Knee Chondral Injuries

What are knee chondral injuries?

Knee chondral injuries, also known as chondral lesions or cartilage injuries, represent a common orthopedic problem that can cause pain, swelling, and functional impairment in individuals of all ages. Chondral injuries involve damage to the articular cartilage that covers the ends of the bones within the knee joint, leading to a loss of its smooth surface and compromising joint function. This comprehensive discussion delves into the causes, symptoms, diagnosis, and treatment options for knee chondral injuries, providing insights into the management of this prevalent musculoskeletal condition.

What are the causes of knee chondral injuries?

Knee chondral injuries can result from various traumatic and non-traumatic factors, including:

1. Trauma: Acute trauma, such as sports-related injuries, falls, or motor vehicle accidents, can cause direct damage to the articular cartilage within the knee joint. Traumatic chondral injuries often involve a sudden impact or twisting motion that disrupts the integrity of the cartilage surface, leading to tears, fissures, or delamination.
2. Repetitive Stress: Chronic overuse or repetitive stress on the knee joint, commonly seen in athletes or individuals engaged in activities that involve running, jumping, or pivoting, can contribute to the development of chondral injuries over time. Repetitive stress may lead to cartilage degeneration, erosion, or softening, resulting in the gradual onset of symptoms such as pain and stiffness.
3. Degenerative Changes: Aging, obesity, genetic predisposition, and underlying joint conditions such as osteoarthritis can predispose individuals to degenerative changes in the articular cartilage of the knee joint. Degenerative chondral injuries involve progressive wear and tear of the cartilage surface, leading to thinning, fibrillation, and the formation of fissures or defects.
4. Meniscal Tears: Concomitant injuries to the meniscus, the fibrocartilage structures that provide cushioning and stability within the knee joint, can increase the risk of chondral damage. Meniscal tears can alter the biomechanics of the knee joint, leading to abnormal loading and increased stress on the articular cartilage surfaces.

What are the symptoms of knee chondral injuries?

The symptoms of knee chondral injuries can vary depending on the location, size, and severity of the cartilage damage. Common symptoms associated with chondral lesions in the knee include:

1. Pain: Persistent or intermittent pain within the knee joint, often exacerbated by weight-bearing activities such as walking, climbing stairs, or running. The pain may be localized to a specific area of the knee or may radiate throughout the joint.
2. Swelling: Swelling or joint effusion, characterized by the accumulation of fluid within the knee joint, may occur in response to inflammation associated with chondral injuries. Swelling may be accompanied by warmth and redness over the affected area.
3. Stiffness: Stiffness or limited range of motion in the knee joint, particularly after periods of inactivity or prolonged sitting. Individuals with chondral injuries may experience difficulty fully extending or flexing the knee joint.
4. Catching or Locking Sensation: Some individuals may experience a catching, locking, or popping sensation within the knee joint during movement, particularly when bending or straightening the knee. These symptoms may indicate the presence of loose cartilage fragments or mechanical abnormalities within the joint.
5. Instability: Instability or a feeling of “giving way” in the knee joint, especially during weight-bearing activities or movements that involve changing directions. Chondral injuries can compromise joint stability, leading to a sensation of instability or insecurity in the affected knee.

It’s essential to note that the symptoms of knee chondral injuries may worsen over time if left untreated, potentially leading to progressive joint damage and functional impairment.

How are knee chondral injuries diagnosed?

Diagnosing knee chondral injuries typically involves a combination of medical history review, physical examination, and imaging studies. During the physical examination, Dr. Shane J. Nho will assess the knee joint for signs of swelling, tenderness, and instability. Specific tests, such as the McMurray test, may be performed to evaluate for meniscal tears or other intra-articular pathologies.

Imaging studies are crucial for confirming the presence of chondral lesions and assessing their size, location, and severity. Common imaging modalities used in the diagnosis of knee chondral injuries include:

1. X-rays: X-rays provide detailed images of the bones within the knee joint and can help identify signs of osteoarthritis, joint alignment abnormalities, or underlying bone pathology. While X-rays are not typically used to visualize cartilage directly, they can provide valuable information about joint space narrowing and bony changes associated with chondral injuries.
2. Magnetic Resonance Imaging (MRI): MRI scans offer high-resolution images of the soft tissues within the knee joint, including the articular cartilage, menisci, ligaments, and synovium. MRI is considered the gold standard imaging modality for detecting chondral lesions and assessing their extent and severity. MRI can help differentiate between various types of chondral injuries, such as focal defects, fissures, or diffuse degenerative changes.
3. Diagnostic Arthroscopy: Arthroscopy is a minimally invasive surgical procedure that involves inserting a small camera (arthroscope) into the knee joint through small incisions. Arthroscopic evaluation allows direct visualization of the articular surfaces and enables the surgeon to assess the extent of chondral damage, identify concomitant intra-articular pathologies, and perform diagnostic and therapeutic interventions simultaneously.

In some cases, additional diagnostic tests such as computed tomography (CT) scans or ultrasound may be utilized to provide additional information about the knee joint’s anatomy and pathology.