Incidence, Presentation, and Treatment of Pediatric and Adolescent Meniscal Root Injuries

BACKGROUND: Despite the increasing incidence of sports-related knee injuries in youth athletes, few studies have reported on the diagnosis and treatment of pediatric and adolescent meniscal root injuries. PURPOSE: To describe traumatic posterior meniscal root injuries in a pediatric and adolescent population and compare the presentation of meniscal root injuries versus that of nonroot injuries. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A study was conducted of all knee arthroscopies performed on consecutive patients treated in a pediatric sports practice from March 2012 through February 2015. All patients who were younger than 20 years at the time of their injury and who underwent an arthroscopy with meniscal injury were included. Patients with discoid lateral meniscus, atraumatic meniscal cysts, partial-thickness meniscal root injuries (LaPrade type 1), and recurrent root tears were excluded. A comparative analysis of root and nonroot injuries was performed. RESULTS: A total of 314 patients had surgery for meniscal injury (mean patient age, 16.0 years; range, 10.5-19.6 years). Of these patients, 58 (18.5%) posterior meniscal root injuries were identified. The root injuries were more likely to have joint line tenderness on preliminary physical examination compared with nonroot injuries (96.5% vs 58.6%, respectively; P < .001). Root injuries rarely occurred in isolation compared with nonroot meniscal tears (6.9% vs 17.6%; P = .021) and were frequently treated in combination with anterior cruciate ligament (ACL) injuries (86.2%). Lateral root injuries occurred more often in conjunction with ACL injuries compared with medial root injuries (84.8% vs 22.2%; P < .001). On review of preoperative imaging, meniscal extrusion occurred more often in root injuries than in nonroot injuries (32.8% vs 3.5%; P < .0001) and was uncommonly seen in the skeletally immature patient. Extrusion was seen more often in medial than lateral root tears (66.7% vs 21.7%; P = .008). A majority of patients (57/58) underwent transosseous suture repair of the meniscal root. CONCLUSION: When treating a pediatric or adolescent patient for a traumatic meniscal tear, a surgeon may expect to see a posterior meniscal root injury in as many as 1 in 6 patients. When treated for an ACL, contact, or multiligament injury or meniscal extrusion, a pediatric or adolescent patient may demonstrate a meniscal root avulsion or complex meniscal tear. These data provide practitioners with an improved ability to identify and treat meniscal root injuries that otherwise lead to rapid cartilage degeneration.