{"id":10934,"date":"2024-02-23T10:36:09","date_gmt":"2024-02-23T09:36:09","guid":{"rendered":"https:\/\/blogs.bmj.com\/bjsm\/?p=10934"},"modified":"2024-02-23T11:35:31","modified_gmt":"2024-02-23T10:35:31","slug":"using-wearable-technology-to-assist-with-decision-making-on-hip-and-knee-replacements","status":"publish","type":"post","link":"https:\/\/blogs.bmj.com\/bjsm\/2024\/02\/23\/using-wearable-technology-to-assist-with-decision-making-on-hip-and-knee-replacements\/","title":{"rendered":"Using wearable technology to assist with decision-making on hip and knee replacements"},"content":{"rendered":"

Keywords<\/b><\/p>\n

Wearable technology, exercise medicine, joint arthroplasty<\/span><\/p>\n

Introduction<\/b><\/p>\n

In 2015, I wrote a BJSM Blog on \u201cDeciding when it is time to have a knee replacement\u201d,<\/span>[1]<\/span> arguing for a shift away from using structural markers to assess need for knee replacement (such as X-ray and MRI) to objective functional markers. I suggested a cut off point of 7000 steps per day; that patients who clearly could not reach this level due to severity of knee pain were the ones who were most in need of knee replacement.\u00a0<\/span><\/p>\n

Since the 2015 non-blinded RCT, <\/span>[2]<\/span> there hasn\u2019t been any further RCTs on knee replacement (vs conservative), but a recent cohort study also showed better pain outcomes after surgery.<\/span>[3]<\/span> There has also been a huge amount of data showing an association between walking 7000 steps per day (or more) and reductions in all-cause mortality.<\/span>[4, 5]<\/span> Although most people elect to have joint replacement aiming to reduce pain levels, from an all-cause mortality viewpoint, it is even more important to prioritise the ability to allow people to complete the (necessary) amount of walking per day. It is also important to note that joint replacements are still somewhat risky procedures, leading to more medical complications than conservative care<\/span>[2]<\/span> and therefore should not be undertaken lightly.<\/span><\/p>\n

Hip versus knee replacements<\/b><\/p>\n

Although we don\u2019t have an RCT to compare hip replacement to an alternative, in the real-world hip replacements are considered to be equal to if not superior to knee replacements in terms of outcomes. Certainly it is more common to return to higher level sport after hip arthroplasty than it is after knee arthroplasty. Two high profile examples are Bo Jackson (Ex-NFL player who returned to play Major League Baseball) and Andy Murray (tennis). It is not rare to see patients who have had successful hip replacements be able to return to high level triathlon activities, for example, and even complete marathons.<\/span>[6]<\/span> However, all joint replacements are associated with risks of serious complications. Three high profile Australians have recently died within weeks of having had hip replacements<\/span>[7, 8]<\/span> even though this is considered a rare event.<\/span>[9]<\/span><\/p>\n

As a general rule, the efficacy of arthroplasty relates to the amount and quality of bone available to fix the prosthesis in place. This means that hip and knee replacements perform better than ankle replacements and exercising individuals tend to do better than sedentary individuals. Short-term results will be better in younger, healthier patients (such as Andy Murray) with the concerns in this group being the risk associated with revision procedures decades down the track.<\/span><\/p>\n

Other considerations relating to quality of daily steps<\/b><\/p>\n

As a raw score, daily step counts of 7000 or over are associated with far superior health outcomes. <\/span>[4, 5]<\/span> Anyone doing fewer than, say, 5000-6000 steps per day should be encouraged to increase to around 6000-7000 steps per day to achieve the health benefits associated with moderate level walking.<\/span>[10]<\/span> There are a few caveats to this advice, however, which are regular features of Exercise Medicine consultations:<\/span><\/p>\n