Pott's disease (also known as Pott disease or Tuberculous Spondylitis) is tuberculosis of the spine, usually due to hematogenous spread from other sites, often the lungs. The lower thoracic and upper lumbar vertebrae areas of the spine are most often affected. It was named for British surgeon Percivall Pott, who first described the symptoms in 1779.

It causes a kind of tuberculous arthritis of the intervertebral joints. The infection can spread from two adjacent vertebrae into the adjoining intervertebral disc space. If only one vertebra is affected, the disc is normal, but if two are involved, the disc, which is avascular, cannot receive nutrients, and collapses. In a process called caseous necrosis, the disc tissue dies, leading to vertebral narrowing and eventually to vertebral collapse and spinal damage. A dry soft-tissue mass often forms and superinfection is rare.

Spread of infection from the lumbar vertebrae to the psoas muscle, causing abscesses, is not uncommon.

Diagnosis

The most common and earliest clinical symptom of Pott's Disease is back pain, often associated with local tenderness, worsening muscle spasms along the spine, and focal edema. For a radiolucent lesion to appear on a plain X-ray, there must be a 30% loss of bone mineral, making it difficult to diagnose the early stages of Pott's Disease with a plain radiograph. CT scans are often used as a guide for biopsies. Overall, it is widely documented that MRI is superior to plain radiographs in diagnosing Pott's Disease.

Initial suspicion of Pott's Disease is usually based on clinical symptoms and imaging findings, but a definitive diagnosis requires isolating the organism by culture, identifying it, and determining its drug susceptibility. The typical lab procedure for clinical specimens involves an AFB (acid-fast bacilli) stain.

The ESR (erythrocyte sedimentation rate) and CRP (C-reactive protein) are also used as biomarkers for spinal tuberculosis.

  • Blood tests
  • Complete blood count: leukocytosis
  • Elevated erythrocyte sedimentation rate: >100 mm/h
  • Tuberculin skin test
  • Tuberculin skin test (purified protein derivative [PPD]) results are positive in 84–95% of patients with Pott disease who are not infected with HIV.

thumb|200px|A girl from [[Oklahoma, who has been affected by bone tuberculosis, 1935]]

  • Radiographs of the spine
  • Radiographic changes associated with Pott disease present relatively late. These radiographic changes are characteristic of spinal tuberculosis on plain radiography:

:# Lytic destruction of anterior portion of vertebral body

:# Increased anterior wedging

:# Collapse of vertebral body

:# Reactive sclerosis on a progressive lytic process

:# Enlarged psoas shadow with or without calcification

:* Additional radiographic findings may include:

:# Vertebral end plates are osteoporotic

:# Intervertebral disks may be shrunken or destroyed

:# Vertebral bodies show variable degrees of destruction

:# Fusiform paravertebral shadows suggest abscess formation

:# Bone lesions may occur at more than one level

  • Bone scan
  • Computed tomography of the spine
  • Bone biopsy
  • MRI

Clinical presentation

thumb|Portion of the spine affected by Pott's disease ([[Sorbonne University).]]

The onset of symptoms is gradual and disease progresses slowly.

It impacts the front of the vertebral body along the subchondral plate. The sum of two cases concluded that about 17% of transmission occurs from patients who have negative results. In regions like Sub-Saharan Africa, where the disease is prevalent, HIV often coexists with spinal TB, significantly complicating management and diagnosis. Data collected in New York and Los Angeles shows that this disease primarily affects foreign-born individuals, African Americans, Asian Americans, and Hispanic Americans.

Vitamin D deficiency has also been correlated with an increased risk of Pott's Disease, particularly spinal TB with caseous necrosis, increasing the risk of necrosis compared to individuals with normal vitamin D levels. A deficiency in vitamin D has been associated with the activation of tuberculosis (TB) for a long time. TB patients typically have lower serum vitamin D levels compared to healthy individuals. Extended TB treatment also leads to a reduction in serum vitamin D levels. Research has indicated that vitamin D plays a crucial role in modulating innate immune responses, acting as a cofactor in the induction of antimycobacterial activity.

In developed countries like the United States, Pott's Disease is primarily found in adults. However, in developing countries, data shows that Pott's Disease occurs mainly in young adults and older children. Crowded and poorly ventilated living and working conditions, which are often linked to poverty, significantly increase the risk of tuberculosis transmission. Undernutrition is another crucial factor that raises the likelihood of developing active TB. Additionally, poverty correlates with limited health knowledge and a lack of empowerment to utilize that knowledge, which results in greater exposure to various TB risk factors, including HIV, smoking, and alcohol abuse.

Epidemiology

About 2% of all cases of tuberculosis are considered Pott's Disease and about half (50%) of the cases of musculoskeletal tuberculosis are Pott's Disease, of which 98% affect the anterior column. The disease can be attributed to 1.3 million deaths per year. There is a correlation between tuberculosis infections and cases of Pott's disease, as it's prevalent in areas where tuberculosis infections are common. Known risk factors like lower socioeconomic status, overcrowding, immunodeficiency, and interactions with people with tuberculosis can influence the rate of diagnosis.

Underdeveloped countries have a higher incidence rate of Pott's disease as it is associated with less ventilated rooms, crowded spaces, poorer hygiene, and less access to healthcare facilities. Increasing food security, reducing poverty, and improving living and working conditions will help to prevent infection and generally enhance the care of those sick.

Tuberculosis affecting bones and joints (osteoarticular TB) accounts for approximately 1% to 15% of cases of extrapulmonary TB, with between 50% to 70% of osteoarticular TB being Pott's disease. Children account for about 50% of Pott's cases, still any age group is at risk for developing the disease. In older populations, the disease is often misdiagnosed, often being disregarded for other degenerative diseases. Children's spines contain more cartilage, increasing the effect of spinal deformations caused by the disease, making the disease more problematic in children.

Prevention

As one type of tuberculosis infections, individuals can't entirely prevent Pott's Disease, but they are able to take steps to reduce the risk of TB (tuberculosis) infection by avoiding prolonged, close contact with someone who has an active TB (tuberculosis) infection and getting tested regularly for TB (tuberculosis) if they're at higher risk or live in a region where TB (tuberculosis) is common.

Controlling the spread of tuberculosis infection can prevent tuberculous spondylitis and arthritis. Patients who have a positive PPD test (but not active tuberculosis) may decrease their risk by properly taking medicines to prevent tuberculosis. To effectively treat tuberculosis, patients must take their medications exactly as prescribed. With early intervention, Pott's disease can be cured and completely eradicated from the patient. Drug-resistant tuberculosis may lead to poorer or possibly life-threatening outcomes in children, the elderly, and immunocompromised patients. Rehabilitation for patients who have just undergone surgery or are recovering from Pott's disease often consist of analgesics for pain management, immobilization of the affected spinal region, and physical therapy for pain-relieving modalities.

Antibiotic Therapy

The treatment prescribed to patients diagnosed with Pott's disease is similar to treatment that is generally given to patients who have other forms of extrapulmonary tuberculosis. According to guidelines, typical treatment begins with a six to nine month course of antibiotics. The regimen usually consists of an initial 2-month intensive phase of Isoniazid (INH), Rifampin (RIF), Pyrazinamide (PZA), and Ethambutol (EMB). However, surgery is up to shared clinical decision making and not an intervention that is defaulted to, as guidelines tend to lead towards less invasive procedures such as chemotherapy and anti-tuberculosis medications.

Typical surgical techniques used are as follows:

  • Posterior decompression and fusion with bone autografts
  • Anterior debridement/decompression and fusion with bone autografts In this procedure, the lumbar (lower back) vertebrae (L1-L5) are exposed and the intervertebral discs and vertebral material impinging on the spinal cord and/or nerves are removed. The anterior approach is often recommended instead of the posterior approach in cases where only single segments of the vertebrae are affected, and in the event that there is no destruction or collapse of the posterior elements. Due to the proportions of their bodies (larger head), limited muscular development, and increased flexibility, gravity can lead to greater deformation and presentation of kyphosis.
  • Vertebral collapse resulting in kyphosis, which is defined as an abnormally curved thoracic spine. This abnormal curve in the spine is not to be confused with the natural curve which serves to absorb shock. The main presentation of kyphosis is gradual onset of pain in patients that may be worse with activity.
  • Sinus formation is a complex form of recurrent tuberculosis.
  • Spinal cord compression occurs and can stop the nerves from functioning properly when pressure builds on the spinal cord. The consequence of this compression and pressure is symptoms such as back pain, trouble walking, and weakness in the arms and/or legs.

History

Evidence of tubercular lesions of the vertebral column have been found from the fourth millennium BC in the form of Mesolithic remains in Liguria, Italy. Additionally, tuberculosis spondylitis has been discovered from 3400 BC in the mummified remains of Egyptians. Tuberculosis had affected humans long before it was identified by Sir Percivall Pott.

Important milestones in the development, understanding, and management of tuberculosis spondylitis include the Bacilli Calmette Guerin (BCG) vaccination in 1945, radiological exams, and accessibility of necessary anti tubular medications in the mid 1900's.

  • Saint Gemma of Lucca had tuberculosis of the spine.
  • English poets Alexander Pope and William Ernest Henley both had Pott disease.
  • Anna Roosevelt Cowles, sister of President Theodore Roosevelt, had Pott disease.
  • Søren Kierkegaard may have died from Pott disease, according to professor Kaare Weismann and literature scientist Jens Staubrand
  • Chick Webb, a swing-era drummer and band leader, was affected by tuberculosis of the spine as a child, which left him hunchbacked, and eventually caused his death.
  • The Sicilian mafia boss Luciano Leggio had the disease and wore a brace.
  • Italian writer, poet, and philosopher Giacomo Leopardi had the disease.
  • American actor Pat Morita was hospitalized as a child with the disease, and when he recovered, was sent directly to an internment camp.
  • It features prominently in the book This Is a Soul, which chronicles the work of American physician Rick Hodes in Ethiopia.
  • Jane Addams, social activist and Nobel Peace Prize winner, had Pott disease.
  • Willem Ten Boom, brother of Corrie Ten Boom, died of tuberculosis of the spine in December 1946.
  • Writer Max Blecher had Pott disease and wrote about the affliction.
  • Marxist thinker and Communist leader Antonio Gramsci had Pott disease which, together with the bad conditions of his incarceration in fascist Italy during the 1930s, contributed to his death.
  • Gavrilo Princip, who assassinated Archduke Franz Ferdinand of Austria, leading to World War I, died in prison of bone tuberculosis.
  • English writer Denton Welch (1915–1948) died of spinal tuberculosis after being involved in a motor accident (1935) that irreparably damaged his spine.
  • Louis Joseph, Dauphin of France, son of King Louis XVI and Marie Antoinette
  • George Mercer Dawson, Canadian surveyor, geologist and president of the Geological Society of America, had Pott's disease.
  • Masaoka Shiki, Japanese poet, author and literary critic, had Pott's disease.
  • Lesya Ukrainka, Ukrainian poet, waged, in her own words, "Thirty Years' War with bone tuberculosis".
  • Alberto Moravia, Italian writer, was bedridden for five years due to the Pott's disease.
  • Lucie Coutaz, French clerical worker who belonged to the French Resistance during the Second World War and afterwards assisted Abbé Pierre in setting up the charity Emmaus, had Pott's disease at 16 years of age.
  • Film director Hayao Miyazaki's mother, Yoshiko Miyazaki, was hospitalized for years, then continued treatment for Pott's disease at home. The director's mother is considered an influence on his work, including her health condition.
  • Max Blecher's semi-autobiographical novel Inimi cicatrizate (1937) is about a young man named Emanuel who is afflicted with Pott disease in a sanatorium, as is the Radu Jude film Scarred Hearts (2016), loosely based on it.
  • A. J. Cronin's story "Two Gentlemen of Verona," includes a character named Lucia with tuberculosis of spine.
  • In William Golding's novel The Spire (1964), Jocelin, the dean who wanted a spire on his cathedral, probably dies as a result of the disease.
  • Katharine Butler Hathaway's memoir The Little Locksmith (1943) is about the effects of spinal tuberculosis on her childhood and adult life.
  • In Victor Hugo's The Hunchback of Notre-Dame (1831) the title character has a gibbus deformity similar to the type caused by spinal tuberculosis.
  • In Henrik Ibsen's play A Doll's House (1879), Dr. Rank has "consumption of the spine."
  • In Sergio Leone's film Once Upon a Time in the West (1968), Morton, the railroad magnate, has the disease and needs crutches to walk.
  • In Ernest Poole's Pulitzer Prize-winning novel, His Family (1917), young Johnny Geer has a terminal case of Pott disease.
  • In Edmund Wilson's Memoirs of Hecate County (1946), the novella "The Princess with the Golden Hair," has a character with Pott disease.

References

Further reading