Renata's up and running

Renata Tane and Ripeka Tane with son Renata Muunu-Te Tane in March 2014, after his operation to remove part of his leg and reattach his foot. Photo / Dean Purcell

A Northland boy, whose lower leg was surgically reversed as part of his cancer care, has been running around so much that the big toe got worn off his new prosthetic limb.

Renata Muunu-Te Tane, of Oromahoe in the Bay of Islands, featured in the Herald last year, after having the unusual surgery in August 2013. He had been diagnosed with Ewing sarcoma, a rare disease that affects only one or two children in every 100,000.

A tumour was found on his left thigh bone, just above the knee. He had chemotherapy and the mid-section of his leg, including the knee, was removed.

In an operation called "rotationplasty", the lower leg was rotated, until the foot pointed backwards, and was screwed on to the remainder of the thigh bone. The procedure involves not cutting the blood vessels and large nerve that go to the lower leg and foot; they are coiled up and placed back within the retained tissue. The ankle joint functions like a knee and the backward-facing foot retains full feeling and movement, and is a natural fit for a prosthetic leg.

The rotated foot functions more like a below-knee amputation, for which prosthetics work better than above-knee amputations. Only a handful of New Zealand youngsters have had the operation.

Seven-year-old Renata can walk/hop on his legs of different lengths and also uses an artificial leg-and-foot. There has been no sign of cancer and Renata is full of energy.

"He's doing really well," says his mother, Ripeka Tane, who is pregnant and has two daughters, aged 5 and 2.

"He's just finished a swim [at Kerikeri Primary School] and at the moment he's on the playground, playing around. It's very hard to keep him away from doing anything active. He enjoys soccer and hockey. His mates, they never leave him out of anything. Nothing holds him back."

Mrs Tane says Renata's prosthetic leg works very well.

"He uses it all the time - so much that the big toe of the prosthetic was fully cut off. For a while he was walking around without a big toe."

This drew concerned looks from people who didn't realise it is an artificial foot.

But he has had to take a six-week break from wearing the prosthetic because of a recent follow-up operation that removed two of the three screws in his leg.

"He wanted them removed because every time he got cold the screws would chill his bone. Every time he knocked his leg he could feel the screws and they didn't need to be there [any longer].

"One screw is still there; the bone has grown over it and it won't be a bother to him."