OrthoLongevity™
Where we practise
Biology-first. Surgery-last.
The first surgeon-built Knee Age™ test. A free knee health check, created by a consultant orthopaedic knee surgeon.
Designed for elite athletes. Now available to everyone.
Surgery · Sports Medicine · Physiotherapy · Strength & Conditioning · Nutrition · Sleep, one framework
PRIME is the five-domain assessment behind your Knee Age: Power, Risk, Injury, Movement, and Endocrine & Metabolic.
Strength and force capacity
Genetic and genomic risk
Injury and load history
Range, mechanics, posture and function
Hormones, metabolism and inflammation
PRIME measures. Knee Age scores. R.E.P.A.I.R.™ treats.
Knee Age™ weighs your answers across the five PRIME domains against published risk factors for joint ageing and the patterns seen in over 25 years of clinical practice. It is an educational estimate, not a diagnosis, and it improves as the evidence does.
Most people see a surgeon when the damage is already significant. Years of preventable deterioration have happened quietly in the biology, the muscles and the metabolism, long before the pain becomes undeniable.
Home of the OrthoLongevity™ Longevity Movement Clinic. Performance laboratory, Biodex isokinetic strength testing, gait analysis, ultrasound-guided procedures, and surgeon-led assessment under one roof.
Register your email today and you will be first to access the full OrthoLongevity™ app and 12-week programme, before public launch, at early-access pricing.
In-depth articles written and reviewed by Dr Arj. Honest, evidence-based guidance on treatments, surgery decisions, and keeping your knees for life.
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Most people only ask this once their knees already hurt. By then the easiest years for prevention have often passed. A knee health test should tell you where you stand before pain decides for you.
The Knee Age test is a free knee health check that takes about 60 seconds. It looks at the five things that drive how knees age: strength, genetic and family risk, injury and load history, movement, and metabolic and hormonal health. You get one number, your Knee Age, set against your real age. Take the free knee health test.
Knee longevity means keeping your knees strong, comfortable and capable for as long as you live, not just until the first scan shows wear. It is built from the same habits that protect the rest of your health: muscle, metabolic health, sleep and sensible load. Most of it is in your hands.
A test cannot examine you. Whatever your score, stop self-managing and get your knee assessed if it gives way, if it locks so you cannot straighten it, or if pain wakes you every night. A hot, swollen knee with a fever needs to be seen the same day.
Yes. The free Knee Age test is a 60-second knee health test built by a consultant orthopaedic knee surgeon. It scores the five things that drive how knees age, strength, genetic risk, injury history, movement and metabolic health, and gives you one number to compare with your real age. It is educational, not a diagnosis.
The quickest way to find out is to compare your Knee Age with your real age. If your Knee Age is at or below your real age, your knees are ageing well. If it is higher, the result shows which areas are adding years, so you know where to start.
Knee longevity means keeping your knees strong, comfortable and capable for as long as you live. It rests on the same habits that protect the rest of your health: muscle strength, metabolic health, sleep and sensible load. Most of it is within your control.
Get your knee assessed rather than self-managing if it gives way, if it locks so you cannot straighten it, or if pain wakes you every night. A hot, swollen knee with a fever needs to be seen the same day.
Your knee age is the biological age of your knees, which can be younger or older than the age on your passport. The Knee Age™ assessment scores you across five clinical domains in around 60 seconds and gives you a single number comparing your knees' biological age to your chronological age.
Probably not the same age as you. Cartilage health, muscle strength, movement quality, injury history and underlying biology all push knee age up or down. The free Knee Age™ test gives you an evidence-informed estimate in about a minute.
Yes. Knee Age™ is the first surgeon-built knee-specific biological age assessment, launched in 2025 and created by Dr Arj Imbuldeniya, a London consultant orthopaedic knee and hip surgeon. Heart Age changed how people think about their hearts; Knee Age™ does the same for your joints.
Knee Age™ focuses on the knee, the joint most likely to limit how you move and age. Many of the domains it measures, such as muscle strength, movement quality and metabolic health, affect every joint in your body, so your result is a strong signal for your wider joint health too.
No. It is an educational assessment, not a diagnosis, and it does not replace a consultation with a doctor. If you have knee pain, swelling, instability or an injury, seek a proper clinical assessment.
Nothing. The Knee Age™ test is free and takes around 60 seconds.
The biggest levers are usually building strength around the joint, steadier metabolic health, and better daily movement. Your genetics and past injuries set the starting line, not the finish. The free Knee Age test shows which single change would take the most years off your Knee Age, so you start where it counts.
A good result is a Knee Age at or below your real age, with your five domains sitting on the healthy side. It means your knees are ageing more slowly than you are. The test shows exactly which domains are helping and which are holding you back.
It is an honest estimate, not a scan. But the five domains it measures, strength, movement, injury history, metabolic health and genetic risk, are the ones that genuinely drive how knees age, so the number is a useful and motivating starting point. If you have pain, swelling or a recent injury, read the safety signs on this page and get your knee properly assessed.
Your knees age fastest when the muscle around them weakens, your metabolic health drifts, and daily movement drops. Rebuild those and the trajectory changes. Progressive strength two or three times a week, steadier blood sugar and better sleep, and simply breaking up long hours of sitting are the levers that move knee health the most, and they compound quietly over years.
Genetics and old injuries set your starting line, not your finish. That is the heart of knee longevity: acting early and consistently on the things you can change, so your joints stay capable for decades rather than declining on schedule. The fastest way to know where to start is to measure it. Take the free Knee Age test and see which single change would take the most years off your knees.
