Orthobiologic Treatment for the Knee

What Is Orthobiologic Treatment?

Orthobiologics is a branch of regenerative medicine that uses biological materials to support the healing of musculoskeletal system (bone, cartilage, ligament, tendon, muscle) injuries or degenerative conditions. The goal of these treatments, by harnessing the body’s own healing potential, is to;

• Reduce inflammation,
• Relieve pain,
• Promote or support the repair of damaged tissue,
• and, in some cases, delay the need for more advanced surgical interventions.

Unlike conventional drug treatments (painkillers, anti-inflammatories) and surgical methods, orthobiologic treatments generally use cells, growth factors, or other bioactive molecules obtained from the patient’s own body (autologous) or from other biological sources.

Main Orthobiologic Methods Used in the Knee

The orthobiologic treatment methods most frequently mentioned for knee joint problems are as follows:

• PRP (Platelet Rich Plasma – Platelet-Rich Plasma):
  
  • How Is It Obtained? It is obtained by drawing a small amount of blood from the patient’s own arm and spinning it at high speed in a special device called a centrifuge to separate it into its components. This process concentrates the platelets (the blood’s clotting cells) and the plasma portion.
  • What Does It Contain? Platelets contain numerous “growth factors” and other bioactive proteins that initiate and regulate tissue healing.
  • Mechanism of Action (Proposed): By injecting concentrated platelets and growth factors into the damaged area, the aim is to suppress local inflammation, stimulate cells to begin repair processes, and reduce pain. PRP is thought to act by improving the existing tissue environment rather than directly forming new tissue.
• “Stem Cell” Therapies (Require a Careful and Realistic Approach):
  
  • What Is It? This term generally refers to “Mesenchymal Stem Cells (MSCs),” which have the potential to transform into different cell types in the body and to self-renew. In knee treatments, these cells are most commonly obtained from bone marrow or adipose (fat) tissue.
  • Sources:
    
    • Bone Marrow Aspirate Concentrate (BMAC): This is the portion of bone marrow, usually collected from the pelvic bone (iliac crest) under local anesthesia, that has been centrifuged and enriched in stem cells and other regenerative cells. It contains not only stem cells but also various growth factors and other cells.
    • Adipose-Derived Stem Cells: These are obtained by taking adipose tissue from the abdomen or hip area using a mini-liposuction-like method and processing it to isolate the stem cells.
  • Mechanism of Action (Current Understanding): Although it was previously thought that stem cells would directly transform into damaged cartilage and regenerate it, current scientific understanding is that when these cells are injected into the knee, they primarily exert a signaling (paracrine) effect. In other words, these cells secrete various molecules into their surrounding environment that suppress inflammation, favorably influence the behavior of other cells, and may help reduce pain. Strong and definitive scientific evidence that injected stem cells produce a meaningful amount of new cartilage in knee osteoarthritis or severe cartilage damage is still limited. Research in this area is continuing intensively.
  • Important Note: It should be noted that some products marketed as “stem cell therapy” (for example, products derived from amniotic fluid or cord blood that do not contain living stem cells) can be misleading. The effect of these products may be limited mostly to the growth factors and hyaluronic-acid-like substances they contain.
• Other Biological Treatments: In addition to the above, there are other biological approaches, such as special serums prepared from the patient’s own blood, like Autologous Conditioned Serum (ACS or Orthokine), or purified amniotic fluid products.

In Which Knee Conditions May Orthobiologic Treatments Be Considered?

The effectiveness of orthobiologic treatments varies depending on the condition being treated, the severity of the disease, the method used, and the patient’s individual characteristics. Potential areas of application are as follows:

• Knee Osteoarthritis (Gonarthrosis): Particularly in mild-to-moderate osteoarthritis, PRP injections can produce results similar to, or sometimes superior to, cortisone or hyaluronic acid injections in reducing pain and improving function. The role and long-term effectiveness of stem cell treatments (BMAC, fat-derived) in this area are still being researched; the focus is generally on pain and function, and cartilage regeneration should not be expected.
• Cartilage Damage (Focal Defects): Their use, alone or as an adjunct to surgical methods (such as microfracture or cartilage transplantation), is being investigated for limited, non-extensive cartilage damage.
• Tendon Injuries and Diseases (Tendinopathy): PRP injections are frequently used to support healing and reduce pain in chronic tendon strains such as the tendon below the kneecap (patellar tendinopathy – Jumper’s Knee) or the tendon above it (quadriceps tendinopathy).
• Ligament Injuries: PRP use may be considered to accelerate healing, particularly in partial medial collateral ligament (MCL) tears, although this is not a routine application.

It should be remembered that not every case of knee pain or osteoarthritis is suitable for these treatments. Proper patient selection is of great importance.

How Is Orthobiologic Treatment Performed?

The procedure is usually performed in an outpatient clinic or office setting:

1. Preparation: If autologous (the patient’s own tissue) methods such as PRP or BMAC will be used, blood is drawn from the patient (for PRP) or bone marrow is aspirated under local anesthesia (for BMAC). Mini-liposuction may be required for fat-derived cells.
2. Processing: The collected blood, bone marrow, or adipose tissue is processed under sterile conditions using special devices (such as a centrifuge) and kits, and prepared for injection. This process usually takes 20-40 minutes.
3. Injection: The prepared biological material (PRP, BMAC, etc.) is injected directly into the knee joint or the damaged tendon/ligament area, usually under ultrasound guidance or using anatomical landmarks. A mild discomfort or sensation of pressure may occur during the injection.
4. Aftercare: A short rest period is generally recommended after the injection. Pain or a feeling of fullness at the site may occur for the first few days; ice application and simple painkillers may be used. Depending on your doctor’s recommendation, you will be asked to avoid overloading the knee for a certain period and then gradually return to normal activities and exercise.

Orthobiologic Treatments: Evidence, Expectations, Limitations, and Risks

Before deciding on these treatments, it is very important to understand the potential benefits, risks, and, in particular, the limitations.

• Scientific Evidence Status:
  
  • Orthobiologic treatments are a field that is developing rapidly but is still evolving.
  • While a growing number of studies show that PRP has positive effects on pain and function in mild-to-moderate knee osteoarthritis and certain tendinopathies, the results are variable. Differences between the PRP kits and preparation protocols used can also affect the outcomes.
  • Strong and consistent evidence that “stem cell” treatments (particularly MSCs) achieve cartilage regeneration in knee osteoarthritis is still limited. Existing studies have focused mostly on pain and function, and more research is needed for long-term outcomes.
  • Higher-quality, large-scale, randomized controlled trials are needed for many applications.
• Potential Benefits:
  
  • Reduced pain and inflammation.
  • Improved knee function and range of motion.
  • Potential delay of the need for surgery.
  • Use of the patient’s own biological materials (particularly in PRP and autologous cell treatments).
  • Generally minimally invasive (small-scale intervention).
• Limitations and Realistic Expectations:
  
  • These treatments are not a “miracle” or “definitive solution,” especially for conditions such as advanced-stage osteoarthritis.
  • They do not reliably regenerate cartilage that has already been lost.
  • Effectiveness can vary significantly from person to person and depending on the method used.
  • The benefits obtained may be temporary, and repeat injections may be required.
  • Cost: These treatments are generally not covered by the Social Security Institution (SGK) or private insurance and can be costly.
  • A full standardization of application protocols (cell count, preparation method, etc.) has not yet been achieved.
• Risks:
  
  • They are generally considered low risk, especially PRP prepared from the patient’s own blood.
  • The most common side effects are temporary pain, swelling, or bruising at the injection site.
  • The risk of infection is low but present with every injection procedure.
  • Rarely, nerve or vascular damage and allergic reactions may occur.
  • Bone marrow aspiration (for BMAC) or liposuction (for fat-derived cells) procedures carry their own small risks (pain, bleeding, infection).
  • One of the most important risks is that the treatment may be ineffective.

Orthobiologic Treatments for the Knee in Ankara and Prof. Dr. Murat Bozkurt’s Approach

With the growing interest in orthobiologic treatments, the number of centers offering these methods in Ankara has also increased. However, the success of these treatments depends on proper patient selection, the use of appropriate technique, and realistic expectations.

When evaluating orthobiologic treatment options for knee problems in Ankara, Prof. Dr. Murat Bozkurt adopts the following principles:

• Evidence-Based Approach: He bases his treatment recommendations on current, reliable scientific literature. He accurately informs his patients about methods that do not yet have sufficient evidence or whose effectiveness is questionable.
• Detailed Evaluation and Proper Patient Selection: Each patient’s situation (age, activity level, disease stage, accompanying conditions) is thoroughly evaluated to determine whether orthobiologic treatment will genuinely provide benefit. Not every case of knee pain is suitable for these treatments.
• Setting Realistic Expectations: He clearly explains the treatment’s limitations and possible risks, without exaggerating its potential benefits. He avoids “miracle treatment” promises.
• Viewing It as Part of a Comprehensive Treatment Plan: He generally regards orthobiologic treatments not as a stand-alone solution, but as part of a holistic treatment plan that may include other conservative methods such as weight loss, exercise, and physical therapy, or that can be used as a bridge before surgery.
• Standard and Reliable Application: If orthobiologic treatment is decided upon, he performs or directs the preparation and injection procedures using standard, reliable, and sterile methods.

According to Prof. Dr. Bozkurt, orthobiologic treatments can be a valuable tool in managing knee problems in selected patients and with the correct indications, but they are not a cure-all. If you are considering these treatments, he emphasizes that you should be sure to consult a specialist physician to learn whether they are suitable for you and what you should expect.