UncoVertebral Joint Luschka

Uncovertebral joint Luschka is a frequent cause of tingling in arms and hands; it is a slender piece of bone that is easily damaged and even fractured in whiplash injuries, especially if you are T boned.

Then it gradually becomes arthritic with tiny spurs entering the intervertebral foramen.

Paresthesias in the upper limb, often with a deep radiating ache, and a whole spectrum of conditions like frozen shoulder, rotator cuff syndrome, and carpal tunnel are frequent complaints in the chiropractic clinics.

In fact, I would go as far as to say that there is barely a chiropractor in the whole world who won't be faced with at least one patient every day suffering from one of these syndromes, directly related to uncovertebral hypertrophy.

The origin of them lies very frequently in the so called UncoVertebral Joints, named after a German anatomist, Hubert Luschka more than 150 years ago.

In most of the spine there are three joints between the vertebrae:

• One disc
  
• Two facet
  

UncoVertebral Joint of Luschka

However, in the lower cervical spine, between the lowermost five bones C3, C4, C5, C6 and C7 are four extra pairs of joints that allow forward flexion and rotation of the neck, whilst limiting lateral translation and lateral flexion: The movements that occur in a side-on (broadside, T-bone collision) whiplash. Or, that occur if your head and neck were turned during a rear-end collision.

These four pairs of joints have been given various names: Joints of Luschka, UncoVertebral joints, paracentric joints, neurocentric joints. And others.

The Uncus or Uncinate process

At the lateral edge of the vertebral body, small ridges of bone jut upwards forming a joint between the uncinate and the vertebral body above. Anatomists argue about the true nature of the UncoVertebral Joint Luschka but on the whole there seems agreement that they are synovial joints.

The inner (medial) surface of the uncus is covered with conventional hyaline cartilage as is the corresponding undersurface of the side of the vertebral body where a concave area is also lined with cartilage. The joint of Luschka. It is covered with a synovial membrane which contains the synovial fluid which brings nutrients to the hyaline cartilage lining the joint surfaces.

Clinical significance

The term "neurocentric" joint is often used today because of the important relationship between the uncovertebral joint Luschka and the mixed nerve root, containing both incoming sensory input, and outgoing motor nerves.

Hence, any uncovertebral hypertrophy (read arthritis) can cause both tingling in arms and hands, arm pain, and weakness in the arms and hands.

The Luschka joints, in yellow, lie just in front, anteriorally, and inside, medially, of the nerve root, in blue.

Equally, the joint could be called a vasculo centric joint, though it isn't. The uncovertebral joint luschka lies just behind, posteriorally and medial to the vertebral artery, in red,  supplying oxygenated blood to the posterior part of the brain. Thus the uncovertebral joint lushka has also the potential to cause vascular brain symptoms such as vertigo.

The disc, the vertebral body, together with the uncovertebral joints of Luschka, form the anterior wall of the foramen through which the spinal nerve passes. The uncus in fact gives some protection to the nerve root from any herniation of the disc.

In theory, the close relationship between the UncoVertebral Joint Luschka and the Vertebral artery might have some clinical significance for the Chiropractor, as it certainly does for the spinal surgeon. 1/1,000 neck operations end in death often because of this vital relationship between the vertebral artery and the Joint of of Luschka.

However, for the chiropractor, it appears to be of little concern. Millions of cervical spines are manipulated every day, many with UncoVertebral Joint arthrosis with no effect on the Vertebral artery.

Those extremely rare (1/ 6,000,000) cases where Stroke Chiropractic do occur appear to be rather to do with the tortuous course of the Vertebral artery in the upper cervical spine.

• Stroke Chiropractic

Whiplash

Cervical Acceleration Deceleration (CAD) injuries of the cervical spine occur in MVA's but obviously in many other ways. Falls off horses, down the stairs, diving into shallow water and in many sports such as rugby and American football.

• Whiplash Chiropractic ...
  

Most of the three million MVA whiplashes in the USA every year would cause trauma to the ligaments, tendons and muscles in the neck. However, a very significant number injure the brainstem and the spinal cord too.

Also, whiplash from a T-bone accident may injure or fracture the uncinate process as the cervical spine is forcibly moved into lateral flexion, exactly the movement that the Uncovertebral Joint Luschka serves to prevent. Arthrosis develops, reducing the size of the foramen and irritating or frankly pinching the nerve root: pain and tingling in the arms and hands ...

• Severe pain radiating down upper arm to pointer finger and thumb - Jane

Test yourself for a pinched nerve

Arm pain

• Arm pain ...

That part of the spine where the UncoVertebral Joint Luschka is found (C3-C7) is sometimes called the "cervico-brachial" spine, "brachial" meaning to do with the arm. Injury to this area "commonly refers pain to the arm."

This is because UncoVertebral hypertrophy / arthritis compromises the "inter vertebral foramen", or IVF, through which the nerve must pass on its way to the arm.

"Pathology in the lower cervial spine can lead to neck pain alone, arm pain alone,  or both neck and arm pain, headache, tingling in arms and hands, altered "myotomes" (ie weakness in specific muscles), restricted movement of the neck, and "radicular" signs. Those to do with a pinched nerve root."

Orthopaedic Physical Assessment (Magee).

Self-manipulation

In the practice, chiropractors are fairly frequently faced with patients who have begun to manipulate their own necks. This bizarre and dangerous procedure usually begins after some trauma to the cervical spine, perhaps a whiplash, which limits the movement between the vertebrae.

Researchers have pointed out that the hyaline cartilage lining all joints is utterly dependent on the movement of the joint for normal nutrition. Decreased range of motion leads to a dearth of cartilage nutrients and oxygen, and a build up of waste products.

In white mice, immobilisation arthritis has been shown to begin within thirteen hours of a joint being immobilised.

This progressive insidious early arthritis leads to vague symptoms of discomfort in the neck emanating from noci ceptors within the UncoVertebral joint of Luschka. Normally, movement of the neck stimulates mechano receptors within the joints, which give rise to a cascade of neurological impulses into the spinal cord, inhibiting the impulses from nociceptors. But, in the presence of joint fixation, the impulses from these nociceptors are in the majority, sending information to the sensory cortex that all is not well in the state of Denmark.

The normal reaction is to turn the neck, moving through the ranges of motion until the fixated joint moves, albeit perhaps less than normal movement due to the injury. The mechanoreceptors fire up, inhibiting the sense of discomfort, even pain, originating from the cartilage starved of nutrients. The synovial fluids in the joint begin to slosh about restoring the cartilage.

One might also go for a massage, start a tai chi or aerobics class, or even consult a chiropractor. Anything that stimulates movement in the offending joint and associated muscles.

But in self manipulators, they discover that crack or two brings relief, which it does but there are problems. Usually the movement induced in the UncoVertebral joint of Luschka is partial, so the manoeuvre has to be repeated an hour or two later; and again, up to ten or more times a day.

In addition, the self manipulation involves movements of lateral flexion and translation in the spine, something the uncovertebral joints of Luschka  are designed to limit. Just watch someone who cracks their own neck; it's horrific and very dangerous.

Furthermore, during a chiropractic adjustment, the joint is distracted to prevent the cartilage violently striking its mate. Self manipulators are unable to do that.

Just how much manipulation of a particular joint is healthy, and how much is excessive, has not been determined; but as a rule of thumb, I personally believe, based entirely on opinion, that more than twenty five adjustments of one particular joint in a year is too much.

Self poppers often achieve that in less than a week. Just as rebound headache is caused by overuse of medication, so too much manipulation, particularly cracking your own neck, actually certainly contributes to the problem.

Just ask anyone who has been manipulating their own neck for five or more years. Arm pain and tingling in arms and hands always begins, and is often severe.

USEFUL LINKS

• Return from Uncovertebral Joint Luschka to Whiplash Chiropractic ...