Bone bruises and meniscal tears on MRI in skeletally immature children with tibial eminence fractures.

BACKGROUND

Earlier studies have found that tibial eminence fractures (TEFs) in children are rarely associated with additional injuries. In skeletally immature patients with this fracture, the rate of meniscal injury is reported to be less than 5%. Most earlier studies that evaluate TEFs are based on conventional radiographic findings and do not address injuries to the subchondral bone and soft tissues of the knee. Therefore, the purpose of this study was to assess additional injuries, specifically bone bruises and meniscal tears identified by magnetic resonance imaging (MRI) in skeletally immature patients who have sustained a TEF.

METHODS

This study is a retrospective evaluation of 20 skeletally immature children with TEFs who have undergone MRI examinations of the knee. Sixteen boys and 4 girls, ranging in age from 7 to 17 years (mean age, 12 y) were included. The TEFs were classified by the modified Meyers McKeever system. The MRI examinations were reviewed for the presence and location of associated subchondral bone contusions and meniscal injuries.

RESULTS

Distribution of the TEF types was: type I, n=6 (30%); type II, n=3 (15%); type III, n=11 (55%); and type IV, n=0. Subchondral bone contusions were seen in 18 children (90%). These were in the lateral femoral condyle (80%), lateral tibial plateau (75%), medial femoral condyle (60%), and medial tibial plateau (30%). Meniscal tears were present in 8 patients (40%), divided equally between the medial and lateral meniscus.

CONCLUSIONS

TEFs in children are associated with a high rate of bone contusion and meniscal injury. The pattern of injuries observed in this series suggests that a mechanism of injury similar to that of adult anterior cruciate ligament tears might also be responsible for TEFs in skeletally immature children. In addition, we found that the incidence of associated meniscal injury is higher than previously reported. MRI examinations may play an important role in the evaluation for additional injuries in these children.

LEVEL OF EVIDENCE

Level IV-Case series.