Differential Diagnosis for Pain in SI Joint after Fall with Negative Imaging
- Single most likely diagnosis
- Ligamentous sprain or strain: The most common cause of pain in the SI joint after a fall, especially with negative imaging, is a ligamentous sprain or strain. The SI joint is supported by strong ligaments, and a fall can cause stretching or tearing of these ligaments, leading to pain and inflammation.
- Other Likely diagnoses
- Sacroiliac joint dysfunction: This refers to any condition that affects the normal functioning of the SI joint, including abnormal movement or malalignment, which can cause pain.
- Muscle strain: The muscles around the SI joint, such as the gluteals and piriformis, can be strained during a fall, leading to pain in the area.
- Bursitis: Inflammation of the bursae around the SI joint can cause pain, especially if the bursae are irritated or inflamed due to the fall.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Fracture not visible on initial imaging: Although initial imaging may be negative, it's crucial to consider the possibility of a fracture that may not be immediately visible, such as a stress fracture or a small avulsion fracture.
- Infection or osteomyelitis: Infection in the SI joint or the surrounding bone can cause severe pain and has the potential for serious complications if not promptly treated.
- Cauda equina syndrome: Although rare, a fall can potentially cause nerve compression or damage leading to cauda equina syndrome, a serious condition that requires immediate medical attention.
- Rare diagnoses
- Sacroiliac joint infection: This is a rare condition where the SI joint becomes infected, often due to bacterial or fungal causes.
- Tumor or metastasis: In rare cases, pain in the SI joint could be due to a primary tumor or metastasis to the area, which would require further investigation.
- Spondyloarthritis: Conditions like ankylosing spondylitis can cause inflammation and pain in the SI joint, although these conditions typically have a more gradual onset and are associated with other systemic symptoms.