Injury to the Posterior Horn of the Lateral Meniscus from a Misplaced Tibial Tunnel for Anterior Cruciate Ligament Reconstruction: A Case Report

Abstract

Specialty: Orthopedics Traumatology Objective: Rare disease Background: Posterior meniscal root avulsions can cause meniscal extrusion, joint space narrowing, and progressive knee arthritis. Iatrogenic posterior meniscal root avulsions after malpositioning of the transtibial tunnels during an-terior cruciate ligament (ACL) reconstruction can account for poor long-term outcomes seen in some patients following ACL reconstruction. Therefore, correct transtibial tunnel placement during ACL reconstruction is es-sential to avoid iatrogenic meniscal damage. Case Report: A 32-year-old man presented with 1 year of right knee pain and instability following a non-contact twisting injury sustained while playing soccer. An ACL tear with no meniscal involvement was diagnosed at an outside institution. A double-bundle reconstruction was performed at that time. Three months after surgery, a medial partial meniscectomy was performed after a medial meniscal tear and failure to reduce initial symptoms dur-ing the index procedure. Advanced imaging at our institution 6 months later demonstrated an iatrogenic later-al posterior meniscal root avulsions after malpositioning of the transtibial tunnels. Given the ACL graft integ-rity upon arthroscopic evaluation, the root tear was repaired using a 2-tunnel transtibial pull-out technique. Advanced imaging 1 year after surgery showed a well-maintained meniscal repair with no extrusion. Conclusions: Accurate transtibial tunnel placement during ACL reconstructive surgery is vital to avoid meniscal root detach-ment and the associated complications resulting in poor patient outcomes from this iatrogenic injury. Clinicians treating patients with a history of cruciate ligament reconstruction presenting with postoperative pain and in-stability should consider this pathology in their differential diagnosis.