Sheep give nags a leg-up

A revolutionary medical experiment on a flock of Perth sheep may not only extend the careers of injured racehorses but may also pave the way for more efficient knee surgery in humans.

Murdoch University surgeon David Murphy said the tests being done on 48 sheep were aimed at establishing a knee cartilage resurfacing practice that would ultimately provide patients with a "one-stop shop" for their dodgy joints.

Currently, practitioners have to harvest stemcells and grow them for up to a month before operating again to put them in place.

The experiment uses the US practice of "micropicking". A surgeon hammers a steel spike up to 4mm through the base of the bone to allow stemcells to be drawn up through it. Collagen membranes, described by surgeons as scaffolds, are applied with tissue glue over the affected area and eventually it becomes cartilage.

The collaborative project, between Murdoch University, University of WA and Perth bio-therapeutic company Orthocell, began in June and the first results are expected in February.

Dr Murphy said about 80 per cent of racehorses would suffer cartilage injury. But he was optimistic the sheep tests would improve their chance of recovery and also prove successful in human surgery.

"You go in and tidy up the joint, do the micropicking to recruit the stemcells, get your membrane and put it in place," he said. "It will then grow better quality cartilage.

"The theory is the membrane will act as protection for the cells to stick to and stop them being rubbed away while the joint is working."