Femoral Head Avascular Necrosis in Heterozygous Sickle Haemoglobin, the Role of Parenteral Drug Abuse: A Case Report

Sickle cell trait is a benign haemoglobin disorder which rarely results in disease or complications. A few cases of osteonecrosis have been reported in the literature in parts of the world with advanced health care system. There are various predispositions to developing avascular necrosis in general, while the sickle beta globin gene inheritance is the most efficient factor. Injection drug abuse has not been strongly link to the development of bone necrosis. Here we report a case of bone necrosis in an elderly man and raise awareness on osteonecrosis being a possible complication of injection drug misuse in heterozygous sickle haemoglobin disorder. A 68 year old retired health dispensary attendant presented at the clinic with an 18 months history of progressive right hip pain associated with difficulty in walking. He had engaged in self prescriptions, procurements and repeated administrations of pentazocine injection into his anterior thighs. He had an abnormal gait with bilateral discharging ulcers on both thighs anteriorly. Haemoglobin protein electrophoresis revealed AS status, while the pelvic X-ray showed necrosis of the right femoral head. Consequently, osteonecrosis may be one of the ultimate complications of parenteral drug abuse in heterozygous sickle haemoglobinopathy.