Anatomic Variations of the Lateral Intercondylar Ridge

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: Methodsmentioning

confidence: 99%

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

“…The intra‐articular anatomy is subject to an inter‐individual variability, and the bony ridges of the femoral condyle have been described as variably present in anatomic series [10, 33, 34]. Further, spatial localization of intra‐articular structures can be challenging when performing arthroscopically assisted surgery, especially in chronic cases of ACL rupture [8].…”

Section: Introductionmentioning

confidence: 99%

The effect of feedback from post-operative 3D CT on placement of femoral tunnels in single-bundle anatomic ACL reconstruction

Inderhaug

Larsen²,

Strand

et al. 2014

“…Osseous landmarks are considered superb hallmarks with great stability and reliability on 3D-CT [7]. The lateral intercondylar ridge (LIR) was previously recognized as a constant osseous landmark, but 6% LIR in 318 femoral specimens has not been observed with great positional variations [35]. The lateral bifurcate ridge (LBR) is another osseous landmark between the AM and PL femoral attachments, but the absence of almost half of the LBR limits its possibility as a stable landmark.…”

Section: Discussionmentioning

confidence: 99%

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.