Little Summer Dutton looks like any other three-year-old as she plays in the sunshine.

It is a scene her mother Fiona had feared she would never see again when, a year ago, Summer was diagnosed with a rare bone infection.

Until March last year Summer was a typical lively toddler.

Then Mrs Dutton noticed Summer's legs hurt when she had her nappy changed.

She was always jumping off things and falling over, though, so her mother thought no more of it.

A week later Summer started limping. Thinking it was a sprained ankle, Mrs Dutton took her to hospital.

An X-ray showed she had an old fracture but doctors were confused because she had never broken her leg or had a serious fall.

Scans failed to reveal the problem and Summer was sent to theatre so surgeons could examine the bone.

They diagnosed the worst case of osteomyelitis - inflammation of the bones, caused by an infection - they had seen. Within a week she was having surgery to remove 3in of thighbone, a procedure used in extreme cases. The bone left behind eventually regenerates.

The youngster was confined to a hospital bed on a drip for five weeks with her leg in traction.

Mrs Dutton, 32, who lives in Mile Oak, Portslade, with husband, Phil, 39, Summer and her brother Sebastian, seven months, said: "Summer went from having a suspected sprained ankle to surgery in a week. It was a terrible time - the doctors said it could be a tumour.

"I was pregnant so my emotions were all over the place but you just go on autopilot. Other people were falling apart but I had to stay together for my little girl. It was heartbreaking to see her in the hospital bed, not allowed to move.

"Summer was amazing through it all. There were complications. The IV drip had to be replaced every couple of days and she had to have a blood transfusion. But she kept smiling and kept us all going."

Summer finally left the Royal Alexandra children's hospital, in Brighton, on Easter weekend last year. She was kept on antibiotics for a further four weeks and allowed back to nursery school in August but could not go back on the slides until October.

A year on, she is back to full health and all she has to show for the experience is a long scar on her thigh.

To thank the surgeons, doctors and nurses at the Royal Alex, Summer are taking part in a sponsored "toddle" on June 5 to raise money for the hospital's Rockinghorse Appeal.

Mrs Dutton said: "I feel I owe a huge debt to the Royal Alex hospital for getting us through that terrible time.

"We may not raise much money but it's our way of saying thank you."

To sponsor Summer call Fiona Dutton on 01273 416807. For more details about the Rockinghorse Appeal, call 01273 730286 or log on to www.rockinghorse.org.uk