Objective: Osteonecrosis (ON) of the head of femur is not uncommon. The characteristics of affected patients and the associated aetiological factors in Nigeria are largely undocumented. To determine the epidemiological characteristics of patients with osteonecrosis of the head of femur, the radiological severity at presentation and associated aetiological risk factorsMethods: A retrospective study was done, of patients with femoral head ON seen between January 2013 and January 2019. Data on patients' characteristics, affected hips and radiological severity were entered onto a proforma and analysed.Results: There were 29 patients with ON of the head of femur involving 32 hips. There were 55.2% females and 44.8% male patients. While 3 (10.3%) patients had bilateral affectation, 26 (89.7%) had unilateral affectation. Their mean age is 26.6years 13.3. The mean age of male and female patients are 29.3 years and 24.3 years respectively. The mean BMI is 21.9 5.2 and no significant difference in the BMI of both genders, p=0.74. Ninety percent of them presented with advanced radiographic stages. Factors found to be associated with ON are sickle cell disease (SCD) 44.8%, trauma 13.8%, CVA 3.4% and idiopathic cases 37.7%. There is no significant difference in the frequency of unilateral and bilateral occurrence in the groups with different hemoglobin genotypes.Conclusions: Osteonecrosis of the head of femur occurs more often in young patients. They present late, with collapse of the head of femur. SCD, especially HbSS is the most common associated risk factor followed by idiopathic cases.
Key words: Osteonecrosis, avascular necrosis, head of femur, sickle cell disease, risk factors
Osteonecrosis of the head of femur in a Nigerian teaching hospital
