Inside Knee Pain: Causes, Symptoms, Diagnosis, and Treatment

Why does my inside knee hurt?

Pain on the inside (medial aspect) of the knee is a common complaint, often stemming from issues with ligaments, cartilage, tendons, or the joint itself, and requires careful consideration of the knee's complex anatomy and biomechanics.

The knee is a marvel of engineering, a complex hinge joint designed to facilitate movement while bearing significant loads. When pain manifests on the inside, or medial side, of the knee, it points to a range of potential issues involving the intricate network of structures in this area. Understanding the anatomy involved is key to deciphering the source of discomfort.

The medial aspect of the knee houses several critical components: the medial collateral ligament (MCL), which provides stability against valgus (inward) forces; the medial meniscus, a C-shaped piece of cartilage that acts as a shock absorber and stabilizer; the pes anserine bursa and tendons (sartorius, gracilis, semitendinosus), which attach to the shin bone (tibia); and the articular cartilage lining the medial compartment of the joint.

Common Causes of Inside Knee Pain

Pain on the medial side of the knee can arise from various conditions, each with distinct characteristics:

• Medial Collateral Ligament (MCL) Injury:

  • Description: The MCL connects the thigh bone (femur) to the shin bone (tibia) on the inside of the knee. Injuries typically occur from a direct blow to the outside of the knee or a sudden twisting motion that forces the knee inward (valgus stress).
  • Symptoms: Pain, tenderness directly over the ligament, swelling, and sometimes a feeling of instability, especially when changing direction. Severity ranges from mild (Grade 1 sprain) to a complete tear (Grade 3).
  • Mechanism: Often seen in sports involving cutting, pivoting, or direct contact, such as soccer, football, and skiing.

• Medial Meniscus Tear:

  • Description: The medial meniscus is one of two crescent-shaped cartilages that cushion the knee joint. Tears can be acute (traumatic) or degenerative (due to wear and tear over time).
  • Symptoms: Sharp pain, especially with twisting or squatting, clicking or popping sensations, stiffness, swelling, and sometimes the knee "catching" or "locking."
  • Mechanism: Traumatic tears often result from a forceful twist of the knee while the foot is planted. Degenerative tears are more common with age and can occur with minimal trauma.

• Pes Anserine Bursitis/Tendinitis:

  • Description: The pes anserine bursa is a fluid-filled sac located between the shin bone and the three tendons of the sartorius, gracilis, and semitendinosus muscles (collectively known as the "pes anserine" or "goose's foot" attachment). Inflammation of the bursa (bursitis) or the tendons (tendinitis) can cause pain.
  • Symptoms: Pain and tenderness about 2-3 inches below the joint line on the inside of the knee, often worse with climbing stairs, standing up from a chair, or at night.
  • Mechanism: Commonly caused by overuse, tight hamstrings or adductor muscles, increased activity, obesity, or improper training techniques, particularly in runners and cyclists.

• Medial Compartment Osteoarthritis (OA):

  • Description: This is a degenerative condition where the articular cartilage on the inside of the knee joint wears away, leading to bone-on-bone friction.
  • Symptoms: Gradual onset of pain, stiffness (especially in the morning or after rest), creaking or grinding sensations (crepitus), reduced range of motion, and swelling. Pain often worsens with activity.
  • Mechanism: Age-related wear and tear, previous knee injuries, obesity, and genetic predisposition contribute to OA development.

• Medial Plica Syndrome:

  • Description: A plica is a fold in the synovial membrane (the lining of the joint capsule). While common and usually harmless, the medial plica can become irritated or inflamed due to overuse or trauma.
  • Symptoms: Aching pain on the inside of the knee, sometimes a snapping or popping sensation, especially when bending and straightening the knee, and tenderness along the medial kneecap.
  • Mechanism: Repetitive knee bending, direct trauma, or prolonged activity can irritate the plica.

• Referred Pain:

  • Description: Sometimes, pain felt in the knee originates from another area, such as the hip or lower back, due to nerve pathways.
  • Symptoms: Pain that doesn't seem to follow a clear pattern of knee movement, or is accompanied by symptoms in the hip, buttock, or back.
  • Mechanism: Sciatica, hip joint issues (e.g., hip osteoarthritis), or nerve impingement in the lumbar spine can refer pain to the knee.

Risk Factors for Medial Knee Pain

Several factors can increase your susceptibility to inside knee pain:

• Improper Training Load: Rapid increases in exercise intensity, duration, or frequency without adequate recovery.
• Muscle Imbalances: Weakness in the quadriceps, glutes, or hip abductors, or tightness in the hamstrings, adductors, or hip flexors.
• Biomechanical Issues: Overpronation of the feet, genu valgum (knock-knees), or poor running/walking gait mechanics.
• Inadequate Warm-up and Cool-down: Skipping these crucial steps can leave tissues unprepared for activity or hinder recovery.
• Poor Footwear: Shoes that lack proper support or are worn out can alter knee mechanics.
• Previous Knee Injuries: A history of sprains or tears can predispose the joint to future issues.
• Age: Degenerative conditions like osteoarthritis become more prevalent with age.
• Obesity: Increased body weight places greater stress on the knee joint.

When to Seek Professional Help

While some mild cases of inside knee pain can resolve with self-care, it is crucial to consult a healthcare professional if you experience:

• Severe pain that prevents you from bearing weight or performing daily activities.
• Significant swelling or bruising around the knee.
• A popping or tearing sensation at the time of injury.
• Instability or a feeling that your knee will give way.
• Inability to fully bend or straighten your knee.
• Locking or catching of the knee joint.
• Pain that worsens over time or does not improve after a few days of self-care.

A thorough clinical examination by a physician, physical therapist, or sports medicine specialist is essential for accurate diagnosis and appropriate treatment planning. This may involve imaging tests such as X-rays, MRI, or ultrasound.

Initial Self-Care Strategies

For mild, acute medial knee pain, these strategies can provide temporary relief:

• R.I.C.E. Protocol:
  • Rest: Avoid activities that aggravate the pain.
  • Ice: Apply ice packs for 15-20 minutes every 2-3 hours to reduce swelling and pain.
  • Compression: Use an elastic bandage to minimize swelling, ensuring it's not too tight.
  • Elevation: Keep your leg elevated above your heart to help reduce swelling.
• Over-the-Counter Pain Relievers: Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen can help manage pain and inflammation, but consult a doctor if you have other medical conditions.
• Gentle Movement: Once acute pain subsides, gentle, pain-free range of motion exercises can help prevent stiffness.
• Modify Activities: Temporarily reduce or alter activities that worsen your pain.

Prevention Strategies

Proactive measures are vital in preventing medial knee pain:

• Strength Training: Focus on strengthening the muscles surrounding the knee, including the quadriceps, hamstrings, glutes, and hip abductors. Incorporate exercises like squats, lunges, deadlifts, and glute bridges.
• Flexibility and Mobility: Maintain good flexibility in the hamstrings, quadriceps, hip flexors, and calf muscles. Regular stretching and foam rolling can improve tissue extensibility.
• Proper Biomechanics: Pay attention to your form during exercise and daily activities. Ensure your knees track over your toes during squats and lunges, and avoid excessive knee valgus (knees collapsing inward).
• Gradual Progression: When starting a new exercise program or increasing intensity, do so gradually to allow your body to adapt. The "10% rule" (do not increase weekly mileage/load by more than 10%) can be a good guideline.
• Appropriate Footwear: Wear supportive shoes that are suitable for your activity and replace them regularly. Consider orthotics if you have significant foot pronation.
• Listen to Your Body: Do not push through pain. If an activity causes discomfort, stop and rest.

Conclusion

Pain on the inside of the knee is a common and often debilitating issue, but understanding its potential causes is the first step toward effective management. From acute ligament sprains and meniscal tears to chronic conditions like osteoarthritis and overuse syndromes, the medial knee is susceptible to various injuries. An accurate diagnosis by a healthcare professional is paramount for developing a targeted treatment plan. By understanding the underlying anatomy, recognizing common symptoms, and implementing appropriate preventive and self-care strategies, you can take proactive steps toward maintaining knee health and returning to pain-free activity.