Spondylodiscitis is an infectious and inflammatory lesion of the intervertebral discs and adjacent vertebral bodies. The disease occurs when infected with bacterial or parasitic agents. The main manifestation is constant back pain, which is not subject to standard medical correction. Later, neurological disorders, mobility limitations, disorders of pelvic organ function are added. To diagnose spondylodiscitis, CT and MRI of the spine, clinical and bacteriological blood tests are performed. Treatment includes antibacterial therapy, prolonged immobilization, and neurosurgical operations.
ICD 10
M46 Other inflammatory spondylopathies
General information
Spondylodiscitis belongs to the group of nonspecific purulent-inflammatory diseases of the spine and accounts for 80% of their total number. Pathology occurs with a frequency of 0.5-2.5 cases per 100 thousand population, mainly develops in patients older than 50 years. In recent years, the number of newly identified cases has been constantly growing. Diagnosis of the disease remains a complex problem of orthopedics and neurology: from the patient’s visit to the doctor to the verification of the diagnosis, an average of 3-12 months pass.
Causes
The pathological condition occurs when the spinal column tissues are affected by infectious agents. The typical causative agent of the disease is called Staphylococcus aureus, gram-negative flora is in second place in frequency of occurrence. Less often, pathology is associated with infection with Mycobacterium tuberculosis, chronic brucellosis, visceral mycoses. Fungal forms of spondylodiscitis occur only in patients with immunosuppression.
For spondylodiscitis, foci of infection in the body are clinically significant, which become a source of infection. Most often, the transfer of pathogenic microbes occurs in infectious diseases of the kidneys and pelvic organs (17%), heart valves (12%), skin and mucous membranes (11%). Less important are infectious and inflammatory processes in the organs of the digestive and respiratory system, caries and other dental diseases.
Risk factors
Spondylodiscitis mainly occurs in people with pre-existing serious diseases: diabetes mellitus, systemic connective tissue diseases, malignant neoplasms. After spinal surgery, pathology develops in 0.2-3.6% of cases. The risk group includes injecting drug users. A higher probability of purulent-inflammatory lesions of the spine in patients with reduced immune status.
Pathogenesis
Infection with pathogenic pathogens occurs by three mechanisms. Most often, a hematogenic type of infection is observed – the transfer of microorganisms with blood flow from distant purulent-inflammatory foci. Less often, the contact pathway is diagnosed when the infection penetrates into the bone-articular structures of the spine from nearby inflammatory foci. There may be a direct hit of pathogens during operations and invasive diagnostic manipulations.
Classification
According to the localization of the inflammatory focus, spondylodiscitis is divided into lumbar (39-55% of all diagnosed cases), thoracic (20-27%) and cervical (9-10%). The predominance of lesions of the lumbar spine is associated with the peculiarities of its blood supply. According to the etiological factor , such forms of spondylodiscitis are distinguished:
- Purulent. The most common clinical variant that occurs when infected with staphylococci, E. coli, Pseudomonas and proteus.
- Granulomatous. A specific type of inflammation that occurs as a complication of pulmonary and extrapulmonary tuberculosis, brucellosis.
- Fungal. The most rare variant of the disease, which is caused by pathogens of deep mycoses.
- Non-infectious. This includes about 34% of cases of the disease, for which, with careful diagnosis, it is not possible to identify a single infectious pathogen.
Symptoms
Patients complain of back pain, mainly in the lumbar region. Uncomfortable sensations are constantly observed, they increase with awkward movements and physical exertion. Most people report high-intensity pain, which corresponds to a score in the range of 7-10 points on a visual analog scale. The pain lasts for several weeks or even months, does not disappear after taking over-the-counter analgesics.
To reduce pain, patients take a forced sitting position with a forward tilt and resting their hands on their knees – the so-called symptom of axial load (Thompson). When feeling or tapping on the processes of the vertebrae of the affected area, the pain increases sharply. The pain syndrome is characterized by irradiation, so occasionally it simulates the clinical picture of an acute abdomen, pyelonephritis, urolithiasis.
When the contents of the spinal canal are involved in the process, neurological symptoms occur. Damage to the spinal cord and its roots more often occurs with cervical and thoracic spondylodiscitis. There are complaints of headaches and dizziness, numbness of the upper extremities, shooting pains like intercostal neuralgia. Involvement of the lumbar segments in the process is manifested by dysfunction of the pelvic organs.
Complications
The untreated inflammatory process spreads to nearby organs with the development of purulent pleurisy, lymphadenitis, mediastinitis and bronchial fistulas. Massive damage to bone structures is fraught with deformation of the spine, loss of its supporting and motor functions. After severe destructive spondylodiscitis, most people get a disability. The mortality rate from purulent-septic complications reaches 5-11%.
Diagnostics
Patients with back pain turn to an orthopedic traumatologist, neurologist or family doctor (therapist). Diagnosis of the disease begins with a detailed collection of complaints and anamnesis, identification of physical signs of the disease, assessment of neurological status. Next, an extended examination program is assigned, which includes the following methods:
- MRI of the spine. The decrease in signal intensity on T1-weighted images and its increase on T2-weighted images, deformation of intervertebral discs, structural changes of vertebral bodies are determined. The sensitivity of magnetic resonance imaging reaches 96%, the accuracy is 94%, so it is considered the “gold standard” of diagnostics.
- Radiography of the spine. The study is informative 3-6 weeks after the onset of the disease. On X-ray images, destruction of vertebral bodies, erosion of the closure plates, and a decrease in the distance between adjacent vertebrae are detected. For clearer visualization, a CT scan of the spine is prescribed.
- Biopsy. The collection of biomaterial from the inflammatory focus allows you to accurately determine the type of pathogen and select etiotropic therapy. Basically, a puncture biopsy is performed under ultrasound control. Its informativeness reaches 74%.
- Blood test. The inflammatory process is manifested by leukocytosis, an increase in the ESR index and the level of C-reactive protein. Dysproteinemia, an increase in procalcitonin and fibrinogen are also diagnosed. According to the degree of increase in indicators, the severity of the systemic inflammatory response is assessed.
- Sowing for hemoculture. To diagnose the causative agent of spondylodiscitis, at least a double bacteriological blood test is required. The most reliable results are obtained when taking biomaterial at fever altitude. At the same time, the study does not detect pathogens in 34-75% of patients.
Differential diagnosis
Spondylodiscitis is differentiated with manifestations of osteochondrosis, intervertebral hernia, spondylolisthesis and spondyloarthrosis. Important clinical criteria are the age over 50 years and the absence of analgesic effect from NSAIDs. Nonspecific pain in spondylodiscitis should be distinguished from the manifestations of sciatica, myelitis. With a comprehensive examination, rheumatic diseases are excluded.
Treatment
Conservative therapy
The key element of pharmacotherapy is taking antibacterial drugs. Etiotropic treatment of spondylodiscitis eliminates the inflammatory focus, prevents complications and promotes a speedy recovery. Antimicrobial therapy is selected based on the results of bacteriological studies, taking into account the type of pathogen. Empirical treatment is acceptable for patients in serious condition.
With spondylodiscitis, massive antibiotic therapy is required. The drugs are prescribed in maximum therapeutic doses for 6 weeks. An oral or parenteral method of administration is used, with an extensive purulent process, intra-aortic use of drugs is advisable. In empirical therapy, a combination of two medications is often used, which, according to the spectrum of pharmacological activity, cover a large list of microorganisms.
In addition to antibiotic therapy, analgesics are prescribed, including from the NSAID group. Before the pain syndrome is eliminated, patients are shown bed rest with spinal immobilization. External corsets take over the supporting function of the vertebrae, limit the pathological mobility of individual segments and contribute to the formation of bone blocks.
Surgical treatment
Surgical intervention is carried out with the ineffectiveness of conservative therapy, pronounced instability of the spine, severe neurological deficit. Indications for surgery are signs of epiduritis, fistulas, the threat of sepsis. In case of an uncupable pain syndrome, the possibility of neurosurgical intervention is considered. Operations for spondylodiscitis are aimed at eliminating the focus of infection, stabilizing bone structures.
Prognosis and prevention
Thanks to the improvement of antibiotic therapy, the mortality rate in spondylodiscitis has halved, but this indicator remains consistently high. Among the surviving patients, the greatest concern is caused by spinal deformity, which restricts mobility and is accompanied by a visible external defect. Prevention of the disease includes timely treatment of infections of different localization, correction of immunosuppressive states.