Purpose

The aim of this study was to determine whether posterior tibial slope (PTS), meniscal slope (MS) and bone bruise pattern (BBP), as observed on magnetic resonance imaging (MRI), differed between patients with or without medial meniscus ramp lesions at the time of anterior cruciate ligament reconstruction (ACLR). The hypothesis was that patients with a ramp lesion had a higher PTS and MS, with a different BBP than patients without a ramp lesion.

Methods

Patients undergoing ACLR were selected from an in-house registry and separated into 2 groups: (1) the RAMP group included patients with primary ACLR and a medial meniscus ramp lesion diagnosed intraoperatively; (2) the CONTROL group included patients with primary ACLR without ramp lesion after systematic arthroscopic exploration. The groups were matched for age, sex and type of concomitant meniscal lesions. Exclusion criteria for both groups were: previous ipsilateral knee surgery, multiligament reconstruction, MRI performed in another institution or more than 8 weeks after the initial trauma, and open growth plates. The medial/lateral-PTS/MS and BBP were subjected to blinded evaluated on the preoperative MRI of the reconstructed knee. Independant student T tests and Chi-square test were used to compare the PTS and MS, and the BBP between both groups. Significance was set at p<0.05.

Results

Twenty eight patients (21 males; 7 females) were included in each group. Median time from injury to MRI was respectively 2 (IQR 2.1) and 1.8 weeks (IQR 1.6) in the RAMP and CONTROL group. No significant difference could be observed between groups in terms of demographical characteristics, PTS and MS. A posteromedial tibial plateau bone bruise (PMTPBB) was more often observed in the RAMP group (n=23/28) compared to the CONTROL group (n=12/28) (p<0.01). The RAMP group was 6.1 (95%CI [1.8; 20.8]) times more likely to present a PMTPBB. The likelihood of having a bone bruise in both the medial and lateral compartments was 4.5 (95%CI [1.2; 16.5]) times higher in the RAMP group. However, a BBP only involving the lateral tibiofemoral compartment was more likely to be observed in the CONTROL group (n=10/28) compared to the RAMP group (n=3/28, p<0.05 – odds ratio 4.6 (95%CI [1.1; 19.2]).

Conclusion

Ramp lesions were 6.1 and 4.5 times more likely to be observed in the presence of a posteromedial tibial plateau bone bruise or a combined bone bruise respectively in both the medial and lateral tibiofemoral compartment. The tibial and meniscal slopes did not differ between patients with or without ramp lesions undergoing ACLR. These findings add further understanding to the occurrence of medial meniscus ramp lesions and allow to better anticipate their repair during ACLR.