Cartilage Transplantation - Indications, Contraindications, Procedures, and Complications

Introduction

Cartilage is a connective tissue that protects and cushions the bones and joints. Cartilage also lines the joint's bone surfaces and helps reduce friction due to movement. Damage to the cartilage may occur suddenly due to injury or trauma, or it may also happen over time as the cartilage wears and tears, resulting in osteoarthritis. Since the cartilage has no nerve endings, damage is only noticed when it becomes severe. Cartilage damage may cause pain, swelling, and reduced mobility of the joints.

What Is Cartilage Transplantation?

Cartilage transplantation is also known as cartilage implantation or chondrocyte transplantation. Cartilage transplantation is an innovative surgical procedure in which cartilage defects are repaired with cartilage cells forming the patient’s body. During cartilage transplantation, healthy cartilage cells and tissues are harvested from a healthy site in the patient’s body or a donor and then transplanted into the damaged area. Cartilage transplantation is most frequently done in the knee. Shoulder, ankle, and elbow are also treated with cartilage transplantation in the earlier stages of joint damage.

What Are the Indications for Cartilage Transplantation?

Cartilage transplantation is indicated in the following cases.

• Younger Patients - Patients who are less than 50 years of age and are highly active are considered for cartilage transplantation to preserve the joint and postpone more invasive joint replacement surgery. It is also indicated for older patients in whom joint replacement is contraindicated.

• Osteoarthritis - It is a common joint condition in which there is a breakdown of cartilage, resulting in chronic pain.

• Trauma - Traumatic injuries such as sports injuries and motor vehicle accident injuries are also treated using cartilage transplantation.

• Condition of the Joint - The joint should be stable with intact ligaments. No loose bodies or tissues should be separated due to cartilage defects. The defect should be in one of the surfaces and should be focal.

• Failure of Non-surgical Management - Cartilage transplantation is considered in patients whose symptoms did not improve with conservative treatments like physiotherapy, medications, injections, etc.

What Are the Contraindications for Cartilage Transplantation?

Cartilage transplantation is contraindicated in the following conditions.

• Severe or Advanced Osteoarthritis - Cartilage transplantation is only effective in patients with focal cartilage defects. In advanced osteoarthritis cases, cartilage transplantation cannot correct excessive cartilage defects.

• Smoking - Cartilage transplantation is contraindicated in smoking patients since smoking increases the risk of complications after surgery and also impairs the healing process.

• Inflammatory Arthritis - Inflammatory arthritis can affect the success of the procedure. Some examples of inflammatory arthritis include psoriatic arthritis and rheumatoid arthritis.

• Infection - The presence of an active infection in the surrounding tissues and the joint causes an increased risk for infection when the procedure is done.

• Steroids - Patients who are under chronic steroid use are contraindicated for cartilage transplantation. Steroids increase the risk of osteonecrosis (death of a bone area due to restricted blood supply)

• Obesity - Excess weight can put additional stress on the joints and may decrease the long-term success of cartilage transplantation.

• Other Conditions - Elderly patients, patients with severe systemic diseases, and patients with pronounced X or O legs are also contraindicated for cartilage transplantation.

What Are the Different Types of Cartilage Transplantation Procedures Done?

• Autologous Chondrocyte Implantation:

The autologous chondrocyte implantation procedure has two steps. In the first step, an arthroscopic procedure takes cartilage cell biopsy from a non-critical joint area. These cartilage cells (chondrocytes) are then cultured in the laboratory to produce more cells required for transplant. In the second step, the cultured cartilage cells are implanted into the defective areas through a surgical procedure. This technique is ideally done for lesions less than two centimeters (cm) in dimension.

• Osteochondral Autograft Transplantation:

In osteochondral autograft transplantation, cartilage is harvested from a noncritical area of the patient's joint and then immediately transplanted into the defective area of the joint. This procedure is done in a single sitting using an arthroscopic method. It cannot be done for lesions larger than two cm.

• Osteochondral Allograft Transplantation:

In osteochondral allograft transplantation, the cartilage graft is obtained from another person (donor), shaped into the patient’s requirement, and then transplanted into the area of defective cartilage.

• Microfracture:

This is a minor procedure in which the defective cartilage is shaved, or small holes are made in the damaged area. This procedure mechanically stimulates the underlying bone marrow and bone to produce new cartilage cells. Microfracture is minimally invasive.

• Meniscus Transplantation:

Meniscus transplantation is done in patients in whom the meniscus had been completely removed in previous surgeries. The patient is transplanted with a donor meniscus to reduce joint pain. This is done with arthroscopy and is minimally invasive. Rejection of graft is very rare in cartilage transplantation.

What Should Be Done After Cartilage Transplantation Surgery?

• The patient is required to avoid weight bearing for about six to eight weeks.

• The joint should be moved without bearing any weight.

• Mild physiotherapy is included in the post-surgical care.

• Stressful sports should be avoided for about one year.

What Are the Complications Associated With Cartilage Transplantation?

Complications after cartilage transplantation are relatively rare. Some of the possible complications include.

• Common complications after surgery, such as bleeding, infection, pain, and damage to surrounding tissues, may be present, but these complications are reduced when a skilled specialist does the procedure.

• Graft failure is a risk associated with cartilage transplantation, which can lead to pain, reduced function, and the need for further surgeries.

• Swelling and stiffness of the joint may require further management, like physiotherapy.

• Blood clots may develop in some cases.

• In rare cases, allergic reactions to medications or other substances used during surgery may occur.

What Are the Positive Outcomes of Cartilage Transplantation?

Some of the positive benefits of cartilage transplantation include:

• Improved joint function by restoring the damaged cartilage.

• Minimally invasive procedures and shorter recovery times are great advantages of cartilage transplantation procedures.

• Reduced need for joint replacement by preventing or delaying it in some patients.

• Long-term improvements in pain and function are seen in many patients.

• Donor site morbidity is avoided since the cells are often not harvested from another part of the body.

Conclusion

Cartilage transplantation can be an effective treatment option for many patients with cartilage damage or degeneration. The procedure is complex and requires specialized doctors. Outcomes of cartilage transplantation may vary depending on a variety of factors.