Commentary: Correlation between trochlear dysplasia and anterior cruciate ligament injury

Correlation of Femoral Trochlear Dysplasia With Anterior Cruciate Ligament Injury in Skeletally Immature Patients

Background

Reports of anterior cruciate ligament (ACL) injury in patients with skeletal immaturity have been increasing. Variations in knee joint anatomy have been linked to ACL injury risk factors.

Purpose

To identify associations between ACL injury, patella alta, and femoral trochlear dysplasia in patients with skeletal immaturity by using magnetic resonance imaging (MRI).

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

This retrospective study included 231 patients with skeletal immaturity-116 with acute complete noncontact ACL injury and 115 without ACL injury (controls)-who underwent knee MRI. Cases of femoral trochlear dysplasia were divided into 4 types according to the Dejour classification scheme. Patellar height and patellar tendon length were measured via sagittal MRI, and the Insall-Salvati ratio (ISR) was calculated.

Results

In the ACL injury group, 56 (48.3%) knees exhibited trochlear dysplasia, including 51 (91.1%) that were Dejour type A; and in the control group, 12 (10.4%) knees exhibited trochlear dysplasia, 12 (100%) Dejour type A. The prevalence of femoral trochlear dysplasia was significantly higher in the ACL injury group than in the control group (P < .001). The ISR was not significantly different between the ACL injury and control groups (0.9 ± 0.2 vs 1 ± 0.2 mm; P = .16). The correlation between ISR >1.2 and presence of ACL injury was not significant.

Conclusion

Femoral trochlear dysplasia was associated with ACL injury in patients with skeletal immaturity. In particular, Dejour type A femoral trochlear dysplasia was correlated with ACL injury patients with skeletal immaturity. Also, the possibility of ACL damage exists in patients with skeletal immaturity and femoral trochlear dysplasia.

Femoral trochlear morphology is associated with anterior cruciate ligament injury in skeletally immature patients

PURPOSE

Knee joint morphology is a known contributor to anterior cruciate ligament (ACL) injury, and the shape of the distal femur condyle is one of the associated factors. However, the relationship between femoral trochlear morphology and ACL injury is unclear, especially in pediatric patients. Therefore, the present study aimed to evaluate the effect of femoral trochlear morphology on ACL injury in pediatric patients and investigate the possibility of gender differences.

METHODS

In total, 116 skeletally immature children aged 3-18 years with primary ACL injuries were matched with a control group of 116 skeletally immature children. Lateral trochlear inclination, trochlear facet asymmetry, trochlear depth, and sulcus angle were evaluated using magnetic resonance imaging (MRI). Differences between patient groups and gender were investigated. Receiver-operating characteristic (ROC) curves were constructed to obtain the sensitivity and specificity of all parameters.

RESULTS

A significant difference was observed in the sulcus angle and trochlear inclination between the ACL injury and control groups (p < 0.05). No significant difference was observed between the ACL injury and control groups with respect to the anatomic patellar instability risk factors. All parameters showed an area under the curve of 0.6 in the ROC analysis, indicative of failure of the diagnostic test.

CONCLUSIONS

There was a significant association between femoral trochlear morphology and increased risk of ACL injury in pediatric patients. No gender difference was found except in the trochlear depth. It was showed that the difference in trochlear morphology should be considered between normal children and pediatric patients with ACL injury to increase the awareness regarding ACL injuries.

LEVEL OF EVIDENCE

III.