Unlike meniscal tears and chondral defects, the mucoid degeneration of the anterior cruciate ligament (ACL) is a rare cause of knee pain and there have been no case reports of mucoid degeneration of both the ACL and the posterior cruciate ligament (PCL). A 48-year-old-male patient presented with knee pain and limitation of motion. The patient's magnetic resonance imaging, arthroscopic findings, and pathologic diagnosis confirmed a clinical diagnosis of mucoid degeneration of both the ACL and the PCL. The symptoms disappeared after arthroscopic partial excision of the ACL and PCL.
Anterior Cruciate Ligament/*pathology/radiography ; Arthralgia/etiology ; Humans ; Joint Diseases/diagnosis/*pathology/radiography ; Knee Joint/*pathology/radiography ; Male ; Middle Aged ; Posterior Cruciate Ligament/*pathology/radiography

Ganglion cysts are more commonly associated with the anterior cruciate ligament than the posterior cruciate ligament (PCL). A literature review showed that all reported cases of ganglion cysts to date involved adults. We report a rare case of ganglion cyst in the PCL of a four-year-old boy, and discuss its aetiology, clinical presentation, imaging features and management. Ganglion cysts of the PCL may be confused with meniscal cysts arising from tears of the posterior horn of the medial meniscus on magnetic resonance (MR) imaging. Hence, the posterior horn of the medial meniscus has to be carefully evaluated to rule out a tear. MR imaging is the method of choice to confirm diagnosis, and arthroscopic resection is a safe treatment modality even in children.
Arthroscopy ; Child, Preschool ; Ganglion Cysts ; diagnosis ; surgery ; Humans ; Knee Joint ; diagnostic imaging ; Magnetic Resonance Imaging ; Male ; Posterior Cruciate Ligament ; injuries ; pathology ; Radiography