Differential Diagnosis for Lower Back Pain
The patient presents with a 2-week history of constant dull ache in the lower back, which started after a motor vehicle accident (MVA). The pain is exacerbated by activity and has been improving. Here is a differential diagnosis, categorized for clarity:
Single Most Likely Diagnosis
- Musculoskeletal Strain: Given the recent history of MVA, where the patient's car was hit from behind, musculoskeletal strain due to the sudden impact and possible whiplash is the most plausible explanation. The improvement in symptoms also supports this diagnosis, as musculoskeletal strains typically resolve with time.
Other Likely Diagnoses
- Lumbar Disc Herniation: The trauma from the MVA could have caused a lumbar disc herniation, leading to lower back pain. However, the absence of numbness, tingling, or bowel/bladder incontinence makes this less likely.
- Ligamentous Sprain: Similar to musculoskeletal strain, ligamentous sprain could occur due to the sudden force exerted during the MVA, causing lower back pain.
Do Not Miss Diagnoses
- Abdominal Aortic Aneurysm (AAA): Although less likely given the patient's symptoms and the context of the MVA, AAA is a critical diagnosis that must be considered, especially in a 67-year-old patient with hypertension. A ruptured AAA can present with lower back pain and is a medical emergency.
- Spinal Fracture: Given the mechanism of injury, a spinal fracture is possible and must be ruled out, especially if the patient's condition worsens or if there are signs of neurological compromise.
- Kidney Injury: The location of the pain could also suggest a kidney injury, which is a possibility after a traumatic event like an MVA.
Rare Diagnoses
- Osteoporotic Compression Fracture: Although the patient's age and gender could predispose to osteoporosis, the acute onset of pain following a MVA makes this less likely unless the patient has a known history of osteoporosis.
- Spinal Infection: Infections like osteomyelitis or discitis are rare but could present with back pain. These would be more likely in the presence of fever, recent infection, or immunocompromised state.
- Tumor: Metastatic disease to the spine could cause back pain, but this would be less likely without other systemic symptoms or a known history of cancer.