Mosaicplasty is a cartilage restoration procedure used to treat selected focal cartilage or osteochondral defects, most commonly in the knee. In simple terms, it involves taking small plugs of healthy cartilage with underlying bone from a low-weight-bearing area of the joint and transplanting them into the damaged area. Because several small plugs may be used side by side, the surface can look like a mosaic, which is where the name comes from. [1][2]

In my practice, I usually explain to patients that mosaicplasty is not a general treatment for all knee pain. It is a targeted procedure for a very specific problem: a localized area of damaged cartilage in an otherwise reasonably suitable joint. For the right patient, it can help restore a more natural joint surface, reduce pain, and improve function. [1][3]

For Bangladeshi patients and families, this topic can be confusing because many people hear the words “cartilage damage” and assume the only surgical option is knee replacement. That is not always true. In younger or active patients with a small to medium-sized focal cartilage defect, cartilage restoration procedures such as mosaicplasty may sometimes be considered instead of replacement surgery. [1][2]

What Is Mosaicplasty?

Mosaicplasty is also known as osteochondral autograft transfer or osteochondral autograft transplantation. The term “autograft” means the graft comes from the patient’s own body. The surgeon transfers cylindrical plugs containing healthy cartilage and bone into the cartilage defect to fill the damaged area with living joint surface tissue. [2][4]

Why cartilage matters

Articular cartilage is the smooth covering on the ends of bones inside a joint. It helps the knee move with low friction and absorbs load during walking, climbing stairs, and sports. When there is a focal defect in this surface, patients may develop pain, swelling, catching, reduced performance, and sometimes progression of joint damage over time. [1]

One important point I want Bangladeshi patients to understand is that cartilage does not heal easily on its own once a full-thickness defect develops. That is one reason focal cartilage injuries can remain troublesome, especially in active people. [1][4]

Which Joint Is Usually Treated?

Mosaicplasty is most commonly discussed for the knee, especially the femoral condyles or other selected focal cartilage lesions. Although osteochondral grafting can be used in other joints in some settings, when most patients search for mosaicplasty, they are usually asking about the knee. [1][2][4]

In this article, I am focusing mainly on mosaicplasty for the knee because that is the most practical and relevant context for most patients in Dhaka and Bangladesh.

Who May Need Mosaicplasty?

Mosaicplasty is usually considered for selected patients who have a symptomatic focal cartilage defect rather than widespread arthritis.

Patients who may be considered

• Younger or middle-aged active adults
• Patients with persistent pain from a localized cartilage defect
• People with symptoms after sports injury or trauma
• Some patients with osteochondritis dissecans
• Patients whose joint alignment, stability, and surrounding cartilage are reasonably suitable [1][2][4]

I often explain that mosaicplasty works best when the problem is specific and contained. It is usually not the right answer for a knee that has diffuse, advanced osteoarthritis affecting large areas of the joint.

Who May Not Be a Good Candidate?

This procedure is not suitable for everyone. When I assess whether mosaicplasty is appropriate, I look beyond the cartilage defect itself.

Mosaicplasty may be less suitable in

• Advanced osteoarthritis
• Very large cartilage defects
• Significant malalignment that is not being addressed
• Major ligament instability that is untreated
• Severe obesity or other factors that place high load on the joint
• Patients unable to follow postoperative rehabilitation [1][2][4]

In some cases, other procedures may be more appropriate, such as microfracture, autologous chondrocyte-based procedures, osteochondral allograft, alignment correction, or even joint replacement, depending on the patient’s age, defect size, joint condition, and goals. [1][3][5]

What Problems Can Mosaicplasty Help Treat?

Common indications

• Focal cartilage injury after trauma
• Symptomatic osteochondral lesions
• Selected lesions related to osteochondritis dissecans
• Some focal defects that have not improved with non-surgical treatment [2][4]

In my practice, I often see patients who say, “My MRI shows cartilage loss, so do I need a replacement?” The answer depends on the pattern. If the defect is focal and the rest of the knee is still reasonably preserved, cartilage restoration may be worth discussing.

What Symptoms Do Patients Usually Have?

Patients with focal cartilage damage may experience:

• Pain during walking, stairs, squatting, or sports
• Swelling after activity
• Knee catching or mechanical discomfort
• Reduced confidence in the joint
• Difficulty returning to running or pivoting activities

The symptoms can overlap with meniscus injuries, ligament problems, or early degenerative changes. That is why the diagnosis must match both the examination and the imaging findings.

How I Evaluate a Patient for Mosaicplasty

When I evaluate someone for cartilage restoration, I do not focus only on the cartilage hole. I assess the whole knee environment, because cartilage surgery tends to do better when the surrounding conditions are also favorable.

Key parts of evaluation

• History of injury, pain, swelling, and activity limits
• Examination for tenderness, swelling, motion, and mechanical symptoms
• Ligament stability
• Meniscal status
• Limb alignment
• MRI to define the cartilage defect
• X-rays and sometimes long-leg alignment films when needed [1][2][4]

This full assessment matters because a cartilage graft alone may not succeed well if the knee also has untreated malalignment, instability, or major meniscal deficiency.

How Is Mosaicplasty Different From Microfracture or Knee Replacement?

This is one of the most important practical questions.

Mosaicplasty vs microfracture

Microfracture is a marrow stimulation technique that encourages repair tissue to form. Mosaicplasty, by contrast, transfers actual plugs of healthy cartilage and bone into the defect. In selected smaller lesions, osteochondral autograft procedures can offer durable results because they place native hyaline cartilage into the damaged area. [2][5][6]