Post-traumatic Subcutaneous Hematoma

After an accident on the lawn, a large bruise developed over the knee of a 58-year-old woman who was otherwise in good health. There were no abrasions. While the bruise had largely resolved within several weeks, she sought medical case because of a persistently tender swelling located just below and just medial to the inferior portion of the left patella.

Key point: Continuing swelling and pain should alert the clinician to a problem more serious than a mere bruise. The lesion was compressible, suggesting a collection of fluid. This is a post-traumatic subcutaneous hematoma-a condition common in elderly women-especially those who are anticoagulated. Untreated, the hematoma can eventuate into an abscess and even lead to sepsis.

Treatment: Following local anesthesia, about 3 µL of blood and serous fluid was evacuated from the affected area, and a pressure dressing applied for 1 week.

Note: Following a fall, traumatic cutaneous hematomas are also a leading cause of morbidity in elderly, hospitalized patients.