Pioneering stem cell treatment has enabled British steeplechaser Knowhere to come back from severe injuries to win Cheltenham's Gold Cup Trial last week.
Ridden by Paddy Brennan in his latest race and trained by Nigel Twiston-Davies, Knowhere had a good start to his racing career as a four-year-old, winning his first two races as a novice hurdler. Subsequent to his second race in late 2004 he suffered injuries to both forelimb superficial digital flexor tendons. The left fore showed low grade tendonitis while the right fore had a significant percentage of fibre rupture. As a promising racing prospect, Knowhere's connections wanted to give him the best possible chance of recovering from his injury so they opted for stem cell therapy. He was treated by Tim Beauregard MRCVS of Summerhill Farm in Gloucestershire.
Bone marrow samples were collected from Knowhere's sternum and were processed in a laboratory over a five week period to generate millions of stem cells. Knowhere was sedated and the tendon area was anaesthetised and then the leg was surgically clipped and disinfected. The stem cells, which had been suspended in serum obtained from the original bone marrow sample, were then injected using ultrasound guidance, into the core of the damaged area of the tendon fibres.
For the first week after the implantation Knowhere was kept in his stable to allow the cells to adapt to their new environment. Each day after this he was given walking exercise in order to stimulate the activity of the stem cells, encouraging them to differentiate into tendon cells and form into strong tendon fibres. The amount of exercise was incrementally increased, building up over a three-month period from five minutes each day to 45 minutes twice a day.
By the autumn of 2005 both of Knowhere's tendons had healed very well and showed good fibre pattern on ultrasonography. He was re-introduced to the racetrack the following year and of the 15 or so races he has been in since then he has finished in the frame on eight occasions and has amassed some £175,000 in winnings.
Vet Tim Beauregard concludes: "Knowhere's successful return to the track has been exciting and immensely satisfying to follow."