Meniscus Injuries

Each knee contains two menisci: the medial meniscus on the inner side of the joint and the lateral meniscus on the outer side. Each is a C-shaped wedge of tough fibrocartilage that sits between the thigh bone (femur) and the shin bone (tibia). The menisci deepen the relatively flat surface of the tibia, absorb shock, distribute load across the joint, and contribute to stability. Each meniscus is anchored to the bone at its front and back ends by strong attachments called roots, which allow it to hold its shape and resist being pushed out of the joint under load.

These structures are not expendable. When meniscal tissue is lost, the contact pressure on the articular cartilage rises sharply, which is why patients who have had a meniscus removed are at meaningfully higher risk of developing arthritis in that compartment years later. Preserving meniscal tissue whenever possible is one of the central principles of modern knee surgery.

Only the outer portion of the meniscus has a meaningful blood supply. Tears in this outer “red zone” have the best potential to heal, while tears in the inner “white zone” have poor blood supply and limited healing potential.

Meniscus injuries fall into two broad categories:

• Traumatic tears: These occur most often in younger, active patients during a twisting or pivoting motion, a deep squat, or a sudden change in direction. They frequently accompany an ACL tear.
• Degenerative tears: These develop gradually as the tissue becomes more brittle with age, and they often occur with little or no injury at all, sometimes from something as ordinary as standing up from a low chair.

Tear patterns matter as much as the cause:

• Vertical and bucket-handle tears: Tears that run along the length of the meniscus, often in the better-vascularized outer portion, and are frequently repairable. A bucket-handle tear is a large vertical tear in which the inner fragment flips into the center of the knee.
• Radial, horizontal, and complex tears: Tears that extend into the inner zone or have multiple planes, which often have less healing potential.
• Root tears: Tears in which the meniscus detaches from its anchor on the bone. Biomechanically, a root tear functions much like removing the entire meniscus, and identifying and repairing one can change the long-term trajectory of the knee.
• Ramp lesions: Tears at the back of the medial meniscus where it attaches to the capsule, commonly seen with ACL tears and easily missed on MRI.

Other factors can increase the risk of a meniscus tear, including ACL deficiency, malalignment that overloads one side of the knee, and a discoid meniscus, a congenitally thickened, disc-shaped lateral meniscus that is more prone to tearing.

Symptoms depend on the size, location, and pattern of the tear. Dr. Rynecki Baker encourages patients not to ignore mechanical symptoms such as catching or locking, as a displaced tear can damage the articular cartilage over time and may become unrepairable if treatment is delayed.

Common symptoms include:

• Joint line pain: Pain localized to the inner or outer side of the knee, along the line of the joint, often reproduced by pressing directly over that spot.
• Swelling: Fluid that develops gradually over the day or two following the injury, rather than the immediate swelling typical of an ACL tear, and that may recur with activity.
• Catching, clicking, or locking: A sense that something is caught inside the knee. A knee that becomes stuck and cannot be fully straightened, known as a locked knee, usually indicates a displaced bucket-handle tear and warrants urgent evaluation.
• Pain with twisting, squatting, or pivoting: Discomfort with deep bending, getting in and out of a car, or rotating on a planted foot.
• Giving way: A feeling of instability or buckling, particularly when a torn fragment shifts within the joint.

Stiffness and loss of motion: Difficulty fully straightening or bending the knee, which may be caused by swelling or by a displaced fragment blocking motion.

Accurate diagnosis begins with a thorough evaluation by Dr. Rynecki Baker. She will take a detailed history, including whether the pain began with a specific injury, whether the knee has locked or caught, and which activities reproduce the symptoms. She will then perform a physical exam assessing range of motion, swelling, gait, and ligament stability, along with specific maneuvers, including joint line palpation, the McMurray test, and the Thessaly test, that help localize the tear and distinguish it from other sources of knee pain.

X-rays do not show the meniscus itself but are essential for assessing the joint space, identifying existing arthritis, and evaluating alignment, all of which influence treatment. Full-length standing x-rays may be obtained when malalignment is suspected, since a bowlegged or knock-kneed limb places excess load on one compartment and affects both the durability of a repair and the appropriateness of surgery. MRI is the gold standard for visualizing the meniscus and defines the tear pattern, its location relative to the blood supply, and any associated ligament or cartilage injury.

One nuance is worth emphasizing. Meniscal changes appear on MRI in a large proportion of adults over the age of forty who have no knee symptoms at all. An MRI report describing a tear does not automatically mean that tear is the source of a patient’s pain, and it does not automatically mean surgery. Dr. Rynecki Baker treats the patient and the exam findings, not the imaging in isolation.

The decisions made about a meniscus tear have consequences well beyond the first year. Whether tissue is repaired or removed, whether a root tear is recognized, and whether an associated ligament injury or malalignment is addressed all influence the health of the knee decades later. Dr. Rynecki Baker’s training at both NYU Langone Health and Hospital for Special Surgery, combined with her published research in sports medicine, means patients are receiving care from a specialist with deep knowledge of knee mechanics and joint preservation.

She also understands this injury from the patient’s side. A former collegiate soccer player, Dr. Rynecki Baker underwent multiple knee surgeries of her own, including a meniscus repair with an ACL reconstruction and a meniscectomy, and returned to play. She understands the mental side of a knee injury as well as the physical one.

She approaches every patient as an individual, taking the time to understand each person’s symptoms, sport, and goals before recommending treatment, and she is candid when the right answer is not surgery. If you are experiencing knee pain, swelling, or a knee that catches or locks, contact Dr. Nicole Rynecki Baker’s office today to schedule a consultation.