Do not ignore persistent pain after total knee arthroplasty: Pseudoaneurysm of the popliteal artery after primary total knee arthroplasty

A popliteal pseudoaneurysm following total knee arthroplasty is a rare but potentially life-threatening complication. The most critical step in diagnosing popliteal pseudoaneurysms is maintaining a high level of suspicion and conducting a clinical assessment. The presence of a pulsatile mass in the popliteal region, edema, ecchymosis in the leg, unusual and persistent posterior knee pain, swelling, and paresthesia are diagnostically valuable indicators for popliteal pseudoaneurysms. Lower extremity venous Doppler ultrasonography and computed tomographic angiography are valuable diagnostic tools for identifying pseudoaneurysms. This case report describes a patient who presented with clinically inconsistent pain on the first postoperative day following primary total knee arthroplasty and was subsequently diagnosed with a popliteal pseudoaneurysm. Additionally, a review of the literature on this topic is provided. An 81-yearold woman with a history of nocturnal knee pain and significant impairment in daily activities underwent total knee arthroplasty. On the first postoperative day, she reported discomfort in the lower extremities and posterior knee pain that did not align with her clinical presentation. Palpation of the distal pulses revealed no abnormalities, and no additional symptoms were observed. Venous Doppler ultrasonography of the patient's left lower extremity identified a spherical, low echogenic structure with pulsation, approximately 3.5 × 2.5 cm in size, located near the prosthesis and adjacent to the popliteal artery. This finding confirmed the diagnosis of a pseudoaneurysm. Following a comprehensive assessment and given the evidence of a neck size exceeding 5 mm and the potential for dissection in the vicinity of the pseudoaneurysm, the decision was made to implant a covered stent. In cases of severe pain that is inconsistent with the clinical and postoperative period, popliteal pseudoaneurysms should be considered.