Infections of the spine

Question 1

what is Pyogenic Infections?

Answer 1

• The axial skeleton is frequently the site of infections that accounts for approximately 2–7% of all cases of osteomyelitis.
• Lumbar spine is the most common site and followed by the cervical vertebrae for pyogenic spondylitis.
• Involvement of pedicle, laminae and spinous process is uncommon (3–12%) and when this does occur, it should arise suspicion of TB.
• Males are affected more frequently than women with the ratios of 1.5–3:1.
• Two peaks that appear prominent at the fifth decade and less prominent at second decade for adults are seen.

Question 2

what can cause pyogenic spinal infection?

Answer 2

•Bacterial, fungal and parasitic organisms can cause spinal infections.
•Staphylococcus aereus (S.aereus)  60% of cases, enterobacter 30% of cases
•Pathways for the spread 
–Hematogenous, and
–Non-haematogeneous
•contiguous source,
•direct implantantion,
•and postoperative.

Question 3

pyogenic infection clinical presentation depends on what?

Answer 3

• Location of the infection,
• The virulence of the organism
• The immune status of the host
• Back or neck pain is the most consistent symptom
• Associated with notable paraspinal muscle spasm

Question 4

pyogenic infection- clinical presentation?

Answer 4

•Usually present regardless of activity level
•Radicular leg or arm pain is less common but may be present with neurologic involvement
•Fever in 50% of patients
•Weight loss
A patient with a psoas abscess may have pain with hip extension
•Cervical abscess formation may lead to torticollis or dysphagia
•Radiculopathy, myelopathy,or even complete paralysis can occur with neural compression as a result of abscess, instability, or spinal deformity
•Direct spread of the infection into the epidural space can cause meningitis.
•Clinical signs and symptoms precede plain film findings by 1 week to 10 days in the appendicular skeleton and 21 days in the spine.
•Young patients present with acute systemic symptoms.
•Adult patients present with symptoms that vary and tend to be more chronic.
•Affects large tubular bones, most commonly the femur.
•Drug addicts are predisposed to Pseudomonas infections involving the “S” joints: Spine,

Question 5

pyogenic infection laboratory findings

Answer 5

–Frequently elevated erythrocyte sedimentation rate,
–white blood cell (WBC) count and
–C-reactive protein values or normal values.
–It is not uncommon for culture of blood or biopsy specimens to be negative.

Question 6

treatment and prognosis of pyogenic spinal infection?

Answer 6

•Treatment:
–Antibiotics;
–Surgical debridement (late)
•Prognosis:
–Good if diagnosed early

Question 7

what is Facet joint infection?

Answer 7

• Isolated pyogenic arthritis is rare.
• Vascular supply of the facet joints differs from the vertebral bodies and may be rarely involved by haematogeneous spread while non-haematogeneous involvement is usual.
• Pain increases by extension and lateral bending but not forward flexion.

Question 8

Facet joint infection- CT abnormalities

Answer 8

–loss of subchondral bone associated with the facet joint,

–loss of density of ligament flavum.

Question 9

POTT’S Disease- general conditions

Answer 9

• Leading cause of death at the beginning of the 20th century.
• Found in patients such as prepubertal children, debilitated geriatrics, AIDS sufferers, silicosis, lymphoma patients, al¬coholics, corticosteroid and drug abusers.

Question 10

POTT’S Disease: etiology

Answer 10

• Mycobacterium tuberculosis is the most common pathogen isolated.
• Two modes of spread exist: inhalation and ingestion.

Question 11

POTT’s disease clinical features

Answer 11

• No sex predilection; rare below the age of 1 year.

* Regional joint pain, decreased range of motion; focal tenderness and swelling are common symptoms.

Question 12

POTT’S Disease pathological features

Answer 12

• Infective organisms travel as emboli via the bloodstream, lodging in the turbulent flow at the endplate arterioles.
• Earliest site of spinal disease is the anterior subchondral end-plate. Disc involvement occurs after endplate destruction.
• Subligamentous dissection of the infective focus occurs down the anterior Longitudinal ligament. Anterior vertebral body scalloping occurs, creating “gouge defects.”
• Abscess formation produces soft tissue swelling which is out of proportion to the degree of bone and disc destruction.

Question 13

POTT’S disease Pathological features

Answer 13

• Infective organisms travel as emboli via the bloodstream, lodging in the turbulent flow at the endplate arterioles.
• Earliest site of spinal disease is the anterior subchondral end-plate. Disc involvement occurs after endplate destruction.
• Subligamentous dissection of the infective focus occurs down the anterior Longitudinal ligament. Anterior vertebral body scalloping occurs, creating “gouge defects.”
• Abscess formation produces soft tissue swelling which is out of proportion to the degree of bone and disc destruction.
• Retropharyngeal, paravertebral (thoracic spine), and psoas abscess are the common presentations.
• Psoas abscesses frequently calcify in a “snowflake” dense pattern. Five percent of spinal TB develop a psoas abscess.
• Pott’s paraplegia may complicate extensive spinal involvement.
• Tubercular appendicular arthritis is most common in the hip and knee.
• Cartilage destruction and marginal erosions characterize the pathologic changes of tubercular arthritis.

Question 14

Pott’s disease treatment and prognosis

Answer 14

•Chemotherapy
–recently it has been shown that the causative organism is becoming some¬ what resistant to the modern drug therapy.

•Surgery is seldom necessary.

Question 15

Pediatric Diskitis

Answer 15

• Vertebral infection should be suspected when the child has
• A lowgrade fever
• Pain,
• Refuses to bear weight
• Assumes a flexed position of the spine

Question 16

Risk factors of spinal infection

Answer 16

•Smokers,
•Obese,
•Malnourished
•Immunosuppressed, either from:
–acquired immunodeficiency syndrome or
–medical treatment for tumors; arthritis; organ transplantation;
•Drug addicts;  
•Diabetics;
•Or those who have undergone recent urinary tract instrumentation.