Insidious Onset of Thigh Swelling After Trauma in a Triathlete

Abstract

HISTORY: A 78-year-old female triathlete presented to clinic to follow-up on injuries sustained during a cycling accident. Evaluation in the ED on the day of injury showed facial bone fractures and small peripheral parenchymal hematomas in the right frontal and temporal lobes for which she had follow-up scheduled. In clinic two days later, she complained of pain and bruising over her right hip. She was diagnosed with an abrasion and contusion of the right hip and treated with ice and NSAIDs. She returned four weeks later with worsening right hip pain, described as constant, throbbing, non-radiating, and worse with weight-bearing. It was associated with swelling and a tender mass that had developed gradually over the right hip. She denied fevers or chills. PHYSICAL EXAMINATION: Vitals were normal at both visits. Initial exam of the right hip showed a large abrasion, mild ecchymosis, and tenderness. She had full range of motion without pain or edema. She also had normal balance and gait. Four weeks later, the right hip had a 15 x 17 cm, warm, tender mass over the lateral aspect of the thigh, without erythema. FABER and FADIR were negative, and muscle strength, pulses, and sensation were normal. The abrasion was well-healed. DIFFERENTIAL DIAGNOSIS: 1. Hematoma 2. Contusion 3. Bursitis 4. Abscess 5. Neoplasm TESTS AND RESULTS: CBC was normal. Radiographs of right hip were negative for fracture or soft tissue abnormalities. MRI of the right lower extremity showed a heterogeneous fluid collection measuring 22 x 4 x 6 cm (H x W x D, 528 cc) overlying the right hip with small internal foci of hemorrhage/debris, and peripheral rim enhancement without any areas of internal enhancement. FINAL WORKING DIAGNOSIS: Morel-Lavallée lesion TREATMENT AND OUTCOMES: The patient underwent aspiration, doxycycline sclerotherapy, and percutaneous drainage. Post-procedure US was negative for any significant fluid collection. Repeat MRI three weeks after the procedure showed incomplete resolution/recurrence of the lesion measuring 20 x 1.5 x 2.8 cm (84 cc). The patient had follow-up with orthopedics and elected for conservative treatment with compression dressings. She returned to triathlon training and has subsequently completed a 100-km bike race at 6 months post injury.