Cartilage Treatment

What is cartilage??

Cartilage, the joint cartilage, is a highly specialized structure designed to bear load in the joint for many years and enable painless movement. It acts as a cushion by covering the surfaces of the bones that make up the joint and face each other.

How does cartilage damage (injury) occur in the knee?

Joint cartilage can be damaged in various ways. Over the years, it becomes worn out, softens first, then frays and flakes off, revealing the underlying bone. This condition, commonly known as “osteoarthritis” or “arthritis,” is the result of wear and tear that occurs with age. This widespread wear and tear cannot be reversed, and it requires medication and eventually surgical treatments. Currently, there is no known treatment method that can regenerate cartilage for osteoarthritis. However, in young individuals, localized damage to the joint cartilage can occur, especially during sports-related impacts. In such cases, treatments that regenerate the damaged portion of the joint cartilage can be performed since only a portion of the cartilage is damaged, while the rest is healthy. The ability of joint cartilage to heal in adults is minimal. Unlike other tissues in the body, joint cartilage does not regenerate itself after injury. Surgical interventions are necessary to stimulate a healing response in the cartilage. Another form of damage occurs as a result of a condition called “osteochondritis dissecans,” where the bone beneath the joint cartilage becomes detached due to a nutritional disorder, resulting in cartilage damage.

What are the symptoms of cartilage damage (injuries)?

The most significant symptom of cartilage damage in young and older individuals is pain focused on the affected area of the joint. Swelling may occur in the joint due to an increase in synovial fluid. This swelling increases with activity or sports and decreases with rest. It can cause complaints such as joint locking, catching, or jamming. If a piece is detached, patients may feel a loose piece floating inside the joint, which is referred to as a “joint mouse.” In cartilage injuries larger than a certain size, the weight-bearing properties of the joint may be compromised, leading to the development of osteoarthritis over time.

How is the diagnosis made in cartilage tissue damage (injury)?

If your doctor suspects cartilage damage based on your medical history and a detailed examination, they will resort to imaging techniques. First, X-ray images are taken. This provides an idea about the bone structures that make up the joint and can help diagnose a previous fracture or osteochondritis dissecans. Signs of dislocations involving the joint can also be detected. Subsequently, if deemed necessary by your doctor, magnetic resonance imaging (MRI) of the relevant joint can be performed. MRI can easily confirm significant and full-thickness cartilage tissue damage. However, standard MRI may not always be successful in diagnosing partial-thickness cartilage injuries. In certain cases, your doctor may request an MRI arthrography examination, which involves the injection of contrast material into the joint or directly into the bloodstream. If other symptoms strongly suggest cartilage injury, your doctor may recommend arthroscopy for both diagnosis and treatment purposes. Arthroscopy can provide a definitive diagnosis of cartilage damage.

What are the treatment options for cartilage damage?

In cases where the cartilage damage in the non-weight-bearing area of the joint is smaller than 1 cm2 and does not cause any symptoms, it can be monitored periodically. However, if the damage is symptomatic, located in the weight-bearing area, and larger than 1 cm, cartilage treatment is necessary. Options such as medication, supplements like glucosamine, physical therapy methods, and intra-articular hyaluronic acid injections can be tried, but they do not have curative properties and only provide temporary relief of symptoms. In young adults, surgical intervention is the treatment for cartilage injuries. The treatment usually begins with arthroscopy and if there are other accompanying problems within the joint, they are also addressed. Subsequently, a procedure specific to the cartilage can be performed either arthroscopically or through open surgery.

Cartilage Surgery (Microfracture Method)

This is a cartilage surgery performed for limited and smaller (less than 3 cm2) cartilage injuries. After the damaged area is cleaned from cartilage debris, holes are created in the bone at intervals of 5 mm and extending a few millimeters in depth. These holes allow access for the stem cells from the bone marrow to reach the damaged area. Stem cells that settle into the blood clot formed in the damaged area have the ability to transform into cartilage-like cells when provided with a suitable environment. In recent years, roof implants called matrices have been developed to improve the adherence and organization of the blood clot to the damaged area. These tissue-like structures, mostly made of collagen, can be attached to the damaged area after microfracture. During the period until the formation of new cartilage-like tissue, it is necessary to protect the joint from loading by using crutches for six to eight weeks after the surgery. Similarly, during the postoperative period, which lasts for a few weeks, a continuous passive motion (CPM) device that slowly and controlledly moves the joint is used to promote the formation of the repaired cartilage tissue. This device can be rented and used at home if necessary. The advantages of the microfracture method include being an easy and inexpensive technique for both the patient and the physician, requiring only one surgery, and being performed with arthroscopy. It is often the preferred method for small-scale cartilage damage. However, the most significant disadvantage of the technique is that the resulting repair tissue is “cartilage-like.” This tissue is different from normal cartilage, and it cannot be expected to function like normal cartilage for many years. In recent years, in addition to the microfracture method and matrix applications, intra-articular platelet-rich plasma (PRP) treatments have increased the success chances of these techniques to some extent.

Cartilage Surgery (Mosaicplasty Method)

Mosaicplasty is the removal of cylindrical pieces, approximately 6-8 mm in diameter and 15 mm in length, consisting of cartilage and bone from the non-weight-bearing area of the joint and their transplantation to the damaged area in the weight-bearing region. This technique is applied for injuries below 4 cm2 and is most commonly performed in the knee and ankle joints. It can be performed arthroscopically or through an open approach. The most significant advantage is the transplantation of a piece of normal cartilage with its architectural structure to the damaged area. The disadvantages include the limitation in the number of tissue grafts that can be performed and the sacrifice of normal cartilage from another part of the joint to perform the transplantation. In some cases of extensive damage, tissue may need to be taken from the healthy joint of the opposite side. Due to the nature of the technique, only 70% of the

damaged area can be filled with the transplanted cartilage, and the space between the transplanted cylinders is healed with a cartilage-like repair tissue. This technique is generally more successful in small cartilage injuries. It may be challenging to recreate the normal shape of the joint in large injury areas. The postoperative period is similar to the microfracture method.

Cartilage Surgery (Cartilage Cell Transplantation)

In recent years, the most extensively researched and scientifically advanced field is cartilage transplantation. In this technique, a few millimeters of cartilage tissue in the non-weight-bearing area of the joint is harvested using arthroscopy when cartilage damage is detected. This tissue is processed under sterile conditions in a laboratory, and the cartilage cells within it are multiplied and produced. After a few weeks of this process, the newly formed cartilage cells are transplanted to the damaged area through open surgery. In the first-generation cartilage transplantation techniques, these cells were injected under a tissue-like structure called a membrane, which was taken from the surrounding tissues and sewn under the damaged area. In recent years, in second-generation techniques, the cartilage cells are produced within a carrier tissue called a matrix, and this tissue is adhered to the damaged area after shaping. The most significant advantage of cartilage transplantation techniques is the ability to transfer the patient’s own cells to the damaged area in the desired amount without damaging any other tissues. There is no size limit, and tissue can be produced in the desired diameter and height. The newly formed cartilage tissue is much closer to normal joint cartilage. The disadvantages of the technique are the requirement for two surgeries and the high cost. Although it is a relatively new method, success rates of 80-90% have been reported in patients followed up for more than ten years worldwide. The postoperative period is similar to other techniques.

Cartilage Tissue Stem Cell Applications

This application, which is not allowed for routine use in our country legally, is only performed in clinical studies with special permission obtained from the ministry. Although the long-term results are not fully known, promising short-term outcomes have been observed in studies conducted, especially in Far Eastern countries.