HI. This is most probably due to Costo-chondritis as all your investigations you noted are normal including the CT scan , ultrasound and blood tests. Costo-Chondritis. :: This is so much suggestive of a condition called costo-chondritis., although the reason here is known to be a trauma. I would advise you to get an MRI of the painful area, telling the Radiologist to be specifically see for the painful- tender area. This will confirm the diagnosis. I would suggest the following treatment. -Rest to the area by means of strapping with the Adhesive tapes during the deep Expiration phase. This will limit the movement, reduce the pain and give rest for healing to occur. -Anti-inflammatory medicines in full dose as per the weight. -Steroids if required for its strong anti-inflammatory role. -Lasix to reduced the edema. This sort of a treatment helps all my patients. and should help you too.