Is There a Role of Meniscal Morphology in the Risk of Noncontact Anterior Cruciate Ligament Rupture? A Case-Control Study

Evaluation of Anatomical Variations with Morphological Measurements and Their Relationship to Meniscal Injury and Ligament Damage

The purpose of this study was to reveal the anatomical risk factors for anterior and posterior cruciate ligament (ACL and PCL) injuries and menisci injury. We aim to investigate whether there are significant relationships between tibial tubercle-trochlear groove (TT-TG) distance, patella angle, trochlear sulcus angle (TSA), trochlear groove depth (TGD), medial and lateral trochlea length (MT and LT), MT/LT ratio, lateral patellar tilt angle (LPTA), patella-patellar tendon angle (P-PTA), quadriceps-patellar tendon angle (QPA), Insall-Salvati index (ISI), medial and lateral trochlear inclination (MTI and LTI) measurements and important common pathologies such as ACL, PCL, medial and lateral meniscal injuries (MM and LM), peripatellar fat pad edema, chondromalacia, and effusion. Thus, the mechanisms of injury will be better understood by revealing important anatomical variations for meniscus and ligament damage. Three hundred eighty patients with knee magnetic resonance imaging examination were included in this study. Our patients who underwent knee magnetic resonance imaging were divided into groups according to the presence of MM tear, LM tear, ACL tear, PCL tear, peripatellar fat pad edema, chondromalacia and effusion. TT-TG distance, patella angle, TSA, TGD, MT, LT, MT/LT ratio, LPTA, P-PTA, QPA, ISI, MTI, and LTI were measured. In patients with ACL tear, age, LT, ML/LT ratio, and QPA measurements were found to be significantly higher. There was no significant difference between the participants' LPTA value and the presence of ACL tear, MM and LM injury. MT and ML/LT ratio were found to be significantly lower in the group with MM tear (p <0.001). The TT-TG distance was found to be significantly lower in the group with LM tear. Increased age, LT, ML/LT ratio, and QPA are predisposed risk for ACL tear. Decreased MT and ML/LT ratio are among the risk factors for MM tear. The anatomical variations are associated with ligament and meniscal injury.

Graft impingement increases anterior cruciate ligament graft signal more than acute graft bending angle: magnetic resonance imaging-based study in outside-in anterior cruciate ligament reconstruction

PURPOSE

In this study, the relationship between patient-specific geometric factors and tunnel placement in graft impingement was identified by using magnetic resonance imaging (MRI) signal intensity of anterior cruciate ligament (ACL) grafts.

METHODS

Ninety-two patients, who were treated between 2014 and 2020, were included retrospectively. These patients underwent primary remnant-preserving outside-in ACL reconstruction (ACLR) and were followed up with postoperative MRI at least one year after surgery. Plain radiographs and computed tomography (CT) were used to analyze tibial and femoral tunnel positions. Postoperative MRI was performed, at 32.8 ± 17.5 months after surgery, to evaluate the graft signal intensity, the ACL/posterior cruciate ligament (PCL) ratio (APR), ACL/muscle ratio (AMR), tunnel positions, and graft impingement. Clinical and stability outcomes were analyzed using the International Knee Documentation Committee (IKDC) subjective and objective scores, Lysholm scores, and side-to-side differences (SS-D).

RESULTS

The mean APR and AMR of the proximal third of the grafts were significantly lower than those of the middle third of the grafts (p = 0.017 and p = 0.045, respectively). Multivariate regression analysis showed that there was a negative association between the mean APR and AMR of entire intra-articular ACL graft and the distance from the anterior end of the intercondylar roof to the center of the tibial tunnel in the sagittal plane (p < 0.001 and p < 0.001, respectively) and the notch width index (p < 0.001 and p = 0.002, respectively). No significant correlations were found between tunneling and geometric factors, and clinical scores or SS-D.

CONCLUSIONS

Graft impingement on the anterior tibial tunnel relative to the end of the intercondylar roof and narrow notch was a more significant contributing factor on increased signal intensities of the ACL graft, compared with the acute femoral bending angle in remnant-preserving outside-in ACLR. Therefore, surgeons should focus on intercondylar notch anatomy during tibial tunnel placement to avoid roof impingement.

LEVEL OF EVIDENCE

Level III.

Lateral Meniscus Height and ACL Reconstruction Failure: A Nested Case-Control Study

Previous work has shown that the morphology of the knee joint is associated with the risk of primary anterior cruciate ligament (ACL) injury. The objective of this study is to analyze the effect of the meniscal height, anteroposterior distance of the lateral tibial plateau, and other morphological features of the knee joint on risk of ACL reconstruction failure. A nested case-control study was conducted on patients who underwent an ACL reconstruction surgery during the period between 2008 and 2015. Cases were individuals who failed surgery during the study period. Controls were patients who underwent primary ACL reconstruction surgery successfully during the study period. They were matched by age (±2 years), gender, surgeon, and follow-up time (±1 year). A morphological analysis of the knees was then performed using the preoperative magnetic resonance imaging scans. The anteroposterior distance of the medial and lateral tibial plateaus was measured on the T2 axial cuts. The nonweightbearing maximum height of the posterior horn of both menisci was measured on the T1 sagittal scans. Measurements of the medial and lateral tibial slope and meniscal slope were then taken from the sagittal T1 scans passing through the center of the medial and lateral tibial plateau. A binary logistic regression analysis was done to calculate crude and adjusted odds ratios (ORs) estimates. Thirty-four cases who underwent ACL revision surgery were selected and were matched with 68 controls. Cases had a lower lateral meniscal height (6.39 ± 1.2 vs. 7.02 ± 0.9, p = 0.008, power = 84.4%). No differences were found between the two groups regarding the bone slope of the lateral compartment (6.19 ± 4.8 vs. 6.92 ± 5.8, p = 0.552), the lateral meniscal slope (-0.28 ± 5.8 vs. -1.03 ± 4.7, p = 0.509), and the anteroposterior distance of the lateral tibial plateau (37.1 ± 5.4 vs. 35.6 ± 4, p = 0.165). In addition, no differences were found in the medial meniscus height between cases and controls (5.58 ± 1.2 vs. 5.81 ± 1.2, respectively, p = 0.394). There were also no differences between cases and controls involving the medial bone slope, medial meniscal slope, or anterior posterior distance of the medial tibial plateau. Female patients had a higher medial (4.8 degrees ± 3.2 vs. 3.3 ± 4.1, p = 0.047) and lateral (8.1 degrees ± 5.1 vs. 5.6 degrees  ± 5.6, p = 0.031) tibial bone slope, and a lower medial (5.3 mm ± 1.0 vs. 6.1 mm ± 1.2, p = 0.001) and lateral (6.6 ± 1.0 vs. 7.0 ± 1.2, p = 0.035) meniscus height, and medial (4.3 ± 0.4 vs. 4.8 ± 0.4, p =0.000) and lateral (3.3 ± 0.3 vs. 3.9 ± 0.4, p = 0.000) anteroposterior distance than males, respectively.The adjusted OR of suffering an ACL reconstruction failure compared to controls was 5.1 (95% confidence interval [CI]: 1.7-14.9, p = 0.003) for patients who had a lateral meniscus height under 6.0 mm. The adjusted OR of suffering an ACL reconstruction failure was 2.4 (95% CI: 1.0-7.7, p = 0.01) for patients who had an anteroposterior distance above 35.0 mm. Patients with a lateral meniscal height under 6.0 mm have a 5.1-fold risk of suffering an ACL reconstruction failure compared to individuals who have a lateral meniscal height above 6.0 mm. Patients with a higher anteroposterior distance of the lateral tibial plateau also have a higher risk of ACL reconstruction failure.

Radiological Evaluation of Femoral Intercondylar Notch and Tibial Intercondylar Eminence Morphometries in Anterior Cruciate Ligament Pathologies Using Magnetic Resonance Imaging

PURPOSE

To determine the relationship between femoral-tibial morphometries and anterior cruciate ligament (ACL) pathologies using magnetic resonance imaging (MRI).

METHODS

We retrospectively evaluated 455 patients (211 females and 244 males) who underwent knee MRI with suspected ACL pathology. Imaging findings were classified as normal ACL (n = 119), degeneration of the ACL (n = 116), partial ACL tear (n = 103), and complete ACL tear (n = 117). In all groups, the femoral intercondylar notch width (INW), intercondylar distance (CD), notch width index (NWI), and intercondylar notch angle (INA), the angles between the tibial plateau and tibial spines (MPA and LPA), intercondylar eminence peak angle (IEA), and tibial slope angles (MSA and LSA) were measured.

RESULTS

Femoral INW and NWI were significantly lower in patients with ACL pathology (p < 0.05). They were also lower in patients with tear compared to degeneration. The INA was significantly smaller in patients with ACL pathology (p < 0.001) and the significance continued in both genders. The LSA was only increased in patients with complete tear (p < 0.01) and the difference seems existing in both genders. It was also found that the LPA and IEA demonstrated significant increases in patients with ACL pathology (p < 0.01 and < 0.05, respectively) and the significance in LPA continued in both genders. Significant differences between males and females were found for the INW and CD in all 4 groups (p < 0.001). In addition, the INA, LPA and LSA were independent predictors in determining the risk of ACL pathology.

CONCLUSION

The ACL pathologies are associated with femoral-tibial morphometries and these associations exist in both genders.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00490-7.