Knee Cartilage Injuries

Articular cartilage covers the ends of the bones in the knee joint, enabling smooth and frictionless movement. Injuries to the articular cartilage can result from acute trauma, such as a fall or a direct blow, or from repetitive stress over time. These injuries may range from small areas of damage to more significant cartilage loss, which can lead to substantial pain and reduced mobility.

The menisci are two C-shaped pieces of cartilage located between the femur (thigh bone) and tibia (shin bone). They act as shock absorbers and provide stability to the knee joint. Meniscal tears are common in sports activities that involve twisting, turning, or sudden stops. These tears can be partial or complete and are often accompanied by symptoms such as pain, swelling, and a catching or locking sensation in the knee.

Osteochondral injuries involve damage to both the cartilage and the underlying bone. These injuries can occur due to a single traumatic event or repetitive microtrauma. They are often seen in younger athletes and can lead to the formation of loose bodies within the joint, causing pain and mechanical symptoms.

Chondromalacia patellae, also known as runner’s knee, refers to the softening and degeneration of the cartilage on the underside of the patella (kneecap). This condition is commonly seen in young athletes and people who engage in activities that place excessive stress on the knee joint, such as running or jumping. Symptoms include anterior knee pain, swelling, and a grinding sensation during knee movements.

The diagnostic process begins with a thorough clinical evaluation by the orthopaedic specialist. This evaluation includes:

• Medical History: The orthopaedic specialist will review the patient’s medical history, including any previous knee injuries, underlying conditions, and the nature of the current symptoms (e.g., onset, duration, and severity of pain, swelling, and functional limitations).
• Physical Examination: A physical examination of the knee will be conducted to assess tenderness, swelling, range of motion, and stability. The orthopaedic specialist may also perform specific tests to identify signs of cartilage damage, such as the McMurray test for meniscal tears.

Imaging studies are important for visualising the extent and location of cartilage injuries. Common imaging techniques include:

• X-rays: While X-rays are not typically used to visualise cartilage, they are useful in identifying bone abnormalities, fractures, and joint alignment issues that may accompany cartilage injuries.
• Magnetic Resonance Imaging (MRI): MRI is commonly used to diagnose knee cartilage injuries. This imaging modality provides detailed images of the knee’s soft tissues, including cartilage, menisci, ligaments, and tendons. MRI can reveal the presence and extent of cartilage damage, such as tears, lesions, and degeneration.
• Computed Tomography (CT) Scans: In some cases, a CT scan may be used to provide detailed images of the knee joint’s bony structures and to assess the alignment and integrity of the joint.

Arthroscopic examination is often considered a last resort after other imaging studies fail to provide sufficient information. This minimally invasive procedure allows the orthopaedic specialist to directly visualise and assess the inside of the knee joint. During arthroscopy, the surgeon can also perform treatments such as removing loose bodies, repairing torn cartilage, or smoothing damaged cartilage surfaces.

Non-surgical treatments are often the first line of management for knee cartilage injuries, especially for less severe cases. These methods include:

• Rest and Activity Modification: Reducing or avoiding activities that exacerbate symptoms can help relieve pain and prevent further cartilage damage.
• Physical Therapy: A structured physical therapy program can improve knee strength, flexibility, and stability. Specific exercises may target the quadriceps, hamstrings, and calf muscles to support the knee joint.
• Medications: Over-the-counter pain relievers, such as acetaminophen or nonsteroidal anti-inflammatory drugs (NSAIDs), can help manage pain and reduce inflammation. In some cases, the orthopaedic specialist may prescribe stronger medications.
• Injections: Corticosteroid injections can provide temporary relief from pain and inflammation. Hyaluronic acid injections may improve joint lubrication and reduce pain in patients with osteoarthritis.
• Bracing and Orthotics: Knee braces or orthotic devices can provide additional support and stability to the knee joint, helping to alleviate symptoms and improve function.
• APS Injection (Autologous Protein Solution): APS is an autologous (from your own body) therapy which is designed to treat joint pain associated with knee osteoarthritis. In laboratory testing, APS has been shown to protect cartilage cells. This protective quality may slow the progression of osteoarthritis as well.

Surgical interventions may be required for more severe cartilage injuries or when non-surgical treatments fail to provide adequate relief. Surgical options include:

• Arthroscopic Surgery: Arthroscopy is a minimally invasive procedure used to diagnose and treat various knee conditions. During arthroscopy, the surgeon can remove loose bodies, repair torn cartilage, or smooth damaged cartilage surfaces.
• Microfracture Surgery: This technique involves creating small fractures in the underlying bone to stimulate the growth of new cartilage. It is often used for small areas of cartilage damage.
• Osteochondral Autograft Transplantation (OAT): In this procedure, healthy cartilage and bone are taken from a non-weight-bearing area of the knee and transplanted into the damaged area.
• Autologous Chondrocyte Implantation (ACI): ACI involves harvesting a small sample of the patient’s cartilage cells, cultivating them in a laboratory, and then implanting the newly grown cells into the damaged area.
• Meniscus Surgery: Meniscus repair or meniscectomy (removal of the damaged meniscus) may be performed if the injury involves a meniscal tear.
• Osteotomy: This surgical procedure involves cutting and reshaping the bones to relieve pressure on the damaged cartilage. It is often used in younger patients with knee misalignment.