Knee cartilage wears away as we get older. As the cushioning fails, pain and swelling develop. So what happens when you have no cartilage in your knee, and what can you do about it? This guide covers the full range of treatment options for knee cartilage damage.

This is the comprehensive treatment guide. For the specific question of whether the damage can be undone, see whether osteoarthritis can be reversed.

Causes of no cartilage in the knee

The commonest cause of knee cartilage damage is osteoarthritis. Cartilage loss can also follow a knee injury such as a ligament tear, patellar dislocation, or meniscal tear. Lifestyle factors — weight gain, diabetes, and high cholesterol — contribute too, and inflammatory conditions such as rheumatoid arthritis can further damage cartilage.

Knee osteoarthritis is not simply ‘wear and tear’. A recent view sees it as a ‘total’ failure of the joint — cartilage, ligaments, and synovial lining together. Pain from knee osteoarthritis relates directly to joint inflammation, synovitis, and the bone beneath the cartilage (subchondral bone).

Symptoms of knee cartilage damage

Worsening cartilage loss causes pain with activity, joint swelling, and reduced function. Simple tasks — walking, housework, standing up from a chair — become harder because of pain, swelling, and stiffness.

No cartilage in the knee: treatment

All is not lost. Treatments range from simple weight loss and exercise to injections and, occasionally, surgery — and we always recommend simple treatments first.

Weight loss

Weight gain worsens symptoms and speeds the progression of osteoarthritis. Extra weight loads the joint, and extra fat cells stimulate insulin and chronic inflammation, both of which degrade cartilage. Obese people develop osteoarthritis earlier and have worse pain. The reverse is also true: a 10% weight reduction leads to a roughly 50% reduction in knee pain from cartilage loss — a major improvement.

Exercise therapy

Strength training and aerobic conditioning improve symptoms of cartilage loss by reducing inflammation, losing weight, and building muscle that offloads the joint. A combination of gym work, Pilates, yoga, and Tai Chi is the most effective, and aquatic exercise, such as swimming or aqua aerobics, also helps significantly.

Exercise works best with a structured, progressive programme following American College of Sports Medicine guidelines — aerobic, resistance, and balance work — ideally supervised. Over 50 high-quality studies show that exercise works for knee arthritis.

Are low-intensity workouts as good as high-intensity ones? Probably. A recent study found that 20–30 minutes, three times a week, produced the same benefit as 90 minutes, three times a week — and the lighter group stuck to it better.

Can I run with knee arthritis? Often, yes — if you enjoy running, it should be the goal, though some people reduce their running time depending on pain. Reassuringly, running at your own pace doesn’t worsen cartilage loss on X-ray and may improve pain, and marathon runners aren’t at greater risk of knee arthritis than average. Couch to 5km is a good start for sedentary people.

Supplements

Some supplements may help knee arthritis pain. Boswellia serrata (Indian frankincense) has anti-inflammatory boswellic acids that reduce pain and stiffness in some studies — we suggest 100–250mg daily for four weeks. Curcumin (from Curcuma longa) is anti-inflammatory through pathways including COX-2, and studies suggest it helps knee arthritis when taken for 12 weeks.

Braces and APOS therapy

An offloading brace helps when cartilage loss is confined to one side of the knee, pushing the joint away from the worn area to reduce pressure — though some people find braces uncomfortable. APOS therapy, a shoe insert with rounded pods on the sole, has a NICE recommendation for severe knee arthritis; it changes forces through the foot and knee and corrects abnormal walking patterns: the footwear and associated treatment cost around £875 per person.

NSAIDs

Over-the-counter ibuprofen reduces pain, though the effect is modest; diclofenac or etoricoxib tends to work best for arthritis. Be aware of side effects — gastritis, reduced kidney function, raised blood pressure — and people with heart disease should generally avoid NSAIDs. Topical NSAID creams are effective for hand and knee osteoarthritis, with far fewer side effects than tablets.

Cortisone injection

Cortisone is a powerful anti-inflammatory. It provides short-term, mild relief for about 8 weeks, but recent studies show it’s no better than a placebo for knee arthritis at 6 months, and repeated injections may cause more cartilage damage. So we use cortisone less for long-standing cartilage loss, reserving it for a severely swollen knee.

Knee gel (hyaluronic acid) injection

A gel injection, or viscosupplementation, delivers hyaluronic acid into the joint — likely lubricating it or reducing inflammation. Examples include Durolane, Ostenil Plus, and Synvisc-1. Modern high-molecular-weight gels require only a single injection and last 6–12 months. High-molecular-weight, non-animal hyaluronic acid, such as Durolane, works best for knee and hip arthritis, and if the first injection works, repeats usually work too (up to about five). Gel works better in a quiet, fluid-free knee so that we may drain the knee first.

PRP injection

Platelet-rich plasma (PRP) is a concentrated source of platelets and their growth factors, spun down from your own blood, which we think helps settle chronic inflammation and reduce pain. PRP improves knee pain for over 12 months compared with gel, cortisone, and other options — 23 randomised trials show PRP outperforms cortisone and hyaluronic acid for cartilage loss. We favour leucocyte-poor PRP (less flare risk). Usually 2–3 injections over 4–6 weeks.

Combining PRP with hyaluronic acid

Combining PRP with hyaluronic acid may outperform PRP alone, with benefits at 3, 6, and 12 months and a lower risk of flare. We typically recommend one high-molecular-weight hyaluronic acid plus two PRP injections.

Nstride and Arthrex ACP Max

Nstride PRP is a second-generation PRP concentrating platelets and white cells; some studies suggest years of relief, but the evidence versus placebo isn’t convincing, and its higher white-cell count can cause a bigger flare. Arthrex ACP Max is a second-generation system that super-concentrates platelets (a 5–12 billion dose) via a dual-syringe double spin, with a low white-cell count, so its flare is generally milder.

Arthrosamid

Arthrosamid is a non-degradable hydrogel that coats the synovial lining, reducing inflammation and lubricating the joint. Studies show pain improvement lasting up to four years, and it works better than hyaluronic acid in younger, slimmer patients.

Which injection is most effective: Durolane, PRP, or Arthrosamid?

Based on the published studies for each injectable, our estimate of effectiveness for knee arthritis is:

  • Durolane (hyaluronic acid): around 65–70%
  • PRP: around 65–70%
  • Arthrosamid: around 75% (patients under 70 do better, roughly 80–95%)

These are broad estimates, not head-to-head figures, and the right choice depends on your age, weight, knee, and budget

Nerve injections for knee osteoarthritis 

Nerve blocks targeting knee sensation called genicular nerves can reduce pain and improve function with knee osteoarthritis.  Studies suggest that these blocks can reduce pain for up to 3 months and may be a good addition to intra-articular injections. 

Surgery for damaged knee cartilage

Surgical options for bone-on-bone cartilage loss are limited. Keyhole surgery is ineffective and may accelerate damage — the only indication is genuine mechanical symptoms (locking or giving way) from a loose body or meniscal flap. High tibial osteotomy can offload a malaligned knee, but the evidence is weak, recovery is long (over six months), and there’s debate about whether it beats a replacement. Knee replacement reliably reduces pain and improves function, though about 16% of people have problems afterwards — so it’s for when pain and activity become unacceptable.

Can knee cartilage be repaired without surgery?

No. No current non-surgical treatment regenerates knee cartilage. Even cartilage-replacement surgery is problematic, and injections, including stem cells, haven’t shown cartilage regeneration — stem-cell injections perform no better than other injections, including placebo. For more on whether the damage can be slowed, see whether osteoarthritis can be reversed.

Frequently asked questions about knee cartilage damage

Will my knee arthritis get worse?

Not necessarily. Your lifetime chance of a knee replacement is only about 30%. The best way to prevent progression is a healthy lifestyle — exercise, weight loss, and stopping smoking. Gaining weight raises the risk (from about 30% to 35%).

What actually causes the pain in knee arthritis?

Contrary to popular belief, the cartilage damage itself doesn’t cause pain. The pain comes from swelling in the bone beneath the cartilage (subchondral bone) and the inflamed synovium.

Does arthroscopic (keyhole) surgery help knee arthritis?

No — some studies suggest it may worsen cartilage loss. It only helps mechanical symptoms, such as locking or giving way from a loose body or flap.

When should I consider a knee replacement?

Everyone’s different, but we suggest considering it if pain forces you below about 7,000 steps a day. The good news: about 85% of people return to their chosen activity (walking, skiing, or even running) around 5 months after a replacement.

Which injection is best for knee arthritis?

We think Arthrosamid has a slight edge over PRP and hyaluronic acid — roughly 75% of patients get meaningful relief, versus about 65–70% for PRP and 65–70% for hyaluronic acid — but Arthrosamid is considerably more expensive.

Can you combine duloxetine with a knee injection?

Yes. Duloxetine is an antidepressant shown to help with osteoarthritis. A recent study found that combining duloxetine with a knee injection (cortisone and hyaluronic acid) beat the injection alone at six months.

Final word from Sport Doctor London about knee cartilage damage

Losing knee cartilage is a normal part of ageing. Weight loss and exercise are the best medicine for pain and function. Use injections sparingly to support those lifestyle changes, favouring knee gel and PRP, and avoid expensive treatments such as stem cell therapy that promise regeneration. Consider a knee replacement only when all else fails and your activity drops.

To book a one-stop knee arthritis assessment with Dr Masci in London, contact the team here or call +44 (0) 203 488 0350.

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