Femoral tunnel placement in single-bundle, remnant-preserving anterior cruciate ligament reconstruction using a posterior trans-septal portal

Kim

Arthroscopy: The Journal of Arthroscopic & Related Surgery

et al. 2021

Purpose: To determine whether the femoral tunnel position remains in an anatomical footprint after tunnel widening and shifting. Methods: Patients who underwent unilateral double-bundle anterior cruciate ligament reconstruction with hamstring autograft and performed computed tomography scan evaluation at the time of 5 days and 1 year postoperatively were included in this retrospective cohort study. Three-dimensional models of the femur and femoral tunnels were reconstructed from computed tomography scan data. The location of the tunnel center and tunnel margins in the anatomical coordinate system, and the mean shifting distance of tunnel center and margin were measured with image analysis software during the period. The change of tunnel center location in Bernard quadrant was confirmed if the tunnel center remained within the boundaries of anatomical position after tunnel widening. Results: A total of 56 patients satisfied the inclusion criteria. The mean shifting distance of AM and PL tunnel centers were 1.7 AE 0.9 mm and 1.6 AE 0.6 mm. The Tunnel margin of the anteromedial (AM) and posteromedial (PL) tunnels were shifted to 2.5 AE 1.3 mm and 2.6 AE 1.4 mm in the anterior direction, and 1.4 AE 0.9 mm and 1.0 AE 0.7 mm in the distal direction, respectively. Among the anatomical located tunnel, 97% (32/33) and 87.1% (27/31) of AM and PL tunnel centers remained in a range of anatomical footprint. The tunnel center was shifted from the anatomical position into a nonanatomical position in 3% (1/ 33) of the AM tunnel and 12.9% (4/31) of PL tunnel after tunnel widening. The tunnel location which shifted nonanatomically were relatively anterior and distal position. Conclusions: Tunnel widening shifts the tunnel position to the anterior and distal direction, which could change the initial tunnel position. Nevertheless, the majority of tunnel positions remained in the anatomical position after tunnel widening and shifting. Level of Evidence: Level III, retrospective cohort study.

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Femoral Tunnel Widening After Double-Bundle Anterior Cruciate Ligament Reconstruction With Hamstring Autograft Produces a Small Shift of the Tunnel Position in the Anterior and Distal Direction: Computed Tomography–Based Retrospective Cohort Analysis

Kim

Arthroscopy: The Journal of Arthroscopic & Related Surgery

et al. 2021

“…The major clinical implication of this study is that tunnel widening at the AM tunnel aperture could be larger when the OI technique is used compared with the TP technique. In recent studies, 25 , 26 there has been increasing interest in the graft position in the tunnel, and the location of the reconstructed ACL graft was located eccentrically, not at the center of the tunnel center. The relatively larger tunnel widening at the tunnel aperture indicates that the graft position could have shifted more in the OI technique.…”

Section: Discussionmentioning

confidence: 99%

Influence of Graft Bending Angle on Femoral Tunnel Widening After Double-Bundle ACL Reconstruction: Comparison of Transportal and Outside-In Techniques

Kim

Orthopaedic Journal of Sports Medicine

et al. 2021

Background: Previous studies have suggested that increased mechanical stress due to acute graft bending angle (GBA) is associated with tunnel widening and graft failure after anterior cruciate ligament (ACL) reconstruction. Few studies have compared the GBA between the outside-in (OI) and the transportal (TP) techniques. Purpose: To evaluate the influence of GBA on clinical outcomes and tunnel widening after ACL reconstruction with OI versus TP technique. Study Design: Cohort study; Level of evidence, 3. Methods: Included in the study were 56 patients who underwent double-bundle ACL reconstruction (n = 28 in the OI group and n = 28 in the TP group). Clinical outcomes (Lysholm, International Knee Documentation Committee, Tegner score, and knee laxity) 1 year postoperatively were evaluated. Computed tomography scans at 5 days and 1 year postoperatively were used for imaging measurements, and the femoral tunnel was divided into the proximal third, middle, and aperture sections. The GBA and cross-sectional area (CSA) were measured using image analysis software and were compared between groups. A correlation analysis was performed to determine if the GBA affected clinical outcomes or tunnel widening. Results: No significant difference was observed in clinical outcomes between the groups. The GBA of both the anteromedial (AM) and posterolateral bundles were more acute in the OI group compared with the TP group ( P < .05). The CSA at the AM tunnel aperture increased significantly in the OI group (84.2% ± 64.3%) compared with the TP group (51.4% ± 36.7%) ( P = .04). However, there were no differences in the other sections. In the Pearson correlation test, GBA was not correlated with tunnel widening or clinical outcomes. Conclusion: Regardless of technique, the GBA did not have a significant influence on tunnel widening or clinical outcomes. Considering a wider AM tunnel aperture, a more proximal and posterior AM tunnel position might be appropriate with the OI technique.

“…The CT images were used to generate a three-dimensional reconstruction of the knee joint, and the position of the femoral tunnel was evaluated on the medial side of the lateral femoral condyle according to the quadrant method. 17,18,21,22 A rectangular measurement frame was drawn over the mediolateral view of the lateral femoral condyle by placing the superior border at the roof of the intercondylar notch (Blumensaat's line; x-axis). The inferior border of this rectangle was a line tangent to the distal subchondral contour of the condyle.…”

Section: Postoperative Measurement Of the Femoral Tunnel Position Using Ct And The Quadrant Methodsmentioning

confidence: 99%

“…The position 3 mm high and 12 mm shallow from the ADC was selected as the femoral tunnel center, and a pointed cone was inserted for positioning through the accessory medial port. 17 A guide needle was drilled through the lateral femoral condyle from inside to outside so that it passed through the point identified using the ruler. A femoral tunnel was drilled through the guide needle by using a hollow drill that matched the graft diameter.…”

Section: Surgical Techniquementioning

confidence: 99%

Reconstruction of the Anterior Cruciate Ligament Using Ruler-Assisted Positioning of the Femoral Tunnel Relative to the Posterior Apex of the Deep Cartilage: A Single-Center Case Series

et al. 2021

The techniques available to locate the femoral tunnel during anterior cruciate ligament (ACL) reconstruction have notable limitations. To evaluate whether the femoral tunnel center could be located intraoperatively with a ruler, using the posterior apex of the deep cartilage (ADC) as a landmark. This retrospective case series included consecutive patients with ACL rupture who underwent arthroscopic single-bundle ACL reconstruction at the Department of Orthopedics, Beijing Tongren Hospital between January 2014 and May 2018. During surgery, the ADC of the femoral lateral condyle was used as a landmark to locate the femoral tunnel center with a ruler. Three-dimensional computed tomography (CT) was performed within 3 days after surgery to measure the femoral tunnel position by the quadrant method. Arthroscopy was performed 1 year after surgery to evaluate the intra-articular conditions. Lysholm and International Knee Documentation Committee (IKDC) scores were determined before and 1 year after surgery. The final analysis included 82 knees of 82 patients (age = 31.7 ± 6.1 years; 70 males). The femoral tunnel center was 26 ± 1.5% in the deep-shallow (x-axis) direction and 31 ± 3.1% in the high-low (y-axis) direction, close to the “ideal” values of 27 and 34%. Lysholm score increased significantly from 38.5 (33.5–47) before surgery to 89 (86–92) at 1 year after surgery (p < 0.001). IKDC score increased significantly from 42.5 (37–47) before surgery to 87 (83.75–90) after surgery (p < 0.001). Using the ADC as a landmark, the femoral tunnel position can be accurately selected using a ruler.