Avascular Necrosis of Femoral Head in the Republic of Bashkortostan: a Clinical and Epidemiological Study

Abstract

Introduction. Avascular necrosis of the femoral head (AVNFH) is a relatively rare complex disease that occurs in people of working age and leads to disability due to irreversible changes in the aff ected hip joint. Aetiology of the disease has not been reliably established so far.Materials and methods. Among a total of 42,877 residents of Ufa surveyed, 71 were diagnosed with AVNFH. Patients granted an informed consent to conduct the survey, access the outpatient history of concomitant pathology, perform hip X-ray and laboratory blood tests.Results and discussion. Th e AVNFH incidence rate was 166 per 100,000 people, with the men to women ratio 1:1.5 and average age of manifestation 50 years. Secondary necrosis was established in 14, and bilateral lesion — in 42 % of cases. A family with hereditary AVNFH (mother, daughter and grandmother) was observed. A significantly higher incidence rate was observed with children in mononational families, which suggests a protective role of crossbreeding against this pathology. In 31 % of patients, the disease manifested atypically resembling lumbago with sciatica, which entailed a late AVNFH diagnosis. Smoking and long-term contact with chemicals were identified as the risk factors, and hypertension, chronic cerebral ischemia, anaemia, hypercholesterolemia and chronic inflammation — as associated disorders. A radiological profi le of the disease is described.Conclusion. Th e study allowed a precise estimation of the AVNFH incidence rate as 1 per 600 people. Idiopathic AVNFH occurred in 86 % of cases, with smoking and professional long-term contact with chemical agents as associated risk factors. Pedigree studies exposed a low incident rate in ethnically mixed families. AVNFH was shown comorbid with the hypertensive disease in 56 and chronic cerebral ischemia — in 42 % of patients. Atypical lumbago-sciatica-like symptoms in 1/3 of AVNFH cases warrant the need to conduct hip X-ray and MRI in this category of patients.