The knee is a complex structure. It consists of four bones, the joints between them, the ligaments that keep it stable, and the muscles that generate strength and motion. Your knees take a lot of stress from regular movements like walking, squatting, and going up and down stairs. The muscles that surround the knee are also used for motion in other joints like the hip or ankle. Because of this, lower extremity muscle balance is key. Knee problems can be caused by overuse, traumatic injury, and/or changes that occur naturally in your body.
Suffering from knee pain? Contact us to learn about treatment options.
How Your Knee Works
The knee consists of four bones: the kneecap (patella), the upper leg thigh bone (femur), and the two lower leg bones – the shin bone (tibia) and an outer bone (fibula). The thigh bone stacks on top of the shin bone, creating the true knee joint. The outer bone runs parallel with the shin bone of the lower leg; together they form the tibiofibular joint. The kneecap comes in contact with the thigh bone in the front of the knee to form the patellofemoral joint. In the space between the thigh bone and shin bone, there is a flexible rim of soft tissue called the meniscus. The meniscus is comprised of two c-shaped pieces, which help increase the stability of the knee and provide shock absorption.
There are four main ligaments in the knee that help provide stability. These ligaments are commonly injured in sports or during traumatic injuries. The anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) wrap around each other deep within the knee attaching the thigh bone to the shin bone. This helps prevent excessive pivoting of the knee and keeps the shin bone from moving forward or backward under the thigh bone. The medial collateral ligament (MCL) and the lateral collateral ligament (LCL) help keep the knee stable from side to side forces. The medial collateral ligament runs vertically along the inside of the knee, whereas the lateral collateral ligament runs vertically on the outside of the knee.
Surrounding the knee joint, there are three main groups of muscles that help power the knee for walking. The quadriceps muscles are located on the front of the thigh bone. They cross the knee over the knee cap attaching to the shin bone via the patellar tendon. On the backside of the thigh are the hamstring muscles, which cross the knee. Some hamstring tendons attach on the fibula while others attach to various places on the shin bone. In the back of the shin bone are the calf muscles (gastrocnemius). These attach to the heel and run up the back of the lower leg, connecting again behind the knee on the backside of the thigh bone.
There are many other muscles that play a role in the knee’s function and assist with tracking of the kneecap, including the IT band and gluteal muscles. In order for the knee to function properly, the bones, joints, ligaments, and muscles must all work in unison.
Evaluating Knee Pain
Evaluation for knee pain starts with you giving us a history of your problem: when and how it started, how it currently feels, and which treatments you have tried so far. We also ask you about other medical conditions that may contribute to your knee pain. We do a physical exam to test the structures of your knee. We check your knee’s range of motion and strength and do special tests that can uncover specific problems. Sometimes we will also check hip strength and range of motion, as this can play a role in your knee pain.
Based on the findings of your physical exam, we may use a cortisone injection as both a clinical test and treatment for your pain. The numbing medicine mixed in the injection helps us determine the source of your pain, whereas the cortisone medication of the injection can provide pain relief. Sometimes we order tests such as x-rays or MRIs to visualize your bones and soft tissues. X-rays can show us things like fractures, spurs, and changes from arthritis. MRIs can show us more detail of the bones, as well as soft tissue damage like tears of the ligaments or the meniscus.
Causes of Knee Pain
- Less common causes– infection, tumors, or nerve problems
Treating Knee Pain
Treatment of knee pain is very specific to the diagnosis and severity of your symptoms.