Two-stage management of a large tibial tunnel cyst and secondary meniscal root tear after anterior cruciate ligament reconstruction

This report describes the case of a woman in her 40s who developed debilitating knee pain and instability 1 year after undergoing an anterior cruciate ligament reconstruction. MRI revealed a complex pathology, including marked widening of both the femoral and tibial bone tunnels, significant perigraft cyst formation, a complete posterior root tear of the medial meniscus with extrusion and a partial tear of the lateral meniscal root. This indicated a functional failure of the primary reconstruction, leading to secondary intra-articular damage. A staged surgical approach was planned with an open excision of the proximal tibial tunnel cyst with meticulous curettage of the tunnel walls, combined with an arthroscopic all-inside repair of the medial meniscus. Substantial bone loss was addressed with autologous iliac crest bone graft. The patient experienced an uneventful recovery with significant symptomatic improvement, evidence-based approach to managing complex postoperative anterior cruciate ligament reconstruction complications.