**2. Pathogenesis of metabolic bone tissue disorders at the site of orthopedic infection**

Current views on chronic osteomyelitis allow its understanding not simply as a "bone-lytic" or "infectious" process, but also as a condition associated with bone metabolism alteration. Understanding the nature of these alterations is one of the key points in treating chronic osteomyelitis. Without this understanding, the process of treatment may not succeed or may be less successful even if supported by superb surgery and antibiotic therapy (**Figure 1**).

As an attempt to describe the links between changes in bone tissue metabolism during orthopedic infection, we created a scheme displayed above. From our point of view, deep understanding of the pathogenesis is of paramount importance for a clinician.

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the same time:

**Figure 1.**

3.Matrix destruction.

*Metabolic Disorders in Patients with Chronic Osteomyelitis: Etiology and Pathogenesis*

The overall scheme can be divided into three major parts, which represent main pathogenetic pathways enforcing and exacerbating each other while developing at

*Pathogenesis of metabolic disorders of the bone tissue, influence of the background factors and laboratory* 

*diagnostic markers (figure credits: Gorbatyuk D.S., Tsiskarashvili A.V., Rodionova S.S.).*

These parts will be discussed separately to make them easier for understanding, even though the pathogenic processes described would influence each other in a "crossing-over" manner. De facto, it is hardly possible to separate them because all of the components take part in general bone metabolism and remodeling process.

• Red blocks represent the "final" changes in the levels of the markers (e.g., betacross-laps (C-terminal telopeptide) increase). These changes can be detected using laboratory methods and are used by a clinician during the diagnostics.

• Yellow blocks represent the background factors (markers and their levels) that

1.Osteoblast cell death and proliferation lowering.

2.Bone remodeling shift to the resorption prevalence.

The color of the blocks is associated with their aim:

• Blue blocks represent the stages of pathophysiological processes.

also can be measured with methods of laboratory diagnostics.

*DOI: http://dx.doi.org/10.5772/intechopen.92052*

*Metabolic Disorders in Patients with Chronic Osteomyelitis: Etiology and Pathogenesis DOI: http://dx.doi.org/10.5772/intechopen.92052*

#### **Figure 1.**

*Clinical Implementation of Bone Regeneration and Maintenance*

known for a long period of time.

viewed similarly as the complications in soft tissues in the purulent surgery, widely

metabolic bone tissue disorders in the presence of bone infection [12, 13].

porotic metabolic processes have similar mechanisms.

Numerous clinical guidelines and publications on osteoporosis and related disorders have much to offer about the pathophysiology of these diseases, but have a rather serious common disadvantage: they do not describe or poorly describe the interaction of pathogen and bone tissue, although the infectious and purely osteo-

Lack of understanding of the metabolic bone tissue disorders as a result of its interaction with bacterial pathogen during orthopedic infection practically eliminated the possibility of providing adequate etiological treatment; in most cases, the treatment methods were limited to surgical treatment (necrectomy, debridement, external fixation, and related methods) and antibiotic therapy. Despite being approved and reliable, these methods themselves are not enough to treat chronic osteomyelitis. The correction of the impaired bone tissue metabolism is also needed. For this purpose, a clinician should be familiar with the aspects of biochemistry, physiology, and pathophysiology of the bone affected by orthopedic infections. At this moment, several fundamental papers in the domain of bone tissue and pathogen interaction are available [14, 15], which can be evaluated as a positive trend. These works can be useful to systematize the knowledge cumulated by the

Within this chapter, we made an attempt to synergize the knowledge in pathophysiology of the disorders described, as well as illustrate the importance of correction of impaired bone tissue metabolism using the results of our own work

**2. Pathogenesis of metabolic bone tissue disorders at the site of** 

Current views on chronic osteomyelitis allow its understanding not simply as a "bone-lytic" or "infectious" process, but also as a condition associated with bone metabolism alteration. Understanding the nature of these alterations is one of the key points in treating chronic osteomyelitis. Without this understanding, the process of treatment may not succeed or may be less successful even if supported by

As an attempt to describe the links between changes in bone tissue metabolism during orthopedic infection, we created a scheme displayed above. From our point of view, deep understanding of the pathogenesis is of paramount importance for a clinician.

Consequently, this falsely simplified view of the problem has led to a shortage of publications. For example, the search query in the PubMed database based on Mesh terms "Osteomyelitis" and "Bone mineral density" (latest access time: December 08, 2019, 0:01 UTC +3) has provided only 30 search results, the earliest of them is signed as published in February 1991. Most publications refer to dentistry and maxillofacial surgery but not to traumatology and/or orthopedics. Another search based on Mesh terms "Osteomyelitis" and "Metabolic disorders" (latest access time: December 08, 2019, 0:03 UTC +3) has provided 596 results, but most papers refer to other topics and problems: "combinations" of chronic osteomyelitis and diabetes mellitus [1, 2], chronic osteomyelitis and bisphosphonate-induced necrosis of the jaw [3, 4]; less papers refer to the problem of treating chronic osteomyelitis in patients with genetic, systemic, neuropathic, and oncological diseases [5–8]. In several papers, the accent is put on the clinical aspects of bone infection with particular pathogens only [9–11]. Some papers can be considered of a relatively good quality but the accent is put on clinical results themselves and not on the pathogenesis of

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scientific community.

published in 2019 [16].

**orthopedic infection**

superb surgery and antibiotic therapy (**Figure 1**).

*Pathogenesis of metabolic disorders of the bone tissue, influence of the background factors and laboratory diagnostic markers (figure credits: Gorbatyuk D.S., Tsiskarashvili A.V., Rodionova S.S.).*

The overall scheme can be divided into three major parts, which represent main pathogenetic pathways enforcing and exacerbating each other while developing at the same time:


These parts will be discussed separately to make them easier for understanding, even though the pathogenic processes described would influence each other in a "crossing-over" manner. De facto, it is hardly possible to separate them because all of the components take part in general bone metabolism and remodeling process.

The color of the blocks is associated with their aim:

