Table of ContentsView AllTable of ContentsInner Knee PainOuter Knee PainOther CausesDiagnosisTreatmentPreventionWhen to Contact a Healthcare Provider
Table of ContentsView All
View All
Table of Contents
Inner Knee Pain
Outer Knee Pain
Other Causes
Diagnosis
Treatment
Prevention
When to Contact a Healthcare Provider
Knee painmay be felt on the inner or outer side of the knee joint depending on which tissues or structures are affected. In addition to pain, you may experience knee instability and a reduced range of motion.
This article describes the possible causes of pain on the side of your knee, including how the different conditions are diagnosed and treated.
Verywell / Laura Porter
Causes of Inner Knee Pain
The inside (medial) portion of the knee contains an array of bones,ligaments, and soft tissues, all contained within a relatively small area. Because these structures are so densely packed, it can sometimes be difficult to pinpoint the exact cause of your pain.
Here are some of the more common causes of medial knee pain:
Medial Compartment Osteoarthritis
Osteoarthritis (OA) of the knee occurs when the slippery cartilage that covers the end of your thighbone (femur) and shinbone (tibia) starts to deteriorate. OA frequently affects the medial portion of the knee, known as themedial tibiofemoralcompartment.
With OA, the increasing friction between joints not only causes pain but also limits therange of motionof the knee. It can also cause the abnormal remodeling of bone, leading to bone spurs (osteophytes).
Symptoms of medial knee OA include:
Knee OA is associated with aging and can develop as a result ofrepetitive knee stress, previous knee injury, and other factors such as genetics and obesity.
Runner’s Knee: Recovering From Acute or Severe Symptoms
Medial Meniscus Tear
Themeniscusis a C-shaped piece of cartilage that acts as a cushion between the femur and tibia. Each knee has twomenisci.
Occasionally, the medial portion of yourmeniscus can tearand lead to pain on the inside of the knee. It can happen suddenly after your leg is sharply twisted during sports or exercise. A tear might also occur as a result of aging-related wear and tear.
Symptoms of a medial meniscus tear include:
MCL Injury
The medial collateral ligament (MCL) is a band of fibrous tissue that runs from the femur to the tibia on the inside of your knee. This ligament provides stability and prevents the knee from buckling inward.
Symptoms of an MCL sprain or tear include:
Pes Anserine Bursitis
One of the less common causes of inner knee pain ispes anserine bursitis. This occurs when a fluid-filled sac in the knee, called abursa, becomes inflamed. This sac acts as a cushion between the tibia and the three maintendonsservicing theadductor musclesof the knee.
Pes anserine bursitis is common in people who engage in repetitive sports such as running or cycling.
Symptoms of pes anserine bursitis include:
With pes anserine bursitis, the pain typically eases or resolves with rest.
Knee Pain When Walking: Potential Causes and What to Do Next
Causes of Outer Knee Pain
As with the inside of your knee, the outside (lateral) portion of the knee joint is a crossroads of many different structures. Because of the complexity of the knee joint, these structures are vulnerable to both long- and short-term injury.
Here are some of the more common causes of lateral knee pain:
Lateral Compartment Osteoarthritis
Along with the inside compartment of the knee and kneecap, OA can also affect the lateral portion of the knee (called the lateral tibiofemoral compartment).
The causes and symptoms of lateral compartment OA mirror those of medial compartment OA. The only real difference is that the pain is experienced on the outside of the knee.
The anatomy, biomechanics, and kinematics (degree of motion) of the outer knee are less prone to wear and tear than the inner knee. For this reason, lateral compartment OA is less common than medial compartment OA.
Lateral Meniscus Tear
Lateral meniscal tearsare another frequently seen cause of outer knee pain. The outer portion of the meniscus is prone to tearing, either as a result of a twisting injury or age-related degeneration.
While the symptoms of a lateral meniscus tear mirror those of a medial meniscus tear, there are key differences. With a lateral tear, your ability to rotate the knee is more affected than your ability to fully straighten or bend the knee.
Moreover, the non-weight-bearing stability of the knee tends more significantly impacted than with a medial meniscus tear.
LCL Injury
Similar to the MCL, the LCL is frequently sprained or torn after a sudden twist or change in direction. Direct blows to the inside of the knee can also damage the LCL.
Outside of its location, the symptoms of an LCL tear are largely the same as those of an MCL tear. However, because the ligament is situated close to theperonealnerve(which supplies movement and sensation to the lower leg), an LCL injury can compress the nerve and cause numbness orpins-and-needles sensationsin the foot.
IT Band Syndrome
Iliotibial(IT) band syndromeis another cause of lateral knee pain common in runners. The IT band is a long strip of connective tissue that runs down the outside of your thigh from the pelvis to the knee.
IT band syndrome is thought to occur when the bottom portion of the band begins to rub or pinch against the end of the femur bone. The friction, which occurs repeatedly when running, eventually leads to knee pain and soreness.
Symptoms of IT band syndrome include:
Like pes anserine bursitis, the pain from IT band syndrome typically worsens with activity and improves with rest.
Other Causes of Side Knee Pain
Baker’s Cysts
Baker’s cysts, orpoplitealcysts, are one of the most common knee disorders. A cyst is a fluid-filled lump. It can show up on the back of the knee and cause stiffness and discomfort.
These cysts are usually the result of an existing knee problem, like osteoarthritis or a meniscus tear. Most improve with changes in activity and anti-inflammatory medication. Some may go away on their own, while others may require surgery.
Osgood-Schlatter Disease
Common in growing adolescents,Osgood-Schlatter diseaseis an inflammation just below the knee, where thepatella (kneecap)attaches to the tibia. It usually occurs during growth spurts. This is when bones, muscles, and tendons undergo rapid change. Participating in activities like running and jumping sports increases a person’s risk for this condition.
Simple measures like rest, ice, and over-the-counter (OTC) medication can help relieve the pain in most cases. Stretching and strengthening exercises are also beneficial.
Cancer
Bone cancer or cancer that spreads to the bones may cause knee pain.
Bone cancer tends to be more common in people who have family members with cancer. Bone fractures (especially from slight injury), bone pain that may be worse at night, and sometimes a mass or swelling at the site can indicate bone cancer.
Infection
Symptoms include extreme swelling, sudden pain, fever, and chills. It’s rare for septic arthritis to affect more than one joint, so you’ll likely have pain in only one knee. Treatment can include antibiotics and joint drainage.
Injury
Injury to the knee joint is fairly common. The knee is vulnerable not only to ligament tears and sprains but also to dislocations and fractures.
Fractures of the bones around the knee joint, like the femur can cause the bone to shatter. The bone fragments will sometimes enter the joint.
Patellar subluxations and dislocations can also occur. Apatellar subluxationhappens when the patella slides partway out of its groove. Aknee dislocationoccurs when the patella is fully out of its groove. These injuries can result from normal movement, twisting your knee, or bumping your patella from the side.
The diagnosis of side knee pain starts with a review of your symptoms and medical history along with a physical examination of the knee.
To help pinpoint the cause, the healthcare provider may ask:
For some conditions, a diagnosis can be made based on these pieces of information alone.
At other times, imaging tests may be needed to confirm the diagnosis, the options of which include:
At-Home Treatment
Some milder knee injuries can be managed at home with the following self-care treatments:
Medical Options
If an injury is severe or you have ongoing pain despite rest and home treatment, there are several treatments your healthcare provider may recommend, including:
Prevention for knee pain comes in many forms and will depend on the underlying condition. Here are some tips based on what may be causing knee pain.
Signs that you need to see a healthcare provider for knee pain include the following:
Summary
Side knee pain has several possible causes, most commonly osteoarthritis or tear and sprain injuries. The pain can affect the inner (medial) side of the knee or the outer (lateral) side.
The symptoms of side knee pain are similar, but the side that is affected can be a helpful clue in diagnosing the condition. For example, IT band syndrome is associated with lateral knee injury while inner knee pain may be due to pes anserine bursitis.
Treatment will depend on the type of injury, severity, and your overall health. Minor injuries often are treated successfully at home but surgery may be needed to repair damage from conditions like a meniscus tear. Your healthcare provider can discuss your options with you.
A Word From Verywell
—ANITA C. CHANDRASEKARAN, MD, MEDICAL EXPERT BOARD
19 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Lespasio M.Knee osteoarthritis: a primer.TPJ. 2017;21(4). doi:10.7812/TPP/16-183American Academy of Orthopaedic Surgeons.Meniscus tears.Michigan Medicine.Medical collateral ligament (MCL) injury.American Academy of Orthopaedic Surgeons.Pes anserine (knee tendon) bursitis.Scott CEH, Nutton RW, Biant LC.Lateral compartment osteoarthritis of the knee: biomechanics and surgical management of end-stage disease.Bone Joint J. 2013 Apr;95-B(4):436-44. doi:10.1302/0301-620X.95B4.30536Grassi A, Dal Fabbro G, Di Paolo S, et al,Medial and lateral meniscus have a different role in kinematics of the ACL-deficient knee: a systematic review.J ISAKOS, 2019;4(5):233-41. doi:10.1136/jisakos-2019-000293Cedars Sinai.Lateral collateral ligament tears.Aderem J, Louw QA.Biomechanical risk factors associated with iliotibial band syndrome in runners: a systematic review.BMC Musculoskelet Disord. 2015;16(1):356. doi:10.1186/s12891-015-0808-7American Academy of Orthopaedic Surgeons.Baker’s cyst (popliteal cyst).American Academy of Orthopaedic Surgeons.Osgood-Schlatter disease (knee pain).MedlinePlus.Knee pain.MedlinePlus.Bone tumor.Arthritis Foundation.Infectious arthritis.American Academy of Orthopaedic Surgeons.Common knee injuries.American Academy of Orthopaedic Surgeons.Distal femur (thighbone) fractures of the knee.MedlinePlus.Kneecap dislocation - aftercare.Pate DR, Villalobos A.Evaluation and management of knee pain in young athletes: overuse injuries of the knee.Transl Pediatr.2017 Jul;6(3):190–8. doi:10.21037/tp.2017.04.05Davis AC, Emptage NP, Pounds D, et al.The effectiveness of neuromuscular warmups for lower extremity injury prevention in basketball: A systematic review.Sports Med Open. 2021;7:67. doi:10.1186/s40798-021-00355-1Arthritis Foundation.Arthritis pain relief and shoe inserts.
19 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Lespasio M.Knee osteoarthritis: a primer.TPJ. 2017;21(4). doi:10.7812/TPP/16-183American Academy of Orthopaedic Surgeons.Meniscus tears.Michigan Medicine.Medical collateral ligament (MCL) injury.American Academy of Orthopaedic Surgeons.Pes anserine (knee tendon) bursitis.Scott CEH, Nutton RW, Biant LC.Lateral compartment osteoarthritis of the knee: biomechanics and surgical management of end-stage disease.Bone Joint J. 2013 Apr;95-B(4):436-44. doi:10.1302/0301-620X.95B4.30536Grassi A, Dal Fabbro G, Di Paolo S, et al,Medial and lateral meniscus have a different role in kinematics of the ACL-deficient knee: a systematic review.J ISAKOS, 2019;4(5):233-41. doi:10.1136/jisakos-2019-000293Cedars Sinai.Lateral collateral ligament tears.Aderem J, Louw QA.Biomechanical risk factors associated with iliotibial band syndrome in runners: a systematic review.BMC Musculoskelet Disord. 2015;16(1):356. doi:10.1186/s12891-015-0808-7American Academy of Orthopaedic Surgeons.Baker’s cyst (popliteal cyst).American Academy of Orthopaedic Surgeons.Osgood-Schlatter disease (knee pain).MedlinePlus.Knee pain.MedlinePlus.Bone tumor.Arthritis Foundation.Infectious arthritis.American Academy of Orthopaedic Surgeons.Common knee injuries.American Academy of Orthopaedic Surgeons.Distal femur (thighbone) fractures of the knee.MedlinePlus.Kneecap dislocation - aftercare.Pate DR, Villalobos A.Evaluation and management of knee pain in young athletes: overuse injuries of the knee.Transl Pediatr.2017 Jul;6(3):190–8. doi:10.21037/tp.2017.04.05Davis AC, Emptage NP, Pounds D, et al.The effectiveness of neuromuscular warmups for lower extremity injury prevention in basketball: A systematic review.Sports Med Open. 2021;7:67. doi:10.1186/s40798-021-00355-1Arthritis Foundation.Arthritis pain relief and shoe inserts.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Lespasio M.Knee osteoarthritis: a primer.TPJ. 2017;21(4). doi:10.7812/TPP/16-183American Academy of Orthopaedic Surgeons.Meniscus tears.Michigan Medicine.Medical collateral ligament (MCL) injury.American Academy of Orthopaedic Surgeons.Pes anserine (knee tendon) bursitis.Scott CEH, Nutton RW, Biant LC.Lateral compartment osteoarthritis of the knee: biomechanics and surgical management of end-stage disease.Bone Joint J. 2013 Apr;95-B(4):436-44. doi:10.1302/0301-620X.95B4.30536Grassi A, Dal Fabbro G, Di Paolo S, et al,Medial and lateral meniscus have a different role in kinematics of the ACL-deficient knee: a systematic review.J ISAKOS, 2019;4(5):233-41. doi:10.1136/jisakos-2019-000293Cedars Sinai.Lateral collateral ligament tears.Aderem J, Louw QA.Biomechanical risk factors associated with iliotibial band syndrome in runners: a systematic review.BMC Musculoskelet Disord. 2015;16(1):356. doi:10.1186/s12891-015-0808-7American Academy of Orthopaedic Surgeons.Baker’s cyst (popliteal cyst).American Academy of Orthopaedic Surgeons.Osgood-Schlatter disease (knee pain).MedlinePlus.Knee pain.MedlinePlus.Bone tumor.Arthritis Foundation.Infectious arthritis.American Academy of Orthopaedic Surgeons.Common knee injuries.American Academy of Orthopaedic Surgeons.Distal femur (thighbone) fractures of the knee.MedlinePlus.Kneecap dislocation - aftercare.Pate DR, Villalobos A.Evaluation and management of knee pain in young athletes: overuse injuries of the knee.Transl Pediatr.2017 Jul;6(3):190–8. doi:10.21037/tp.2017.04.05Davis AC, Emptage NP, Pounds D, et al.The effectiveness of neuromuscular warmups for lower extremity injury prevention in basketball: A systematic review.Sports Med Open. 2021;7:67. doi:10.1186/s40798-021-00355-1Arthritis Foundation.Arthritis pain relief and shoe inserts.
Lespasio M.Knee osteoarthritis: a primer.TPJ. 2017;21(4). doi:10.7812/TPP/16-183
American Academy of Orthopaedic Surgeons.Meniscus tears.
Michigan Medicine.Medical collateral ligament (MCL) injury.
American Academy of Orthopaedic Surgeons.Pes anserine (knee tendon) bursitis.
Scott CEH, Nutton RW, Biant LC.Lateral compartment osteoarthritis of the knee: biomechanics and surgical management of end-stage disease.Bone Joint J. 2013 Apr;95-B(4):436-44. doi:10.1302/0301-620X.95B4.30536
Grassi A, Dal Fabbro G, Di Paolo S, et al,Medial and lateral meniscus have a different role in kinematics of the ACL-deficient knee: a systematic review.J ISAKOS, 2019;4(5):233-41. doi:10.1136/jisakos-2019-000293
Cedars Sinai.Lateral collateral ligament tears.
Aderem J, Louw QA.Biomechanical risk factors associated with iliotibial band syndrome in runners: a systematic review.BMC Musculoskelet Disord. 2015;16(1):356. doi:10.1186/s12891-015-0808-7
American Academy of Orthopaedic Surgeons.Baker’s cyst (popliteal cyst).
American Academy of Orthopaedic Surgeons.Osgood-Schlatter disease (knee pain).
MedlinePlus.Knee pain.
MedlinePlus.Bone tumor.
Arthritis Foundation.Infectious arthritis.
American Academy of Orthopaedic Surgeons.Common knee injuries.
American Academy of Orthopaedic Surgeons.Distal femur (thighbone) fractures of the knee.
MedlinePlus.Kneecap dislocation - aftercare.
Pate DR, Villalobos A.Evaluation and management of knee pain in young athletes: overuse injuries of the knee.Transl Pediatr.2017 Jul;6(3):190–8. doi:10.21037/tp.2017.04.05
Davis AC, Emptage NP, Pounds D, et al.The effectiveness of neuromuscular warmups for lower extremity injury prevention in basketball: A systematic review.Sports Med Open. 2021;7:67. doi:10.1186/s40798-021-00355-1
Arthritis Foundation.Arthritis pain relief and shoe inserts.
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