Spontaneous subcapital femoral neck fracture complicating osteonecrosis of femoral head

Spontaneous subcapital fracture (SSF) of femoral neck in pre-existent osteonecrosis head (ONFH) is a rare presentation. Only few cases have been reported so far and majority them to unilateral hip involvement. We retrospectively reviewed clinical-radiological data 10 patients (12 hips) with SSF complicating ONFH. All underwent uncemented total arthroplasty. the available publications English language based medical literature were critically results summarized. The median age presentation was 32 years (range : 24 61 years). They followed up for mean duration 25 months 12 59 months). most common risk factor corticosteroid consumption (7 out patients). except one (modified Ficat Arlet stage II) belonged advanced ONFH {stage III 3 (3 hips), IV 6 (8 hips)}. time lag 22.3 5 60 months), 13.8 days 1 day 28 days). Mean pre- operative Harris Hip Score 10.8 8 14), which improved 93 91 96) after arthroplasty when last (p<0.05). Corticosteroids induced has propensity develop SSF. This entity should find place existing classification system.