Knee pain when bending can disrupt daily activities. This discomfort often signals an underlying knee joint condition. Understanding the reasons for this pain is the first step to management. The knee, a hinge joint, relies on bones, cartilage, ligaments, and tendons.
Common Reasons for Pain When Bending
Patellofemoral pain syndrome (PFPS), or “runner’s knee,” frequently causes pain around or behind the kneecap when bending. It can present as a dull ache or sharp pain during activities like squatting, climbing stairs, or prolonged sitting. PFPS is associated with repeated stress on the kneecap, muscle imbalances, or alignment issues.
Osteoarthritis, a degenerative condition, commonly causes knee pain when bending. It occurs when protective cartilage cushioning bone ends wears away. This “wear and tear” leads to pain, swelling, and stiffness, worsening with movement and improving with rest. Cartilage deterioration results in less smooth joint gliding, causing friction and discomfort during flexion.
Meniscal tears frequently cause pain when bending the knee. The menisci are C-shaped cartilage pieces acting as shock absorbers between the thighbone and shinbone. A tear, often from a sudden twisting motion while bearing weight, can cause pain, swelling, difficulty bending or straightening, and sensations of locking or catching. Pain can be sharp, especially with twisting or squatting.
Patellar tendonitis, or “jumper’s knee,” involves inflammation of the patellar tendon, connecting the kneecap to the shinbone. This causes burning pain at the base of the kneecap, worsening with repetitive stress from activities like jumping or running. Pain is noticeable during flexion, especially under load.
Bursitis can cause pain when bending the knee. Bursae are small, fluid-filled sacs cushioning the outside of the knee. When inflamed due to repeated pressure or overuse, they cause swelling, warmth, and pain, making knee bending uncomfortable.
Iliotibial (IT) band syndrome causes pain on the outer side of the knee, which may spread to the hip or thigh. This condition involves inflammation of the IT band, a thick tissue band running along the outside of the thigh from the hip to just below the knee. Common in runners, it causes burning pain, especially when the knee flexes and extends, as the IT band rubs over the bony prominence.
When to Consult a Healthcare Professional
While minor knee pain might resolve with self-care, certain symptoms warrant professional medical attention. Seek evaluation if knee pain is severe or persists beyond a few days despite home remedies. Sudden onset of intense pain, especially if it limits movement or prevents bearing weight, indicates prompt assessment.
Other signs requiring consultation include significant or sudden swelling around the knee, visible deformity, or warmth and redness indicating inflammation or possible infection. A knee that locks, catches, or gives way, or a noticeable decrease in the ability to fully bend or straighten, signals a need for medical advice. If knee pain is accompanied by fever or other signs of general illness, seek immediate attention.
Immediate Steps for Relief
For immediate relief of knee pain when bending, especially after injury or overuse, the RICE protocol is a recommended first-aid approach. Rest involves stopping activities that aggravate pain to prevent further injury and allow healing. Apply ice to the affected area for 15-20 minutes every few hours to reduce pain and inflammation. Avoid applying ice directly to the skin by wrapping it in a towel.
Compression, achieved by wrapping the knee with an elastic bandage, helps minimize swelling and provides support. The bandage should be snug but not too tight to avoid restricting circulation. Elevating the injured knee above heart level, using pillows or cushions, promotes fluid drainage and reduces swelling. This elevation can alleviate throbbing. Gentle stretching and modifying activities to avoid painful movements contribute to comfort while the knee recovers.
Approaches to Treatment
Professional treatments for knee pain when bending are tailored to the specific diagnosis. Physical therapy is a common and effective conservative option, focusing on strengthening muscles around the knee, hip, and thigh to improve stability and support. Therapists guide individuals through exercises to enhance flexibility, balance, and movement patterns, reducing stress on the knee. Manual therapy techniques, such as gentle joint mobilization and soft tissue massage, may be incorporated to restore proper motion and decrease tension.
Medication can help manage pain and inflammation. Over-the-counter options like acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen are recommended for mild to moderate pain. Topical pain relievers, including creams with numbing agents or NSAIDs, provide localized relief. For severe cases, a healthcare provider may prescribe higher-dose NSAIDs or other medications.
Injections directly into the knee joint are a treatment option. Corticosteroid injections reduce inflammation and provide temporary pain relief, which may last months. Hyaluronic acid injections, similar to natural joint lubricating fluid, aim to improve mobility and ease pain, with effects potentially lasting six months. Platelet-rich plasma (PRP) injections, using components from an individual’s own blood, are sometimes used to promote tissue regeneration.
When conservative treatments do not provide sufficient relief, surgical interventions may be considered. Arthroscopic surgery is a minimally invasive procedure where small incisions allow a camera and instruments to address issues like torn cartilage or loose debris within the joint. For extensive damage, particularly from severe arthritis, partial or total knee replacement surgery may be necessary. Partial knee replacement targets only the damaged portion; total knee replacement replaces the entire joint surface with artificial implants. Osteotomy is another surgical option, involving bone removal to realign the knee and reduce pressure.