If your knee MRI shows nothing but pain persists, it often means the issue isn't a major structural tear, but rather subtle inflammation (tendinitis, bursitis), nerve irritation, patellofemoral pain syndrome (runner's knee), or functional problems, requiring deeper investigation through physical exams, advanced scans (like MRI arthrogram), or exploring nerve/soft tissue issues with EMG or ultrasound, as MRI isn't always perfect.
It's not unusual for patients who are suffering with knee pain to have a “negative” MRI. This situation is relatively common. In cases of a strain or inflammation the MRI may indeed be negative for structural problems.
This article highlights five knee injuries that, in the author's experience, are commonly overlooked by readers inexperienced in knee MRI: ramp lesions, meniscocapsular tears, meniscal root ligament tears, posterior capsular ligament tears, and partial anterior cruciate ligament tears.
It can be caused by a variety of factors, including injury, overuse, and arthritis. In some cases, people may experience knee pain even when their doctor says nothing is wrong. A doctor will typically diagnose knee pain by taking a medical history, performing a physical exam and ordering imaging tests.
If your magnetic resonance imaging (MRI) scan came back normal, but you're still in pain, it may have failed to detect an injury. Even with advanced diagnostic imaging like MRI scans, some injuries, including soft tissue injuries and nerve damage, can be challenging to identify definitively.
Nerve Irritation Without Compression
Nerves don't need to be visibly pinched to cause pain. Subtle irritation, inflammation, or tension can disrupt nerve signaling and create symptoms without appearing on MRI.
However, meniscus tears do not always appear on MRIs. Meniscus tears, indicated by MRI, are classified in three grades. Grades 1 and 2 are not considered serious. They may not even be apparent with an arthroscopic examination.
Serious knee pain involves severe swelling, deformity, inability to bear weight or move the knee, intense pain after a major injury (especially with a "pop"), fever with redness/warmth, or persistent instability, signaling potential fractures, ligament tears, or infection requiring immediate medical attention. Less severe but persistent pain, difficulty with daily activities, or locking/popping needs a doctor's evaluation if it doesn't improve with rest and home care.
Most knee pain that's not related to a direct injury involves the connective tissues (ligaments and tendons) or cartilage.
Identifying Knee Pain Red Flags
Severe swelling: If your swollen knee feels warm and looks red, it might be a condition requiring medical evaluation. Inability to bear weight: If you have difficulty putting weight on your knee, it may indicate a serious injury.
MRI has been quoted in the literature as being only about 76% accurate for medial meniscal tears, 75% accurate for lateral meniscal tears1 and about 86% accurate for diagnosing ACL tears2. Therefore, for even the most common knee injuries MRI can miss up to ¼ of all potential actual pathologies!
It's almost always in just one spot. Typically, people with a hairline fracture won't have pain until they're walking or running on it. The pain will appear during exercise; for example, they can run two miles with no problem but as soon as they get to two and a half miles, they experience pain.
Three key signs of a meniscus tear are pain (especially with twisting or bending), swelling and stiffness, and a catching, locking, or popping sensation in the knee, sometimes accompanied by difficulty fully straightening the leg. You might feel a "pop" at the moment of injury, and symptoms often worsen over a few days.
Knee pain may be the result of an injury, such as a ruptured ligament or torn cartilage. Medical conditions — including arthritis, gout and infections — also can cause knee pain. Many types of minor knee pain respond well to self-care measures. Physical therapy and knee braces also can help relieve pain.
Because bursitis and tendonitis pain may be felt near the joints, it is sometimes mistaken for arthritis. Knowing the differences between these conditions can help you identify and address the root cause of your joint pain to get you back to an active life.
Diagnosing a knee injury or problem includes a medical examination and usually the use of a diagnostic procedure(s) such as an x-ray, MRI, CT scan or arthroscopy. Both non-operative and surgical treatment options are available to treat knee pain and problems depending on the type and severity of the condition.
Several common injuries might cause knee discomfort without any noticeable swelling. These include strains, sprains, and tendon injuries.
Learn about the ten signs you shouldn't ignore when dealing with knee pain.
In the front of your knee: Common causes of pain here include arthritis, bursitis or patellofemoral pain syndrome. Behind your knee: Tendon and ligament injuries, arthritis, Baker's cysts or overly tight leg muscles can all cause pain here.
Swelling or stiffness. Pain, especially when twisting or rotating your knee. Difficulty straightening your knee fully. Feeling as though your knee is locked in place when you try to move it.
The #1 mistake making bad knees worse is excessive rest and a sedentary lifestyle, leading to weaker supporting muscles, stiffness, and a vicious cycle of more pain; instead, gentle, consistent movement (like walking, swimming) is crucial to strengthen the joint and improve function, though it must be balanced with avoiding activities that cause sharp pain. Other major errors include ignoring pain signals, carrying excess weight, wearing unsupportive shoes, and poor movement patterns, says Parkside Sports Physiotherapy and Coastal Empire Orthopedics.
Knee bursitis is swelling, also called inflammation, of one or more of the bursae in the knee. Knee bursitis is a condition in which one or more small fluid-filled sacs near the knee joint become inflamed. The sacs are called bursae.
Symptoms may go away but can come back from overuse or when you do activities that involve twisting. The pain may come and go over a period of years if the tear isn't treated. Larger tears usually cause more pain and immediate swelling and stiffness.
The overall sensitivity and specificity of MRI in diagnosing medial meniscus tears were found to be 87.9% and 75.3%, respectively, with an accuracy of 81.7%.
Common extra-articular pathologies that can mimic lateral meniscal tears include iliotibial band syndrome, proximal tibiofibular joint instability, snapping biceps femoris or popliteus tendons, and peroneal nerve compression syndrome or neuritis.