Rationale: Several case reports about the diagnostic and therapeutic approaches of hemarthrosis after total knee arthroplasty using angiogram have been reported, owing to the probability of bleeding caused by vascular injuries. However, there were only few cases of spontaneous hemarthrosis of the knee joint in the elderly patient that have not undergone total knee arthroplasty that have been previously reported.
Patients concerns: An 82-year-old male presented to our outpatient department with acute left knee pain. He had no history of trauma. The patient had under gone several times of therapeutic arthrocentesis for treatment of left knee joint effusion at a local clinic.
Diagnosis: Arthroscopic examination was performed at the local clinic and was not able to reveal any focus of intra-articular bleeding. We consulted this case with the department of radiology to angiographically find out abnormalities of the genicular arteries. Angiographs showed hyper vascularity of the superior and inferior lateral genicular artery, and superior medial genicular artery.
Intervention: One-step embolization using micro-catheter and 50 to 150 μm gelfoam particles was conducted. The hypervascular findings shown on angiogram were markedly subsided after embolization.
Outcomes: Until 1 year after embolization, there were no signs of recurrence on outpatient follow-up sessions LESSONS:: Degenerative changes of the genicular arteries may be a cause of spontaneous knee joint hemarthrosis in the elderly patients. Angiographic diagnosis and treatment may be effective for such cases.