Osteoporosis. Artwork of a hip with a fractured femur (lower left) caused by osteoporosis (brittle bone disease). Behind is a magnified view of the bony trabeculae (pale pink) which make up the spongy interiors of bones. In osteoporosis there is a loss of bone density, making them thinner, more brittle and more likely to fracture. The round femur head articulates with the pelvis at the hip socket (lower left). The femur is fractured at the neck between the head and shaft of the bone. Osteoporosis is most common in women after the menopause as their ovaries no longer produce the oestrogen hormones which help to maintain bone mass.