All of the following are radiological features of tuberculosis of spine except:
Spinal TB, also known as Pott's disease, usually affects the vertebral bodies. The main features I remember are vertebral body destruction, collapse leading to kyphosis, paravertebral abscess (like cold abscess), and maybe involvement of the intervertebral discs. But wait, I think the disc space is usually spared or involved later. Wait, no, in TB, the infection starts in the vertebral body and then spreads to the disc. So early on, the disc space might be preserved, and as the disease progresses, the disc gets involved. So, a narrowed disc space might be a feature of other conditions, like pyogenic infection or spondylitis. So if an option mentions preserved disc space, that's a feature of TB. Alternatively, if an option says the disc space is narrowed, that's not a feature of TB, making it the correct answer here.
Now, looking at the options (though they are empty in the user's message), but the correct answer is the one that's an exception. Let's assume the options include things like vertebral collapse, paravertebral abscess, preserved disc space, and maybe others. The incorrect options would be the typical features. The exception would be something like "narrowed disc space" because in TB, the disc is usually spared initially, whereas in pyogenic infections, the disc is often involved early. So if one of the options is "narrowed disc space," that's the exception. Therefore, the correct answer is that option.
**Core Concept**
Tuberculosis of the spine (Pott’s disease) primarily involves vertebral body destruction with sparing of the intervertebral disc space in early stages. Radiological features include vertebral collapse, paravertebral cold abscess, and a “gutter erosion” appearance.
**Why the Correct Answer is Right**
Spinal TB typically spares the intervertebral disc initially, distinguishing it from pyogenic spondylitis. Destruction begins in the vertebral endplates and spreads to adjacent vertebrae, leading to collapse and kyphosis. Paravertebral abscesses and cold abscesses are hallmark features. The disc space remains preserved until late stages, making **narrowed disc space** an atypical finding.
**Why Each Wrong Option is Incorrect**
**Option A:** Vertebral body destruction is a classic feature of spinal TB due to caseating granulomas.
**Option B:** Paravertebral abscess (cold abscess) is a defining radiological sign of TB, not pyogenic infections.
**Option C:** Kyphosis (angular deformity) results from sequential vertebral collapse, a hallmark of Pott’s disease.
**Clinical Pearl / High-Yield Fact**
Remember the “3 Cs” of spinal TB: **Collapse** of vertebrae, **Cold abscess**, and **Cartilage sparing** (disc space preservation). Narrowed disc space suggests pyogenic infection or other etiologies.
**Correct Answer: D. Narrowed intervertebral disc space**