In March 2013, Mr. A, a 25-year-old male, was playing football when another player's knee collided with his thigh. He remembered immediate pain and swelling over his upper quadriceps. However, he was able to continue playing and later that evening the pain increased in severity. Mr. A was unable to sleep and the next morning he presented to the university sports injury clinic. At this stage, examination noted visible swelling but no neurological or vascular compromise. Initial treatment consisted of rest, ice, and analgesia and the patient was discharged with crutches.
Unfortunately, 5 days later, Mr. A returned with increased swelling, bruising, and paraesthesia. He was referred to the emergency department for further assessment.  Figure 3 shows the extent of the thigh swelling. His routine blood tests revealed haemoglobin of 80 g/L (normal 135 g/L-175 g/L). CT scan of thigh estimated the haematoma volume at >2 L and given his early neuropathy he was referred for urgent fasciotomy.
After fasciotomy (Figure 4), Mr. A required two units of packed red cells. A coagulation screen preoperatively showed normal PT and APTT and increased fibrinogen. Six days after fasciotomy closure, Mr. A re-presented with swelling and a discharging wound. The wound was evacuated and further packed red cells were transfused. Another coagulation screen was performed prior to skin grafting, which revealed a prolonged APTT of 34 seconds (normal range 21-32 seconds).
Further investigations by haematology revealed a low Factor IX of 27.2% in keeping with a diagnosis of mild haemophilia B. Prophylactic enoxaparin was discontinued and regular tranexamic acid was started. Mr. A made a full recovery within 2 months and is now under the care of a comprehensive care haemophilia centre. He had extended family screening confirming his mother and maternal grandmother as carriers of haemophilia as well as a maternal aunt whose son was confirmed to have haemophilia.