Acute Bilateral Posterior Meniscal Root Tears in the Setting of a Noncontact Anterior Cruciate Ligament Rupture.

Abstract

Combined medial and lateral posterior meniscal root tears in the setting of an acute anterior cruciate ligament (ACL) rupture are extremely rare. The following case report demonstrates a high school football player who sustained a noncontact knee injury while performing a spin move at practice. The patient is a 17-year-old high school football defensive end who was presented to the clinic 1 week following the injury complaining of persistent knee pain with associated swelling, limited range of motion (ROM), and complaint of instability. During physical examination, the patient was found to have anterior cruciate laxity. Magnetic resonance imaging (MRI) demonstrated a complete midsubstance tear of the ACL and increased signal within the posterior horn of the medial meniscus with no obvious signs of pathology localized to the lateral meniscus. ACL reconstruction (ACLR) was performed and intraoperatively, both medial and lateral root tears were found. A standard bone patellar-tendon bone (BTB) autograft ACLR was performed with combined medial and lateral root repair utilizing a transtibial pull-out method for both. The clinical importance is root tears with associated ACL tears can be hard to diagnose on preoperative MRI, especially laterally, so careful assessment of both meniscal roots at the time of arthroscopy is critical. Furthermore, careful creation of the needed root repair tunnels for transtibial repair is critical to avoid coalescence with the ACL tibial tunnel.