Avascular necrosis in children with sickle cell disease: prevalence and pattern of presentation in Jos, Nigeria
Background: Avascular necrosis (AVN) is a common orthopaedic complication of sickle cell disease (SCD). Despite the previously reported childhood-onset of AVN, its actual prevalence among children with SCD in Nigeria is not known. Hence, we determined the prevalence and pattern of presentation of AVN in a homogenous paediatric population with SCD in Jos.
Methods: A cross-sectional study of children with SCD aged 5-17 years using a review of data from the SCD-registry of the Paediatric Haematology-oncology unit of Jos University Teaching Hospital from January 2016 to January 2021.
Results: Of the 589 children, 523(88.8%) had haemoglobin SS genotype while 59 (10%) and seven (1.2%) had haemoglobin SS+F and SC genotypes respectively. Thirty- eight children (20 males (52.6%) and 18 (47.4%) females) were diagnosed with AVN of the femoral head giving an overall prevalence of 6.5%. Five of the 38 children had a concomitant AVN of the shoulder giving a prevalence of 0.8%. Their ages at the time of diagnosis of AVN ranged from 7-17 years (mean: 13.6±3.2 years). The prevalence of AVN increased from 1.9% to17.3% among age groups 5-9 years and 15-17 years respectively. Majority of the children (75.8%) presented at the late stages of the disease.
Conclusion: Avascular necrosis of the hip is common among children with SCD and it could occur early in childhood. Most of the children presented at the late stages of the disease. Therefore, we recommend early and routine screening of children with SCD for AVN in Nigeria.