Cartilage does not contain nerves. It is one of the few tissues in the human body that is completely aneural, meaning no nerve fibers run through it. This is why cartilage damage can progress silently for years before you feel any pain. The pain you eventually feel from a cartilage problem comes from the richly innervated tissues surrounding it.
Why Cartilage Lacks Nerves
Articular cartilage, the smooth, slippery type that covers the ends of bones inside joints, is devoid of blood vessels, lymphatic channels, and nerves. It is a form of hyaline cartilage, typically 2 to 4 mm thick, and its job is to provide a low-friction surface for joint movement while absorbing and transmitting loads. The tissue gets its nutrients not from blood flow but from the synovial fluid that bathes the joint, which seeps into the cartilage matrix when the joint is compressed and released during movement.
This absence of nerves has a major practical consequence: cartilage injuries produce no direct pain signal. A chunk of cartilage can crack, fray, or wear away without triggering any sensation at all. This is part of why conditions like osteoarthritis often develop quietly, with significant cartilage loss already present by the time symptoms appear.
Where Joint Pain Actually Comes From
If cartilage itself can’t feel anything, why do cartilage problems hurt so much? The answer lies in the surrounding structures. The joint capsule, synovial membrane (the tissue lining the inside of the joint), and the subchondral bone just beneath the cartilage surface are all densely packed with sensory nerve endings that respond to pain, pressure, and inflammation.
When cartilage wears down, these neighboring tissues take the hit. The synovial membrane becomes inflamed, releasing chemical signals that sensitize nearby nerve endings and generate pain. The subchondral bone, which is laced with free nerve endings entering through tiny channels, becomes exposed to forces it was never meant to handle on its own. In late-stage osteoarthritis, when cartilage has broken down substantially, changes in the nerves within the subchondral bone appear to be a major driver of pain.
Bone-on-bone contact, swelling, and inflammation of the soft tissues around the joint all contribute to the pain experience. This is why two people with identical-looking cartilage loss on an X-ray can have very different pain levels: the state of the surrounding tissues matters as much as the cartilage itself.
The Meniscus: A Partial Exception
Not all cartilage is identical. The menisci in the knee are made of fibrocartilage, a tougher, more fibrous variety, and they follow a different rule. The outer two-thirds of each meniscus body contains nerve fibers, including pain receptors and several types of sensors that detect pressure, stretch, and joint position. The anterior and posterior horns of the menisci (the points where they anchor to the bone) are richly innervated throughout, with an even denser concentration of nerves than the body.
The inner third of the meniscus, however, is thin, has a more hyaline-like quality, and lacks nerve supply entirely. This is why the location of a meniscus tear matters for symptoms. A tear in the outer zone can be acutely painful. A tear in the inner zone may produce mechanical symptoms like catching or locking but less direct pain.
Cartilage Cells Still Sense Pressure
Even though cartilage has no nerves, the cells within it (called chondrocytes) are not oblivious to their mechanical environment. Chondrocytes have their own system for detecting physical forces. They contain specialized ion channels in their membranes that change shape under loading, hair-like projections called cilia that extend into the surrounding matrix and respond to force, and proteins called integrins that connect the cell to its surroundings and relay mechanical information.
When you walk, jump, or compress a joint, these structures convert physical force into chemical signals inside the cell. This process helps chondrocytes regulate their behavior, maintaining the cartilage matrix and responding to changes in load. But none of this produces anything you consciously feel. It is an entirely local, cellular conversation that never reaches the brain as sensation.
Nerves Can Invade Damaged Cartilage
One striking finding in osteoarthritis research is that the aneural status of cartilage is not always permanent. As joints degenerate, new blood vessels begin growing into areas that are normally avascular, and sensory nerves follow along with them. These nerves can eventually penetrate into the noncalcified articular cartilage, into bony growths called osteophytes that form at the joint margins, and into the inner regions of the menisci that are normally nerve-free.
This process is driven by shared biological pathways. The same growth factors that stimulate new blood vessel formation also promote nerve growth. The result is that a tissue which was once completely insensitive can become a source of pain signals. This nerve ingrowth is one reason that osteoarthritis pain tends to worsen over time and may help explain why some people experience pain that seems disproportionate to the visible joint damage.
Why Healing Is So Slow
The lack of nerves is part of a broader problem. Cartilage also has no blood supply, which means it has no easy way to deliver the cells, nutrients, and inflammatory signals that drive tissue repair elsewhere in the body. When you cut your skin, blood rushes to the site, clots form, immune cells arrive, and new tissue grows. None of that happens in cartilage.
Cartilage defects tend to either remain as they are or slowly enlarge over time. The tissue has very limited capacity to regenerate on its own. This is the central challenge in orthopedic medicine: a tissue that works beautifully under normal conditions but has almost no ability to fix itself once damaged. Surgical techniques like microfracture (which creates tiny holes in the underlying bone to encourage healing) essentially try to work around this limitation by introducing blood and stem cells into the cartilage layer from below, though the repair tissue that forms is often fibrocartilage rather than the original hyaline type.