Cartilage Surgery

What Is Articular Cartilage and Why Is It Important?

Articular cartilage (also known as hyaline cartilage) is a highly specialized connective tissue that covers the joint surfaces of bones. Its smooth surface minimizes friction, allowing joints to move comfortably, while also absorbing the impact generated during activities such as walking and running. Healthy cartilage is essential for the knee to remain pain-free and functional for many years.

Focal Cartilage Defect vs. Widespread Osteoarthritis: Cartilage surgery generally targets a condition different from knee osteoarthritis, in which the cartilage is worn down and thinned extensively over a large area. What is being discussed here are full-thickness or near-full-thickness cartilage losses in a limited area (focal defects), located in a specific region of the knee where the surrounding cartilage is relatively intact.

The Goal of Cartilage Surgery: The primary goal of these surgical methods is to;

• Repair or regenerate the damaged cartilage area,
• Reduce pain and improve knee function (movement, weight-bearing),
• Prevent or delay the progression of cartilage damage into widespread osteoarthritis.

Why Does Cartilage Damage (Focal Defect) Occur in the Knee?

Cartilage damage in a limited area generally occurs for the following reasons:

• Acute Trauma: Direct blows to the knee, falls, or sudden twisting of the knee can cause fractures or tears in the cartilage (chondral or osteochondral fractures—involving the cartilage together with the underlying bone). This is frequently associated with sports injuries.
• Repetitive Microtrauma: Continuous abnormal loads on the knee or repeated minor impacts can lead to wear and localized damage in the cartilage over time.
• Osteochondritis Dissecans (OCD): Seen especially in children and adolescents, this is a condition in which the blood supply to the bone fragment underlying the cartilage is disrupted, causing the fragment to separate or become loose within the joint along with the cartilage.
• Associated Injuries: Conditions such as meniscus tears or ligament injuries (especially of the anterior cruciate ligament) can disrupt the biomechanics of the knee, causing excessive load on the cartilage in certain areas and leading to damage over time.

Risk factors include being young and active, and participating in contact sports or high-impact sports.

What Are the Symptoms of Cartilage Damage?

The symptoms of focal cartilage damage vary depending on the location, size, and depth of the damage. Common symptoms include:

• Pain: Usually sharp or stabbing pain localized over the damaged area. Pain increases especially with weight-bearing, twisting, or movements that apply pressure to the affected region.
• Catching, Locking, or Popping Sensation: A damaged or loose cartilage fragment becoming trapped during joint movement can cause a sudden catching, locking, or popping sensation in the knee.
• Swelling: Recurrent swelling (effusion) in the knee, especially after activity.
• Noise (Crepitus): Friction or grinding sounds from the knee during movement.
• Feeling of Instability: A feeling of the knee giving way may rarely be seen as well.

Since these symptoms can be confused with other knee problems, it is necessary to consult a specialist physician for an accurate diagnosis.

How Is Cartilage Damage Diagnosed?

Prof. Dr. Murat Bozkurt uses the following methods to diagnose focal cartilage damage:

• Detailed Patient History: Information is gathered on how the injury occurred, when and how the symptoms began, and which movements aggravate the complaints.
• Physical Examination: Tender points in the knee, swelling, range of motion, crepitus, signs of locking, and ligament stability are carefully evaluated.
• X-ray: Usually the first imaging study ordered. It does not directly show small cartilage damage, but it can reveal bone fractures, loose bone fragments (joint mice), Osteochondritis Dissecans, or narrowing of the joint space (in advanced stages). It provides information about the general condition of the knee.
• Magnetic Resonance Imaging (MRI): The most valuable method for diagnosing focal cartilage damage. MRI;
  
  • Clearly shows the location, size, and depth of the cartilage defect.
  • Evaluates the condition of the bone beneath the cartilage (bone marrow edema, etc.).
  • Detects other associated pathologies such as meniscus or ligament injuries. It is indispensable for surgical planning.
• Diagnostic Arthroscopy: Rarely, in patients who cannot be diagnosed by other methods or in whom surgery is planned, direct visualization and evaluation of the cartilage surfaces may be required by looking inside the knee joint with a small camera (arthroscopy). Arthroscopy can also be therapeutic.

Knee Cartilage Surgery Options

There are various techniques for the surgical treatment of focal cartilage damage, selected based on the size, location, and depth of the damage, as well as the patient’s age, activity level, and expectations. Prof. Dr. Murat Bozkurt determines and applies the most suitable method for his patients in Ankara:

1. Debridement and Lavage (Cleaning):
   
   • Principle: Using arthroscopy to enter the joint, loose fragments that have broken off or are about to break off from the damaged cartilage are removed, and irregular cartilage edges are trimmed.
   • Who Is It For? Generally performed for small, partial-thickness (not full-thickness) damage, or solely to relieve symptoms.
   • Advantage/Disadvantage: A simple procedure that can provide temporary relief, but it does not repair or regenerate the cartilage.
2. Bone Marrow Stimulation Techniques (Microfracture / Nanofracture):
   
   • Principle: Small holes (microfracture) or holes made with finer needles (nanofracture) are created arthroscopically in the bone beneath the damaged cartilage area. Blood and bone marrow stem cells (including MSCs) that seep from these holes form a blood clot in the damaged area, and over time this clot transforms into repair tissue called “fibrocartilage.”
   • Who Is It For? Generally preferred for small (< 2-4 cm²) full-thickness cartilage damage in young patients.
   • Advantage/Disadvantage: A single-session, arthroscopic, relatively low-cost method. However, the resulting fibrocartilage is not as durable or smooth as the original hyaline cartilage, and its long-term durability may be limited.
3. Osteochondral Autograft Transplantation (Mosaicplasty / OAT):
   
   • Principle: Cylindrical, healthy tissue plugs (grafts) containing both cartilage and the underlying bone, taken from the non-weight-bearing areas of the patient’s own knee (generally the edges of the knee), are transplanted into the damaged cartilage area in a mosaic pattern.
   • Who Is It For? Generally effective for medium-sized (approximately 1-4 cm²) full-thickness cartilage damage.
   • Advantage/Disadvantage: Fills the damaged area with original hyaline cartilage. It is a single-session procedure. However, the amount of graft that can be harvested is limited, so it cannot be applied for very large defects. Pain or problems may occur at the graft harvest site (donor site).
4. Osteochondral Allograft Transplantation:
   
   • Principle: Similar to mosaicplasty, a graft containing cartilage and bone is used, but this graft is not taken from the patient but is obtained from a cadaveric donor (allograft) of appropriate size supplied by a tissue bank.
   • Who Is It For? Generally preferred for large (> 3-4 cm²) cartilage damage, in cases where mosaicplasty is not suitable or previous surgeries have failed.
   • Advantage/Disadvantage: Offers the ability to fill large defects with original hyaline cartilage in a single piece. There is no donor site issue. However, finding a suitable graft can take time, the cost is high, and there is a very low but nonzero risk of disease transmission or tissue rejection.
5. Autologous Chondrocyte Implantation / Transplantation (ACI / MACI):
   
   • Principle: This is a two-stage method:
     
     • Stage 1: A small cartilage sample (biopsy) is taken arthroscopically from a healthy area of the patient’s knee. These cartilage cells (chondrocytes) are cultured and expanded in the laboratory using special methods (approximately 3-6 weeks).
     • Stage 2: In a second operation (open or arthroscopic), millions of cartilage cells cultured in the laboratory are placed into the damaged area. These cells are implanted either under a membrane (periosteal or collagen membrane) (ACI) or seeded onto a special carrier scaffold (matrix) (MACI – Matrix-Associated ACI).
   • Who Is It For? Generally considered for young patients with large (> 2-4 cm²) full-thickness cartilage damage, in cases where other methods have failed or are not suitable.
   • Advantage/Disadvantage: Offers the potential to repair large defects with the patient’s own cells and to form hyaline-like cartilage. However, it requires two operations, is technically demanding, is costly, and the rehabilitation process is very long and critical.

Surgical Choice, Risks, Benefits, and the Critical Recovery Process

Many factors are taken into account when deciding which cartilage surgery method to apply: the size, location, and depth of the damage, the patient’s age, weight, activity level, and expectations, other knee problems (ligament injury, meniscus damage, alignment disorder), and the surgeon’s experience.

• Benefits: A successful cartilage surgery aims to reduce pain, improve knee function (relieving mechanical symptoms such as catching and locking, improving movement), and slow the progression of osteoarthritis in the long term.
• Risks: As with any surgical procedure, general risks such as infection, blood clotting (DVT), anesthesia risks, and knee stiffness exist. Method-specific risks include failure of the repair, displacement or dissolution of the graft, problems at the graft harvest site in mosaicplasty, excessive cell growth (hypertrophy) in ACI/MACI, or inadequate repair tissue. Sometimes symptoms may not completely resolve, or a second operation may be required.
• Recovery Process (VERY IMPORTANT!):
  
  • The recovery process after cartilage surgery is long, requires patience, and is critically important for the success of the treatment.
  • Depending on the technique applied, generally a long period (6-12 weeks or more) of non-weight-bearing or very restricted weight-bearing on the knee is required after surgery. Crutches are used during this period.
  • To support the healing and maturation of the repaired cartilage, knee movement exercises are usually performed with special devices called a CPM (Continuous Passive Motion) machine.
  • An intensive and long-term physical therapy program is essential. Range of motion, muscle strength, balance, and coordination exercises are carried out with a physiotherapist.
  • Return to normal daily activities takes months. Return to high-impact sports such as running and jumping generally takes 9-18 months or longer and may not always be possible.
  • The patient’s strict adherence to the rehabilitation protocol is essential for the success of the surgery.

Knee Cartilage Surgery in Ankara and Prof. Dr. Murat Bozkurt’s Approach

Focal cartilage damage in the knee is a complex condition that requires accurate diagnosis and treatment planning. The treatment of such injuries should be performed by an orthopedic surgeon who is experienced and specialized, particularly in surgical methods. In Ankara, Prof. Dr. Murat Bozkurt offers patients modern and personalized treatment options in this field.

Prof. Dr. Bozkurt’s approach to cartilage surgery:

• Precise Diagnosis: Clearly determining the type, size, and location of the cartilage damage and any associated problems through the patient’s history, a detailed physical examination, and especially high-resolution MRI.
• Individualized Surgical Selection: Choosing the most appropriate surgical technique (microfracture, mosaicplasty, allograft, ACI/MACI, etc.) based on the patient’s age, activity level, expectations, and characteristics of the damage, and thoroughly informing the patient about these options.
• Meticulous Surgical Technique: Applying the chosen cartilage repair or regeneration technique with current surgical principles and high precision.
• Managing Rehabilitation: Planning the postoperative rehabilitation process—which is as important as the surgery itself—guiding the patient, and monitoring the process in close collaboration with physiotherapists.

Prof. Dr. Murat Bozkurt supports patients with knee cartilage damage in Ankara with his expertise and experience, from diagnosis through surgical treatment and the subsequent long rehabilitation process.

Focal cartilage damage in the knee is a condition that can cause pain and loss of function but can be treated with modern surgical techniques. A successful outcome requires an accurate diagnosis, selection of the appropriate surgical method, and, most importantly, a long rehabilitation process carried out with patience. You can contact Prof. Dr. Murat Bozkurt for an expert opinion on this matter in Ankara.

For detailed information and appointments, you can contact Prof. Dr. Murat Bozkurt at 0312 502 70 74.