About Knee Pain

Knee pain is a common complaint that affects people of all ages. Knee pain may be the result of an injury, such as a ruptured ligament or torn cartilage. Medical conditions  including arthritis, gout and infections  also can cause knee pain.

Many types of minor knee pain respond well to self-care measures. Physical therapy and knee braces also can help relieve pain. In some cases, however, your knee may require surgical repair.

Types of Knee Pain

• Acute: Sudden pain due to injuries like ligament tears (ACL, PCL), fractures, or dislocations.
• Chronic: Persistent pain from arthritis (osteoarthritis, rheumatoid arthritis), infections, or tendinitis.
• Overuse: Repetitive stress injuries like patellofemoral syndrome (runner’s knee) or bursitis.

Knee Pain : Signs and Symptoms

Knee pain can be classified based on its duration and underlying cause. Understanding the type of symptoms can help identify whether the condition is acute, chronic, or related to referred pain.

* Acute Symptoms

These typically arise suddenly, often due to injury or trauma. Common acute symptoms include:

• Swelling – Rapid buildup of fluid around the knee joint.
• Instability – A feeling that the knee may give way or buckle.
• Popping sounds – Often heard or felt at the time of injury, possibly indicating ligament or meniscus damage.
• Inability to bear weight – Severe pain or instability may make walking or standing difficult or impossible.

* Chronic Symptoms

These develop gradually over time, often linked to overuse, arthritis, or degenerative conditions. Common chronic symptoms include:

• Stiffness – Particularly noticeable after periods of inactivity, such as waking up in the morning.
• Reduced mobility – Difficulty in bending or straightening the knee fully.
• Warmth – A sensation of heat around the joint, possibly due to ongoing inflammation.
• Progressive joint deformity – Changes in the shape or alignment of the knee due to long-term damage.

* Referred Pain

Sometimes, knee pain may not originate from the knee itself but from nearby joints or structures. This type of discomfort may result from:

• Hip issues, such as arthritis or impingement.
• Lower back problems, including sciatica or spinal disc herniation.
• Ankle misalignment or instability, which can alter gait and stress the knee.

Knee Pain Causes

Knee pain can result from a variety of conditions involving injury, degeneration, mechanical problems, or infections. Understanding the root cause is key to determining the right treatment and management approach.

• Injuries
  Sudden trauma or overuse can lead to damage in the structures of the knee. Common injury-related causes include:
  
  • Ligament tears – Such as the ACL (anterior cruciate ligament) or PCL (posterior cruciate ligament), often caused by sports or accidents involving sudden stops, pivots, or impacts.
  • Meniscus damage – Tearing of the cartilage that cushions the knee, which may result from twisting movements or heavy lifting.
  • Tendon ruptures – Partial or complete tears in the quadriceps or patellar tendons, often seen in athletes or during forceful jumping and landing.
• Arthritis
  A leading cause of chronic knee pain, arthritis can present in different forms:
  
  • Osteoarthritis – A degenerative condition where the protective cartilage in the knee gradually wears away, leading to pain and stiffness.
  • Rheumatoid arthritis – An autoimmune disease that causes inflammation of the joint lining, often affecting both knees symmetrically.
  • Gout – Caused by uric acid crystal buildup, leading to sudden and intense pain, swelling, and redness in the joint.
• Mechanical Issues
  These involve structural or functional abnormalities that interfere with normal knee movement:
  
  • Loose bodies – Fragments of bone or cartilage that move around in the joint space, potentially causing pain or locking.
  • Iliotibial band syndrome – An overuse injury common in runners and cyclists, where the IT band becomes tight and rubs against the outer knee.
  • Patellar dislocation – When the kneecap shifts out of its normal position, often resulting from trauma or anatomical misalignment.
• Infections
  Though less common, infections can cause significant and rapid knee pain:
  
  • Septic arthritis – A serious condition caused by bacterial or fungal infection in the knee joint, leading to severe pain, swelling, redness, fever, and reduced mobility. It requires urgent medical attention.

Knee Pain Risk Factors

• Age: Cartilage degeneration increases with aging.
• Obesity: Excess weight stresses knee joints.
• Sports: High-impact activities (basketball, football) or improper training.
• Medical history: Prior knee injuries, autoimmune disorders, or metabolic conditions like gout.

Knee Pain Complications

• Chronic disability: Untreated arthritis or ligament damage can lead to permanent joint dysfunction.
• Infection spread: Untreated septic arthritis may cause systemic infection.
• Joint deformity: Advanced osteoarthritis or rheumatoid arthritis may alter knee structure

Diagnosis of Knee Pain

Diagnosing the cause of knee pain involves a combination of clinical evaluation, imaging studies, and sometimes laboratory testing. A thorough diagnosis helps guide appropriate treatment and management.

* Physical Examination

The first step in diagnosing knee issues is a hands-on evaluation by a healthcare provider. This includes:

• Inspecting for swelling, redness, or deformity
• Palpating the knee to identify tenderness, warmth, or abnormal fluid buildup
• Assessing range of motion to detect stiffness or restricted movement
• Testing stability by performing maneuvers that evaluate the integrity of ligaments and joint structures

* Imaging Studies

Imaging helps visualize internal structures of the knee to pinpoint the source of pain:

• X-rays – Ideal for detecting bone-related issues such as fractures, dislocations, or signs of arthritis like joint space narrowing and bone spurs.
• MRI (Magnetic Resonance Imaging) and CT (Computed Tomography) scans – Provide detailed images of soft tissues such as ligaments, tendons, cartilage, and the meniscus. These are especially useful for identifying ligament tears, meniscus injuries, or subtle bone abnormalities.
• Ultrasound – A dynamic imaging tool often used to visualize tendon or bursa inflammation, fluid buildup, or cysts in real-time, especially during movement.

* Laboratory Tests

When infection or systemic disease is suspected, lab tests may be recommended:

• Blood tests – Can detect markers of infection, such as elevated white blood cell counts or C-reactive protein (CRP), and autoimmune indicators like rheumatoid factor (RF) or anti-CCP antibodies.
• Joint aspiration (arthrocentesis) – Involves extracting synovial fluid from the knee for analysis. This can confirm infections (septic arthritis), gout (uric acid crystals), or inflammatory conditions.

Knee Pain Treatment

• Non-surgical:
  • Medications: NSAIDs (ibuprofen), corticosteroids, or hyaluronic acid injections.
  • Physical therapy: Strengthening exercises and gait training.
  • Lifestyle modifications: Weight management and activity adjustment

Note: Medication is only advisable under doctor's consideration.

Arthroscopy

A minimally invasive surgical procedure used to diagnose and treat a variety of knee problems. Surgeons make small incisions and insert a tiny camera (arthroscope) into the joint to view the structures and perform repairs. Common uses include:

• Trimming or repairing torn meniscus
• Reconstructing torn ligaments, such as the ACL
• Removing loose bodies, inflamed synovial tissue, or damaged cartilage
• Cleaning out the joint to reduce pain and inflammation

Arthroscopy typically has a shorter recovery time and less postoperative pain compared to open surgery.

Joint Replacement (Knee Arthroplasty)

Recommended for severe osteoarthritis or other degenerative joint conditions when pain and loss of function significantly impact daily life. It involves:

• Partial knee replacement – Only the damaged portion of the knee is replaced, preserving healthy bone and tissue.
• Total knee replacement – The entire joint surface is replaced with metal and plastic components to restore alignment and function.