The concurrence of osteochondromatosis and bone infarction in a patient with anterior cruciate ligament rupture: a rare case report.

Introduction: Synovial osteochondromatosis and bone infarction are two uncommon conditions that typically present independently and are frequently misdiagnosed due to their nonspecific symptoms. This case highlights an exceptionally rare clinical scenario, underscoring the importance of meticulous imaging evaluation and integrated surgical management. Presentation of case: A 38-year-old male diver with a history of heavy smoking presented with knee instability, pain, and swelling following trauma. Examination revealed anterior cruciate ligament (ACL) rupture with concomitant meniscal tears. Imaging demonstrated multiple intra-articular calcified loose bodies, synovial proliferation consistent with synovial osteochondromatosis, and bone infarctions of the distal femur and proximal tibia. Arthroscopic management included loose body removal, synovectomy, meniscal repair, tibial drilling for infarct revascularization, and all-inside ACL reconstruction. Histopathology confirmed chronic synovitis and osteochondromatosis. At the 12-month follow-up, the patient demonstrated significant functional improvement, as assessed by clinical outcome scores. Discussion: The patient's occupation and smoking habit may have contributed to vascular compromise, repetitive microtrauma, and synovial metaplasia. Arthroscopy offers a minimally invasive approach, enabling the simultaneous treatment of all lesions. Persistent mild pain was likely related to underlying bone infarction. Conclusion: To the best of our knowledge, this is an extremely rare case involving the concurrence of synovial osteochondromatosis, bone infarction, and ACL rupture in a single patient. Arthroscopic management was feasible and was associated with satisfactory short-term clinical and functional improvement in this patient.