For trochanteric bursitis, a diagnostic injection is typically definitive because it produces what outcome?

• A. Relief from symptoms after injection
• B. No relief
• C. Pain with resisted hip abduction
• D. X-ray changes

Answer: (A)

A diagnostic injection into the trochanteric bursa is definitive because it temporarily numbs the inflamed bursa. If the pain truly originates from trochanteric bursitis, numbing the bursa relieves the symptoms, confirming the bursa as the source. This immediate relief distinguishes bursitis from other causes of hip or lateral thigh pain.

If there’s no relief, the pain likely comes from another structure or pathology, so the injection wouldn’t confirm bursitis. X-ray changes aren’t diagnostic for bursitis either, since bursitis is a soft-tissue problem and radiographs often don’t show it. The key takeaway is that the defining outcome of the diagnostic injection is symptom relief after the injection.