Recurrent spontaneous hemarthrosis after lateral unicompartmental knee arthroplasty treated with selective embolization
Background: Recurrent intra-articular hematoma is a rare complication after knee joint replacement surgery. In this report, we describe a case of recurrent intra-articular hematoma in a knee joint that was successfully treated using embolization. Case presentation: A 62-year-old woman underwent lateral unicompartmental knee arthroplasty for right knee osteoarthritis at our hospital. The postoperative recovery of the patient was overall positive, though some swelling developed in the knee with excessive movement. However, 4 years after the surgery, the patient returned to the clinic with a primary complaint of right knee pain. A right ballottement was observed, and a hematoma of approximately 50 cc was found at the puncture site. Symptoms of the patient improved after the puncture, but the hematoma continued to recur. Therefore, the patient was kept under rest, and oral tranexamic acid was administered. However, the conservative treatment did not improve her symptoms, and she was readmitted to our hospital. Right knee ultrasonography revealed a blood clot in the joint capsule. The synovial membrane was diffusely thickened, and contrast-enhanced blood flow in the synovial membrane was observed. The lateral superior knee artery was suspected to be the source. Based on these results, the patient underwent embolization by a radiologist. Contrast-enhanced images of the synovial membrane were obtained in the lateral superior and inferior knee arteries, followed by embolization of these vessels using Embosphere®. The patient had a positive postoperative recovery and was discharged in a few days. After discharge, the knee condition improved, and she became more active, engaging in activities, including shopping and movie outings. This could be the cause of the recurring intra-articular hematoma. Approximately one month after the previous embolization, she was readmitted to the hospital and underwent another embolization. Embolization was performed again using Embosphere® and imipenem/cilastatin. Postoperatively, the patient was not allowed to leave the hospital early. Instead, a knee extension brace was applied for 2 weeks, and the patient was instructed to be bed-rested as much as possible. Three weeks after the surgery, no recurrence was confirmed, and the patient was discharged. Conclusions: In cases of recurrent intra-articular hematoma of the knee after knee arthroplasty, the recommended first-line treatment for patients who do not respond to conservative treatment is addressing the intra-articular hematoma. This can be treated with either intravascular surgery or embolization. Postoperative rest is also important.
