Understanding Knee Cartilage

The knee joint is formed by three bones:

• Femur (thigh bone)
• Tibia (shin bone)
• Patella (kneecap)

The ends of these bones are covered with articular cartilage, a smooth hyaline cartilage that:

• Allows bones to glide smoothly during movement
• Absorbs shock
• Reduces friction within the joint

Hyaline cartilage is avascular, meaning it does not have a direct blood supply. Because of this limited healing capacity, cartilage injuries often require structured medical management.

The underside of the patella is also covered with cartilage that articulates with the femoral groove (trochlear groove), forming the patellofemoral joint.

In addition to articular cartilage, the knee contains two crescent-shaped structures called the menisci, which act as shock absorbers and help distribute weight evenly across the joint.

When cartilage surfaces become disrupted, patients may experience pain, inflammation, swelling (joint effusion) and mechanical symptoms such as catching or locking.

What Is a Cartilage Injury?

A cartilage injury occurs when the smooth articular surface is damaged due to trauma, overuse, instability or degenerative changes. These injuries range from small soft areas to full-thickness defects that expose underlying bone.

Common causes include:

• Sports injuries involving twisting or pivoting
• Direct impact or falls
• Repetitive stress
• Knee instability from ligament injuries (such as ACL tears)
• Degenerative changes associated with osteoarthritis
• Prior trauma to the knee joint

Related conditions may include:

• Meniscus tears, which involve damage to the C-shaped cartilage pads
• Loose bodies, where fragments of cartilage or bone detach inside the joint
• Osteochondritis dissecans (OCD), a condition involving reduced blood flow to a segment of bone and cartilage

Because cartilage lacks its own blood supply, healing without medical intervention is often limited.

What Is Chondromalacia?

Chondromalacia refers to softening and breakdown of the cartilage, most commonly affecting the underside of the patella. It is frequently associated with anterior knee pain and patellofemoral joint irritation.

Chondromalacia patellae are often seen in young adults and athletes who repeatedly stress the knee joint. It is more common in females due to anatomical and biomechanical factors, including a wider pelvis and increased Q-angle, which may influence patellar tracking.

Contributing factors include:

• Patellar malalignment or tracking disorders
• Patella alta (high-riding patella) or lateral patellar tilt
• Femoral anteversion affecting lower limb biomechanics
• Quadriceps weakness, particularly the vastus medialis
• Hip muscle weakness or imbalance
• Repetitive stress from running or jumping
• Previous knee injury

If left untreated, cartilage softening may progress to more advanced degeneration and exposure of subchondral bone.

Symptoms of Cartilage Damage and Chondromalacia

Symptoms vary depending on severity and location, but commonly include:

• Dull, aching knee pain
• Pain behind or around the kneecap
• Swelling or joint effusion
• Grinding or popping sensations (crepitus)
• Catching or locking
• Pain with stairs, squatting, kneeling or prolonged sitting
• Knee stiffness

It is important to note that cartilage itself does not contain nerve endings. Pain is typically generated by surrounding structures such as the synovium, joint capsule or fat pad.

Symptoms often worsen gradually with continued activity.

How Cartilage Injuries Are Diagnosed

Accurate diagnosis is essential for developing an effective treatment plan.

At OrthoTexas, evaluation includes:

Comprehensive Clinical Examination

• Detailed medical and activity history
• Assessment of pain location
• Evaluation of patellar alignment and tracking
• Quadriceps and hip strength testing
• Range-of-motion assessment
• Gait analysis

Imaging Studies

• X-rays to evaluate joint space and alignment
• MRI to assess cartilage defects, joint effusion, meniscus injuries and ligament involvement
• Diagnostic arthroscopy in select cases

MRI is particularly useful for identifying early cartilage softening and isolated chondral defects.

Non-Surgical Treatment Options

Many cartilage injuries and cases of chondromalacia improve with conservative care.

Activity Modification

Reducing high-impact activities decreases joint stress and inflammation.

Physical Therapy

A structured physical therapy rehabilitation program focuses on:

• Strengthening the quadriceps and hip muscles
• Improving patellar tracking
• Correcting biomechanical imbalances
• Enhancing flexibility
• Improving extensor mechanism strength

Low-impact activities such as cycling may be incorporated to maintain muscle strength without excessive joint stress.

Bracing or Taping

Supportive bracing or taping may improve kneecap alignment and reduce symptoms.

Medications

Nonsteroidal anti-inflammatory drugs (NSAIDs) may help manage short-term pain and inflammation.

Injections

In selected cases:

• Corticosteroid injections for inflammation
• Hyaluronic acid injections for lubrication

Conservative treatment is often effective in reducing symptoms and slowing progression.

Surgical Treatment for Cartilage Injuries

Surgery may be considered if symptoms persist despite appropriate non-surgical treatment.

Treatment depends on defect size, depth, location, patient age and activity level.

Common procedures include:

Arthroscopic Chondroplasty

Removes unstable cartilage fragments and smooths the joint surface.

Microfracture Procedure

Stimulates new fibrocartilage growth over small defects.

Osteochondral Autograft Transfer (OATS)

Transplants healthy cartilage from a non-weight-bearing area to a damaged region.

Autologous Chondrocyte Implantation (ACI)

A two-stage cartilage restoration procedure that grows cartilage cells in a laboratory and implants them into the defect.

Realignment Procedures

In cases of patellar maltracking, procedures such as tibial tubercle osteotomy may reduce pressure on damaged cartilage.

Surgical decisions are made after thorough evaluation to ensure the most appropriate treatment strategy.

Recovery and Rehabilitation

Recovery timelines vary depending on treatment type:

• Minor arthroscopic procedures: Several weeks
• Cartilage restoration procedures: Several months
• Gradual return to sport: Often 4-9 months

Structured physical therapy is critical to protect healing tissue and restore strength, stability and mobility.

Most patients experience meaningful improvement with appropriate treatment and rehabilitation.

Preventing Cartilage Damage

While not all injuries are preventable, you can reduce risk by:

• Strengthening hip and thigh muscles
• Maintaining a healthy body weight
• Using supportive footwear
• Gradually increasing activity intensity
• Performing proper warm-up routines
• Addressing knee instability early

Early evaluation of persistent knee pain can help prevent long-term cartilage deterioration.

When to See a Knee Specialist

Schedule an appointment at OrthoTexas if you experience:

• Persistent knee pain lasting more than a few weeks
• Pain behind the kneecap
• Swelling or grinding sensations
• Mechanical symptoms such as catching or locking
• Difficulty with stairs or prolonged sitting

Prompt evaluation allows for earlier treatment options and improved long-term outcomes.

Comprehensive Knee Cartilage Care at OrthoTexas

OrthoTexas provides advanced care for cartilage injuries and chondromalacia, including:

• Advanced diagnostic imaging
• Conservative rehabilitation programs
• Injection therapy
• Minimally invasive arthroscopic procedures
• Advanced cartilage restoration techniques
• Personalized rehabilitation planning

Our fellowship-trained orthopedic specialists are committed to relieving knee pain, preserving joint function and helping you return to the activities you enjoy.