title: Tibial avulsion fracture of the posterior root of the medial meniscus in a skeletally-immature child - a case report.
abstract: It has been theorized that a traumatic tibial avulsion fracture of the posterior root of the medial meniscus (MM) is the cause of the so-called meniscus ossicle (MO). We report the delayed appearance of a tibial avulsion fracture of the posterior root of the MM after a valgus, twisting injury in a 12-year-old boy with open physes. Magnetic resonance imaging (MRI) scans performed 3 days after the injury did not demonstrate a definitive tibial avulsion fracture of the posterior root of the MM; whereas, a repeat MRI for 3 months post-injury did. Medial extrusion of the MM was also noted on the 3 month MRI. Arthroscopic reattachment of the avulsed posterior root of the MM using a trans-physeal nonabsorbable suture tied over a proximal tibia staple was performed. Follow-up MRI at 6 months postoperatively demonstrated healing of the tibial avulsion fracture of the posterior root of the MM in an anatomic position. The patient had a complete resolution of symptoms and there was no angular deformity or limb-length discrepancy at 2 years postoperatively. To our knowledge, this is the first report describing a tibial avulsion fracture of the posterior root of the MM in a skeletally-immature patient successfully treated by a trans-physeal arthroscopic suture. This case also illustrates the development of the MO of the posterior root of the MM.
authors.affiliation: Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Matava
authors.forename: Young-Mo
authors.initials: YM
authors.lastname: Kim
mesh_terms: D001915:Braces; D002648:Child; D017102:Fracture Healing; D018460:Fractures, Comminuted / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007718:Knee Injuries / Q000473:pathology* / Q000601:surgery; D007719:Knee Joint / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology* / Q000601:surgery; D016059:Range of Motion, Articular; D053441:Suture Anchors; D013978:Tibial Fractures / Q000473:pathology* / Q000601:surgery; D000070600:Tibial Meniscus Injuries; D016896:Treatment Outcome