Atlantoaxial Instability/C1-2 Disorders

Atlantoaxial Instability/C1-2 Disorders/Atlantoaxial Joints Instability or Atlantoaxial Dislocation refers to a loss of stability between the atlas and axis (C1–C2), resulting in loss of normal articulation. The atlantoaxial joints can lose stable articulation from traumatic, inflammatory, idiopathic, or congenital abnormalities.

The atlantoaxial segment consists of the atlas (C1) and axis (C2) and forms a complex transitional structure bridging the occiput and cervical spine. The functional result of the joint is two-fold: (1) providing support for the occiput and (2) providing the greatest range of motion and flexibility possible while still maintaining stability.  The instability in this joint is usually congenital, but in adults, it may be due to an acute traumatic event or degenerative disease.,,

Anatomy of Atlantoaxial Instability/C1-2 Disorders

Atlantoaxial Joints Instability

The C1-C2 complex is responsible for 60° of axial rotation []. The ligaments and articulations of the occipitoatlantoaxial complex control mobility and restriction in movement. The ring of C1 articulates with the base of the skull via the occipital condyles and is restrained by the tectorial membrane. Atlas (C1) is also connected to the skull via the anterior atlantooccipital membrane, which connects the anterior arch of C1 to the anterior margin of the foramen magnum. Additionally, the posterior arch of C1 is connected to the posterior margin of the foramen magnum via the posterior atlantooccipital membrane.

Axis (C2) has several articulations with atlas (C1) to reinforce the occipitoatlantoaxial complex. The anterior arch of C1 articulates with the odontoid process of C2 in a synovial joint that is constrained by the transverse ligament, which holds the dens to the anterior arch of C1 via a strap-like mechanism, and prevents anterior translation of C1 relative to C2. This anatomy is susceptible to damage from RA, resulting in neurologic compression and craniocervical instability.

Lateral and median joints

There are three atlantoaxial joints: one median and two lateral. The median atlantoaxial joints is sometimes considered a triple joint:[rx]

  • one between the posterior surface of the anterior arch of atlas and the front of the odontoid process
  • one between the anterior surface of the ligament and the back of the odontoid process
  • The lateral atlantoaxial joint involves the lateral mass of atlas and axis.[rx] Between the articular processes of the two bones, there is on either side an arthrodial or gliding joint.


The ligaments connecting these bones are:

  • Articular capsules
  • Anterior atlantoaxial ligament
  • Posterior atlantoaxial ligament
  • Transverse ligament of the atlas


The atlantoaxial articular capsules are thick and loose and connect the margins of the lateral masses of the atlas with those of the posterior articular surfaces of the axis.

Each is strengthened at its posterior and medial part by an accessory ligament, which is attached below to the body of the axis near the base of the odontoid process, and above to the lateral mass of the atlas near the transverse ligament.

Types / Classification of Atlantoaxial Instability/C1-2 Disorders

Fielding and Hawkins classification

Fielding and Hawkins classified rotatory atlantoaxial dislocation into four types.[rx]

  • Type I – Rotatory atlantoaxial dislocation with no anterior displacement of the atlas (Atlanta dental interval of 3 mm or less). The transverse ligament is intact and the dens act like a pivot. The rotation of the atlas on the axis is >45°. This is the most common type of rotatory atlantoaxial dislocation
  • Type II – Rotatory atlantoaxial dislocation with anterior displacement of the atlas by 3–5 mm. This type is associated with a deficiency of the transverse ligament and unilateral anterior displacement of one lateral mass of the atlas while the opposite joint is intact and acts as the pivot.  In these patients, there is abnormal anterior displacement of the atlas on the axis, and the amount of fixed rotation is in excess of normal maximum rotation. The rotation usually exceeds 40°
  • Type III – Rotatory atlantoaxial dislocation with anterior displacement of an atlas by more than 5 mm. This type is associated with the disruption of both the transverse and alar ligaments. Both lateral masses of the atlas are displaced anteriorly, one more than the other, thus producing the rotated position. The rotation is more than 40°, and the atlas is displaced forward from the odontoid by more than 5 mm
  • Type IV – Rotatory atlantoaxial dislocation with posterior displacement of the atlas. This type is rare and occurs when the odontoid process is deficient or fractured. There is a posterior shift of one or both lateral masses of the atlas, one of them shifting more than the other thus causing rotation. Levine and Edward added to this classification by describing the extreme injury pattern of rotatory dislocation
  • Type V – Frank rotatory atlantoaxial dislocation.

Based on the staging system, the general treatment guidelines are as follows:

  • Type I – Stable subluxations manage conservatively with a collar
  • Type II – Potentially unstable and if asymptomatic, the neurosurgeon should be involved in making the treatment decision
  • Type III – Unstable joint, requires surgical stabilization
  • Type IV – Unstable joint, requires surgical stabilization


A four-stage classification scheme based on rotatory displacement has been developed:

  • Type I – Simple rotatory displacement with an intact transverse ligament
  • Type II – Anterior displacement of C1 on C2 of 3 to 5 mm with one lateral mass serving as a pivot point and a deficiency of the transverse ligament
  • Type III – Anterior displacement exceeding 5 mm
  • Type IV – Posterior displacement of C1 on C2

Type III and type IV are highly unstable, and emergent treatment is recommended.

Atlantoaxial Joints Instability

Causes of Atlantoaxial Instability/C1-2 Disorders


  • os odontoideum
  • Down syndrome (20%)
  • Morquio syndrome
  • spondyloepiphyseal dysplasia
  • osteogenesis imperfecta
  • Marfan disease
  • neurofibromatosis type 1 (NF1)


  • rheumatoid arthritis
  • psoriatic arthritis
  • Reiter syndrome (reactive arthritis)
  • ankylosing spondylitis
  • the systemic lupus erythematosus (SLE)


  • trauma
  • retropharyngeal abscess / Grisel syndrome
  • surgery
  • upper respiratory tract infection

The list of common disorders associated with atlantoaxial instability includes the following:

  • Achondroplasia
  • Congenital scoliosis
  • Down syndrome
  • Morquio syndrome
  • Neurofibromatosis
  • Osteogenesis imperfecta
  • Rheumatoid arthritis

Others Causes

  • Trauma  – (one major trauma or repetitive microtrauma or delayed or missed diagnosis of cervical spine injury after trauma (car accident rugby neck injury). The traumatic flexion-extension moment exerted on the spine can cause ligamentous disruption with subsequent atlantoaxial instability (AAI) / upper cervical instability.
  • Inflammatory arthritides – Ankylosing Spondylitis, Rheumatoid arthritis, due to the progressive destruction of the cervical skeletal structures. The most affected region is the upper cervical spine and C4-C5. 
  • Congenital collagenous compromise – (e.g. syndromes: Down’s, Ehlers-Danlos, Grisel, Morquio) The atlantoaxial instability (AAI) is considered as a developmental anomaly often occurring inpatient with the down’s syndrome (DS). It affects 6.8 to 27% of the population with DS. Usually, persons with congenital anomalies do not become symptomatic before midlife adulthood. The spine is assumed to be able to accommodate differing regions of hypermobility and fusions. With time, the degenerative changes occurring in the lower cervical spine increase rigidity and alter the balance. This gradual loss of motion places increasing loads on the atlantoaxial articulation
  • Recent neck head dental surgery.

Atlantoaxial Joints Instability

Symptoms of Atlantoaxial Instability/C1-2 Disorders

  • Cervical pain aggravated by movement
  • Referred pain (occipital reason and upper back of the head, between the shoulder blades, upper limbs)
  • Retro-orbital or temporal pain (from C1 to C2)
  • Cervical stiffness—reversible or irreversible
  • Vague numbness, tingling, or weakness in upper limbs
  • Dizziness or vertigo
  • Poor balance
  • Rarely, syncope triggers a migraine, “pseudo-angina
  • Poorly localized tenderness
  • Intolerance to prolonged static postures
  • Fatigue and inability to hold head up
  • Better with external support, including hands or collar
  • Frequent need for self-manipulation
  • Feeling of instability, shaking, or lack of control
  • Frequent episodes of acute attacks
  • Sharp pain, possibly with sudden movements
  • Head feels heavy
  • Neck gets stuck, or locks, with movement
  • Better in an unloaded position such as lying down
  • Catching, clicking, clunking, and popping sensation
  • Past history of neck dysfunction or trauma
  • Trivial movements provoke symptoms
  • Muscles feel tight or stiff
  • Unwillingness, apprehension, or fear of movement
  • Temporary improvement with clinical manipulation
  • Tenderness in the cervical region
  • Referred pain in the shoulder or paraspinal region
  • Cervical radiculopathy
  • Cervical myelopathy
  • Headaches
  • Paraspinal muscle spasm
  • Decreased cervical lordosis
  • Neck pain with sustained postures
  • Hypermobility and soft end-feeling in passive motion testing
  • Poor cervical muscle strength (multifidus, longus capitis, longus colli)

Diagnosis of Atlantoaxial Instability/C1-2 Disorders

The 12 physical examination findings included:

  • Poor coordination/neuromuscular control, including poor recruitment and dissociation of cervical segments with movement
  • Abnormal joint play
  • Motion that is not smooth throughout range (of motion), including segmental hinging, pivoting, or fulcruming
  • Aberrant movement
  • Hypomobility of upper thoracic spine
  • Increased muscle guarding, tone, or spasms with test movements
  • Palpable instability during test movements
  • Jerkiness or juddering of motion during cervical movement
  • Decreased cervical muscle strength
  • Catching, clicking, clunking, popping sensation heard during movement assessment
  • Fear, apprehension, or decreased willingness to move during examination
  • Pain provocation with joint-play testing

Because a definitive diagnostic tool has not been developed, cervical clinical instability will continue to be diagnosed through clinical findings, including history, subjective complaints, visual analysis of active motion quality, and manual examination methods[rx].

Atlantoaxial Joints Instability

The following tests can be used to measure cervical instability[rx] but little is known about the diagnostic accuracy of upper cervical spine instability tests:

  • Sharp-Purser test
  • Transverse Ligament Stress Test
  • Cervical flexion-rotation test
  • Neck Flexor Muscle Endurance Test and Craniocervical flexion test


Radiologic Diagnosis of Instability:

Cervical radiographs

  • Segmental kyphosis greater than 11 degrees
  • Anterolisthesis greater than 3.5 mm of one vertebral body on another

Lateral neutral, flexion and extension X-rays

  • Forward displacement of one vertebra on another: spondylolisthesis
  • Backward displacement of one vertebra on another: retrolisthesis
  • Narrowing of the intervertebral foramen and loss of disc thickness
  • An abrupt apparent change in pedicle length

Anteroposterior Xrays with lateral bending

  • Bending to one side or another
  • Decreased bending to one side with loss of both vertebral rotation and tilt with the actual opening of the disc on the side to which the patient is bending
  • An abnormal degree of disc closure on the side to which the patient is bending
  • Malalignment of spinous processes and pedicles
  • Lateral translation of one vertebra on another due to an abnormal degree of rotation


MRI is a study of choice to evaluate the degree of the spinal cord and nerve root compression

  • effacement of CSF indicates functional stenosis
  • spinal cord signal changes are seen as a bright signal on T2 images (myelomalacia) 
     signal changes on T1-weighted images correlate with a poorer prognosis following surgical decompression
  • compression ratio of < 0.4 carries poor prognosis CR = smallest AP diameter of cord / largest transverse diameter of cord


  • has a high rate of false-positive (28% greater than 40 will have findings of HNP or foraminal stenosis)

CT without contrast

  • can provide complementary information with an MRI, and is more useful to evaluate OPLL and osteophytes

CT myelography

  • more invasive than an MRI but gives excellent information regarding degrees of spinal cord compression
  • useful in patients that cannot have an MRI (pacemaker), or have an artifact (local hardware)
  • contrast is given via C1-C2 puncture and allowed to diffuse caudally, or given via a lumbar puncture and allowed to diffuse proximally by putting the patient in Trendelenburg position.

Nerve conduction studies

  • high false-negative rate
  • may be useful to distinguish peripheral from the central process (ALS)

Electromyogram (EMG)

This test measures the electrical activity in your nerves as they send signals to your muscles when the muscles are contracting and when they’re at rest. The purpose of an EMG is to assess the health of your muscles and the nerves that control them.

Treatment of Atlantoaxial Instability/C1-2 Disorders

Non- Pharmacological

  • Cold and Heat – Your doctor may recommend careful use of ice, heat, massage, and other local therapies to help relieve symptoms. Applying a cold pack to the painful part of the back contracts inflamed muscle and relieves pain. This treatment helps a great deal when the disk has recently ruptured and swelling is at its greatest. A heating pad or warm pack helps with residual pain.
  • Continued Physical Activity – Though pain or weakness seems like good reasons to rest the neck, excessive bed-rest worsens the symptoms of a slipped disc in the neck. Moving around too little allows muscles to grow weaker and prevents the body from healing. Periods of rest interspersed with periods of normal activity throughout the day keep the back muscles in shape. Physical therapists show slipped disc sufferers’ ways to move that do not cause pain. Occupational therapists teach skills that allow patients to return to a productive life.
  • A good massage – A massage is one of the natural methods of relieving pain. Individuals who get a massage weekly for several months stand a better chance of alleviating neck pain. A good massage provides a person with many health benefits that lessen neck pain. A massage triggers the release of endorphins. Endorphins aid in decreasing anxiety and relieving pain. They offer a relaxation effect by softening muscles that are injured preventing cramping.
  • Undertaking yoga or isometric exercise– Yoga is an applicable strategy for keeping the level of back pain at minimal levels. Taking yoga sessions often is very effective method of dealing with neck pain. With yoga, there is a high likelihood of proper body functions. The use of pain prescriptions is also diminished. Patients suffering from neck pain related issues do not have to rely on these prescriptions to manage pain. Incorporating laughter in yoga is a good way of exercising. Yoga incorporates simple yet appropriate exercises that enhance the stretching of muscles. Laughter with yoga stimulates relieving of pain. It facilitates increased uptake of oxygen, little anxiety, and the production of endorphins. All these variables play an essential role in diminishing neck pain.
  • Spinal manipulation and spinal mobilization  – Are approaches in which professionally licensed specialists (doctors of chiropractic care) use their hands to mobilize, adjust, massage, or stimulate the spine and the surrounding tissues. Manipulation involves a rapid movement over which the individual has no control; mobilization involves slower adjustment movements. The techniques have been shown to provide small to moderate short-term benefits in people with chronic neck pain. Evidence supporting their use for acute or subacute neck pain is generally of low quality. Neither technique is appropriate when a person has an underlying medical cause for neck pain such as osteoporosis, spinal cord compression, or arthritis.
  • Traction  – involves the use of weights and pulleys to apply constant or intermittent force to gradually “pull” the skeletal structure into better alignment. Some people experience pain relief while in traction, but that relief is usually temporary. Once traction is released the back pain tends to return. There is no evidence that traction provides any long-term benefits for people with low back pain.
  • Adjusting sleeping position – A simple sleeping mistake can immensely contribute to neck pain. A poor sleeping position can cause stress and tension on the muscles contributing to neck pain. Altering one’s sleeping position and adopting a style that does not exert a lot of stress on the back is a recommended tactic. Nurturing sleeping habits such as assuming a reclining position, using wedge-shaped cushions and getting adjustable beds from reputable medical institutions are easy techniques to endorse. If a reclining position does not suit an individual, the other two techniques can be embraced.
  • Heat therapy – Several considerations should be observed when using heat therapy. The right temperature ought to be set so as to ensure a patient does not face risks associated with too much exposure to heat. The key objective should be to ensure enough access to heat to the muscles to yield benefits for the patient. The adoption of heat therapy for easing neck pain is determined by the magnitude of pain a person is experiencing. In cases where relatively low back pain is encountered, short heat therapy sessions are recommended. On the other hand, if an individual is experiencing prolonged back pain, long heat therapy sessions are the most applicable.
  • Taking hot baths – This is a form of heat therapy that aims at relieving neck pain. It guarantees permeation of heat into the muscles leading to reduced pain. Many individuals opt for this method since they believe it achieves competent results. Hot baths initiate a fast process of blood supply to stiff neck muscles. When this happens, the muscles relax and stretch leading to decreased pain. To avoid interference with one’s sleeping patterns, a hot bath should be taken several hours before retiring to bed.
  • Aquatic therapy – This natural technique involves physical therapy in a pool. Individuals get the best out of this therapy by relying on the resistance of water. Consistency in undertaking this therapy is what ascertains getting back pain relief. Integrating aquatic therapy in an individual’s life for the better part of the week enhances the reduction of back pain quickly.
  • Soft cervical collar – This is a padded ring that wraps around the neck and is held in place with velcro. Your doctor may advise you to wear a soft cervical collar to limit neck motion and allow the muscles in your neck to rest. A soft collar should only be worn for a short period of time since long-term wear may decrease the strength of the muscles in your neck.
  • Cervical Pillow – It is important to use the right pillow to give your neck the right type of support for healing from a cervical disc bulge and also to improve the quality of sleep.
    Specific treatment for lumbar disk disease will be determined by your health care provider based on
  • Enlighten others – Individuals have the power to devise their own natural strategies that aid them in coping with back pain. The strategies can also be a good remedy for others going through similar circumstances. An individual can use social media platforms to equip others with important tips on how to keep back pain at bay. Further, becoming a member of associations that address back pain issues enables better communication of the knowledge gained from personal experience.


Consultation with a health care provider is advised before use. The following are the main types of medications used for low back pain:

  • Analgesic medications  – are specifically designed to relieve pain. They include OTC acetaminophen and aspirin, as well as prescription opioids such as codeine, oxycodone, hydrocodone, and morphine. Opioids should be used only for a short period of time and under a physician’s supervision. People can develop a tolerance to opioids and require increasingly higher dosages to achieve the same effect. Opioids can also be addictive. Their side effects can include drowsiness, constipation, decreased reaction time, and impaired judgment. Some specialists are concerned that chronic use of opioids is detrimental to people with back pain because they can aggravate depression, leading to a worsening of the pain.
  • Nonsteroidal anti-inflammatory drugs (NSAIDS) – relieve pain and inflammation and include OTC formulations (ibuprofen, ketoprofen, and naproxen sodium). Several others, including a type of NSAID called COX-2 inhibitors, are available only by prescription. Long-term use of NSAIDs has been associated with stomach irritation, ulcers, heartburn, diarrhea, fluid retention, and in rare cases, kidney dysfunction and cardiovascular disease. The longer a person uses NSAIDs the more likely they are to develop side effects. Many other drugs cannot be taken at the same time a person is treated with NSAIDs because they alter the way the body processes or eliminates other medications.
  • Anticonvulsants—drugs primarily used to treat seizures—may be useful in treating people with radiculopathy and radicular pain.
  • Antidepressants – such as tricyclics and serotonin and norepinephrine reuptake inhibitors have been commonly prescribed for chronic low back pain, but their benefit for nonspecific low back pain is unproven, according to a review of studies assessing their benefit.
  • Muscle Relaxants – If the muscles around the slipped disc experience painful spasms, a muscle relaxant such as Valium may be useful. The drawback to drugs like these is that they do not limit their power to the affected nerve. Instead, they have a generally relaxing effect and will interfere with daily activities. Such as cyclobenzaprine, might be prescribed to relieve the discomfort associated with muscle spasms. However, these medicines might cause confusion in older people. Depending on the level of pain, prescription pain medicines might be used in the initial period of treatment.
  • Vitamins B1, B6 and B12 – nourish the nerves and help them recover from the disk accident. Usually, doctors prescribe them as a part of the treatment, but it is worth mentioning anyway.
  • Steroids – If inflammation is severe, a doctor may also prescribe a steroid. Steroids, such as cortisone, reduce swelling quickly. A cortisone shot directly in the affected area will have an immediate effect on the displaced disc.
  • Counter-irritants – such as creams or sprays applied topically stimulate the nerves in the skin to provide feelings of warmth or cold in order to dull the sensation of pain. Topical analgesics reduce inflammation and stimulate blood flow.
  • Nerve Relaxant — Pregabalin or gabapentin and anti-inflammatory drugs help to relieve pain and stiffness, allowing for increased mobility and exercise. There are many common over-the-counter medicines called non-steroidal anti-inflammatory drugs (NSAIDs). They include aspirin, ibuprofen, and naproxen (Naprosyn, Aleve).
  • Spinal injections — An injection of a cortisone-like anti-inflammatory medicine into the lower back might help reduce swelling and inflammation of the nerve roots, allowing for increased mobility.
  • Biofeedback  – It is used to treat many acute pain problems, most notably back pain and headache. The therapy involves the attachment of electrodes to the skin and the use of an electromyography machine that allows people to become aware of and self-regulate their breathing, muscle tension, heart rate, and skin temperature. People regulate their response to pain by using relaxation techniques. Biofeedback is often used in combination with other treatment methods, generally without side effects. The evidence is lacking that biofeedback provides a clear benefit for low back pain.
  • Nerve block therapies  – aim to relieve chronic pain by blocking nerve conduction from specific areas of the body. Nerve block approaches range from injections of local anesthetics, botulinum toxin, or steroids into affected soft tissues or joints to more complex nerve root blocks and spinal cord stimulation. When extreme pain is involved, low doses of drugs may be administered by catheter directly into the spinal cord. The success of a nerve block approach depends on the ability of a practitioner to locate and inject precisely the correct nerve. Chronic use of steroid injections may lead to increased functional impairment.
  • Glucosamine and chondroitin / Nutrition – In order to restore the disc we also are going to need to include different substances in our diet. You can try one with glucosamine and chondroitin, but I didn’t feel any different. So, if you have the opportunity to take these with the food or from more natural sources, it will be great. You can find these substances in seafood and animal cartilages and by digesting them we ensure the building blocks for the connecting tissue for our joints and spine. Also, we will need more
  • Omega 3 fatty acids –  which can be supplied from cold-pressed oils, fatty fish, flax seeds, chia and many more. Vitamins from the B group are very beneficial for people with and all kinds of issues with the peripheral nervous system.
  • Calcium & vitamin D3 – To improve bone health and healing quickly. As a general rule, men and women age 50 and older should consume 1,200 milligrams of calcium a day, and 600 international units of vitamin D a day.
  • Glucosamine  Diacerein & Chondroitin sulfate – can be used to tightening the loose tendon, cartilage, ligament, and cartilage, ligament regenerates cartilage or inhabits the further degeneration of cartilage, ligament.
  • Codeine – If your pain is more severe, your GP may prescribe the mild opiate painkiller called codeine. This is often taken in combination with NSAIDs or paracetamol. A common side effect of taking codeine is constipation. To prevent constipation, drink plenty of water and eat foods high in fiber, such as wholegrain bread, brown rice, pasta, oats, beans, peas, lentils, grains, seeds, fruit, and vegetables.
  • Amitriptyline – If pain persists for more than a month, and has not responded to the above painkillers, your GP may prescribe a medicine called amitriptyline. Amitriptyline was originally designed to treat depression, but doctors have found that a small dose is also useful in treating nerve pain. You may experience some side effects when taking amitriptyline.
  • Gabapentin – Gabapentin (or a similar medication called pregabalin) may also be prescribed by your GP for helping radiating arm pain or pins and needles caused by nerve root irritation. This medicine is otherwise used as an anti-epileptic drug. Some people may experience side effects that disappear when they stop the medication, such as a skin rash or unsteadiness. Gabapentin needs to be taken regularly for at least two weeks before any benefit is judged.
  • Injection of a painkiller – If your radiating arm pain is particularly severe and not settling, there may be an option of a ‘transforaminal nerve root injection’, where steroid medication is injected into the neck where the nerves exit the spine. This may temporarily decrease inflammation of the problem nerve root and reduce pain
  • Steroid-based injections – Many patients find short-term pain relief from steroid injections. The most common procedures for neck pain include:
  • Cervical epidural block – In this procedure, steroid and anesthetic medicine is injected into space next to the covering of the spinal cord (“epidural” space). This procedure is typically used for neck and/or arm pain that may be due to a cervical disk herniation, also known as radiculopathy or a “pinched nerve.”


  • Clinically asymptomatic – Clinical and radiographic surveillance or posterior C1-C2 internal fixation and fusion
  • Symptomatic os odontoideum or C1-C2 instability – Posterior C1-C2 internal fixation and fusion
  • If rigid C1-C2 fixation is  not achievable – Postoperative halo immobilization
  • Atlantoaxial dislocation with irreducible dorsal cervical – medullary compression with or without occipital-atlantal instability – Occipital-cervical fixation and fusion with or without C1 laminectomy
  • Irreducible ventral cervical-medullary compression – Ventral decompression

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Summary of posterior surgical techniques
Method Stability Complications Surgical procedure
transarticular screw fixation with sublaminar wiring Very high fusion rates, up to 100%, due to direct fusion and stability The neurologic damage can occur due to wire loosening, which has been reported in up to 50% of patients (Matsumoto et al 2005) transarticular screw fixation placement risks damage to the vertebral artery, hypoglossal nerve; most difficult posterior procedure.
One of the gold standard treatments Procedure risks damage to the vertebral artery Articular screw placement requires steep angle and joint exposure that can cause C2–C3 instability
Transarticular screw fixation with C1 hook Added stability compared with transarticular screw fixation alone, three-point fixation Minimizes risk of neurologic damage (no wire) and subaxial instability (from dissection for wire insertion) Fluoroscopic imaging required for proper placement of screws to avoid complications
Transarticular screw fixation with morselized autograft Less stable than other transarticular screw fixation constructs Minimizes risk of neurologic damage (no wire) Wiring risks neurologic damage, and tissue dissection for wiring can cause weakness or longer healing process
Sufficient biomechanical stability Instrumentation breakage has been reported, maybe due to screw C1 hook or autograft obviates the risk of tissue dissection
C1L-C2PSF Best overall stability; more stable than intact spine on axial rotation, lateral bending, and AP translation; less stable on flexion/extension No complications reported in the main clinical series of this procedure Extension to occiput or subaxially is simple if necessary
C1L is compatible with most anatomical variations, imaging unnecessary
C2P pedicle variations make placement challenging; ∼20% of patients have insufficient pedicles for placement
The intraoperative reduction is possible
C1L-C2LSF Not as stiff as transarticular screw fixation and C1L-C2PSF, especially on lateral bending Early hardware failure Weaker in extension to occiput than C1L-C2PSF construct
Less stable than C1L-C2PSF on axial rotation as well Relatively safe regarding neurovascular injury, probably safest of the techniques C1L is compatible with most anatomical variations; intraoperative imaging unnecessary
Should be reserved for when anatomy restricts to this construct (Finn et al 2008) C2L key structures can be visualized during the procedure, less challenging
The technically less complicated procedure, but less stability


Physical Therapy Management of Atlantoaxial Joints Pain

Conservative treatment is indicated when cervical clinical instability does not severely involve or threaten neurological structures. The goal of nonsurgical treatment should be to enhance the function of the spinal stabilizing subsystems and to decrease the stresses on the involved spinal segments.

Posture Education and Spinal Manipulation

  • Decreases stress on the passive subsystem
  • Proper posture – reduces the loads placed on the spinal segments at end-ranges and returns the spine to a biomechanically efficient position
  • Spinal manipulation – can be performed on hypermobile segments above and below the level of instability, which eventually will result in a distribution of the spinal movement across several segments. Also, the mechanical stresses on the level of clinical instability are believed to be decreased

Strengthening Exercises

  • Enhances the function of the active subsystem.
  • The cervical multifidus may provide stability via segmental attachments to cervical vertebrae.
  • The longus colli and capitus provide anterior stability.
  • Strengthening the stabilizing muscles may enable those muscles to improve the quality and control of movement occurring within the neutral zone.[7][13]

Proprioception Exercises

One of the main goals of the non-surgical treatment is to improve the quality of controlled motion. Therefore proprioception exercises must be used, this will improve the control of movement in the neutral zone.

Post-Operative Rehabilitation

In a more specific situation such as post-operative rehabilitation the treatment can differ:

  • The patient is not required to wear a brace.
  • After 6 weeks it is not encouraged to do any lifting more than 4kg as also overhead work.
  • The rehabilitation begins in week 6, mostly a basic stability exercise program.
  • No cervical strengthening or ranges of motion exercises are encouraged in the first 6 months.
  • The exercises or mainly focused on the neutral postural alignment, were the patients are recommended to us there trunk, hips, and chest to produce proper cervical alignment.

Rehabilitation Management of Atlantoaxial Joints Pain

Anita R. Gross et al listed an evidence-based home neck care exercise program that can be included if the CCFT test was found positive. It is in 3 progressive phases. These exercises should be judiciously tailored to individual circumstances and applied as indicated based on a clinical examination

Phase 1

  • Craniocervical flexion – Start with pressure biofeedback inflated to 20 mmHg. Make sure your chin and forehead are lined up. Nod your head, keeping the large neck muscles soft and bringing the reading up to 22 mmHg. Work up to ten 10-second holds. Then progress to 24, 26, and 28 mmHg.
  • Neck active range of motion – Start with your head in neutral, then:
    1. Tilt backward
    2. Bend forward
    3. Tilt side to side
    4. Turn side to side
  • Resisted shoulder extension with the elbow flexed – Set your cervical spine, abdominals and scapulae, then extend your arm with elbows bent backward.
  • Resisted shoulder extension with elbow straight – Set your cervical spine, abdominals, and scapulae, then extend your arm backward.
  • Resisted shoulder shrug – Set your cervical spine, abdominals, and scapulae, then slightly abduct arms and minimally shrug shoulders.
  • Resisted elbow exercise – Set your cervical spine, abdominals, and scapulae, then:
    1. Bend
    2. Straighten level 1
    3. Straighten level 2 your elbows.

Phase 2

  • Headlift – Start with your head in neutral (chin and forehead lined up), do a chin nod and lift your head, while maintaining your chin tucked. Hold for a count of 5 to 10 seconds and return smoothly with your chin still tucked.
  • Isometric neck strength – Place your hand on your head and resist. Hold for a count of 5 to 10 seconds:
    1. Bending
    2. Tilting backward
    3. Tilting sideways
    4. Turning your head
  • Shoulder stretches – Set your cervical spine, abdominals, and scapulae hold for 20 seconds.
    1. Clasp your hands behind your back and squeeze your scapulae together
    2. Hold your arms out in front of you and reach forward feeling a stretch between your scapulae
    3. Reach your arms overhead
  • Shoulder stretches – “Set” your cervical spine, abdominals, and scapulae, hold for 20 seconds.
    1. With elbows at shoulder level, lean into a corner to feel a stretch in the front of your chest
    2. With elbows at eye level lean into a corner to feel a stretch
  • Transverse abdominus – Tense your lower abdomen by imagining drawing your hip bones together (or apart if that works better), hold for 10 seconds. Then let the 1 leg fall out over a 10-second count
  • Wall sit – Set cervical spine, transverse abdominus, and scapulae, then slide down the wall into a semi-squat position. Hold for as long as you can, working up to 2 minutes.

Phase 3

  • Shoulder strength – Set cervical spine, abdominals, and scapulae then “hug a tree.”
  • Shoulder strengthen – Set cervical spine, abdominals, and scapulae, then elevate arms into a “reverse fly.”
  • Resisted neck – craniocervical flexion and oblique flexion – “Set” cervical spine, abdominals, and scapulae, then
    1. Nod head
    2. Nod head at a slightly oblique angle
  • Resisted neck extension – Set cervical spine, abdominals, and scapulae:
    1. First nod your head
    2. Then tilt your head backward
    3. The focus of the extension is in the lower neck
  • Resisted neck side flexion – Set cervical spine, abdominals, and scapulae, then tilt head to the side.
  • Resisted neck rotation – Set cervical spine, transverse abdominus, and scapulae, then rotate the head.


Other individuals may develop the following neurological deficits:

  • Lack of coordination
  • Clumsiness
  • Difficulty with gait
  • Sensory deficits
  • Neurogenic bladder
  • Spasticity, clonus, hyperreflexia
  • Paraplegia, quadriplegia
  • Neck pain
  • Myelopathy
  • Spasticity
  • Radicular symptoms
  • Acute torticollis
  • Aortic Aneurysm
  • Active peptic ulcer disease
  • Diskitis
  • Old age
  • Osteomyelitis
  • Osteoporosis
  • Ligamentous instability
  • Primary or metastatic tumor
  • Spinal cord tumor
  • Myelopathy
  • Pregnancy
  • Severe anxiety
  • Untreated hypertension
  • Vertebral-basilar artery insufficiency
  • Midline herniated nucleus pulposus
  • Restrictive lung disease
  • Hernia


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Atlantoaxial Joints Instability

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