Introduction
Cartilage is a stiff but flexible tissue that aids in the proper functioning of joints. A joint is a point where the ends of two or more bones meet. A synovial joint is the most common form, allowing for much movement. For example, the knee, elbow, hip, ankle, and wrist are synovial joints. A thin layer of articular cartilage covers the bones that meet at synovial joints.
What Are the Components of a Synovial Joint?
At the end of each bone in the joint, articular cartilage creates a smooth, resilient covering (nearly like linoleum). Fluid from the synovial joints lubricates this cartilage, allowing the opposing bones to glide over one another quickly and with little friction—for example, when the knee or elbow bends.
How Do Articular Cartilage Injuries Occur?
Injury or misuse can degrade articular cartilage, which is robust and capable of carrying enormous loads and withstanding decades of use. Articular cartilage injuries can be caused by a variety of factors, including:
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Sports injuries or a fall can cause forceful impacts on the joint.
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Repeated, minor hits on the joint.
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When the foot is placed, twist a joint while carrying weight, such as the knee.
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Wear and tear accumulated over time, frequently over several decades of use.
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Due to a congenital (meaning "from birth") defect or a past injury, joints are misaligned.
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The knee is the most typical site for articular cartilage injuries, but they can also affect the hip, ankle, shoulder, and ankle.
The damage is usually limited to the thin layer of articular cartilage at the end of a bone, known as a chondral injury or chondral defect. Chondral wounds seldom heal effectively on their own, partly because articular cartilage lacks a blood supply, which aids healing.
What Are the Signs and Symptoms of Articular Cartilage Injuries?
Articular injuries can result in a variety of symptoms, such as:
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Swelling and pain in the joint.
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When bending or moving the joint, there is a "catching" sensation.
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Turning or moving the joint makes a crackling, grating, or crackling sound and sensation.
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Locking of the joints (an inability to fully extend or flex the joint)
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Feeling as if the joint is about to give way or feels unsteady.
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Stiffness.
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The range of motion is limited.
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Some articular injuries have no symptoms at all.
How Are Articular Cartilage Injuries Diagnosed?
Obtaining a medical history, completing a physical exam, and ordering one or more diagnostic tests are typically used to diagnose cartilage injuries and damage. Pain and other symptoms in and around the afflicted joint will be discussed with the doctor. They might also inquire about previous surgeries, whether any specific accident caused the symptoms, and the types of physical activity you usually engage in. The doctor will examine how the joint moves during the physical examination. They may bend and rotate the joint to assess pain, edema, range of motion, and ligament stability. They may also instruct the patient to make specific movements; for example, if the knee is injured, the patient may be instructed to squat, walk, or "duck walk."
A weight-bearing X-ray and a magnetic resonance imaging (MRI) study are two imaging investigations that may be required. A clinician can use these tests to detect and assess any injury to the articular cartilage, underlying bone, surrounding tissues, and ligaments.
Weight-bearing X-rays in arthritis patients with severe cartilage loss will show the bones touching one another.
Arthroscopy may be used to diagnose articular cartilage damage or injury. Arthroscopy is a minimally invasive surgical procedure in which a surgeon makes one or two small incisions on the skin around the afflicted joint and inserts an arthroscope—a thin, pencil-sized tube with a camera and surgical equipment into the joint. The camera sends a video of the inside of the joint to a monitor, allowing the surgeon to examine the joint's architecture and tissues.
How Are Articular Cartilage Injuries Treated?
There are a variety of non-surgical and surgical treatments and therapies available.
The kind and severity of the articular cartilage damage, the patient's age and overall health, physical activity level, intended post-treatment activities, and the type and severity of the articular cartilage injury all influence treatment options.
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Non-Surgical Treatments: These are used to alleviate symptoms and halt or prevent cartilage deterioration. Non-surgical treatments can enhance the quality of life by reducing pain and increasing strength and mobility, but they cannot restore articular cartilage degeneration. They are frequently utilized in the aftermath of an injury or when cartilage loss is severe, such as arthritis.
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Resting.
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To minimize swelling, apply ice to the affected joint for 15 minutes every one or two hours.
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To minimize swelling, elevate the joint.
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To relieve discomfort and swelling, take over-the-counter anti-inflammatory drugs such as Acetaminophen.
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Sports and activities that cause pain or require substantial use of the afflicted joint should be avoided.
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Unloading (or reducing the weight on) the cartilage damage with an unloader brace.
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Injections of corticosteroids to relieve inflammation and pain.
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Viscosupplementation: It is a treatment in which a physician injects hyaluronic acid into the afflicted joint. This lubricates the afflicted joint, reducing friction and pain between the joint's bones. A doctor will frequently send a patient to a physical therapist, who will create an exercise and stretching program for the patient. The goal is to improve joint stability and range of motion by strengthening the muscles surrounding the afflicted joint.
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Surgical Intervention: Surgery is frequently the best therapy choice because injured articular cartilage does not mend effectively.
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Some surgeries are performed to alleviate symptoms, while others are performed to repair and restore damaged articular cartilage.
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Arthroscopic surgery is used to treat articular cartilage injuries in most instances.
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It is important to note that articular cartilage repair techniques are not intended to treat the significant cartilage loss associated with osteoarthritis.
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Microfracture Surgeries: Under the injured articular cartilage, the surgeon drills tiny holes in the bone and bone marrow. These holes cause the bone to self-heal, prompting bone marrow cells to mend the damaged cartilage. However, the freshly generated cartilage tissue is fibrocartilage. While this fibrocartilage can prevent the bones in a joint from rubbing against each other, it is not as practical or long-lasting as usual, healthy articular cartilage.
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Mosaicplasty or Osteochondral Autograft: A small plug of healthy articular cartilage and underlying bone is removed from a non-weight-bearing region of the joint during this treatment. The plug (or numerous plugs) is inserted at the site of the injury, where a small hole has been bored. The smooth surface of the articular cartilage is restored during this process, allowing the joint to move freely and painlessly. Because there are just a few non-weight-bearing places in the knee from which plugs can be extracted, the amount of cartilage loss that can be corrected this way is limited.
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Allograft of the Chondral Bone: This method is similar to the osteochondral autograft described above, except that it employs cadaveric tissue (a donor). It is beneficial for healing severe articular cartilage injuries; nevertheless, the transplanted cartilage is not as long-lasting as the patient's own.
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Implantation of Autologous Chondrocytes (ACI): A surgeon removes healthy articular cartilage from a non-weight-bearing region of the joint during this surgery. The cells in this tissue, known as chondrocytes, are collected and cultured in a laboratory over several weeks. The physician implants chondrocytes into the injured articular cartilage and covers the area with a patch or adhesive in a second surgical procedure. After that, the chondrocytes produce new cartilage.
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Matrix Autologous Cartilage Implantation (MACI): With one exception, this process is comparable to ACI. MACI takes a similar strategy. However, only the chondrocytes are grown on a collagen membrane (also known as a matrix or scaffold) that is later inserted into the injured articular cartilage by a surgeon.
What Is the Prognosis for People with Articular Cartilage Injuries?
Patients with these injuries have a good prognosis, albeit not everyone can resume all activities. Both non-surgical and surgical treatments can help to ease pain and suffering. Surgical methods can efficiently repair and restore articular cartilage when it is damaged.
Healthy people under 40 who have minor articular cartilage injuries have the most excellent prognosis and can typically return to pre-injury activities. However, only some patients are good candidates for cartilage replacement. Therefore, these procedures are ideal for those under 50 who are active.
Conclusion
Articular cartilage injuries can progress to osteoarthritis, a disorder in which the articular cartilage wears away, revealing the underlying bone if left untreated. Osteoarthritis may necessitate joint replacement surgery.
