Pain on the side of your knee when you bend it is often related to injuries to the collateral ligaments, arthritis, or meniscus tears. Let's break down each of these potential causes:
1. Collateral Ligament Injuries:
- What they are: The collateral ligaments (medial collateral ligament - MCL on the inside, and lateral collateral ligament - LCL on the outside) provide stability to your knee. They prevent excessive sideways movement.
- How they cause pain: Injuries to these ligaments, such as sprains or tears, can occur from direct blows to the knee or sudden twisting motions.
- Pain characteristics: Pain is typically felt on the inside (MCL injury) or outside (LCL injury) of the knee, especially when bending, twisting, or putting pressure on the affected side. Swelling and instability are also common.
2. Arthritis:
- What it is: Osteoarthritis, the most common type, involves the breakdown of cartilage in the knee joint.
- How it causes pain: As cartilage wears away, the bones rub together, leading to pain, stiffness, and inflammation.
- Pain characteristics: Arthritis pain often develops gradually and worsens with activity, especially bending, squatting, or walking. You may experience pain on either side of the knee or throughout the joint. Stiffness is usually worse in the morning or after periods of inactivity.
3. Meniscus Tears:
- What they are: The menisci are C-shaped pieces of cartilage that act as shock absorbers between the femur (thigh bone) and tibia (shin bone).
- How they cause pain: Tears can occur from twisting or pivoting movements, especially with force. These tears can occur in different locations.
- Pain characteristics: Meniscus tears can cause pain along the joint line (the area where the femur and tibia meet), which can be on the inside or outside of the knee. You may also experience clicking, locking, or catching sensations in the knee. Pain is often exacerbated by bending, squatting, or twisting.
Summary Table:
| Condition | Location of Pain | Pain Characteristics | Other Symptoms |
|---|---|---|---|
| Collateral Ligament Injury | Inside/Outside Knee | Sharp pain, especially with stress on the ligament | Swelling, instability |
| Arthritis | Inside/Outside/Whole Knee | Gradual onset, worsening with activity | Stiffness, swelling, decreased range of motion |
| Meniscus Tear | Joint Line (Inside/Outside) | Sharp pain, often with specific movements | Clicking, locking, catching |
What to Do:
If you're experiencing persistent pain on the side of your knee when you bend, it's essential to consult a healthcare professional for a proper diagnosis. They can perform a physical exam, and possibly order imaging tests like X-rays or MRIs, to determine the underlying cause of your pain and recommend the appropriate treatment plan. Treatment options may include rest, ice, compression, elevation (RICE), physical therapy, pain medication, or, in some cases, surgery.
