{"text":[[{"start":4.96,"text":"Years of ultra-marathon running when he lived in Hong Kong took its toll on Jim Sweeney’s joints. “I pounded my knees excessively. Every step I took was painful,” says Sweeney, a financial executive in the City of London. Earlier this year, he had his left knee partially replaced in a robotic operation."}],[{"start":24.36,"text":"At 60, he is younger than the traditional knee replacement patient, but his experience is becoming more common. The average age for joint replacements has fallen as more middle-aged people wear them out. It was a typical case in another way: Sweeney’s partial knee was made by the US company Stryker and the procedure was done with its Mako surgical robot."}],[{"start":45.2,"text":"Stryker has led a surgical revolution in which many knee replacements are now carried out by surgeons with robot assistance. But the change has been painful for Smith & Nephew, the FTSE 100 medical equipment company, which had lower knee replacement revenues this year. This has contributed to sluggish growth in orthopaedics, its biggest division by sales."}],[{"start":66.08,"text":"Shares in Smith & Nephew have fallen 20 per cent over the past year as Deepak Nath, chief executive, has tried to revitalise the business. Some investors have called for it to spin off orthopaedics and focus on faster-growing areas such as sports medicine and wound care. The activist fund Cevian acquired a stake two years ago and raised it to 14 per cent in August."}],[{"start":86.8,"text":"So there is a lot riding on Smith & Nephew’s attempt to fight back in the battle of the knee replacement robots. The company last month gained US regulatory approval for its new artificial knee, called Landmark. The joints can be implanted by surgeons using its Cori handheld robotic platform, which it says is cheaper and more flexible than Mako and others."}],[{"start":107.605,"text":"The UK has a history of artificial joint innovation: a partial knee replacement developed at Oxford university in the 1970s is part of the portfolio of US company Zimmer Biomet. But most innovation now comes from the US, the world’s largest medical devices market. More than 1mn total knee replacements are performed there annually, of the 3mn global total."}],[{"start":126.44,"text":"One of the biggest changes has been the move towards robot-assisted surgery, with surgeons using scans, software and robotic arms to cut less bone and to help implant artificial knee and hip joints. This helps make the operations quicker: US knee replacements are often completed in less than an hour."}],[{"start":145.12,"text":"Robotic precision has encouraged a shift towards “cementless” joint replacements in which bones regrow around implants rather than the latter being cemented in position. Stryker’s Mako epitomises these trends: since its launch a decade ago, it has been used for more than 1mn total knee replacements."}],[{"start":162.64,"text":"Mako robots are priced at about $1mn but are often supplied at a discount under contracts linked to the use of Stryker joints. As more surgeons use them, they become harder to displace: Smith & Nephew ranks fourth in orthopaedics after Zimmer Biomet, Stryker and Johnson & Johnson’s DePuy Synthes."}],[{"start":182.32,"text":"Smith & Nephew’s Cori platform combines a handheld device with software and screens. It is smaller and cheaper than Mako, which the company hopes will persuade hospitals and US day surgery centres to switch. It is also looking to regain ground in the UK, where it lags behind despite slower adoption of robots in the NHS."}],[{"start":202.82,"text":"The company’s own knees are also ageing. Journey, its predecessor to Landmark, was launched two decades ago but suffered from being complex to implant, with surgeons prioritising speed and simplicity. It was overtaken by Stryker’s Triathlon knee and now faces combinations such as Zimmer Biomet’s Persona knee and Rosa robot."}],[{"start":222.62,"text":"There is an opportunity. “The average knee patient is getting younger and more active. We’re seeing people in their forties and early fifties get replacements,” says Mayank Shandil, S&N’s head of marketing for orthopaedics and robotics. Landmark mimics human knee movement more closely for patients who are likely to need them longer."}],[{"start":240.32,"text":"Sweeney, who also had a partial hip replacement five years ago, is one such customer. He has regained mobility on his Stryker knee after a few months of physiotherapy. “It’s working pretty well,” he says. “I’ll hopefully be getting a full ski season this year.” But it will take Smith & Nephew more time to recover and investors are impatient."}],[{"start":261.32,"text":""}]],"url":"https://audio.ftcn.net.cn/album/a_1792779924_7734.mp3"}