 15.1% from the notch roof (perpendicular to Blumensaat line) for the AM and TT techniques, respectively. Conclusion The AM portal technique provides more anatomical graft placement than TT techniques. Level of Evidence Level I, randomized ...
Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 2017
The anteromedial (AMP) portal technique was introduced to position the femoral tunnel in anterior cruciate ligament (ACL) reconstruction to more closely replicate the original ACL footprint compared to the transtibial (TT) approach. Few randomized trials have evaluated differences in these techniques with respect to clinical outcomes. The purpose of this study was to determine if there are any differences in clinical outcome between the AMP and TT approaches. This is a single-blinded, prospective, randomized controlled trial. Participants were randomized to undergo ACL reconstruction using the AMP or TT approach. The primary outcome measure was the ACL quality of life (ACL-QOL), and secondary outcomes were the IKDC knee assessment, side-to-side difference in anterior-posterior knee laxity (KT-1000) and tunnel orientation (X-ray findings) at preoperative, 3, 6, 12, and 24 months postoperative. Statistical comparisons were performed using a series of t tests for independent groups wit...
Arthroscopy: The Journal of Arthroscopic & Related Surgery, 2011
To compare drilling the femoral tunnel with an offset aimer and BullsEye guide (ConMed Linvatec, Largo, FL) to perform an anatomic single-bundle reconstruction of the anterior cruciate ligament (ACL) through the anteromedial portal. Methods: Seven matched pairs of cadaveric knees were studied. The intent was to drill the femoral tunnel anatomically in all cases. In group A the femoral tunnel was drilled arthroscopically with an offset aimer. In group B the femoral tunnel was drilled arthroscopically with the BullsEye guide. Two tunnels were drilled through the same entry point in each knee. One was done at 110°of knee flexion and the other at 130°. They were scanned by computed tomography and reconstructed 3-dimensionally. Volume-rendering software was used to document relations of the drilled tunnel to the bony anatomy and tunnel length. Results: In group B the femoral tunnel was placed at the center of the femoral insertion site. The center of the tunnel was 9.4 mm from the high cartilage margin and 8.6 mm from the low cartilage margin. In group A the tunnels were placed deeper (5.4 mm and 12.6 mm, respectively) (P ϭ .018). There were no differences in tunnel length for either knee flexion degree. Three of the tunnels drilled at 110°in group A compromised the posterior tunnel wall and measured less than 25 mm in length. Conclusions: Accurate placement in the center of the femoral footprint of the ACL is better accomplished with the BullsEye guide rather than 5-mm offset aimers. Five-millimeter offset aimers might cause posterior tunnel blowout and present the risk of obtaining short tunnels when performing oblique femoral tunnel placement through the anteromedial portal at 110°of knee flexion. Clinical Relevance: The BullsEye guide might be better than standard offset aimers in the performance of anatomic single-bundle ACL reconstruction.