Delayed pulmonary embolism after unicompartmental knee arthroplasty: A case report

INTRODUCTION: Although venous thromboembolism (VTE) is relatively rare after unicompartmental knee arthroplasty (UKA), symptomatic pulmonary embolism (PE) can be fatal. Whether routine thromboprophylaxis or thrombolytic treatment is necessary for patients undergoing UKA remains unclear. Here, we present a case of delayed pulmonary embolism after UKA. PATIENT CONCERNS: A 57-year-old women underwent cemented UKA for left localized medial knee pain. There were no risk factors of VTE besides high BMI before surgery. 2 months after surgery, the patient presented with dyspnea and palpitation, and these symptoms could not be alleviated after rest. DIAGNOSIS: An arterial blood gas analysis showed decreased PO(2), SO(2) and PCO(2). Pulmonary CTA showed multiple pulmonary embolism in the trunk of the right lower pulmonary artery and the branch of the left lower pulmonary arteries. The final diagnosis was delayed pulmonary embolism after UKA. INTERVENTIONS: Urokinase thrombolysis was administered intravenously. Low molecular weight heparin and warfarin were prescribed for anticoagulation. OUTCOMES: The patient's symptoms abated, and chest CTA showed that the pulmonary embolism had dissolved. No further thrombosis has been observed for more than 6 years. CONCLUSIONS: We presented an unusual case of delayed pulmonary embolism after UKA. Despite the low incidence, its life-threatening nature makes it imperative for surgeons to be well-informed about thrombosis and pay more attention to its prevention strategies.