Final answer:
The diagnoses to explore further in a 49-year-old with low back pain and a normal lumbar/sacral spine x-ray are spinal stenosis and herniated nucleus pulposus, as they may not be visible on an x-ray and can cause significant pain.
Step-by-step explanation:
You asked which diagnosis to explore further for Bet, age 49, who comes in with low back pain and has a normal x-ray of the lumbar/sacral spine. Since scoliosis typically presents with visible deformity and would likely show up on an x-ray, and osteoarthritis would also generally be visible on x-ray through joint space narrowing or bone changes, these conditions are less likely culprits if the x-ray is normal.
The remaining options, spinal stenosis and herniated nucleus pulposus (often referred to as a herniated disc), can both occur without definitive changes on x-ray, especially if the condition is in the early stages or is mild. Spinal stenosis is a narrowing of the spinal canal which may not always be evident on an x-ray, and a herniated disc can occur where the nucleus pulposus protrudes through a weakened anulus fibrosus causing pain and potentially sciatica without necessarily showing on a plain x-ray. Therefore, both spinal stenosis and herniated nucleus pulposus are worth exploring further through clinical evaluation and potentially an MRI or CT scan for better soft tissue detail.