Case Report: Idiopathic avascular necrosis of the femoral head following pregnancy

Abstract

Background: Hip pain during pregnancy is very common, but avascular necrosis (AVN) represents a very rare entity. Osteonecrosis of the head of the femur during the pregnancy, or shortly after the pregnancy, is a rare clinical problem. Little is known about pregnancy as an etiological factor for AVN of the femoral head. Case: In this case report, a documented case of femoral head osteonecrosis, a rare complication after pregnancy is presented. The patient presented with complaints of pain in the left hip that gradually worsened and led to restriction of movement. The patient was advised an X-ray, which showed a fracture of neck of the left femur, and an MRI following the X-ray revealed features of AVN of the hip. The patient was later taken for total hip arthroplasty, which was uneventful. On follow-up, the patient had relief from her symptoms and had no complications. Alcoholism, steroid use, systemic lupus erythematosus, organ transplantation (particularly following kidney or bone marrow transplantation), dyslipidemia (particularly hypertriglyceridemia), Gaucher disease, decompression sickness, and drepanocytosis are known risk factors for osteonecrosis. We can list pro-coagulation abnormalities, chemotherapy, and HIV among the less established factors. Here, we present a case of a patient with postpartum AVN of the femoral head that suffered AVN of the left hip in the post-partum period, her symptom of hip pain was neglected as a benign cause initially, which led to aggressive treatment (total hip arthroplasty) at a young age. Conclusions: Having high suspicion of the diagnosis of AVN and a low threshold for magnetic resonance imaging (MRI) imaging in a pregnant woman with hip pain is a requirement to avoid complications. This case highlights the need for high suspicion of osteonecrosis as a cause of hip pain in the post-partum period.