Magnetic Resonance Imaging Analysis of Associated Anterolateral, Deep Medial Collateral Ligament, and Meniscal Findings in Acute Anterior Cruciate Ligament-Injured Knees.

BACKGROUND

Few reports have examined the relationship between anterolateral ligament (ALL) injury or deep medial collateral ligament (dMCL) and meniscal injury in an acute anterior cruciate ligament (ACL)-injured knee.

PURPOSE/HYPOTHESIS: The purpose of this study was to investigate the association between ALL or dMCL injury observed on magnetic resonance imaging (MRI) in acute ACL injury with meniscal ramp lesions and lateral meniscus (LM) oblique radial tears (LMORTs) or localization of bone marrow lesions (BML), preoperative anterior tibial translation (ATT), and rotational instability. It was hypothesized that ALL or dMCL injuries accompanying acute ACL-injured knees are linked to meniscal injuries, such as ramp lesions or LMORT, BML, and increased knee instability.

STUDY

DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

This study included 164 patients who underwent MRI ≤1 month after primary ACL injury. All participants underwent evaluation of the side-to-side difference in ATT on stress radiographs and manual pivot-shift test preoperatively. ALL or dMCL injury and BML localization were diagnosed using MRI, and meniscal injuries were diagnosed via arthroscopy during ACL reconstruction. The relationship between concomitant meniscal injuries, BML, and knee instability in the ALL-injured and -intact groups, as well as in the dMCL-injured and -intact groups, was evaluated.

RESULTS

Overall, 89 of 164 (54.3%) knees had ALL injuries, 101 (61.6%) knees had dMCL injuries, and 64 (39.0%) knees had both ALL and dMCL injuries on MRI. ALL injuries were significantly correlated with ramp lesions, other LM injuries, and BML in both the lateral femoral condyle (LFC) and the lateral tibial plateau (LTP) (P < .05). dMCL injury was significantly correlated with LMORT, other LM injuries, BML in the LFC, and BML in the LTP (P < .05). ALL or dMCL injuries observed on MRI did not increase knee instability. Ramp lesions (odds ratio [OR], 3.70; P = .001), BML in LFC (OR, 2.17; P = .03), and BML in LTP (OR, 2.00; P = .04) were independent factors that increased the odds of finding associated ALL injury, whereas LMORT (OR, 3.01; P = .04) and BML in LTP (OR, 2.90; P = .002) independently increased the odds of dMCL injury.

CONCLUSION

In the acute phase of ACL injury, ramp lesions and BML in LFC, and BML in LTP were an independent factor that increased the odds of finding ALL injury, whereas LMORT and BML in LTP independently increased the odds of having associated dMCL injury.