What Does Uncovertebral Mean in the Cervical Spine?

“Uncovertebral” refers to a set of small joints unique to the cervical spine, formed where hook-shaped bony ridges on the sides of one vertebra meet the body of the vertebra above. These structures, formally called uncovertebral joints or joints of Luschka, play a meaningful role in guiding neck movement and protecting nearby nerves and blood vessels. The term shows up frequently on MRI and CT reports, usually when age-related wear has started changing the shape of these joints, and understanding what it means can take a lot of the anxiety out of reading your imaging results.

The Anatomy Behind the Name

Each cervical vertebra from C3 down to C7 has a pair of small, upward-pointing bony projections along the upper edges of its body, one on the left and one on the right. These are the uncinate processes, from the Latin word for “hook.” When the spine is stacked together, each uncinate process sits just beneath the outer rim of the vertebra above it, creating a shallow joint on each side. That joint is the uncovertebral joint. The name itself is a compound: “unco-” for the uncinate process below, and “-vertebral” for the vertebral body above.

These joints sit right at the back corners of the intervertebral disc, forming the inner wall of the bony tunnel (the foramen) through which spinal nerve roots exit the neck. The vertebral artery also runs nearby, passing through small holes in the transverse processes just lateral to the uncinate processes. That tight neighborhood of disc, nerve, and artery is exactly why uncovertebral joints matter clinically: when they change shape, the consequences can ripple into several important structures at once.¹

The vertebral bodies in the lower cervical spine are also characterized by the uncinate processes being involved in spinal stabilization, and the annulus fibrosus of the disc develops transverse fissures in close relation to these joints as degeneration progresses.²

What These Joints Do for Your Neck

Uncovertebral joints are not just passive landmarks. They actively shape how your neck moves. Their primary biomechanical role is regulating extension (tilting your head back), lateral bending (tilting ear toward shoulder), and rotation (turning your head side to side). The posterior portion of each joint is especially involved in controlling twisting motions.³

Biomechanical modeling of the cervical spine has shown that uncovertebral joints carry real contact forces during lateral bending and axial rotation. During head-turning, the uncovertebral joints on one side and the facet joints on the opposite side work together as a counterbalance system, sharing the load and keeping the motion stable. When researchers simulated removing the uncinate processes entirely, the range of motion in lateral bending and rotation increased substantially, while forward and backward bending was barely affected.⁴

Think of the uncinate processes as guide rails. Without them, the vertebrae above and below would slide too freely sideways and would twist too far. The joints essentially channel movement through a safe range, preventing the kind of unchecked side-to-side shifting that could pinch nerves or compress blood vessels.

How Uncovertebral Joints Degenerate

Like most joints in the body, uncovertebral joints wear down over time. The process is closely linked to what happens in the intervertebral disc between the same two vertebrae. As the disc loses water content and height with age, the space between the uncinate process and the vertebra above it narrows. That narrowing increases friction and mechanical stress on the joint surfaces, which the body responds to by growing extra bone, called osteophytes or bone spurs.⁵

A CT-based study of uncovertebral joint degeneration in a healthy population confirmed this cascade: as disc degeneration worsens and intervertebral height decreases, uncovertebral joint degeneration follows. The relationship runs in both directions, too. Because the uncovertebral joints normally help limit lateral motion, their breakdown can accelerate disc wear by allowing abnormal movement patterns. The result is a feedback loop where disc and joint degeneration worsen each other.⁶

This is the condition your imaging report is usually describing when it mentions “uncovertebral hypertrophy,” “uncovertebral spurring,” or “uncovertebral osteoarthritis.” These are all ways of saying that the joint has enlarged with extra bone. The lower cervical levels, particularly C5-C6 and C6-C7, tend to degenerate earliest and most severely because they bear the most mechanical load and undergo the most movement during everyday activities.

When Bone Spurs Start Pressing on Nerves

Uncovertebral osteophytes are among the most common causes of cervical radiculopathy, which is the medical term for a pinched nerve root in the neck. Because the uncovertebral joint forms the inner wall of the nerve exit tunnel, any extra bone growing from it projects directly into the path of the spinal nerve. The nerve root essentially gets squeezed between the osteophyte and the surrounding bone.

The symptoms depend on which nerve is compressed. You might feel sharp or burning pain radiating from your neck down into your shoulder, arm, or hand. Numbness, tingling, or weakness in specific muscles can follow, depending on the spinal level involved. These symptoms often worsen when you tilt or turn your head toward the affected side, because that motion further narrows the already-tight foramen.

With degeneration, the joints become clinically significant by compressing nearby structures, most importantly the spinal nerve root and the vertebral artery. The articulations have also been linked to torticollis (a fixed, tilted neck posture) when they become swollen or inflamed, and they can be damaged acutely in severe head and neck trauma.¹

If you see the phrase “uncovertebral hypertrophy causing foraminal narrowing” on your imaging report, that is the radiologist describing exactly this scenario: bone spurs from the joint have grown large enough to reduce the size of the nerve exit tunnel. Whether or not you have symptoms from it is a separate question. Many people have significant foraminal narrowing on imaging with no symptoms at all, which is why doctors treat the person and not just the scan.

Vertebral Artery Complications

The vertebral arteries run in a bony channel just lateral to the uncovertebral joints, making them vulnerable when osteophytes grow outward. In rare but serious cases, large uncovertebral bone spurs can compress or even occlude a vertebral artery, potentially reducing blood flow to the back of the brain.

Case reports have documented strokes linked to this mechanism. In one case, a 77-year-old man developed slurred speech upon waking, and imaging revealed a cerebellar stroke. The cause was traced to bilateral uncovertebral osteophytes at C5-C6 compressing both vertebral arteries.⁷

A related condition, rotational vertebral artery syndrome, occurs when head turning compresses the artery against a spur. Patients experience dizziness, visual disturbances, or near-fainting when they rotate their head to a particular position. In one reported case involving an osteophyte at C5-C6, the symptoms completely resolved after the uncovertebral joint was surgically removed and the segment was fused.⁸

These vascular complications are uncommon compared to nerve compression, but they are worth knowing about because the symptoms (dizziness, visual changes, or balance problems that worsen with head movement) can be confusing and easy to misattribute to inner-ear problems or other causes.

What “Uncovertebral” on Your Imaging Report Actually Means for You

If you are reading this because an MRI or CT report mentioned uncovertebral changes, some perspective is helpful. Degenerative changes at the uncovertebral joints are extremely common in adults and become nearly universal past middle age. The lower cervical spine is affected by degeneration across multiple structures simultaneously: the disc, the uncovertebral joints, and the facet joints at the back of the spine all tend to wear together.²

Radiologists describe what they see, and they report findings that may or may not be causing your symptoms. Phrases like “mild uncovertebral hypertrophy” or “uncovertebral spurring without significant foraminal stenosis” are generally reassuring: they indicate age-appropriate wear that is not pinching anything important. On the other hand, “moderate to severe foraminal stenosis secondary to uncovertebral osteophyte” paired with arm pain on the same side is a more meaningful finding because the imaging matches the clinical picture.

The key is correlation. A finding on a scan becomes clinically important when it lines up with specific symptoms. Your doctor will typically compare the level and side of the imaging abnormality against the pattern of your pain, numbness, or weakness before recommending any treatment beyond conservative measures.

Surgical Options When Conservative Treatment Fails

Most people with symptomatic uncovertebral degeneration improve with non-surgical approaches: physical therapy to strengthen the supporting neck muscles, anti-inflammatory medications, activity modifications, and sometimes targeted injections. Surgery enters the conversation when radiculopathy is severe, progressive, or has not responded to months of conservative care.

The most common surgical approach is anterior cervical discectomy and fusion, where the surgeon works from the front of the neck, removes the damaged disc, and sometimes also removes part or all of the offending uncinate process to free the compressed nerve. This uncinate process resection (often called uncinatectomy) directly addresses the bone spur responsible for foraminal narrowing. In cases of severe stenosis, removing the uncinate process during the fusion procedure can achieve complete nerve root decompression and significant symptom relief.⁹

However, there is some debate about whether aggressive uncinate removal is always necessary. When the disc is removed and the space is restored to its normal height with a spacer or cage, the osteophyte can sometimes resorb on its own over time as the mechanical stresses that caused it are eliminated. Symptoms can improve through this indirect decompression even without physically drilling away the bone spur.¹⁰

One concern with extensive uncinatectomy is the proximity of the vertebral artery. The uncinate process hypertrophy often extends laterally, right up to the edge of the foramen where the artery travels. Removing bone in that area requires precision to avoid vascular injury. Additionally, removing the uncinate process eliminates one of the spine’s natural motion-limiting structures, which can affect the alignment of the fused segment. Research has shown that fusion with partial uncinatectomy may have a small negative effect on cervical sagittal alignment compared to fusion alone, though both approaches provide satisfactory clinical outcomes.¹¹

Posterior approaches also exist. Endoscopic techniques that approach the osteophyte from behind the spine, sometimes using a bone tunnel through the lamina, have been developed specifically for cases where uncovertebral osteophytes are causing radiculopathy.¹² Transpedicular approaches, which create a path through the pedicle of the vertebra, have also been used to reach and remove osteophytes that are compressing the nerve root.¹³

Why Only the Cervical Spine Has Them

One detail that surprises many people: uncovertebral joints exist only in the neck. The thoracic and lumbar spine do not have uncinate processes, and therefore have no uncovertebral joints. This is not an accident of development but reflects the cervical spine’s unique combination of wide range of motion and the need to protect the vertebral arteries and dense bundle of nerve roots exiting at each level.

Comparative anatomy offers an interesting window into this. In baboons, whose cervical anatomy is broadly similar to ours, the uncovertebral joints are actually more prominent than in humans, even though the baboon spine is roughly half the size. Baboon vertebral endplates are also more concave, which may reflect different mechanical demands from quadrupedal posture.¹⁴

Across primates more broadly, the size and shape of uncinate processes vary with body size. Smaller primates tend to have taller, more pronounced uncinate processes relative to their vertebrae, while larger primates have comparatively reduced ones. Body size alone explains roughly half of the variation in uncinate shape across primate species, suggesting that the geometry of these structures is partly driven by the basic physics of supporting and moving the head.¹⁵

The Feedback Loop Between Disc and Joint

One of the more clinically relevant aspects of uncovertebral joint degeneration is how tightly it tracks with disc degeneration at the same level. This is not just a case of both structures wearing out at the same time by coincidence. The relationship is mechanical. As the disc loses height, the uncinate processes are pushed closer to the vertebra above, increasing contact pressure and friction. That accelerated contact drives osteophyte formation. Meanwhile, the breakdown of the uncovertebral joint’s ability to limit lateral motion feeds abnormal movement back into the disc, hastening further disc deterioration.⁶

This mutual reinforcement helps explain why cervical spondylosis tends to worsen in a stepwise fashion rather than gradually. A level can remain stable for years and then deteriorate relatively quickly once the cycle of disc-and-joint breakdown gains momentum. It also means that when surgeons fuse a level and restore disc height, they are breaking the mechanical cycle for both structures simultaneously, which is part of why fusion tends to be effective even when the osteophyte itself is not completely removed.

For people managing early or mild uncovertebral changes without surgery, this feedback loop underscores the value of maintaining good disc health through staying active, keeping neck muscles strong, and avoiding prolonged static postures that load the cervical spine unevenly. None of this will reverse existing osteophytes, but it can slow the mechanical cascade that drives further degeneration at a given level.