What is Pyogenic Spondylitis?
Pyogenic spondylitis is a fatal neurological condition where there is infection and destruction of the spine and paraspinal structures. Pyogenic spondylitis consists of various other clinical entities, such as septic discitis, pyogenic spondylodiscitis, epidural abscess and vertebral osteomyelitis.
As there is worsening of pyogenic spondylitis, there is increase in the inflammation and destruction of the vertebrae and the inflammation spreads to the paraspinal and epidural spaces. The most damaging complication of pyogenic spondylitis includes neurologic deficits.
The incidence of pyogenic spondylitis is increasing. The diagnosis of pyogenic spondylitis is made based upon the clinical, tissue and blood cultures, histopathological and radiological findings. Majority of the patients suffering from pyogenic spondylitis can be treated without resorting to surgery. Surgery is needed in about 10 to 20% of patients suffering from pyogenic spondylitis. Surgery for pyogenic spondylitis consists of anterior decompression, debridement and fusion. Instrumentation can be done after surgical debridement after which the patient is put on antibiotics.
What are the Causes of Pyogenic Spondylitis?
Pyogenic Spondylitis is commonly caused by hematogenous spread from other infections, such as respiratory tract, skin, gastrointestinal tract, genitourinary tract, or oral cavity infections, which result in bacteremia. The organisms of these infections infiltrate the end-arterial arcades present in the metaphyseal region near the spinal disc and from here the infection spreads through the end-plate into the spinal disc. The infection in pyogenic spondylitis can also extend from the vertebral body to the epidural space, subligamentous paravertebral region, and contiguous vertebral bodies. A blunt trauma to the spinal column is also one of the causative factors of pyogenic spondylitis. In about 35% of the patients with pyogenic spondylitis, the cause is not identified.
The common causative organisms of pyogenic spondylitis include streptococcus species and Staphylococcus aureus. Gram-negative bacilli are found in patients who are intravenous drug abusers. In immunocompromised patients, Mycobacterium tuberculosis, parasitic infestations and fungal infections, which though rare, are seen as causes of pyogenic spondylitis.
What are the Symptoms of Pyogenic Spondylitis?
The onset of symptoms of pyogenic spondylitis is usually insidious, with neck or back pain being the commonest symptom of pyogenic spondylitis with about 90% of patients reporting this symptom in pyogenic spondylitis. Other symptoms of Pyogenic Spondylitis consist of kyphosis and bony destruction, which leads to neurological complications in the patient. Fever may also be present in pyogenic spondylitis. Other symptoms of pyogenic spondylitis consist of nausea, vomiting, anorexia, lethargy, weight loss and confusion. Problems in swallowing occur due to cervical pyogenic spondylitis along with retropharyngeal abscess.
Patient may also experience limb numbness, weakness and dysfunction of the sphincter, which occurs as a result of spinal cord or cauda equina compression.
Neurological complications of pyogenic spondylitis can also develop which are however, not that common and are caused by direct neural infiltration and ischemic damage to the spinal cord.
How is Pyogenic Spondylitis Diagnosed?
The diagnosis of pyogenic spondylitis is made based upon the clinical, blood and tissue cultures, radiological and histopathological findings of the patient.
What is the Treatment for Pyogenic Spondylitis?
Non-Surgical Treatment for Pyogenic Spondylitis
Antibiotics for Treating Pyogenic Spondylitis: Non-surgical treatment can be successfully done for majority of patients suffering from pyogenic spondylitis. Patient needs to get septic work-up and biopsy of the tissue done after which antibiotics are started. The type of antibiotics chosen for patient with pyogenic spondylitis depends on the results of the bacterial culture. First generation cephalosporin can be prescribed to cover the common bacteria, such as streptococcus and staphylococcus. Broader spectrum antibiotics are prescribed in patients who are intravenous drug abusers or in immune-compromised patients. These antibiotics have good bone penetration and are effective in treating spinal infections.
Studies recommend six to eight weeks of intravenous antibiotic therapy, which can be later changed to oral antibiotics.
Rest is Important for Treating Pyogenic Spondylitis: Bed rest is important for patients suffering from pyogenic spondylitis till there is improvement in the symptoms of pyogenic spondylitis, especially pain.
Brace or Cast in Treatment of Pyogenic Spondylitis: Patient should ambulate using an appropriate brace or cast. External immobilization helps in decreasing pain, stabilizing the spine and prevents deformity. Depending on the amount of bony destruction or deformity, the brace can be worn for about three to four months.
What Is The Success Rate Of Non-Surgical Treatment Of Pyogenic Spondylitis?
The success of non- surgical treatment of pyogenic spondylitis can be gauged by improvement in pain, fever, laboratory tests and radiographic imaging. The success rate of non-surgical treatment of pyogenic spondylitis is quite high. About 6 to 24 months after development of pyogenic spondylitis symptoms, many of the patients who are treated conservatively experience spontaneous interbody fusion. However, there is some relapse rate and complications of pyogenic spondylitis, such as neurological deficit, worsening of symptoms, significant spinal deformity and spreading of the infection.
Surgical Treatment for Pyogenic Spondylitis
Open surgery is needed in only about 10 to 20% of patients who have pyogenic spondylitis. Surgery is needed in patients who have compression of spinal cord or cauda equina along with worsening neurological deficits. Prognosis for neurological recovery is better in surgical decompression in such patients when compared to non-surgical treatment.
Surgical treatment for pyogenic spondylitis consists of anterior decompression and debridement following which an anterior fusion is done. Debridement of the infected tissues is done and drainage of the abscesses is done. Debridement is done till the healthy bleeding bone so that there is faster tissue healing. After the infected tissue is extensively debrided, the surgeon does a structural bone or cage grafting simultaneously or at a later date.
What Are The Indications For Surgery In Pyogenic Spondylitis?
Indications for surgery in pyogenic spondylitis include, if the diagnosis is not certain in which case open surgery is done to obtain tissues for confirming the diagnosis of pyogenic spondylitis with bacteriological and histological tests. Surgery for pyogenic spondylitis is also done if conservative or non-surgical treatment has failed and there is no improvement in the patient. Surgery for pyogenic spondylitis is also needed if there is significant progressive spinal deformity in the patient with biomechanical instability.