The quadrant method measuring four points is as a reliable and accurate as the quadrant method in the evaluation after anatomical double-bundle ACL reconstruction

PurposeTo elucidate whether sagittal graft tunnel affects the signal intensity in anatomical ACL reconstruction (ACLR) and to clarify the prevalence of intercondylar roof impingement. It was hypothesized that if the tunnel apertures are located within the anatomical footprint of ACL, tunnel position would not affect the signal intensity. MethodsA total of 132 patients who underwent anatomical double‐bundle ACLR (DB‐ACLR) using hamstring autograft were recruited. Tunnel position was determined by the quadrant method on three‐dimensional computed tomography; the femoral tunnel position was defined as “high and low” or “deep and shallow”, while that of the tibial side was defined as “anterior and posterior” or “medial and lateral”. Subjects were divided into three groups according to the tertile of % deep–shallow. The signal intensity was evaluated by the region of interest value of the antero‐medial bundle (AMB) and postero‐lateral bundle on magnetic resonance imaging at 12 months after reconstruction. Linear regression analysis was conducted to elucidate the relationship between the percentage position of each tunnel and the graft signal intensity. ResultsIn the shallow tertile group, AMB signal intensity increased in the anterior position of the tibial tunnel (β = − 0.34; P = 0.025). In the intermediate and deep tertile groups, the tunnel position did not correlate with the signal intensity. ConclusionsA more anterior tibial tunnel position increases AMB signal intensity in shallower femoral tunnel. Conversely, this correlation is attenuated for deeper femoral tunnels. Surgeons should pay attention to sagittal femoral tunnel position to create a more anterior tibial tunnel position. Level of evidenceLevel III.

Section: Discussionsupporting

confidence: 83%

Combination of anterior tibial and femoral tunnels makes the signal intensity of antero-medial graft higher in double-bundle anterior cruciate ligament reconstruction

Chiba

Yamamoto

Kimura

et al. 2020

“…Compared with a simple radiograph, 3D-CT is conceptually similar to cadaver measurement techniques, with a perfect perspective of bony aperture and osseous landmarks [8]. Several studies have shown its excellent inter-and intra-rater reliability in the evaluation of femoral tunnel position [24,26], which was also proven in our research. The quadrant method has been extensively used in the evaluation of femoral tunnel position, but there are some non-negligible factors afecting its accuracy on 3D-CT. Iriuchishima reported that morphologic variations of Blumensaat's line may not only disturb the arthroscopic creation of tunnel placement but also inluence the postoperative results measured with the quadrant method.…”

Section: Discussionsupporting

confidence: 64%

The apex of the deep cartilage is a stable landmark to evaluate the femoral tunnel position in ACL reconstruction

Shi

Zhang²,

Meng³

et al. 2022

PurposeTo develop a simple and effective method for evaluating the femoral tunnel position using the apex of the deep cartilage (ADC) as the landmark. MethodsA total of 52 patients who underwent arthroscopic ACL reconstruction were recruited between June and September 2021. The femoral tunnel was placed on the central point of the anteromedial footprint with an accessory anteromedial and a high anterolateral portal. Then, the length from the ADC to the shallow cartilage margin (L1) and to the center of the femoral tunnel (l1), as well as the center to the low cartilage margin (H1, intraoperative height), was measured under arthroscopy and on postoperative CT scans (L2, l2 and H2). Moreover, intraoperative and postoperative cartilage ratios were equivalent to l1/L1 and l2/L2, respectively. Linear regression, Pearson correlation and Bland–Altman analysis were performed to evaluate the consistency between these two measurements of cartilage ratio (l/L) and height (H). ResultsThe mean age at the time of surgery was 28.7 years; 42 patients were male, and 17 patients were hurt in the left knee among 52 patients. The intraoperative cartilage ratio was 0.37 ± 0.04, and the height was 8.1 ± 1.1 mm with almost perfect inter‐observer reproducibility. After the surgery, the cartilage ratio and height were measured as 0.39 ± 0.04 and 8.2 ± 1.3 mm on 3D–CT, respectively, with almost perfect intra‐ and inter‐observer reproducibility. Significant positive correlations and linear regression were detected in the cartilage ratio (r = 0.844,p < 0.001), and height (r = 0.926,p < 0.001) intraoperatively and postoperatively. The Bland–Altman plot also showed excellent consistency between arthroscopy and 3D–CT. ConclusionsThe ADC is a good landmark in the assessment of femoral tunnel position, with excellent consistency between intraoperative arthroscopic measurements and postoperative 3D–CT.ClinicalTrials.gov Identifier: NCT04937517. Level of Evidence Level III.

“…After ACL reconstruction, the femoral and tibial tunnel locations were evaluated on a 3D‐CT according to the modified quadrant method [25]. The total sagittal length of the lateral condyle and the maximum depth of the intercondylar notch were measured and the femoral tunnel location was determined in terms of the percentage ratios in deep–shallow and high–low direction.…”

Section: Methodsmentioning

confidence: 99%

Tibial slope, remnant preservation, and graft size are the most important factors affecting graft healing after ACL reconstruction

Okutan

Kalkışım

Gürün

et al. 2021

Purpose The aim of this study was to determine the anatomic, operative and biological factors that inluenced graft healing after single-bundle anterior cruciate ligament (ACL) reconstruction. Methods One hundred fourteen consecutive patients who underwent anatomic single-bundle ACL reconstruction with quadrupled hamstring tendon autografts between 2016 and 2019 were retrospectively analyzed. Ninety-four patients met the inclusion criteria with minimum follow-up of 12 months. Patients were evaluated with multiple clinical measurements, including International Knee Documentation Committee Subjective Knee Form (IKDC-SKF), Lyshom Scores, and Marx activity scale. To evaluate graft healing, the signal-to-noise quotient (SNQ) was measured at intra-articular graft and intratunnel integration were evaluated on magnetic resonance imaging (MRI) at one year after surgery. Potential factors afecting graft healing, including age, sex, body mass index, time from injury to surgery, posterior tibial slope, lateral femoral condyle ratio, notch width index, meniscal injury, remnant preservation, tunnel aperture locations, graft size, graft bending angle, graft/remaining notch volume ratio were evaluated for their association with graft SNQ value by stepwise regression analysis. Results A total of 94 patients were evaluated with mean follow-up 28.5 ± 9 months. Univariate regression analysis showed that posterior tibial slope, notch width index, remnant preserving procedure, high femoral tunnel, anterior tibial tunnel, graft bending angle, and graft/remaining notch volume ratio signiicantly associated with graft SNQ values. Multivariate regression analysis showed that lateral tibial slope, remnant preservation, and graft/remaining notch volume ratio were independent factors correlated with graft SNQ values. Also, the graft SNQ values was weakly correlated with femoral tunnel integration and Marx activity scale at one year. There was no correlation between graft SNQ values and IKDC-SKF and Lysholm scores. There was no correlation between graft SNQ values and International Knee Documentation Committee and Lysholm scores. Conclusions Tibial slope, remnant preservation and graft/remaining notch volume ratio were signiicant independent associated factors of graft SNQ value at one year. The graft SNQ values were also weakly correlated with femoral tunnel integration and the Marx activity scale. These factors should be taken into account for ensuring the ideal graft healing and for the return to sport decision-making. Level of evidence Level IV.