Graft Size and Orientation Within the Femoral Notch Affect Graft Healing at 1 Year After Anterior Cruciate Ligament Reconstruction

Abstract

Background: The combined influence of anatomic and operative factors affecting graft healing after anterior cruciate ligament (ACL) reconstruction within the femoral notch is not well understood. Purpose: To determine the influence of graft size and orientation in relation to femoral notch anatomy, with the signal/noise quotient (SNQ) of the graft used as a measure of graft healing after primary single-bundle ACL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: A total of 98 patients with a minimum 2-year follow-up after primary single-bundle ACL reconstruction with hamstring tendon autografts were included. Graft healing was evaluated at 1 year on magnetic resonance imaging (MRI) scan as the mean SNQ measured from 3 regions situated at sites at the proximal, middle, and distal graft. Patient characteristics, chondropenia severity score, tunnel sizes, tunnel locations, graft bending angle (GBA), graft sagittal angle, posterior tibial slope (PTS), graft length, graft volume, femoral notch volume, and graft-notch volume ratio (measured using postoperative 3-T high-resolution MRI) were evaluated to determine any association with 1-year graft healing. The correlation between 1-year graft healing and clinical outcome at minimum 2 years was also assessed. Results: There was no significant difference in mean SNQ between male and female patients ( P > .05). Univariate regression analysis showed that a low femoral tunnel ( P = .005), lateral tibial tunnel ( P = .009), large femoral tunnel ( P = .011), large tibial tunnel ( P < .001), steep lateral PTS ( P = .010), steep medial PTS ( P = .004), acute graft sagittal angle ( P < .001), acute GBA ( P < .001), large graft volume ( P = .003), and high graft-notch volume ratio ( P < .001) were all associated with higher graft SNQ values. A multivariate regression analysis showed 2 significant factors: a large graft-notch volume ratio ( P = .001) and an acute GBA ( P = .004). The 1-year SNQ had a weak correlation with 2-year Tegner Activity Scale score ( r = 0.227; P = .026) but no other clinical findings, such as International Knee Documentation Committee subjective and Lysholm scores and anterior tibial translation side-to-side difference. Conclusion: The 1-year SNQ value had a significant positive association with graft-notch volume ratio and GBA. Both graft size and graft orientation appeared to have a significant influence on graft healing as assessed on 1-year high-resolution MRI scan.

Magnetic Resonance Imaging 1 Year After Hamstring Autograft Anterior Cruciate Ligament Reconstruction Can Identify Those at Higher Risk of Graft Failure: An Analysis of 250 Cases

“…If this occurs after a return to pivoting sports, there are multiple possible causative patient factors or technical failures. It could be a repeat of a significant mechanism of injury similar to rupture of a native ACL, poor muscular or dynamic control of the limb, 15 insufficient 19 or excessive 22 amount of graft, positioning of the graft, 3 or, with the present study, higher graft signal indicating incomplete healing and integration of the graft. Appearances of high signal at the Figure 5.…”

“…The present study used the same suspensory fixation on both the tibial and the femoral sides, yet significantly higher signal was seen on the femoral side. This has been recognized before, with a number of possible explanations: a more acute graft-bending angle proximally as the graft enters the joint 25 ; the potential for femoral notch impingement, especially if there is a graft-notch mismatch 22 ; or a femoral tunnel placed closer to the posterolateral bundle origin. 16 This study adds to previous evidence that suggests that the proximal femoral-sided graft may be the rate-dependent area for healing of the entire graft.…”

“…Assessment of the intra-articular graft was made using the sagittal oblique reconstructed image parallel to the graft using 3 equally spaced ROIs (proximal, midportion, and distal) as described in previous studies. 4,22 The distal graft ROI was set just proximal to the tibial aperture, and its distal edge was aligned to the tibial joint surface. The midsubstance graft ROI was set so that its center was aligned at the level of the anterior-distal intercondylar notch.…”

Comparison of hamstring and quadriceps strength after anatomical versus non-anatomical anterior cruciate ligament reconstruction: a retrospective cohort study

“…Femoral tunnel malposition is 3 times more frequent than tibial tunnel malposition [33]. In our study, the femoral tunnel position was measured with the use of Bernard quadrant method, which was applied in several studies [5,27]. The anatomic position of the femoral tunnel socket for single-bundle ACLR is de ned in line with the study of Xu et al [22].…”

“…Graft healing may be affected by tunnel position as well. Oshima et al [27] reported low femoral tunnel was one of the factors signi cantly associated with high graft signal/noise quotient value, which indicated inferior graft healing. On the other hand, the study of Novaretti et al [28] proved that de cit of quadriceps strength did not predict return to preinjury level of sport at 6 months postoperatively, which were consistent with the outcomes of 12 months after surgery in our study.…”