ABSTRACT
BACKGROUND: Anticoagulation treatment after lower limb surgery is one of the key methods to avoid thrombosis, and low-molecular-weight heparin is the treatment that is most frequently used in clinical practice. But one uncommon side effect of low-molecular-weight heparin is heparin-induced thrombocytopenia (HIT), which can develop into thrombosis if not caught early or managed incorrectly. CASE SUMMARY: We present a case of a patient who underwent hip arthroplasty and experienced thrombocytopenia due to HIT on the 9th d following the application of low-molecular-weight heparin anticoagulation. We did not diagnose HIT in time and applied 1 unit of platelets to the patient, which led to thrombosis. Luckily, the patient recovered following effective and timely surgery and treatment with rivaroxaban. CONCLUSION: Patients using low-molecular-weight heparin after lower limb surgery need to have their platelet counts regularly checked. If HIT develops, platelet treatment should be given with caution.