Spinal tuberculosis

Dr Muhammad Ijaz wazir

Tmo Orthopedic B ward HMC

Introduction

• Known by many names: spinal tuberculosis, tuberculous spondylitis, Pott disease or Pott’sdisease

• First described in 1782 by Percival Pott, a British orthopedic surgeon

Pott Disease: Epidemiology

• Pott disease is common in the developing countries

• Skeletal tuberculosis Accounts for 10% of all cases of extrapulmonary TB

• Targets the hips, knees, spine• Spinal tuberculosis is most common, accounts for

50% all skeletal TB cases• men & women equally affected• Targets thoracic & lumbar vertebrae

Pott Disease: Pathophysiology

– Tuberculous bacilli infiltrates the spine via Hematogenous spread through the dense vasculature of cancellous bone of the anterior vertebral bodies

– Lymphatic spread from para‐aortic lymph nodes possible but rare

– Up to 75% of infected individuals develop a soft tissue infection Commonly occurs in the psoas muscle

– Left untreated, degeneration and inflammation of the vertebrae causes Herniation into the cord space , cord compression

– Kyphosis , gibbous (severe kyphosis)– Paraplegia

CLINICAL FEATURES

• Slowly progressive constitutional symptoms are predominant in the early stages of the disease, including weakness, malaise, night sweats, fever, and weight loss, Pain is a late symptom associated with bone collapse and paralysis.

• Cervical involvement can cause hoarseness because of recurrent laryngeal nerve paralysis, dysphagia,

and respiratory stridor (known as Millar asthma).

Diagnosis

• History• Physical examination• Laboratory investigations• Plain x rays of the spine• CT of the spine• MRI of the spine• Biopsy• Bone scan• Ultra sound scan

Pott Disease: Lab FINDINGS

• Laboratory studies suggest chronic disease. Findings include anemia, hypoproteinemia, and mild elevation of ESR and CRP. Skin testing may be helpful but is not diagnostic. The test is contraindicated in patients with prior tuberculous infection because of the risk of skin slough from an intense reaction and is not useful in patients with suspected reactivation of the disease.

Radiographs: General Features

– Features of Pott’s on radiograph includeSigns of infection with lytic lucencies in anterior portion of vertebrae

– Disk space narrowing

– Erosions of the endplate

– Sclerosis resulting from chronic infection

– Compression fracture

– Continuous vertebral body collapse

– Kyphosis; gibbous (severe kyphosis)

CT: Features

Soft tissue findings Abscess with calcification is diagnostic of spinal TB; CT is excellent modality to visualize soft tissue calcifications

Pattern and severity of bony destruction Pattern of vertebral body destruction, osteolytic, localized and sclerotic, and subperiosteal

Used to guide needle in percutaneous needle biopsy of paraspinal abscess

MRI: Features

• Highly sensitive and specific for spinal TB

• Provides early detection

• Best to distinguish exact extent of spinal cord and soft tissue involvement

• Features Edema of vertebrae and disk space

• Signs of spinal compromise i.e. cord compression

MRI Features

MRI features

Differential Diagnosis

• Pyogenic & fungal infections

• Secondary metastatic disease

• Primary bone tumors

• Sarcoidosis

Pott Disease: Treatment

• Various imaging modalities are useful in determining extent of disease.

• Treatment options then depend on the degree of spinal destruction

Conservative Treatment

• Early Disease:

• Treat with a four drug regimen for six to twelve months

• Common antibiotics are Rifampin, Isoniazid, Pyrazinamide, Ethambutol

• Most individuals experience full resolution of symptoms with appropriate anti‐tuberculosis treatment

Surgical Interventions

• Late Disease:Loosely defined by neurologic deficits, spinal kyphosis >40%, or failure of medical therapy

• Surgical debridement, abscess drainage, and/or vertebral fusion and spinal fixation in addition to antibiotics

Treatment

• Depends upon the type of lesion

• Type 1 A

• The lesion is localised to one vertebra & one disc degeneration ,no collapse,no abscess & no neurological deficits.

• The treatment is fine needle biopsy & drug therapy .

Treatment continued

• Type 1 B

• Abscess formation ,one or two level disc degeneration but no collapse & no neurological deficits.

• The treatment is abscess drainage & debridement.

Treatment continued

• Type 2

• Abscess formation, vertebral collapse,kyphosis,stable deformity with or without neurological deficit.

• The treatment is ;

• Anterior debridement & fusion

• Decompression

• Bone grafting

Treatment continued

• Type 3

• Severe vertebral collapse,abscessformation,severe kyphosis & instable deformity with or without neurological deficit.

• The treatment is;

• Anterior debridement & fusion

• Decompression

• Correction of deformity & internal fixation

Surgical treatment

Summary

• Imaging modalities are plain film, CT and MRI; MRI is gold standard for imaging spinal

• Diagnosis and treatment of spinal TB in endemic areas is difficult given resource limitations; rely on radiographs and clinical signs to facilitate early diagnosis.

• Conservative versus surgical treatment of Pottdisease depends on degree of spinal destruction, making early diagnosis essential for a positive outcome.

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