Background: The purpose of this study is to characterize meniscal pathology associated with anterior cruciate ligament (ACL) rupture in skeletally immature patients. We also evaluate the accuracy of preoperative magnetic resonance imaging (MRI) in predicting ACL and meniscus pathology.
Methods: A retrospective chart review was performed on 124 skeletally immature patients who underwent arthroscopically assisted ACL reconstruction within 3 months of injury. Operative reports and arthroscopic images were reviewed to determine patterns of meniscal injury. The accuracy of preoperative MRI in predicting ACL rupture and meniscus pathology was also compared.
Results: One hundred twenty-four patients, including 80 males with an average age of 14.3 years, and 44 females with an average age of 14.1 years were included. The lateral meniscus was torn in 51 patients, the medial meniscus in 17 patients, and both menisci in 19. The prevalence of meniscus tear was 69.3%. Location of the tear occurred in the posterior horn in 69 tears (65.0%), the middle and posterior horn in 31 tears (29.2%), the middle horn in 4 tears (3.7%), and the anterior horn and posterior horn in 2 tears (1.8%). MRI showed 95.6% sensitivity in detecting complete ACL rupture. Further, MRI had a sensitivity of 58.6% and a specificity of 91.3% in characterizing meniscus tears.
Conclusions: There are many studies that evaluate ACL rupture in the skeletally immature population, but few studies focus on the meniscus pathology that is associated with these injuries. We reinforce the fact that meniscal injury is commonly associated with ACL rupture in patients with open physes (prevalence of 69.3%). We were able to conclude that lateral meniscus tears are more common than medial meniscus tears, which were equally as common as combined tears in our patient population. The posterior horn is injured in most of patients, and is usually in a repairable configuration and vascular zone. These findings will help to guide surgeons in their clinical evaluation and treatment of skeletally immature patients with ACL rupture.
Level of evidence: Level IV, retrospective case series.