Atlantoaxial Osteoarthritis


Top ContributorsMarie Avau, Debby Decock, Gloria Carbonell Villanueva, Evan Thomas and Wout Lippens Laure-Anne Callewaert en Farrie Bakalli

Search Strategy

To be successful in identifying the best reference resources, we used a list of keywords and synonyms: Atlantoaxial osteoarthritis, atlanto odontoid osteoarthritis, osteoarthritis of the atlanto-axial joint, upper cervical osteoarthritis AND treatment, physical therapy, physiotherapy, … Search term connectors, like AND, OR, and NOT allowed us to combine different aspects of the topic and find different word variations. We applied this search process on different databases: Pubmed, PEDro, eMedicine, Medscape and Cochrane Database.

Definition/Description

Atlantoaxial Osteoarthritis is a metabolically active, dynamic process that involves all joint tissues such as cartilage, synovium/capsule, ligaments and muscles. It refers to a clinical syndrome of joint pain accompanied by varying degrees of functional limitation and reduced quality of life[1][2].(Level of evidence 5, Level of evidence 1B)

Atlantoaxial osteoarthritis can be divided into:

  • idiopathic
  • degenerative 
  • posttraumatic osteoarthritis

Atlantoaxial Osteoarthritis in elderly is most often a result of a degenerative disorder and in younger patients it is because of a trauma.[3][4] (Level of evidence 3A, Level of evidence 4) This joint, similar to other joints in the body is prone to arthritis, but degenerative arthritis of this joint is an uncommon pathology [5][6] (Level of evidence 2B, Level of evidence 4)


Artrosis atlas axis.JPG

Clinically Relevant Anatomy

See Atlanto-axial joint and Cervical Vertebrae

Epidemiology /Etiology

Idiopathic osteoarthritis occurs in the elderly, whereas posttraumatic osteoarthritis occurs more often in the younger population. It has a prevalence between 4 and 8%[7][8] . Only a minority of patients become symptomatic. Most (symptomatic) patients are female (74%) and present a unilateral osteoarthritis, which is typically triggered by rotation and can ascend to the occiput and towards the front.[8][9]

Liu et al. found that the rate of osteoarthritis was 16% in the age group 18-25 years, 23% in the age group 25-30 years, 33% in the age group 30-40 years, 54% in the age group 40-50 years, 70% in the age group 50-60 years, 87% in the age group 60-70 years, and 93% in the age group >70 years. [10] In addition, the severity of the osteoarthritis increases with age.[10][11]


The presence or severity of ostearthritis of the atlanto-odentoid joint is not gender dependent.[10][12] (Level of evidence 2B, Level of evidence 2B)


The incidence of atlanto-odontoid degeneration is very high in patients who have had an odontoid fracture but it's remarkable that the lateral atlantoaxial joints are relatively spared.[12]Head loading is also a known cause of degeneration affecting the occipito-cervical region. [11] (Level of evidence 2B)

Characteristics/Clinical Presentation

The most clinical symptom of atlantoaxial osteoarthritis is unilateral occipitocervical pain aggravated by head rotation. The pain ascends unilaterally to the occiput, the parietal skull and in some cases even to the eye. Degenerative changes of atlantodens and atlanto-axial facet joints can contribute to pain, and motion and sensory limitations that increase exponentially with age. [13] [11]:


Clinical Presentation: 

  • A unilateral neck pain occurs with the slightest head rotation. The pain ascends unilaterally to the occiput, the parietal skull and sometimes even to the eye. [7][8]
  • Visual problems often leading to an ophthalmologic work up. [7][8]
  • A painful audible crepitation with head rotation. [7][8]
  • Spasms in the surrounding muscles and by limiting the range of motion (ROM) of the neck, especially in the plane of axial rotation of C1-C2. [14][7]

The severity of the symptoms does not seem to correspond with the severity of the atlanto-axial osteoarthritis. In a study of Badve et al. there is no statistically significant association between presence of radiologic changes in male porters and their symptoms.[11] According to Betsch MW et al. degeneration is associated with dens fractures, therefore cervical spine radiographs should be assessed for changes of atlantodens and atlanto-axial facet joints. [13]


Differential Diagnosis

Common: [15]

Uncommon:[15]


Because of the rare prevalence, degenerative fibrosis of atlantoaxial osteoarthritis can be confused with other pathologic entities, such as rheumatoid fibrosis, tumors and migrated disc herniation.[7]
It is also important that atlantoaxial joint osteoarthritis should be considered in the differential diagnosis in elderly patients examined for neck pain with or without progressive quadriparesis.
The identification of a periodontoid ligamentous degenerative mass suggests the presence of instability of the atlantoaxial joint.[9]


Diagnostic Procedures

The clinical evaluation is important for making a diagnosis. It consists of : [14][14][7]


• The medical history which includes: the type, the start, the location and duration of symptoms, joint function, medical condition of the patient, medication, other treatments, family history, things that cause or aggravate pain, red flags… [7]They are all important considerations in assessing cervical spine patients.[14]


Physical examination, which includes: pain on range of motion tests, limitation of range of motion, evaluation of spinal joints (pseudoclaudication caused by spinal stenosis), nerve tests (motor weakness caused by nerve root impingement), lower extremity sensory loss, reflexes, active examination, ... Gait troubles, loss of function, coordination issues and symptoms consistent with relative progression, are all important factors to consider. [14]

A diagnosis can easily be made based on the history of the patient and the physical examination. Osteoarthritis is a clinical diagnosis. Questionnaires and visual analog scores can be helpful for quantifying debility and how much the pathology is affecting daily life activities.

Radiology can be helpful in confirming the diagnosis and ruling out other pathologies (see ‘differential Diagnosis’). It can identify degeneration of joints, the presence of trauma, and bone related disorders. However, radiologic findings of osteaoarthritis do not correlate to the severity of the osteoarthritis and associated symptomes. The findings are nonspecific and imaging is limited because of difficulties in direct visual assessment of the related joint, manifestations of non specific symptoms and unfamiliarity with the pathology of the care provider. [10](level of evidence 4)  Conventional computed tomography , multidetector computed tomography and other advanced imaging techniques (such as MRI or CT) can be used to examine the presence of atlantoaxial osteoarthritis unless the diagnosis is uncertain.[11][10] [14]
Blood tests and laboratory testing can be done to rule out other conditions such as arthritis, a fracture, spinal tumor, infections, tumors, ... [14][7]
A CT scan may also be helpful in determining the extent of osteophyte formation and for planning surgery. Verification of the origin of pain by intra-articular blocks is recommended.[8]


Outcome Measures


Examination

The examination consists of a clinical and/or radiological diagnosis. The radiological diagnosis is primarily made on a standard atlas view, showing you the narrowing of the C1-C2 joint space. A bone scan showing increased uptake can also help to establish the diagnosis but is not mandatory. A CT scan can be performed to rule out a tumor or to assess the anatomical details of C1/C2 prior to screw fixation. Both clinical and radiological diagnoses have to be confirmed by intra-articular C1-C2 blocks.[8][8] (level of evidence 2B)

(See Category:Cervical Examination and Cervical examination for more information)


Medical Management

One of the medical interventions used for atlantoaxial osteoarthritis is the injection of glucocorticoid. These injections are placed into the lateral atlantoaxial joints and have shown to be a valid treatment alternative in patients who fail to respond to conventional noninvasive therapy.[16](Level of evidence 2B)


Furthermore the drug gabapentin may be useful in the symptomatic treatment of atlantoaxial osteoarthritis because of occipital neuralgia (greater or lesser). In the absence of subluxation or causes that require surgery, gabapentin may be a second-choice oral therapy before invasive procedures. Also high-dose nonsteroidal anti-inflammatory drugs, muscle relaxants, tricyclic antidepressants, prednisone, and tapered or short-term narcotic agents have been suggested as oral medications. [9](Level of evidence 2A)


If all conservative treatment fails, the third and last option is surgery, more specifically spinal fusion of C1-2. In this procedure the vertebral body of C1 and C2 is fused with screws to regain full stability. [8](level of evidence 4). A meta-analysis about posterior C1-C2 fusion indicates that posterior C1-2 fusion is a safe and effective solution for patients with lateral AAOA combined with neck pain.

If conservative therapies fail to provide sufficient pain relief, modern fusion options offer low risk of morbidity and a high rate of arthrodesis.[10](Level of evidence 2A). A retrospective study by Grob et al showed positive results on several outcomes after C1-2 fusion. All the patients showed solid fusion, 89% was pain free or showed a significant decrease in pain and only 11% had minor complications. This resulted in 85% of the patients who would perform the surgery again. [8] (level of evidence 3B). The polyaxial screw–rod system is one of the possibilities which has been proven to be effective. The authors of a series of cases concluded that the possibility of a temporary fixation without damage to the atlantoaxial joints and of reduction after the screws and rods had been inserted is quite unique. [16] (level of evidence 4)


Physical Therapy Management

The physical therapy for atlantoaxial osteoarthritis includes a combination of different treatments such as neck support exercise programs, manipulation in combination with joint mobilization, low-power laser therapy, pulsed electromagnetic therapy, infra-red stimulation of local trigger points therapy, dry hot pack therapy , intermittent traction and short waved therapy. But the management of symptomatic disease is still far from optimal [14][11][12][13][15]. First and foremost, the patient should be encouraged to take a minimum of bed rest the first 48 hours after being diagnosed with acute osteoarthritis.[14] (level of evidence 3A )


Exercise programs

Neck support exercises are most efficient for mechanical neck disorders with or without headache. Manual therapies should be combined with exercise therapy for improving pain sensation and patient satisfaction. The findings of a review by H Sarig Bahat revealed relatively strong evidence supporting the effectiveness of proprioceptive exercises and dynamic resisted strengthening exercises of the neck–shoulder musculature for chronic or frequent neck disorders.[14] (Level of Evidence 3A)

Neck pain is often caused by the upper trapezius muscle and is called trapezius myalgia. Exercise programs can target the painful trapezius muscle with simple and inexpensive training equipment. These exercises are dynamic exercises with controlled movements: lifting and lowering the dumbbell should be done in about 3 seconds, each repetition without sudden jerks or accelerations. The patient should use a weight that could be lifted for 8 repetitions (80% 1 RM). [8](level of Evidence 4)
The use of strengthening and endurance exercises for the cervico-scapulothoracic and shoulder may be beneficial in reducing pain and improving function. No beneficial effects may be expected of stand-alone stretching exercises. [16] (Level of Evidence 1A)

A good exercise consists of at least two sets of 3 repetitions (ie, a total of 6 repetitions) with rest periods of 2 minutes between sets to avoid muscle fatigue. For all exercises, the heaviest weight that can be lifted for an 8-repetition maximum (8-RM) are used. [8](level of Evidence 4)

The following exercises can be used to lower the tensioning of the upper trapezius: [8] (level of Evidence 4)


Shrugs (SHR):
1. Starting postion: Stand erect, hold the dumbbells to the side
2. Action: Elevate the shoulders while focusing on contracting the upper trapezius muscle.

One-arm rows(ONE):
1. Starting position: Bend torso forward to approximately 30 degrees from horizontal with one knee on the bench and the other foot on the floor.
2. Action: Maintain one arm in extension to support the body on the bench. Meanwhile, pull the dumbbell toward the ipsilateral lower rib.

Upright rows (UPR):
1. Starting position: Stand erect and hold the dumbbells while the arms hang relaxed in front of the body.
2. Action: Lift the dumbbells toward the chest in a vertical line close to the body while the elbows are flexed and the shoulder abducted. (The elbows point out and upward.)

Reverse flys (REV):
1. Starting Position: Lay on your chest at a 45-degree angle from horizontal with the arms pointing toward the floor.
2. Action: Raise the dumbbells until the upper arms are horizontal, while the elbows are in a static, slightly flexed position (∼5°) during the entire range of motion.

Lateral raises (LAT):
1. Starting position: Stand erect and hold the dumbbells to the side.
2. Action: Abduct the shoulder joints until the upper arms are horizontal. The elbows are in a static, slightly flexed position (∼5°) during the entire range of motion.

1 Nek1.png

Manual Therapy - Manipulations and mobilizations

There is strong evidence that demonstrates that manual therapy was not significantly superior to other interventions like exercise, physical therapy, medication and short wave diathermy for relief of neck pain. However, patients who received manual therapy are significantly more satisfied with their care than patients who received any other single therapy. Furthermore there is a trend (found in 3 studies) showing that the combination of manual therapy with exercise leads to larger improvements in pain, disability and patient-perceived recovery than manual therapy alone. The combination of manual therapy and exercise may be useful in treatment of mechanical neck disorders. [9](Level of Evidence 1A)


Mobilization and/or manipulation used in combination with exercise are beneficial for persistent mechanical neck disorders with or without headache. A significant difference was found in reduction in pain, improvement in function and global perceived effect. Mobilization and/or manipulation as a stand-alone treatment were not beneficial. [16] (Level of Evidence 1A)


The case series by Yu H et al. suggests that symptoms of atlantoaxial osteoarthritis may be improved by upper cervical spinal manipulation combined with mobilization with a mechanical device called the S.M.A.R.T. adjuster This device consists of a lever-actuated mechanical jig and a pressure sensor so that it can detect tissue changes (temperature and density) thought to be a result of reduced spinal segmental motion. The device can transmit up to 20 lb/inch2 force impulse through a piezoelectric force sensor to mobilize joints. 10 patients were treated with a combination of upper cervical manipulation and mechanical mobilization device therapy. The frequency and intensity of cervical manipulations were set up on a case-by case basis, largely depending on patients’ tolerance to the manipulation. The age of the patient, cause, duration, and course of the arthritis were all taken into consideration. To patients whose symptoms were at the initial stage or who were in the early stage of recovery from injury, higher frequency and lower intensity were usually applied. When the symptoms of the osteoarthritis were under control a different frequency of care, such as once a week, was used. [7] (Level of Evidence 3A)
Spinal manipulation has been shown to mobilize the facet joints and increase facet joint space, which not only relieves the pain caused by joint degeneration but also restores joint mobility and lessens the degenerative process.[11](Level of Evidence 1B) It is very important to know that chiropractic manipulation can only be provided to patients who present no neurovascular deficits and no acute injuries. Subsequent to the upper cervical HVLA manipulation, patients receive supplementary mobilizations of the upper cervical region.

NEk 2.png




Low-power laser therapy

According to Ozdemir et al. low laser therapy can have a beneficial effect on pain and function. Pain, paravertebral muscle spasm, lordosis angle, the range of neck motion and function were observed. All these items showed a significant improvement. However the article indicates that further research needs to be done to determine the exact beneficial mechanisms of Low-power Laser Therapy[13][14]. (level of evidence 1B)


Monteforte P. et al found a non significant pain improvement in a assessment after 20 days. They also found a significant difference in the thickness of the subcutaneous soft tissue layer overlying the two superior trapezia. [12] (Level of Evidence 4)


Ozdemir et al conducted a study aiming to evaluate the analgesic efficacy of LPL therapy and related functional changes in COA. A placebo group and LPL therapy were evaluated (60 patients): pain, paravertebral muscle spasm, lordosis angle, the range of neck motion and function were observed to improve significantly in the LPL group, but no improvement was found in the placebo group. LPL seems to be successful in relieving pain and improving function in osteoarthritic diseases.[13]level of evidence 1B)

Pulsed electromagnetic fields.

During PEMF treatment, a pulsating electromagnetic field is produced. PEMF may promote the formation of collagen and human chondrocytes. In a study by Sutbeyaz ST et al., patients with cervical osteoarthritis lay on a mat for 30 min per session twice a day for 3 weeks. The whole body is treated by using a mat 1.8 x0.6 m in size. A mean intensity of 40 lT and a frequency range from 0.1 to 64 Hz was used. This therapy has a positive influence on pain levels, flexion and extension ranges and paravertebral muscle spasm. [14](Level of Evidence 1B)


The study by Trock et al. shows benefit from pulsed electromagnetic fields in painful osteoarthritis of the cervical spine. By the end of the treatment and one month later the experimental group has a better outcome in pain, pain on motion and tenderness than the placebo group. [12] (Level of Evidence 1B)


Infra-red stimulation of local trigger points

Local heat seems to be particularly useful in treating osteoarthritis pain. Infra-red stimulation causes a short term pain relief. Important to keep in mind is that the stimulation is applied on the areas of higher tension, the trigger points.[15] (level of evidence 1B)


In a systematic review of Chow et al, RCT’s were analyzed to confirm the positive effects of infra-red on neck pain. Significant positive effects were reported in four of five trials in which infrared wavelengths (λ = 780, 810–830, 904, 1,064 nm) were used. Heterogeneity in outcome measures, results reporting, doses, and laser parameters precluded formal meta-analysis. Effect sizes could be calculated for only two of the studies. They concluded positive effects are present, but more studies need to be performed to analyze parameters (duration, intensity,..). [15] (level of evidence 1A)


Massage

Massage is often used in clinical practice, for treating patients with neck and neck related problems. This although evidence about the clinical effectiveness is scarce, as seen below. If positive results are found, is mostly on the short or intermediate term.


A review of Ezzo J et al. included 19 trails where massage as a stand-alone treatment or as a part of a multimodal intervention have been examined. Because of inconclusive results of the trails, no recommendations for practice can be made. [13](Level of Evidence 1A)
The Cohrane review of Patel KC. et al included 15 trails. Because of the uncertain effectiveness of massage, no recommendations for practice could be made. Yet, massage for mechanical neck disorders as a stand-alone treatment was found to provide an immediate or short-term effectiveness or both in pain and tenderness. [15](Level of Evidence 1A)
In further studies the massage treatment need to be characterized (frequency, duration, number of sessions, and massage technique) and the long-term effects need to be assessed.[13] [15]


Short term results of physiotherapy

The study of Hey et al. showed significant results of physiotherapy as initial conservative therapy of degenerative spine diseases. Improvement can be expected in sleeping, reading/writing, working/doing homework and carrying heavy things. The therapeutic modalities are joint mobilization, dry hot pack, intermittent traction, short-wave therapy and interferential electrical stimulation.[11] (level of evidence 1C)


Key Research

Gross A, Kay TM, Paquin JP, Blanchette S, Lalonde P, Christie T, Dupont G, Graham N, Burnie SJ, Gelley G, Goldsmith CH, Forget M, Hoving JL, Bronfort G, Santaguida PL, Cervical Overview Group. Exercises for mechanical neck disorders (Cochrane review) Cochrane Database of Systematic Reviews 2015;Issue 1

Resource

http://snyderphysicaltherapy.com/tag/cervical-manipulation/


Clinical Bottom Line

Osteoarthritis of the atlantoaxial joints can be idiopathic degenerative and posttraumatic. The prevalence of the osteoarthritis increases with age and is not gender dependant. Only a minority of the patients become symptomatic. Radiological presence/signs of atlantoaxial osteoarthritis do not correlate with the severity of the patients symptoms if those are presented. Those symptomatic patients complain mostly about unilateral neck pain occurring with the slightest head rotation and a painful audible crepitation with head rotation. There is evidence that physical therapy including neck support exercise programs, manipulation in combination with joint mobilization, low power laser therapy, pulsed electromagnetic therapy, infra-red stimulation of local trigger points therapy, dry-hot pack therapy, intermittent traction and short waved therapy have a beneficial effect on the recovery. There is no current research exists that compares the most effective therapy. Current evidence notes that manual therapy was not significantly superior to other interventions as exercise, physical therapy, medication and short wave diathermy for relief of neck pain. However, patients who received manual therapy reported being significantly more satisfied with their care than patients who received any other single therapy. Besides, they saw in three studies that there was a trend that manual therapy combined with exercise returned moderately larger improvements, although not statistically significant, in pain, disability and patient-perceived recovery than manual therapy alone. However, more research need to be done in this area that focuses on the most effective therapy treatments for this injury.

Recent Related Research (from Pubmed)

Guha, D., et al, Occipital neuralgia secondary to unilateral atlantoaxial osteoarthritis: Case report and review of the literature. Eur. Spine J., 2015.

Josten, C., et al, Anterior transarticular atlantoaxial screw fixation in combination with dens screw fixation for type II odontoid fractures with associated atlanto-odontoid osteoarthritis. Eur. Spine J., 2016.


Resources

  1. Philip Conaghan et al. Osteoarthritis National clinical guideline for care and management in adults. Royal College of Physicians, 2008. (evidence level: 5)
  2. Serap Tomruk et al. The effect of pulsed electromagnetic fields in the treatment of cervical osteoarthritis: a randomized, double-blind, sham-controlled trial. Rheumatol Int. 2006 Feb;26(4):320-4. Epub 2005 Jun 29
  3. Yu H, Hou S, Wu W, He X. Upper cervical manipulation combined with mobilization for the treatment of atlantoaxial osteoarthritis: a report of 10 cases. J Manipulative Physiol Ther. 2011 Feb;34(2):131-7. (level of evidence 2C)
  4. Schaeren S, Jeanneret B. Atlantoaxial osteoarthritis: case series and review of the literature. Eur Spine J. 2005 Jun;14(5):501-6. (evidence level: 4)
  5. A.Goel, A. Shah, Craniovertebral instability due to degenerative osteoarthritis of the atlantoaxial joints: analysis of the management of 108 cases, journal of neurosurgery: spine, Jun 2010 / Vol. 12 / No. 6 / Pages 592-601 (level of evidence 2B)
  6. 37. Ak H, Özlem B, Aylin O. Effectiveness of gabapentin in unilateral atlantoaxial osteoarthritis as a cause of painful neck. World Neurosurgery, 2014. (level of evidence 4)
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 Yu H, Hou S, Wu W, He X. Upper cervical manipulation combined with mobilization for the treatment of atlantoaxial osteoarthritis: a report of 10 cases. J Manipulative Physiol Ther. 2011 Feb;34(2):131-7. (level of evidence 2C)
  8. 8.00 8.01 8.02 8.03 8.04 8.05 8.06 8.07 8.08 8.09 8.10 8.11 8.12 Schaeren S, Jeanneret B. Atlantoaxial osteoarthritis: case series and review of the literature. Eur Spine J. 2005 Jun;14(5):501-6. (evidence level: 4)
  9. 9.0 9.1 9.2 9.3 A.Goel, A. Shah, Craniovertebral instability due to degenerative osteoarthritis of the atlantoaxial joints: analysis of the management of 108 cases, journal of neurosurgery: spine, Jun 2010 / Vol. 12 / No. 6 / Pages 592-601 (level of evidence 2B)
  10. 10.0 10.1 10.2 10.3 10.4 10.5 Liu K, Lü Y, Cheng D, Guo L, Liu C, Song H, Chhabra A. The prevalence of osteoarthritis of the atlanto-odontoid joint in adults using multidetector computed tomography. Acta Radiol. 2014 Feb;55(1):95-100. doi: 10.1177/0284185113492722. Epub 2013 Jul 22. (Level of Evidence 2B)
  11. 11.0 11.1 11.2 11.3 11.4 11.5 11.6 11.7 Badve SA, Bhojraj S, Nene A, Raut A, Ramakanthan R. Occipito-atlanto-axial osteoarthritis: a cross sectional clinico-radiological prevalence study in high risk and general population. Spine (Phila Pa 1976). 2010 Feb 15;35(4):434-8. doi: 10.1097/BRS.0b013e3181b13320. (Level of evidence 2B)
  12. 12.0 12.1 12.2 12.3 12.4 Lakshmanan P, Jones A, Howes J, Lyons K. CT evaluation of the pattern of odontoid fractures in the elderly--relationship to upper cervical spine osteoarthritis. Eur Spine J. 2005 Feb;14(1):78-83. Epub 2004 Jun 15. (Level of Evidence 2B)
  13. 13.0 13.1 13.2 13.3 13.4 13.5 13.6 Betsch MW, Blizzard SR, Shinseki MS, Yoo JU. Prevalence of degenerative changes of the atlanto-axial joints. Spine J. 2015 Feb 1;15(2):275-80. doi: 10.1016/j.spinee.2014.09.011. Epub 2014 Sep 30. (Level of Evidence 2B)
  14. 14.00 14.01 14.02 14.03 14.04 14.05 14.06 14.07 14.08 14.09 14.10 14.11 Serap Tomruk et al. The effect of pulsed electromagnetic fields in the treatment of cervical osteoarthritis: a randomized, double-blind, sham-controlled trial. Rheumatol Int. 2006 Feb;26(4):320-4. Epub 2005 Jun 29.
  15. 15.0 15.1 15.2 15.3 15.4 15.5 15.6 BMJ Publishing Group Limited 2015, Assessment of neck pain. BMJ Best Practice. Retrieved fromhttp://bestpractice.bmj.com/best-practice/monograph/943/diagnosis/differential-diagnosis.html (Level of Evidence 5)
  16. 16.0 16.1 16.2 16.3 Glémarec J, Guillot P, Laborie Y, Berthelot JM, Prost A, Maugars Y. Intraarticular glucocorticosteroid injection into the lateral atlantoaxial joint under fluoroscopic control. A retrospective comparative study in patients with mechanical and inflammatory disorders. Joint Bone Spine 2000 jan (Level of evidence 2B)