Pathomorphological and pathochemical characteristic of the osteomyelitis focus in patients with diabetic osteoarthropathy (Charcot foot)

BACKGROUND: Osteomyelitis in diabetic osteoarthropathy occurs in 65 % of cases, and it is the main cause of non-traumatic amputations. The choice of optimal treatment technologies should be based on understanding the pathogenetic characteristics of this disease.AIM: To study the pathomorphological and pathochemical picture of osteomyelitic focus in patients with diabetic neuroosteoarthropathy.MATERIALS AND METHODS: Object — 20 patients (55.3±9.33 years) with Type 2 diabetes mellitus, diabetic neuroosteoarthropathy, chronic osteomyelitis of the foot bones. The treatment consisted in surgical debridement of the purulent focus with the material collection for pathomorphological and biochemical studies, and in reposition and alignment of bone fragments with the leg and foot fixation using the Ilizarov fixator in order to form bone ankylosis of the compromised joint.RESULTS: Subacute and acute course of chronic osteomyelitis was registered in 80 % of cases. As for the pathohistological changes in bone tissue, the following ones were the most significant: necrosis and the presence of an inflammatory infiltrate of varying severity depending on the phase of the inflammatory process. The articular cartilage structure was broken in all the cases. Activation of osteoclasts was observed in the osteomyelitis focus, especially in the subchondral zone. There was no subchondral bone plate in most cases, or only its fragments remained. Pathohistological examination of the soft tissues associated with the osteomyelitis focus indicated the presence of mirocirculatory and denervation disorders due to necrosis and hyalinosis of a significant part of microvessels against the background of compensatory hypervascularisation and chronic inflammation, narrowing and obliteration of the lumens of feeding arteries, almost complete absence of nerve elements in the tissues or their destructive changes. An increase in the activity of lytic enzymes was revealed in the interstitial environment of the tissues surrounding the osteomyelitis focus (138-fold increase in the activity of acid phosphatase, interstitial osteolytic index was 7.2-fold higher than blood serum index).CONCLUSION: The pathomorphological signs of chronic osteomyelitis subacute and acute processing were observed in most patients. Breaking the articular cartilage structure was accompanied by invasion of vessels, inflammatory infiltrate, and by activation of osteoclasts in the subchondral zone. Destructive changes of vessels and nerves in the soft tissues associated with the osteomyelitis focus can be etiopathogenetic factors of this disease development. The technologies for stopping this process should be based on obligatory debridement of the focus with sequestrnecrectomy, with regular monitoring of the operated segment condition