Knee Surgery for Cartilage Damage: What Are the Options?

By Emma Glynn - The Hip & Knee Physio

If you are searching for knee surgery for cartilage, the first thing to know is that “cartilage” can mean different things. Some people are talking about the meniscus. Some are talking about the smooth articular cartilage on the end of the bones. Others have been told they have “no cartilage left” and are really dealing with knee osteoarthritis.

Those are not the same problem, and they do not have the same treatment pathway.

The right decision about knee surgery for cartilage depends on the type of cartilage involved, the pattern of symptoms, your age, your activity goals, and whether the issue is traumatic, focal or degenerative.

I am Emma Glynn, an APA Titled Musculoskeletal Physiotherapist in Camberwell. I work exclusively with hip and knee conditions, and I often see people who have been told there is “cartilage damage” on a scan but are still not clear on what that actually means.

For a broader overview of knee arthritis, you can visit my knee osteoarthritis page. If you already know surgery is likely, this guide to knee replacement recovery with physio may also be useful.

First: what does “cartilage damage” mean?

In the knee, people often use the word cartilage to describe more than one structure.

There are two common meanings:

• Meniscus cartilage: The meniscus is the C-shaped shock-absorbing cartilage between the thigh bone and shin bone. You have a medial and lateral meniscus.

• Articular cartilage: This is the smooth lining on the end of the bones that helps the joint surfaces glide.

Then there is knee osteoarthritis, which is a whole-joint condition involving cartilage, bone, joint lining, menisci, ligaments, muscles and pain sensitivity. It is often described as cartilage loss, but it is not just a cartilage problem.

Before deciding whether surgery is useful, you need to know whether the problem is a meniscus tear, a focal articular cartilage defect, or more widespread knee arthritis.

This matters because a cartilage repair procedure that may be considered for a small focal defect in a younger person is very different from treatment for advanced knee osteoarthritis.

Meniscus surgery: repair versus trimming

When patients say they have “torn cartilage”, they are often talking about a meniscus tear. Meniscus tears can happen after a clear injury, such as twisting during sport, or they can be degenerative and appear gradually with age and knee osteoarthritis.

There are two broad types of meniscus surgery:

• Meniscus repair: The surgeon stitches the torn meniscus where healing is possible.

• Partial meniscectomy: The surgeon removes or trims the torn part of the meniscus.

Meniscus repair is generally about preserving tissue where possible, while partial meniscectomy removes the torn portion that is not considered repairable.

The decision depends on the tear pattern, location, blood supply, age of the tear, knee stability, presence of arthritis, and symptoms. A young person with a traumatic repairable tear may have a very different pathway from a 58-year-old with gradual knee pain and a degenerative meniscus tear on MRI.

This is where scan findings can mislead people. Meniscus tears are common on imaging, especially as people get older, and they are not always the main reason the knee hurts.

When meniscus surgery may be considered

Meniscus surgery may be discussed when symptoms and imaging fit together, and when the tear is likely to be driving the problem.

It may be more relevant when there is:

• A clear traumatic injury

• True locking where the knee physically gets stuck

• A displaced tear, such as a bucket-handle tear

• Repeated catching that matches the tear pattern

• Failure to improve with appropriate non-surgical care

• A repairable tear in an otherwise suitable knee

True mechanical locking is different from pain, stiffness, clicking or a vague catching sensation.

A knee that is painful to fully bend or straighten is not automatically locked. A knee that physically cannot move through range because something is obstructing it is a different clinical picture and usually needs medical review.

When surgery is less likely to help

Surgery is often less useful when the “cartilage damage” is part of a more degenerative knee pattern, especially when symptoms are more consistent with knee osteoarthritis.

This may include:

• Gradual onset knee pain over months or years

• Age-related meniscal changes on MRI

• Widespread cartilage thinning

• X-ray changes consistent with knee osteoarthritis

• General aching, stiffness and swelling rather than true locking

• Pain that changes with overall load, walking, stairs and flare-ups

If the main issue is uncomplicated knee osteoarthritis, arthroscopy to clean out or trim cartilage is generally not recommended as a routine treatment.

That does not mean surgery is never appropriate for knee arthritis. It means the type of surgery and the reason for surgery matter. Knee replacement, osteotomy or other surgical options are different conversations from arthroscopic debridement or trimming.

If you are trying to understand your non-surgical options first, this article on non-surgical treatment for knee osteoarthritis may help.

Articular cartilage damage: focal defects versus arthritis

Articular cartilage damage refers to damage to the smooth joint surface on the end of the bones. A small, localised defect after injury is different from widespread cartilage loss across the knee.

This distinction matters.

Focal cartilage defects may sometimes be considered for cartilage restoration procedures, while widespread degenerative cartilage loss usually follows a different pathway.

A focal articular cartilage defect may occur after:

• A sports injury

• A direct blow to the knee

• A dislocation episode

• Osteochondritis dissecans

• A localised traumatic cartilage injury

Widespread cartilage loss is more typical of knee osteoarthritis. It often comes with bone changes, stiffness, swelling, reduced function and symptoms that behave according to load.

The same word, “cartilage”, gets used for both. Naturally, this causes chaos. The knee was apparently designed by committee.

Types of surgery for articular cartilage damage

Surgery for articular cartilage damage is usually considered in selected cases, often when there is a focal defect and symptoms have not improved with appropriate non-surgical management.

Options may include:

• Chondroplasty: Smoothing unstable cartilage flaps.

• Microfracture or marrow stimulation: Creating small holes in the underlying bone to stimulate repair tissue.

• Osteochondral autograft transfer: Moving small plugs of bone and cartilage from one part of the knee to another.

• Osteochondral allograft: Using donor bone and cartilage for larger defects.

• Autologous chondrocyte implantation: Taking cartilage cells, growing them, and implanting them into the defect in selected cases.

• Osteotomy: Realigning the leg when one compartment is overloaded due to alignment.

• Knee replacement: Replacing joint surfaces when arthritis is advanced and function remains significantly limited.

These operations are not interchangeable; each is used for different cartilage patterns, different knees and different goals.

A cartilage restoration procedure is not usually the same thing as treatment for advanced arthritis. That is why “what surgery do I need?” cannot be answered properly from the scan wording alone.

Does cartilage surgery grow normal cartilage back?

This is where expectations matter. Some cartilage procedures aim to fill or restore a defect, but the new tissue may not be identical to original healthy articular cartilage. Some procedures form fibrocartilage, which behaves differently from native joint cartilage.

Cartilage surgery is not a simple reset button for the knee.

That does not mean it cannot help selected people. It means the expected outcome, recovery time, rehabilitation requirements and long-term plan need to be clearly discussed with the surgeon.

Patients should ask:

• What type of cartilage is damaged?

• Is this a meniscus problem, articular cartilage defect or osteoarthritis?

• Is the damage focal or widespread?

• What operation is being recommended?

• What is the goal of the operation?

• What are the risks?

• What does rehab involve?

• What happens if I do not have surgery now?

• What non-surgical options are still appropriate?

A good decision is not just “the scan shows cartilage damage, therefore surgery”. That is not clinical reasoning. That is admin with a scalpel.

Where physiotherapy fits before surgery

Physiotherapy does not regrow cartilage. Let us not wander into fantasy land. But physio can still be useful before a surgical decision because symptoms are not always caused only by the scan finding.

A thorough assessment can help clarify:

• What movements and loads reproduce symptoms

• Whether swelling is present

• Whether strength deficits are contributing

• Whether the knee behaves like arthritis, meniscus irritation, patellofemoral pain or another pattern

• Whether symptoms improve with load modification and strengthening

• Whether medical or surgical review is needed

Physio can help determine whether the knee has capacity to improve without surgery, or whether the pattern suggests surgical review is appropriate.

Pre-surgery rehab may include:

• Swelling management

• Quadriceps strengthening

• Hip and calf strengthening

• Walking and stair modification

• Load management

• Return-to-sport or return-to-activity planning

• Education about flare-ups and pain response

• Preparing the knee if surgery is likely

If you are already preparing for surgery, building strength and understanding your baseline can also help guide the post-operative rehab plan.

Where physiotherapy fits after cartilage surgery

Rehabilitation after cartilage surgery depends heavily on the operation. Meniscus repair, partial meniscectomy, microfracture, osteochondral grafting, ACI and knee replacement all have different timelines and restrictions.

The rehab plan after cartilage surgery should follow the surgeon’s protocol and be adapted to the procedure, tissue healing, swelling, strength and goals.

Post-operative physio may involve:

• Protecting the surgical site early

• Managing swelling and pain

• Restoring knee range of motion

• Rebuilding quadriceps activation

• Progressing weight-bearing when cleared

• Normalising walking

• Rebuilding strength

• Progressing stairs, cycling or gym work

• Return-to-running or sport progressions where appropriate

• Monitoring response to load

Some cartilage procedures require a slow and staged return to loading. This is not the time for motivational nonsense. The tissue needs time, and the rehab plan needs to respect the operation.

When to seek medical or surgical review

Not every cartilage finding needs urgent review. But some symptoms should be checked promptly.

Medical or surgical review is important when the knee is locked, severely swollen, unstable, or not behaving like a straightforward load-related pain problem.

Seek review if you have:

• True locking where the knee cannot straighten

• A large sudden swelling after injury

• Inability to weight-bear

• Significant instability or giving way

• A traumatic twisting injury with ongoing swelling

• Fever, redness or feeling unwell

• Calf swelling or shortness of breath

• Symptoms that are worsening despite appropriate care

• A scan showing a loose body, displaced tear or significant cartilage injury

If you are unsure whether your knee needs physio first, imaging, GP review or orthopaedic review, an assessment can help you choose the next step more sensibly.

What to do next

If you have been told you need knee surgery for cartilage, or you have a scan showing cartilage damage and do not know what it means, the first step is to clarify the diagnosis.

The key question is not just “Do I have cartilage damage?” It is “What type of cartilage problem is this, and does it match my symptoms?”

You may benefit from an assessment if:

• Your MRI mentions cartilage damage or a meniscus tear

• You are unsure whether surgery is necessary

• You have knee pain, swelling or catching

• You have been told you have arthritis but do not know what to do next

• You want to understand whether rehab is worth trying first

• You are preparing for surgery and want a stronger starting point

• You need help with post-operative rehab after cartilage surgery

If you are based in Melbourne’s inner east, including Camberwell, Hawthorn, Kew, Canterbury, Surrey Hills, Glen Iris or nearby, you can book an in-person knee assessment. I will assess your knee, explain what I think is contributing to your symptoms, and help you work out whether rehab, medical review or surgical review is the most sensible next step.

Emma

References

Australian Commission on Safety and Quality in Health Care. (2024). Osteoarthritis of the knee clinical care standard. ACSQHC. https://www.safetyandquality.gov.au/standards/clinical-care-standards/osteoarthritis-knee-clinical-care-standard

Brittberg, M., & colleagues. (2024). Treatment of knee cartilage lesions in 2024. Journal of Experimental Orthopaedics.

National Institute for Health and Care Excellence. (2017). Autologous chondrocyte implantation for treating symptomatic articular cartilage defects of the knee (Technology appraisal guidance TA477). NICE. https://www.nice.org.uk/guidance/ta477

Siemieniuk, R. A. C., Harris, I. A., Agoritsas, T., Poolman, R. W., Brignardello-Petersen, R., Van de Velde, S., Buchbinder, R., Englund, M., Lytvyn, L., Quinlan, C., Helsingen, L., Knutsen, G., Olsen, N. R., Macdonald, H., Hailey, L., Wilson, H. M., Lydiatt, A., Kristiansen, A., & Guyatt, G. H. (2017). Arthroscopic surgery for degenerative knee arthritis and meniscal tears: A clinical practice guideline. BMJ, 357, j1982. https://doi.org/10.1136/bmj.j1982

American Academy of Orthopaedic Surgeons. (2021). Management of osteoarthritis of the knee: Evidence-based clinical practice guideline. AAOS. https://www.aaos.org/oak3cpg

Medical disclaimer

This blog is general educational information only and is not a substitute for individual medical advice, diagnosis or treatment. If you have severe or worsening knee pain, a locked knee, sudden swelling after injury, inability to weight-bear, fever, redness, calf swelling, shortness of breath, significant instability, or symptoms that concern you, please seek medical review promptly.