2022, Number 2
Spondylodiscitis. Assessment, diagnosis and treatment
Full text
10.35366/105503
Language: English
References: 31
Page: 135-140
PDF size: 225.32 Kb.
ABSTRACT
Spondylodiscitis is a pathology with increasing incidence at the world level, secondary to the increase in life expectancy, higher prevalence of diseases like diabetes that can present immunosuppression to the patients besides the increasing number of procedures in the spine also present a risk of develop spondylodiscitis; therefore, the correct clinical assessment, the use of diagnostic tools in a protocolized manner, multidisciplinary management and appropriate treatment by the doctor specialized in spine surgery have a positive impact. Based on the diversity of management protocols and diagnosis, it was decided to carry out a narrative review of the literature in the databases Google academic, PubMed, with Mesh terms: discitis, spine, postoperative infection, spondylodiscitis, spondylodiscitis management algorithm; contributing in this way to the decision making from the doctor of first contact to the physician specialist in spine. We suggest the use of an algorithm based on the experience of our center supported with the review of available literature and at present, in order to make decisions in patients who present this pathology in specific.INTRODUCTION
Spondylodiscitis is an infectious process that mainly affects the disc and vertebral bodies but can involve all posterolateral and perineural structures;1 the most frequent location is the lumbar region (60%), followed by the thoracic region (30%) and cervical region (10%); it affects a vertebral only one segment in (65%), involvement of multiple continuous levels (20%) and non-continuous levels (10%).2,3
It represents 2-7% of musculoskeletal infections, with peaks of incidence in children under 20 years and patients between 50 and 70 years, with predominance in males,4 this disease has an increased incidence associated with longer life expectancy, greater number of surgical interventions in the spine, use of intravenous drugs,2 as well as, studies have shown that chronic kidney disease and diabetes mellitus are the main comorbidities related to spondylodiscitis.5-7
Mortality varies between 2-20% in developed countries and its severity depends on the comorbidities of the patient and the virulence of the etiological pathogen, the pathogens are mainly bacteria and parasites, fungi such as aspergillus and candida, which generate granulomatous infections.8-10 The most common bacterial were Staphylococcus aureus in 80-90% of cases and other rare cases like clostridium perfringens.11
ANATOMY AND PATHOPHYSIOLOGY
Spinal vascular anatomy is important to understand the mechanism of the pathogen spread. Hematogenous infection is the main cause of inoculation, either by segmental arterial route, which gives rise to metaphyseal and periosteal irrigation of the vertebral body or retrograde by Batson's venous system.2 This vascular arrangement explains why the necrosis begins in the anterior part of the body that corresponds to the trunks of the segmental arteries. The infection by the Batson's plexus is presented by retrograde infection either by urinary tract infections or pelvic organ infections can spread to the lumbar region.12-14
CLINICAL MANIFESTATIONS
Non-mechanical and progressive pain occurs in more than 90% of cases, followed by fever in 60 and 34% may develop some degree of neurological involvement that can affect the medullar spine or radicular nerves, depending on the vertebral level.15,16 This infection can be presented with abscesses which are often located at the subdural, epidural, posterior paraspinal or retroperitoneal level with a predominance of iliopsoas muscle, this can lead to early diagnosis and treatment.17-19
IMAGING STUDIES
The utility of imaging studies is variable depending on the time of evolution of the infection, as well as the affected vertebral segment. The first radiological image is radiography which has a specificity and sensitivity of 58%, because it needs to be affected bone mineralization to show changes. On the other hand computed tomography, which has sensitivity and specificity close to 90% with changes 3-6 weeks after the infection began.2,20,21 The contrasted magnetic resonance imaging is the ideal diagnostic test because it has greater sensitivity and specificity in the first 2 weeks of the infection with 97 and 93% respectively. Among the characteristic findings of spondylodiscitis, hypo intensity is found in the vertebral bodies in T1 sequence and hyperintensity in the intervertebral bodies in T2 sequence (Figures 1 and 2). The use of contrast medium and the STIR sequence allows to delimit the abscesses and differentiate them even more clearly in instrumented patients (Figure 3).22,23
LABORATORY TESTS
In the presence of a spinal infection, the etiological organism and time of onset is important according to laboratory tests. Leukocytosis is a laboratory finding with low specificity and sensitivity. Otherwise, acute phase reactants such as CRP (C-reactive protein) and ESR (Erythrocyte sedimentation rate) are tests with high sensitivity (95%) but very low specificity.2 Likewise, blood culture seeks to identify the causal pathogen, however, it is only positive in 50-60% of cases.21 For a correct diagnosis, the taking of a guided percutaneous biopsy with Tomography should be indicated, since it allows greater safety and precision, considering that microorganisms of 14-76% in the first biopsy therefore if the culture is negative a second take is indicated.24-26 In cases where the identification of the microorganism is essential, an open biopsy can be performed, since it allows better sampling, but greater comorbidities.27,28
COMPLICATIONS
Due to the non-specific symptomatology and the lack of expertise of the medical staff, the diagnosis can be made late (more than two months after the infection began) this is associated with greater neurological complications, longer hospital stays and greater need for emergency surgical treatments due to instability and neurological deficit that led us to a negative impact on health systems.29,30
DISCUSSION
The relevance of carrying out an adequate anamnesis, physical examination and, and the diagnostic studies that lead us to the early identification of the causal microorganism, will guide us in making decisions for therapeutic management:
- 1. Conservative management: refers to the use of intravenous specific antibiotic therapy the first six weeks28 with periodic taking of acute phase reactants that suggest infection control, considering that patients with CRP > 2.75 md/dl and ESR > 55 mm/h have a higher risk of treatment failure.29,30 It can continue six more weeks with oral antibiotic therapy, depending on the microorganism, as well as the data observed in magnetic resonance imaging that suggest control of the infection.23,30
- 2. Surgical management: the decision must be made considering several suggested criteria such as failed conservative therapy, bone destruction, segmental instability, epidural abscess, neurological deterioration, and paravertebral involvement. Based on these criteria, we consider classifying in type A, B, C with which we can orient ourselves in the choice of management alternatives that have shown good results in the short and medium term31 (Tables 1 and 2).
CONCLUSION
Spondylodiscitis is a pathology with a tendency to higher incidence and prevalence secondary to multiple factors in today's society, therefore, high suspicion must be had to make an early diagnosis and appropriate treatment individualizing each case, therefore, we suggest an algorithm based on the experience of the authors and the review of the literature carried out, oriented to unify flowchart criteria 1 (Table 3).
REFERENCES
AFFILIATIONS
1Medical Research;
2Spine Surgeon;
3Chef of Spine Surgery. Hospital Universitario Fundación Santa Fe de Bogotá.
Conflict of interest: The authors express no conflict of interest.
CORRESPONDENCE
Santiago Rosales-Camargo. E-mail: rc.santiago105@uniandes.edu.coReceived: 01/12/2021. Accepted: 11-01-2022.