Knee Cartilage Injury - Causes, Diagnosis, and Management

Introduction:

In the athletic population, articular cartilage lesions are becoming more common. Because these lesions cannot heal independently, they might eventually cause escalating discomfort and functional limitations. Isolated cartilage lesions may develop into global or progressive chondrogenic (complete loss of cartilage) if left untreated. It is frequently associated with acute ligament or meniscus injuries (C-shaped cartilage that serves as a stress absorber between the shinbone and the thigh bone, injured by the sudden forceful twist of the knee), dislocations of patellar (a jumping muscle located at the thigh which extends your knee to promote kicking, running and jumping) and osteochondral injuries or may develop from chronic ligamentous instability or malalignment. These wounds frequently prevent an athlete from participating in sports and put them at risk of developing early joint degeneration.

What Is Cartilage Injury of the Knee?

Cartilage is the flexible tissue that is engaged between the joints to promote smooth or gliding movements when the knee bends, eventually absorbing the shock while running, kicking, and jumping. Unfortunately, cartilage is more prone to injury and cannot heal spontaneously due to its lack of blood supply within the tissue. The knee joint is composed of three bones – the thigh bone (femur), the shin bone (tibia), and the kneecap (patella). Articular cartilage, a tough, white, Teflon-like substance that covers the ends of the bones, aids in the smooth mobility of bones during joint action. A direct hit to the knee, a twisting or pivoting injury, or the articular cartilage potentially causes damage. It is also known as chondral injury. Damage to the cartilage tissue results in knee pain brought on by joint friction, and the cartilage injury occasionally causes arthritis. Cartilage knee injury is common among athletes by accident, leading to tearing meniscus during sports such as tennis, hockey, football, or skiing.

What Are the Causes of Cartilage Injury of the Knee?

The major cause of cartilage injury in the knee is trauma while playing a sport that involves rotating or bowing the knee. It might harm cartilage and loosens it from underlying bone. Athletes who participate in sports requiring cutting, jumping, turning, quick retraction, and changing direction are more prone to cartilage injury. The sports which commonly engage in these activities are football, basketball, and handball. Other major causes are aging which can lead to osteoarthritis, which makes the person more prone to cartilage injury. Occasionally, cartilage lesions can happen independently and commonly co-occur with ligament and meniscus injuries.

What Are the Signs and Symptoms of Cartilage Injury?

The cartilage injury is generally asymptomatic. However, the partially torn cartilage typically does not heal independently and frequently worsens over time. The most common symptoms are:

• Predominant joint pain while sitting and lying down.

• Joint stiffness while bending the knee or elbow.

• Swelling on the affected site.

• Redness.

• Warmth.

• Joint weakness and instability affect daily activities like walking, climbing stairs, bending, squatting, and kneeling.

• The sensation of catching, grinding, or clicking while bending or straightening the knee.

• The later stage leads to osteoarthritis due to insufficient shock absorber function.

Why Does It Affect Athletes More?

Athletes are at high risk of cartilage damage because they are intended to strain their joints and are more likely to sustain problems. High-impact sports like football, basketball, soccer, and tennis are more prone to cause cartilage injuries due to sports accidents on the field or may be due to bad technique during a move. The most common cause of injuries while playing sports are:

• Knee contact with a hard surface.

• A rough landing or terrible fall after a jump.

• Sudden twisting or bending.

• Overextending or overstraining the knee while playing.

• Overuse or repeated action of the specific area.

How to Diagnose Cartilage Injury?

Initially, the diagnosis of knee cartilage damage is based on physical examination, mainly with tenderness, stiffness, swelling, and movement difficulties. The investigations are X-ray and MRI.

• X-rays are done to confirm the presence of arthritis and additionally check for the alignment of the knee joint and degenerative changes.

• MRI (magnetic resonance imaging) is done to evaluate the damage to soft tissue like cartilage, tendons, and muscle.

What Are the Possible Treatment Options for Cartilage Injury?

The course of treatment will depend on the severity of the injury. Cartilage lacks a source of blood flow, which would aid in the healing process; hence, it cannot repair itself after injury. Rarely some cartilage cells can repair independently; however, medical aids are required for a complete cure. Damage to the cartilage, when left untreated, can eventually cause arthritis and excruciating joint pain. The effective treatment options are.

• RICE: Rest, ice, compression, and elevation are the four major factors that aid in the initial stage of treatment. Athletes are advised to have plenty of rest and halt sports practice. Ice pack compression and elevation decrease the swelling and inflammation at the affected site.

• Physical Therapy: Exercise strengthens the muscles surrounding your joints, reducing discomfort and minimizing the risk of future injuries.

• Injections: Using platelets extracted from the patient's blood or platelet-rich plasma (PRP) helps manage pain and promotes recovery.

• Surgery: When non-operative treatment and regenerative injections don't respond, surgery is required to repair the severely injured cartilage. The types of surgery depend on the severity of the injury.

However, cartilage injury can be prevented by regular, high-impact activity, maintaining a healthy weight, and adhering to preventative programs for other sports injuries like ACL(Anterior Cruciate Ligament).

What Are the Types of Surgery for Cartilage Injuries?

The surgery depends on the severity of the injury after evaluating the injury, medical history, and joint movement.

• Microfracture: Tiny holes are made in the bone beneath the cartilage. These openings provide a blood supply, which aids the cartilage cells in healing.

• Osteochondral Transfer System (OATS): The damaged portion of the cartilage is replaced with a healthy portion taken from the knee.

• Meniscus Repair: Meniscus is the shock-absorbing cartilage between your shin and thigh. Severely injured meniscus are transplanted from a donor's healthy meniscus.

• Autologous Chondrocyte Implantation (ACI): ACI is frequently suggested for young athletes. The cartilage of the patient is obtained and developed into a personalized implant.

Conclusion:

Recently, cartilage regeneration and several surgical procedures have been developed. To satisfy the demands of these novel procedures, rehabilitation standards are being created to improve the biology of articular cartilage repair and additionally repair cartilage tissue that can sustain the intense mechanical stresses when athletes twist or bend a knee spontaneously.