# Skeletal Tuberculosis and Pott's Spine

> Skeletal tuberculosis and Pott's spine for NEET-PG Medicine: paradiscal vertebral lesions, cold abscess, MRI features and surgical indications for spinal TB.

- Canonical URL: https://prepelephant.com/topics/neet-pg/medicine/skeletal-tuberculosis-and-potts-spine
- Exam / course: NEET-PG · Subject: Medicine
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-14
- Last updated: 2026-10-14
- Reference basis: Maheshwari's Essential Orthopaedics; Harrison's Principles of Internal Medicine; National TB Elimination Programme Operational Guidelines
- How to cite: "Skeletal Tuberculosis and Pott's Spine", PrepElephant, https://prepelephant.com/topics/neet-pg/medicine/skeletal-tuberculosis-and-potts-spine

## Direct answer

Skeletal tuberculosis is Mycobacterium tuberculosis infection of bone and joints, and the spine is its most common site, where it is called Pott's spine. Vertebral TB typically begins in the anterior body next to the disc, the paradiscal lesion, causing wedge collapse, kyphosis and a cold abscess. Diagnosis rests on MRI, histology or CBNAAT, and surgery is reserved for neurological deficit, instability or failed medical therapy.

## What you must remember

- **Site:** the spine is the commonest bone site for tuberculosis, with the thoracic and lumbar regions most affected.
- **Paradiscal lesion:** the anterior vertebral body is destroyed next to the disc, which is spared early, unlike pyogenic spondylitis where the disc is lost early.
- **Gibbus:** sharp angular kyphosis from anterior collapse is the classic deformity of established Pott's spine.
- **Cold abscess:** a paravertebral collection with little inflammation that can track down the psoas muscle to the groin or thigh.
- **Neurology:** paraparesis or paraplegia results from cord compression by granulation tissue or abscess, and a progressive deficit is the main surgical indication.
- **MRI:** the most sensitive imaging for early marrow oedema, paravertebral abscess and epidural extension.
- **Joint TB:** the hip is the commonest joint affected after the spine, followed by the knee.

## A pathway from back pain to a surgical decision

Spinal tuberculosis is slow and often mistaken for mechanical back pain, so the diagnosis depends on a high index of suspicion. The steps below run from the clinical clue to the decision on surgery.

1. **Suspect the diagnosis.** Night pain, evening fever, weight loss and a stiff spine in a patient from an endemic area point to spinal TB.
2. **Image the spine.** X-rays show wedge collapse, but MRI detects marrow oedema and abscess earlier and defines the extent of the disease.
3. **Confirm the organism.** An image-guided biopsy or aspirate is sent for CBNAAT or culture, and histology showing caseating granulomas supports the diagnosis.
4. **Start antitubercular therapy.** Treatment follows the national programme, with bracing or bed rest used for pain and mechanical support, and neurological checks continue throughout treatment.
5. **Assess for surgery.** Progressive neurological deficit, instability, cord compression by abscess or failure of medical therapy calls for decompression and stabilisation.

## Where the exam tries to catch you

Most lost marks come from confusing spinal TB with pyogenic infection or with a postural deformity.

- **Trap:** a vertebral lesion with the disc spared early is read as pyogenic discitis. **Correct:** disc preservation with a paradiscal body lesion is the classic feature of tuberculosis, while pyogenic infection destroys the disc early.
- **Trap:** a sharp gibbus is treated as postural kyphosis with physiotherapy alone. **Correct:** a sharp angular deformity with neurological signs is spinal TB and needs MRI and a full neurological assessment.
- **Trap:** surgery is offered first for every patient with spinal TB. **Correct:** most patients are managed with antitubercular therapy, and surgery is reserved for neurological deficit, instability or failed medical treatment.

## Frequently asked questions

### Which imaging is best for early Pott's spine?

MRI is the most sensitive imaging for early Pott's spine, showing marrow oedema, paradiscal involvement and paravertebral abscess. X-ray changes such as wedge collapse appear later in the course of the disease.

### What is a cold abscess in spinal tuberculosis?

A cold abscess is a paravertebral collection of pus with little inflammation, typical of tuberculosis. It can track down the psoas muscle to the groin or thigh, presenting as a swelling away from the spine.

### When is surgery indicated in Pott's spine?

Surgery is indicated for progressive neurological deficit, spinal instability, cord compression by abscess or granulation tissue, or failure of medical therapy. The usual approach is decompression with stabilisation, chosen according to the level and the severity of the deficit.

### Which joint is most commonly affected by tuberculosis after the spine?

The hip is the commonest joint affected by tuberculosis after the spine, followed by the knee. Hip TB often presents with groin pain, a limp and restricted movement, and early diagnosis prevents joint destruction.

### Why is the paradiscal lesion characteristic of Pott's spine?

Tuberculosis starts in the anterior vertebral body next to the disc and spreads beneath the cartilage, so the disc is spared early. Pyogenic spondylitis, by contrast, destroys the disc early in the process.