Knee pain is an extremely common complaint that affects people of all ages. The knee joint is complex and vulnerable to injury and degeneration. Determining the exact cause of knee pain can be challenging, but is the first step toward finding the right treatment. Not all knee pain can be “fixed” completely, but most causes of knee pain can be successfully treated to reduce symptoms and restore function.
What causes knee pain?
There are many potential causes of knee pain, including:
- Arthritis – Osteoarthritis, rheumatoid arthritis, and post-traumatic arthritis are common causes of knee pain. Arthritis leads to degeneration of the joint cartilage and bones.
- Injuries – Sprains, strains, tears of ligaments, tendons or cartilage, fractures, and dislocations can all cause acute knee pain and long-term issues if not treated properly.
- Tendonitis – Irritation and inflammation of a tendon, like patellar tendonitis (jumper’s knee) or quadriceps tendonitis.
- Bursitis – Inflammation of a bursa, a fluid-filled sac that reduces friction between tissues. Pes anserine bursitis and prepatellar bursitis are common around the knee.
- Osgood-Schlatter Disease – Common in adolescents and young adults and causes pain below the knee cap.
- Chondromalacia patellae – Softening and damage of the cartilage under the kneecap.
- Baker’s cyst – a fluid-filled swelling behind the knee that puts pressure on tissues.
- Iliotibial band syndrome – Irritation of the thick band of tissue that runs along the outside of the thigh from the hip to the shin.
- Loose bodies – Pieces of cartilage or bone floating in the knee joint space that cause pain when they get caught between the bones of the joint.
Common locations of knee pain
The location of knee pain can sometimes provide clues as to the underlying cause:
| Location of Pain | Potential Cause |
|---|---|
| Inside (medial) knee | Medial meniscus tear |
| MCL sprain | |
| Pes anserine bursitis | |
| Outside (lateral) knee | Lateral meniscus tear |
| LCL sprain | |
| Iliotibial band syndrome | |
| Front knee | Patellar tendonitis |
| Chondromalacia patellae | |
| Osgood Schlatter disease | |
| Back of knee | Baker’s cyst |
| Loose bodies |
Risk factors for knee injuries and arthritis
A number of factors can increase a person’s risk of developing knee problems including:
- Age – The risk of osteoarthritis increases with age due to cumulative wear and tear on the joints. Middle age is a common time for osteoarthritis symptoms to become problematic.
- Prior injury – Joint damage, even if repaired surgically, predisposes the joint to osteoarthritis later in life. It also makes the joint more prone to re-injury.
- Obesity – Excess weight puts increased pressure on the joint surfaces, especially the knees that bear the brunt of body weight.
- Improper alignment – Knock knees, bow legs, unequal leg lengths, and other alignment issues increase wear in the knee joint.
- High impact activities – Sports with repetitive impact like running and jump sports increase the risk of overuse injuries.
- Muscle weakness – Weak thigh and hip muscles lead to poor shock absorption in the knees.
- Occupational hazards – Jobs requiring heavy lifting, extensive kneeling or squatting, or vibration exposure can lead to knee damage.
- Genetics – Some people inherit a predisposition for developing osteoarthritis or tendon/ligament injuries.
When to see a doctor
It’s a good idea to consult a doctor for knee pain that:
- Doesn’t improve with a few days of self-care
- Is severe, persistent, or interferes with sleep and daily activities
- Is accompanied by swelling, instability, locking, or popping sounds
- Results from a significant injury
- Occurs without a clear cause in a person over 50
- Occurs with other symptoms like fever, leg weakness, or rash
Seeking prompt medical attention for knee injuries increases the chances of a good recovery. Warning signs of knee arthritis also should not be ignored since early treatment can help slow the condition.
Diagnosing knee pain
To properly diagnose the underlying cause of knee pain, a doctor will typically:
- Take a full medical history
- Conduct a physical examination of the knee and leg
- Order imaging tests – x-rays, CT or MRI scans
- Analyze fluid from the knee joint
- Assess the limb alignment
- Evaluate the patient walking and performing movements
Based on the examination and test findings, the doctor will diagnose the problem and determine an appropriate treatment plan.
Common knee conditions and treatment options
Here are some of the main knee disorders and typical treatment approaches:
| Condition | Treatments |
|---|---|
| Arthritis | Pain relievers, anti-inflammatories, injections, physical therapy, braces, surgery for end-stage arthritis |
| Bursitis | Rest, ice, NSAIDs, aspiration of fluid, injections, knee pad |
| Chondromalacia patellae | Physical therapy, knee brace, activity modification, anti-inflammatories, surgery if severe |
| Baker’s cyst | Treating underlying problem, draining cyst, injections, surgery if persists |
| Iliotibial band syndrome | Rest, ice, anti-inflammatories, physical therapy, injections |
| Loose bodies | Removal via arthroscopic surgery |
| Meniscus tear | Rest, ice, crutches, physical therapy, surgery to repair or remove torn portion |
| Patellar tendonitis | Rest, ice, anti-inflammatories, taping, physical therapy, shock wave therapy |
| Osgood Schlatter disease | Rest, ice, braces, physical therapy, activity modification until growth completed |
| ACL/PCL tear | Rehabilitation exercises, knee brace, reconstructive surgery |
Lifestyle remedies for knee pain
Along with medical treatment, there are many lifestyle adjustments that can help manage knee pain:
- Lose excess weight to reduce knee joint stress
- Do muscle strengthening exercises for the thighs, hips and core
- Wear supportive footwear with good shock absorption
- Use braces or sleeves to compress and support the joint
- Take frequent breaks when doing repetitive motions like kneeling
- Limit activities that aggravate the knee like jumping and deep squats
- Switch to lower impact exercises like swimming and cycling
- Use proper posture and body mechanics when lifting objects
- Consider taking glucosamine/chondroitin supplements for arthritis
- Use ice and elevation to reduce pain and swelling as needed
When is surgery necessary for knee pain?
Surgery may be recommended for knee pain when:
- There is significant damage to knee ligaments or cartilage that won’t heal without repair
- Non-surgical treatments have failed to relieve pain and improve function
- The knee joint is unstable or locked due to injury
- There are loose bodies or bone spurs in the joint that need removal
- Advanced knee arthritis interferes severely with daily activities
- Malalignment in the leg requires realignment osteotomy
Common knee surgeries include:
- Arthroscopy – Small incisions to insert camera and instruments to diagnose and treat problems inside the joint.
- Ligament reconstruction – Using a graft to reinforce or replace torn ligaments.
- Meniscectomy – Removing the damaged portion of a meniscus.
- Cartilage grafting procedures – Transplanting cartilage to repair defects.
- Osteotomy – Cutting and realigning bones to redistribute knee loads.
- Total knee replacement – Resurfacing the femur, tibia, and patella with artificial implants.
Recovering from knee surgery requires extensive rehabilitation and physical therapy to regain strength and range of motion.
Preventing knee injuries and pain
Some tips for avoiding knee problems include:
- Maintain a healthy weight to reduce knee joint stresses.
- Build strength, flexibility and balance with regular exercise.
- Use proper biomechanics and technique when exercising.
- Warm up adequately before sports and don’t overdo activities.
- Wear supportive shoes for everyday activities and sports.
- Taping or bracing for extra support during sports.
- Take regular breaks when doing repetitive knee bending tasks.
- Ensure workout equipment and furniture heights suit your body.
- Correct muscle imbalances or poor movement patterns.
- Listen to your body and rest inflamed joints.
Conclusion
Knee pain has many potential causes and treatments must be tailored to each individual. While not all knee conditions can be permanently “fixed”, most causes of knee pain can be successfully managed or treated to restore function and reduce discomfort. This often requires a combination of medical treatment, physical therapy, and lifestyle adjustments. Surgery may be required in some cases if more conservative treatments fail. Preventative measures are also important to avoid knee injuries and reduce wear and tear that can lead to arthritis.
