Extraarticular Pretibial Synovial Cyst After Arthroscopic Anterior Cruciate Ligament Reconstruction: A Case Report

Arthroscopic reconstruction of the anterior cruciate ligament has been modernized through new materials and novel surgical techniques. The usage of bioabsorbable screws for tibial fixation may potentially lead to complications, such as formation of a tibial tunnel or pretibial cysts. This is a relatively rare complication, but it has been described in the literature. The pathomechanism of cyst formation, however, still remains poorly understood. In this case report, we present a case of a healthy 23-year-old gentleman who had left tibia vara, which was treated surgically with proximal tibia corrective osteotomy with plate and screw fixation and subsequent hardware removal. Later in his life, he injured his anterior cruciate ligament, which required arthroscopic reconstruction. Years after, he developed a pretibial synovial cyst, which was visualized on magnetic resonance imaging. We reviewed previously published cases with similar presentations to help describe the possible etiology of intraosseous (tibial tunnel) cysts.