<prompt> Commonest complication of Trans-cervical fracture of femur is-Non unionMalunionAvascular necrosisAll of the above  <response>: AVN is the most common complication of femoral neck fracture. Mc affects Femoral Head Mc site Anterolateral aspect Being principal Wt. bearing poion Incidence;dt t Steroid usage Trauma AVN only occurs in FATTY MARROW, which contains a Sparse vascular supply. In contrast to Hematopoietic marrow which has a rich blood supply CAUSES Trauma Alcohol consumption Coicosteroid intake Gout and hyperuricemia Hypercholesterolemia Hypercoagulable states Hypercoisolism Hyperlipidemia Cushing disease Hyperparathyroidism Hemoglobinopathies Intravascular coagulation SCD;Hb SC;Polycythemia Organ transplantation Caisson disease Pregnancy Dysbaric osteonecrosis Congenital dislocation Hip Pancreatitis Ehlers-Danlos synd Neoplasms Heredity dysostosis CRF Legg-Calve-Pehes dis Hemodialysis Fabry disease Cigarette smoking Gaucher disease Collagen Vascular dis Giant cell aeritis SLE Thrombophlebitis Idiopathic Ref: Essential of ohopedics surgery maheswari 9th ed p.426 