Knee Anatomy & Regenerative Treatment Options

knee arthritis

Knee Anatomy & Regenerative Treatment Options

The knee is a hinge joint because the primary motions are in one plane. The two motions in this one plane are flexion (when the calf gets closer to the back of the thigh) and extension (when the knee moves toward its straight-leg position). The knee is a weight-bearing joint, so injuries and degeneration are common causes of knee pain. 

Knee Anatomy: Medial Condyle & Lateral Condyle

The knee joint is where the end of the thigh bone (femur) makes contact with the shin bone (tibia). The second bone in the calf, called the fibula, serves a role in muscular attachments but does not participate directly in joint function. The end of the femur flares out to create two rounded surfaces called condyles. If you reach down to your right knee with both hands (one on each side), your right hand is over the lateral aspect of your right knee, and your left hand is over the medial aspect. The atomical term medial means toward the body’s midline, and lateral means away from the midline. The two condyles are specifically named the lateral femoral condyle and the medial femoral condyle. The kneecap (patella) glides in a notch between the medial condyle and the lateral condyle.

Knee Anatomy: Articular Cartilage & Meniscus

Both the lateral condyle and the medial condyle, as well as the back surface of the patella, are covered by a layer of cartilage called articular cartilage. Articular cartilage has a smooth, firm, rubbery texture to allow joint surfaces to glide efficiently upon one another. The meniscus is attached to the top of the tibia and provides shock absorption. The meniscus is precisely shaped to accommodate the contours of the rounded condyles and is also identified as the lateral meniscus and the medial meniscus. On an MRI, a healthy meniscus appears like a black bowtie because the outer perimeter of the meniscus is much thicker than the tapering edge toward the center of the joint.

Knee Anatomy: Ligaments

The purpose of ligaments is to provide stability to a joint. The lateral collateral ligament connects the femur to the tibia on the lateral aspect of the knee. The medial collateral ligament provides the same function on the medial part of the knee. These ligaments are commonly referred to by their acronyms, LCL and MCL. A second pair of ligaments stabilize the knee from within, called the cruciate ligaments. They originate from the groove between the medial femoral condyle and the lateral femoral condyle called the intercondylar groove. The anterior cruciate ligament (ACL) derives from the back of this intercondylar groove and crosses in a forward (anterior) direction to insert into the front of the tibia. The posterior cruciate ligament (PCL) originates from the front aspect of the intercondylar groove and crosses backward (posterior) to insert into the back of the tibia. These ligaments allow the knee to remain stable while moving or standing.

Knee Injuries

The knee can be injured by a traumatic event such as an athletic injury or a fall. In such circumstances, there is typically a discreet injury to one or more structures. A ligament could be wholly or partially torn; the same is true for the meniscus. There can also be localized damage to the articular cartilage on the lateral or medial condyle. There are specific orthopedic surgical procedures for these injuries. Another type of knee injury is much more gradual and occurs through degeneration. This begins when the articular cartilage breaks down, damaging the tissue’s smooth, gliding function. Because cartilage tissue lacks an adequate blood supply, articular cartilage can never be restored to its original smooth surface. As cartilage continues to break down, it becomes thinner. With a thinner layer of cartilage between them, the joint’s bones now move closer together. Supporting joint ligament attachments are now also slightly closer together, which results in slack (laxity) of the supporting joint ligaments—adding instability to a joint from ligament laxity results in more advanced cartilage breakdown. This process is painful and leads to swelling and altered joint function. Walking, taking stairs, and even standing can become painfully difficult. This is the degenerative process known as osteoarthritis. 

Traditional Treatments for Knee Degeneration

There is the option to surgically replace knees when the degeneration has reached an advanced stage. There is growing interested in many people to intervene in some way before a knee joint reaches the stage where surgical replacement becomes the best option. As with every other medical condition, early intervention for knee osteoarthritis will result in the best outcome. Understanding the sequence of events representing the knee osteoarthritis process clarifies why specific non-surgical interventions are helpful. Activity modification helps minimize mechanical factors that may exceed what a given joint can tolerate. Weight loss is significant in decreasing the burden on weight-bearing knee joints. Physical therapy and independent exercise programs help to maintain a good range of motion and muscular strength to support ideal knee joint motion. Non-steroidal anti-inflammatory drugs (NSAIDs) are available to swallow, apply topically, or inject to address the inflammatory component of knee osteoarthritis. These medications help with the symptoms of pain, swelling, and stiffness, but they don’t change the degenerative process. NSAIDs can also cause organ damage with prolonged use. 

Steroid medications can be injected into arthritic knee joints and provide the same anti-inflammatory benefits of relieving pain, swelling, and stiffness. Steroids are more potent than NSAIDs, so the symptom relief is more prominent and lasts longer. Steroids, however, can cause or worsen many other health conditions and may eventually lead to the acceleration of articular cartilage degeneration with repeated injections. These factors limit the use of steroids for osteoarthritis.

Regenerative Treatments for Knee Osteoarthritis 

Regenerative Medicine is driven by an ever-increasing number of people who want to avoid joint replacement surgery for their knee osteoarthritis symptoms. Two specific treatments that are becoming progressively more popular are Bone Marrow Regenerative Cell Therapy and Platelet Rich Plasma (PRP) Therapy. 

Bone Marrow Regenerative Cell Therapy for the Knee

Your bone marrow is a rich source of regenerative cells that have the potential to accelerate healing. Your bone marrow occupies the hollow center cavities of your bones and is a “factory” for replacing cells that circulate in your bloodstream. Bone marrow regenerative cells recruit cell signaling recovery molecules (cytokines) and other healing cells to migrate into the injured area to assist with recovery. Bone marrow regenerative cells can be beneficial in restarting and accelerating the healing process of articular cartilage within a degenerative joint. Although the articular cartilage can never be restored to its original status, improvement in the “smoothness” of the articular cartilage can help slow the progression of osteoarthritis and help lessen pain. Regenerative cells can also stimulate improved integrity of the joint’s stabilizing ligaments. Addressing this laxity can also help slow the progression of osteoarthritis. Compared to purchasing “frozen regenerative cells in a vial,” using your own bone marrow regenerative cells ensures that no one else’s genetic material is injected into you; avoids the possibility of germ or other contamination introduced during processing; and guarantees that the cells have never been exposed to preservatives or subjected to a freeze/thaw cycle which potentially impacts their viability.

PRP (Platelet Rich Plasma) Therapy for the Knee

Your “whole blood” is primarily liquid (plasma) containing solid particles like red cells, white cells, and smaller platelets. During a PRP procedure, a syringe of your whole blood is obtained from your vein and then placed in a centrifuge to separate the plasma layer containing a high concentration of platelets. The desirable growth factors and other cytokines (cell signaling molecules) useful in healing are associated with platelets. After this platelet-rich layer of your plasma has been isolated, it can be injected back into your body to target an area of tissue damage in muscles, tendons, ligaments, or joints.

The Regenerative Spine & Joint Center specializes in non-surgical treatment for knee osteoarthritis. Learn more at or call us today at (614) 999-9899 to find out if Bone Marrow Regenerative Cell Therapy or PRP is a suitable options for your knees.

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I’m Boris Terebuh MD, Ohio’s first and most experienced Discseel® provider. I am also the Founder & Medical Director of the Regenerative Spine & Joint Center