Calcium pyrophosphate dihydrate crystal deposition in and around the atlantoaxial joint: association with type 2 odontoid fractures in nine patients

A retrospective study of the prevalence of calcium deposits around the dens axis via cone beam computed tomography

OBJECTIVE

This study aimed to evaluate the relationship between the presence of calcium deposits (CDs) around the dens axis and patients' age, gender, and systemic diseases.

METHODS

This retrospective study was carried out by examining CBCT. Basic descriptive statistical analyses and normality tests were performed on all variables. The assumption of normality was checked using the Shapiro-Wilk method. The statistical significance level was accepted as a p-value less than 0.05.

RESULTS

CDs were observed in a total of 99 (21.9%) individuals. The incidence of CDs statistically significantly increased with age (p < .01),while it didn't statistically significantly differ between genders (p = .47). 13% were systemically healthy, while 55% had hypertension. The incidence of CDs was statistically significantly higher in individuals with hypertension.

CONCLUSIONS

In the presence of CDs, the patient should be referred to a medical doctor to confirm the diagnosis of CDS and prevent possible complications.

Imaging Assessment of Nontraumatic Pathologic Conditions at the Craniovertebral Junction: A Comprehensive Review

Nontraumatic pathologic conditions of the craniovertebral junction encompass a range of conditions affecting the complex anatomy of this region without direct physical injury. These conditions include congenital syndromes that predispose individuals to ligamentous laxity, potentially leading to instability. Additionally, rare but noteworthy cases such as Grisel syndrome, a cause of pediatric torticollis, may arise without a traumatic trigger. Inflammatory diseases, including rheumatoid arthritis, ankylosing spondylitis, and crystal deposition, can lead to cervical instability and spinal cord compression. Infections at the upper cervical spine are dominated by tuberculosis, typically transmitted through hematologic or lymphatic routes with characteristic imaging findings. On the other hand, purulent bacterial infections in this area are rare. Furthermore, although tumors involving the structures of the craniovertebral junction are infrequent, they can lead to significant complications, albeit less frequently through cord compression and more commonly via pathologic fractures or subluxation. The craniocervical junction is a complex anatomic region comprising ligaments, bones, joints, and muscles that support the head's weight and enable its wide range of motion. Accurate recognition and understanding of the complex anatomy and the various nontraumatic pathologic conditions at the craniovertebral junction are pivotal for initiating timely and appropriate treatment strategies. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Rare presentation of intradural calcium pyrophosphate dihydrate crystal deposition

Calcium pyrophosphate dihydrate crystal deposition (CPPD), also known as pseudogout, can have spinal manifestations in roughly one quarter of patients. We present a rare, intradural manifestation of CPPD requiring surgical intervention, with a review of pertinent differential diagnoses on imaging. A 48-year-old male presented with urinary retention, and was found to have an intradural lesion with peripheral enhancement on gadolinium T1-weighted magnetic resonance imaging. Due to the patient's progressive neurological deterioration, he was taken for a minimally invasive approach for resection of the lesion. Histopathological analysis revealed crystal deposits with rhomboidal birefringence consistent with CPPD. The imaging features of this lesion were atypical for any of the traditional intradural extramedullary lesions. Typically seen extradurally, recognizing CPPD as a potential culprit for intradural compression is helpful to recognize for providers.

Axial Spondyloarthritis: Mimics and Pitfalls of Imaging Assessment

Axial spondyloarthritis (axSpA) is a chronic inflammatory disorder that predominantly involves the axial skeleton. Imaging findings of axSpA can be divided into active changes, which include bone marrow edema, synovitis, enthesitis, capsulitis, and intra-articular effusion, and structural changes, which include erosions, sclerosis, bone fatty infiltration, fat deposition in an erosion cavity, and bone bridging or ankylosis. The ability to distinguish between imaging lesions suggestive of axSpA and artifacts or lesions suggestive of other disorders is critical for the accurate diagnosis of axSpA. Diagnosis may be challenging, particularly in early-stage disease and magnetic resonance imaging (MRI) plays a key role in the detection of subtle or inflammatory changes. MRI also allows the detection of structural changes in the subchondral bone marrow that are not visible on conventional radiography and is of prognostic and monitoring value. However, bone structural changes are more accurately depicted using computed tomography. Conventional radiography, on the other hand, has limitations, but it is easily accessible and may provide insight on gross changes as well as rule out other pathological features of the axial skeleton. This review outlines the imaging evaluation of axSpA with a focus on imaging mimics and potential pitfalls when assessing the axial skeleton.

Cervical CT-Dependent Diagnosis of Crowned Dens Syndrome in Calcium Pyrophosphate Dihydrate Crystal Deposition Disease

PURPOSE

The purpose of this study is to assess the presence of crowned dens syndrome in patients with calcium pyrophosphate disease. We report 34 patients with crowned dens syndrome in one of the largest series from a single tertiary medical center in North America.

METHODS

A retrospective chart review was conducted at the University of Kansas Medical Center from November 1, 2005-November 1, 2017. A total of 191 patients with calcium pyrophosphate disease were identified. The available cervical computed tomography scans were analyzed by a musculoskeletal radiologist for the presence of periodontoid calcifications and erosions.

RESULTS

Of the 191 patients with calcium pyrophosphate disease, 57 had cervical computed tomography scans; 34 of them (34/57, 59.64%) had periodontoid calcifications. Only 12/34 patients were formally evaluated and diagnosed by rheumatologists with crowned dens syndrome. Twenty-two of 34 were either not seen by a rheumatologist or were not diagnosed with crowned dens syndrome. The median age was 78.5 years, with 73.52% over 70 years old; 24/34 (70.58%) were female; 17/34 patients (50%) were symptomatic; 28/34 (82.35%) had additional sites of chondrocalcinosis on available radiographs; 8 (28.57%) had 3 or more sites of chondrocalcinosis in typical calcium pyrophosphate disease locations. Six patients did not have any radiographs.

CONCLUSION

Crowned dens syndrome is an under-recognized entity that should be considered in elderly patients with neck pain in the setting of calcium pyrophosphate disease. Our data demonstrated a high percentage (about 60%) of patients with calcium pyrophosphate disease who had cervical computed tomography findings consistent with crowned dens syndrome. This underscores the importance of performing cervical computed tomography when evaluating patients with neck pain and calcium pyrophosphate disease.

Atlanto-axial Pannus in Patients with and without Rheumatoid Arthritis

Objective.

Pannus formation in the atlanto-axial joint is a well-recognized complication of rheumatoid arthritis (RA). Occasionally, atlanto-axial pannus is reported when patients without a history of RA undergo magnetic resonance imaging (MRI) of the cervical spine. We sought to further characterize these patients.

Methods.

The Partners HealthCare Research Patient Data Registry was free-text searched for “atlanto-axial” AND “pannus” in cervical spine MRI reports from 2001 to 2015. Cases with MRI reports describing pannus were reviewed. Clinical data were extracted by chart review in cases with confirmed atlanto-axial pannus (n = 105).

Results.

Twenty-nine patients (27.6%) had RA, all of whom except one carried this diagnosis at the time of the MRI scan. Only 1 of 77 patients without a history of RA was subsequently diagnosed with RA (1.3%, 95% CI 0.1–7.0%, median followup 3.6 yrs). Non-RA patients were significantly older (median age 79 vs 63 yrs, p < 0.0001), less frequently female (55% vs 86%, p = 0.0032), and more likely to have undergone prior cervical spine surgery (18% vs 0%, p = 0.016) compared with RA patients. Thirty-four non-RA patients (44.7%) either had a clinical diagnosis of calcium pyrophosphate dihydrate disease (CPPD) or imaging evidence for tissue calcification. There were no significant differences in age or sex between the CPPD subgroup and other non-RA patients. Twenty-eight patients (26.7%) underwent cervical spine surgery.

Conclusion.

Patients without RA diagnosis and incidental atlanto-axial pannus on cervical spine MRI are unlikely to have previously unrecognized RA. Degenerative disease and tissue calcification may contribute to pannus formation in these patients.

Calcium pyrophosphate dihydrate crystal deposition disease and MRSA septic arthritis of the atlantoaxial joint in a patient with Tourette syndrome

A 45-year-old male patient with Tourette syndrome presented to the emergency department with worsening neck pain and stiffness of 1-week duration. Associated symptoms included headache, hoarse voice, trismus and odynophagia. The patient was haemodynamically stable without fevers or leucocytosis. He exhibited cervical spinal and paraspinal tenderness with very limited range of motion. Erythrocyte sedimentation rate and C reactive protein were elevated, and blood cultures grew methicillin-resistant Staphylococcus aureus (MRSA). Lumbar puncture was unremarkable. CT and MRI of the neck showed calcification of the longus colli, fluid and capsular distention of C1-C2 joints, enhancement of the joint capsule and retropharyngeal oedema suggestive of septic arthritis. Fluid was aspirated from C1 to C2 joint by interventional radiology and showed calcium pyrophosphate crystals and heavy MRSA colonisation, consistent with both pseudogout and septic arthritis of the cervical vertebrae. The patient was started on a 6-week course of daptomycin and showed gradual improvements in neck pain and mobility.

Non-union rate of type II and III odontoid fractures in CPPD versus a control population

OBJECTIVE

The objective was to determine if there is a significant difference between rates of non-union of type II and III odontoid fractures in patients with calcium pyrophosphate dihydrate deposition (CPPD) compared with a control population.

MATERIALS AND METHODS

A 10-year retrospective picture archive and communications system review was performed of 31 CPPD patients and 31 control patients. Imaging studies were reviewed for radiographic or CT evidence of osseous union and complications.

RESULTS

There was a significant difference in the rates of non-union between the two groups, with the non-union rate reaching 90.3% in the CPPD group and 32% in the control group. Comparing the degree of displacement and angulation of the two groups did not show a significant difference.

CONCLUSION

The results indicate that odontoid fracture non-union rates are significantly higher in CPPD patients and should be taken into consideration when diagnosing odontoid fractures and deciding on appropriate treatment.

Crowned Dens Syndrome as a cause of acute neck pain: a Case Report and Review of the Literature

Crowned dens syndrome (CDS) is a rare clinical entity characterized by acute neck pain due to calcification around the odontoid process of the axis in “crown-like” configuration. Crystalline deposition in cervical vertebrae is less well known disease entity and only a limited number of cases have been reported to date. I here present a case of 79-year- old woman who developed acute severe neck pain and stiffness. Cervical computed tomography (CT) scan detected periodontoid calcification and a diagnosis of Crowned dens syndrome was made. Crowned dens syndrome should be considered in the differential diagnosis of acute neck pain, particularly in old age patients.

Prevalence of asymptomatic chondrocalcinosis in the pelvis

OBJECTIVE

To determine trends in incidentally detected age- and gender-associated chondrocalcinosis on pelvic CT.

MATERIALS AND METHODS

Twenty patients of each gender at the center of each decade of life who underwent a CT scan of the pelvis performed 2009-2013 were identified and selected for a total of 400 pelvic CTs. Images were reviewed independently by two radiologists for the presence or absence of chondrocalcinosis within the pelvis. Patients with hip or low back pain, known CPPD arthropathy or any known predisposing condition, prior hip arthroplasty, or articular fracture were excluded. Logistic regression was used to predict the presence/absence of chondrocalcinosis as a function of patient age and gender.

RESULTS

The presence/absence of chondrocalcinosis was found to be associated with patient age (p = 0.016) but not patient gender (p = 0.929). In the pelvis, chondrocalcinosis was most frequently identified at the pubic symphysis. Incidental chondrocalcinosis was not identified in any patients under 50 years of age. Chondrocalcinosis increased in frequency from 12.5 at 55 years of age to 27.5 % of patients 95 years of age.

CONCLUSIONS

Chondrocalcinosis is common and more prevalent in late adulthood, occurs without a gender predilection, and is infrequently identified in patients younger than 50 years of age.

Posterior C1-C2 calcium pyrophosphate dihydrate crystal deposition disease

Calcium pyrophosphate dihydrate (CPPD) crystal deposition disease rarely occurs in the posterior aspect of the craniocervical junction (CCJ). To the best of our knowledge, there have been only 2 previously reported cases of patients with posterior CPPD lesions in this region that have led to cervical myelopathy. We report the case of a 70-year-old man presenting with neck pain and cervical myelopathy with multilevel stenosis from C1-C6. The stenosis was worst at C1-C2, secondary to compression by a CPPD lesion posterior to the spinal cord. The patient underwent a C2-C6 laminectomy and fusion with resection of the CPPD lesion. In this report, we discuss the patient and present a novel theory to explain the preponderance of CPPD lesions in the CCJ occurring anteriorly and not posteriorly to the spinal cord.

Atlantoaxial subluxation and nasopharyngeal necrosis complicating suspected granulomatosis with polyangiitis

Granulomatosis polyangiitis (GPA, formerly Wegener granulomatosis) is a vasculitis that typically involves the upper respiratory tract, lungs, and kidneys. The 2 established methods to confirm a suspicion of GPA are the antineutrophil cytoplasmic antibody (ANCA) test and biopsy. However, ANCA-negative cases have been known to occur, and it can be difficult to find biopsy evidence of granulomatous disease.We report a case of suspected granulomatosis with polyangiitis limited to the nasopharynx. With a negative ANCA and no histological evidence, our diagnosis was founded on the exclusion of other diagnoses and the response to cyclophosphamide therapy. This case is unique because the patient's lesion resulted in atlantoaxial instability, which required a posterior spinal fusion at C1-C2. This is the first reported case of suspected GPA producing damage to the cervical spine and threatening the spinal cord.

Crowned Dens Syndrome: Report of Three Cases and a Review of the Literature

BACKGROUND

Patients with crowned dens syndrome (CDS), which is pseudogout of the atlantoaxial junction induced by "crown-like" calcifications around the dens, present with symptoms of severe neck pain, rigidity, and high fever. CDS patients are often misdiagnosed as having meningitis or polymyalgia rheumatica, leading to potentially unnecessary invasive procedures for diagnosis and treatment.

CASE REPORT

We report 3 patients with CDS who had characteristic findings on computed tomography (CT), all of whom quickly recovered with nonsteroidal antiinflammatory drug (NSAID) administration. In addition, we reviewed 72 published cases, including our patients. CDS typically occurs in elderly people (mean age 71.4 years). Common symptoms include neck pain (100%), neck rigidity (98%), and fever (80.4%), and most show elevated inflammatory markers (88.3%) on serum laboratory tests. Neck pain on rotation is a characteristic and helpful symptom in the diagnosis. The most useful modality is CT (97.1%), showing linear calcium deposits around the dens, mostly in the transverse ligament of atlas (TLA). CT number is especially helpful to distinguish a normal TLA (35-110 HU) from a calcified one (202-258 HU) in our cases. The most effective treatment is NSAID administration (85%), which usually leads to marked resolution of symptoms within days or weeks. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Due to acute and severe symptoms, CDS patients often present to an emergency department. To avoid unnecessary invasive procedures for diagnosis and treatment, CDS should be considered in the differential diagnosis of febrile neck pain.

Acute neck pain caused by arthritis of the lateral atlantoaxial joint

BACKGROUND CONTEXT

Many diseases can cause acute neck pain in elderly individuals. We conducted the present prospective study based on the hypothesis that arthritis of the lateral atlantoaxial joint may be involved in acute neck pain in elderly patients with limited neck rotation.

PURPOSE

To clarify whether the lateral atlantoaxial joint is involved in acute neck pain among elderly individuals by conducting lateral atlantoaxial joint puncture.

STUDY DESIGN

A prospective study.

PATIENT SAMPLE

Twenty-seven patients (13 men, 14 women) aged 50 years or more who provided consent for atlantoaxial joint puncture met the following four inclusion criteria: acute neck pain with limited cervical rotation of less than 20° as the chief complaint; visual analog scale pain score of 70 mm or more at initial visit; tenderness in the paraspinal muscle of upper cervical vertebrae; and serum C-reactive protein level of 0.5 mg/dl or more.

OUTCOME MEASURES

Visual analog scale pain score and radiologic findings.

METHODS

Patients underwent puncture of the lateral atlantoaxial joint and were evaluated clinically and radiologically.

RESULTS

Computed tomography obtained before puncture showed calcification of the transverse ligament of the atlas in the posterior dens in 22 patients (81.5%), calcification in the longus colli in 2 patients (7.4%), and no calcification in 3 patients (11.1%). Of 27 patients who underwent lateral atlantoaxial joint puncture, joint fluid was collected from 16 patients (59.3%) and calcium pyrophosphate dihydrate crystals were identified in 10 patients (62.5%). For the entire patient population, mean VAS score before puncture was 81.9±16.3 mm, significantly improving to 35.6±24.4 mm by 30 minutes after puncture (p<.001).

CONCLUSIONS

The results of this study suggest that crystal-induced arthritis (pseudogout) of the lateral atlantoaxial joint may be closely involved with acute neck pain in the elderly.

Association between advanced degenerative changes of the atlanto-dens joint and presence of dens fracture

BACKGROUND

Dens fractures in elderly patients are often related to issues associated with aging. We examined the association between degenerative changes of the atlanto-dens joint and the risk of dens fracture.

METHODS

We conducted a retrospective study of trauma patients, fifty-five years of age or older, who had undergone a computed tomography scan of the cervical spine as part of their admission to a single level-I trauma center. There were 1794 patients who met the inclusion criteria; scans were evaluated for all fifty-six who presented with a dens fracture and for a random sample of 736 without a dens fracture. Intraosseous cyst formation, synovitis, and joint space narrowing were recorded from the scans. The prevalence of degenerative changes was compared between patients with and patients without a dens fracture.

RESULTS

An intraosseous cyst in the dens was found in 16.4% of the patients without a dens fracture and in 64.3% of those with a fracture (p < 0.001). The dens fracture extended through the existing cyst in twenty-four (66.7%) of thirty-six patients with a cyst and a dens fracture. Retro-dens synovitis was present in 4.2% of the patients without a dens fracture and 25.0% of those with a fracture (p < 0.001). After adjustment for age and sex, both cysts (odds ratio [OR] = 7.7, 95% confidence interval [CI] = 4.2 to 14.1) and synovitis (OR = 4.6, 95% CI = 2.1 to 10.0) were significantly associated with dens fracture.

CONCLUSIONS

Intraosseous dens cysts and retro-dens synovitis were associated with dens fracture; those with a dens fracture were nearly eightfold more likely to have an intraosseous cyst and nearly fivefold more likely to have synovitis compared with those without a dens fracture. Because the atlanto-dens joint is a synovial joint, its degeneration can lead to subchondral cyst formation and synovitis and predispose affected individuals to fracture.

Retro-odontoid calcium pyrophosphate dehydrate deposition: surgical management and review of the literature

Study Design Case report and review of the literature.

Objective A retro-odontoid mass is a rare cause of cervical compression and myelopathy. The differential diagnosis includes the following: metastatic disease, primary tumor, collagen disorder, or inflammatory disease. Calcium pyrophosphate dihydrate (CPPD) deposition has been referred to as “crowned dens syndrome” when there are periodontoideal calcifications. There are only a few reported cases where CPPD presents as a cystic retro-odontoid mass in the atlanto-dens interval. In previous descriptions of surgical intervention, transoral resection of the mass is associated with significant morbidity and usually requires stabilization. The objective of this article is to report a case of an unusual presentation of CPPD disease of C1/C2, where we used a novel, minimally invasive surgical technique for decompression without fusion.

Patients and Methods An 83-year-old female patient presented with progressive cervical myelopathy over a 3-month period. Computed tomography and magnetic resonance imaging demonstrated a cystic odontoid mass with a separate retro-odontoid compressive mass. A novel, minimally invasive transoral aspiration was performed. Histologic confirmation of CPPD was obtained.

Results Postop imaging showed satisfactory decompression, which was maintained at the 6-month follow-up. This correlated with clinical improvement postop and 6-month follow-up.

Conclusion CPPD in the atlanto-dens interval may present as a cystic retro-odontoideal mass and should be included in the differential. We used a transoral minimally invasive approach to aspirate the cyst. This novel technique avoided the need for a stabilization procedure or morbid transoral resection and provided excellent results immediately and at 6 months.

Frequency of atlantoaxial calcium pyrophosphate dihydrate deposition at CT

PURPOSE

To determine (a) the prevalence of atlantoaxial calcium pyrophosphate dihydrate (CPPD) crystal deposition in a population of patients undergoing computed tomography (CT) for acute trauma and (b) the association between atlantoaxial CPPD crystal deposition and retro-odontoid soft-tissue thickness.

MATERIALS AND METHODS

This HIPAA-compliant study was approved by the institutional review board, and the requirement to obtain informed consent was waived. In 513 consecutive patients, CT scans of the cervical spine obtained for acute trauma were retrospectively reviewed for the presence of atlantoaxial CPPD crystal deposition, and the maximal thickness of the retro-odontoid soft tissues was measured. The relationships among imaging findings, age, and sex were assessed with the t test, the χ(2) test, Spearman correlation, and logistic and linear regression models as appropriate.

RESULTS

The overall prevalence of atlantoaxial CPPD crystal deposition was 12.5% (64 of 513 patients), and prevalence increased with age (P < .0001, logistic regression coefficient). In patients aged 60 years and older, the prevalence of CPPD crystal deposition was 34% (58 of 170 patients). In patients aged 80 years and older, the prevalence of CPPD crystal deposition was 49% (37 of 75 patients). There was a positive correlation between age and retro-odontoid soft-tissue thickness (Spearman ρ = 0.48, P < .0001). The mean retro-odontoid soft-tissue thickness in patients with CPPD crystal deposition was greater than that in patients without CPPD crystal deposition (3.4 mm vs 2.2 mm, respectively; P < .0001, t test).

CONCLUSION

CPPD crystal deposition in the cervical spine is seen with a higher prevalence than previously reported. CPPD crystal deposition shows a positive correlation with age and retro-odontoid soft-tissue thickening.

Factors influencing on retro-odontoid soft-tissue thickness: analysis by magnetic resonance imaging

STUDY DESIGN

A retrospective, consecutive case series.

OBJECTIVE

To analyze the relationship between retro-odontoid soft-tissue thickness and patients' age, sex, and degenerative changes of cervical spine and to investigate the effect these factors have on retro-odontoid soft-tissue thickness.

SUMMARY OF BACKGROUND DATA

Thickening of the soft tissue posterior to the odontoid process can form a retro-odontoid pseudotumor causing symptoms of spinal cord compression. Rheumatoid arthritis and long-term dialysis have been reported as possible causes for this. However, there have been reports of retro-odontoid pseudotumors without coexisting diseases.

METHODS

Findings from a total of 503 cases of cervical spine magnetic resonance images were reviewed, and retro-odontoid soft-tissue thickness was measured. The values were matched for age, sex, presence of degenerative changes, rheumatoid arthritis, and dialysis and were analyzed for significance.

RESULTS

Retro-odontoid soft tissue thickened with age, and this was also seen in male patients and patients with degenerative changes. Significant increase in thickness was also observed in patients undergoing dialysis and further increased with prolonged dialysis. There was no significant association with presence of rheumatoid arthritis.

CONCLUSION

There is association between age, sex, degenerative cervical spine changes, and dialysis with retro-odontoid soft-tissue thickness. With dialysis, retro-odontoid soft-tissue thickness increases with increasing duration. Thus, reviewing magnetic resonance image from daily practice indicates that cervical spine degeneration is associated with the development of retro-odontoid pseudotumors.

Subchondral cysts of the atlantoaxial joint: a risk factor for odontoid fractures in the elderly

BACKGROUND CONTEXT

Scholars have postulated that cervical degeneration can predispose the upper cervical spine to injury after minor trauma. Subchondral cysts have previously been recognized as potentiators of fracture in the hip and knee but no cases of cervical degenerative cysts contributing to fracture have been reported.

PURPOSE

This report documents a case series in which patients sustained significant injury to the upper cervical spine in the setting of subchondral cervical cysts.

STUDY DESIGN/SETTING

Case series/academic level I trauma center.

METHODS

Between 2004 and 2008, six patients (ages 73-91 years) with cervical pathology were admitted to the trauma service at our Level I trauma center. The most common mechanism of injury was a low velocity fall, which occurred in 5 out of 6 patients. All patients suffered an odontoid fracture. In all cases, there was radiographic evidence of cyst formation, and computed tomographic imaging demonstrated fracture communication with the subchondral cyst.

RESULTS

Of the six cases, four were treated definitively with immobilization in a cervical orthosis and two required surgery. One patient was treated with an occipital-cervical fusion, whereas the other underwent Brooks wiring. All patients ultimately went on to heal their fractures.

CONCLUSIONS

Degenerative changes in the cervical spine have previously been recognized to potentiate injury. This report raises the question of whether degenerative processes at the C1-C2 articulation predispose elderly patients to injury at this level. The presence of cystic degeneration at the atlantoaxial joint should be recognized as a potential risk factor for cervical injury after relatively minor trauma.

Calcium pyrophosphate dihydrate crystal deposition in the craniovertebral junction

Object

Calcium pyrophosphate dihydrate (CPPD) deposition is a rare cause of retroodontoid mass lesions in elderly individuals. However, this condition may be severely underdiagnosed if sufficient attention is not paid to imaging characteristics and clinical presentation. The authors sought to evaluate the decision-making process in both the diagnosis and surgical treatment of CPPD.

Methods

A retrospective review of University of Iowa medical records and radiographs accumulated between 1977 and 2006 was performed. The inclusion criterion was histopathological findings consistent with pseudogout at the craniovertebral junction (CVJ). Twenty-one patients with a mean age of 70.3 years and a mean symptom duration prior to presentation of 17.5 months were identified and included in this study.

Results

The patients presented most frequently with occipital and neck pain (85%) and numbness or paresthesias (61%). Lower cranial nerve deficits were seen in 29%. Calcification of the mass or transverse ligament was seen on computed tomography in all included patients. Gross-total resection was achieved in all patients: 19 of 21 patients underwent transoral–transpalatopharyngeal resection, with only 16 requiring concomitant dorsal occipital–cervical fusion. The mean follow-up duration was 15 months. Eighteen patients (86%) had improvement or resolution of symptoms after treatment, and 3 were lost to follow-up.

Conclusions

Although rare, CPPD deposition at the CVJ should be suspected on finding calcification of and around the transverse ligament on neuroimaging. Transoral–transpalatopharyngeal resection is preferred to halt the progression of neurological deterioration; dorsal fusion is not always mandatory as concomitant ligamentous calcification and atlantoaxial joint ankylosis may provide added stability.

Cervicomedullary compression secondary to massive calcium pyrophosphate crystal deposition in the atlantoaxial joint with intradural extension and vertebral artery encasement

BACKGROUND

Deposition of CPPD crystals occurs in the fibrous and hyaline cartilage of the joints and intervertebral disks of the spine. Half of patients known to have chondrocalcinosis had asymptomatic calcification in the odontoid region. The cases of 12 patients with a spinal cord syndrome secondary to CPPD deposition in the odontoid region were published in the literature. In all those cases, the mass lesion was extradural in location with good outcome after surgical decompression via the transoral route.

CASE DESCRIPTION

We report on a rare case of large periodontoid CPPD deposition causing cervicomedullary compression, erosion of the overlying bone, and underlying dura with intradural extension and vertebral artery encasement.

CONCLUSIONS

Calcium pyrophosphate dihydrate is a rare cause of cervicomedullary compression. Intradural extension of periodontoid CPPD has not been reported on.

Cervical myelopathy induced by pseudogout in ligamentum flavum and retro-odontoid mass: a case report

STUDY DESIGN

Retrospective case study.

OBJECTIVES

Report a rare case of cervical myelopathy induced by calcium pyrophosphate dehydrate (CPPD) deposition in multiple cervical levels.

SETTING

An area teaching hospital in Taiwan.

METHOD

A patient with cervical myelopathy was evaluated by computerized tomography (CT) scan and magnetic resonance (MR) image. CPPD deposition known as pseudogout was diagnosed and approved by a polarized microscope.

RESULT

A prominent hypertrophy of ligmentum flavum and a retro-odontoid bulging mass induced cord compression were found in CT scan and MR image. CPPD deposition was confirmed by the histological examinations in the ligamentum flavum at the spinal levels of C3-C6. After decompression surgery of spine and comprehensive rehabilitation, the patient's neurological symptoms subsided and her neurological functions improved leading to a good prognosis.

CONCLUSION

CPPD deposition in cervical spine occurring at multiple levels is rare. Image studies with CT scan and MR are complementary in the diagnosis of CPPD-induced myelopathy. Surgical decompression is always required and expected to have a good outcome.

Cervical spine and crystal-associated diseases: imaging findings

The cervical spine may be specifically involved in crystal-associated arthropathies. In this article, we focus on the three common crystals and diseases: hydroxyapatite crystal deposition disease, calcium pyrophosphate dihydrate (CPPD) deposition disease, and monosodium urate crystals (gout). The cervical involvement in crystal-associated diseases may provoke a misleading clinical presentation with acute neck pain, fever, or neurological symptoms. Imaging allows an accurate diagnosis in typical cases with calcific deposits and destructive lesions of the discs and joints. Most of the cases are related to CPPD or hydroxyapatite crystal deposition; gout is much less common.

Periodontoid pseudotumor: CT and MRI imaging

Periodontoid pseudotumor (PP) can be a severe and disabling disease. This disease process typically presents in elderly patients with a longstanding history of myelopathy. We reviewed four cases of PP in order to summarize the clinical and imaging features.

Calcium pyrophosphate dihydrate and calcium hydroxyapatite crystal deposition diseases: imaging perspectives

Calcium pyrophosphate dihydrate crystal deposition disease and calcium hydroxyapatite deposition disease are common crystal diseases that have characteristic imaging appearances. This article gives a background on each disorder and discusses the qualities that distinguish them from each other and from other arthropathies.

Reducción de las masas periodontoideas tras artrodesis posterior: revisión a propósito de 2 casos no vinculados a artritis reumatoide

Inflamatory periodontoid pannus is quite common in patients with rheumatoid arthritis. However, the occurrence of a pannus-like periodontoid mass that is unassociated with rheumatic inflammation is less frequent. Transoral surgery associated with a posterior stabilization has long been considered one of the most efficient methods to resolve the problem of instability in patients presenting neurological deficits secondary to the pannus. We present two cases of non rheumatic etiology, in which an occipito-cervical arthrodesis was used to resolve the proliferative lesion around the odontoid apophysis. Two women (67 and 60 years old respectively) presented symptoms of pain and neurological deterioration with an antecedent of possible past odontoid fracture in one case, and a previous large anterior cervical arthrodesis to correct spondylarthrosis in the other case. Both patient's neurological condition improved after placement of an arthrodesis through a posterior approach.

Calcium pyrophosphate dihydrate and hydroxyapatite crystal deposition in the joint: new developments relevant to the clinician

The major types of crystals containing calcium, which causes arthropathy and periarticular disease, are calcium pyrophosphate dihydrate and basic calcium phosphates, including hydroxyapatite. Exciting advances include the identification of mutations in the gene ANKH associated with disordered inorganic pyrophosphate (PPi) transport in some kindred with familial chondrocalcinosis linked to chromosome 5p. In addition, central basic mechanisms governing cartilage calcification and their relationship to aging and osteoarthritis have now been elucidated. These include the role of plasma cell glycoprotein-1, the PPi-generating ecto-enzyme, in chondrocalcinosis and the linkage of low- grade inflammation to expression and activation of two cartilage-expressed transglutaminase isoenzymes with direct calcification-stimulating activity. This review discusses clinically pertinent new information on pathogenesis. The authors also address, in detail, current diagnostic and therapeutic issues pertaining to calcium pyrophosphate dihydrate and hydroxyapatite crystal deposition in the joint, as well as possible therapeutic directions for the future.

Imaging in dialysis spondyloarthropathy

Destructive spondyloarthropathy has recently been described in patients who undergo maintenance hemodialysis for chronic renal disease. The condition most frequently involves the lower segment of the cervical spine, although the craniocervical junction also may be affected. Although the pathogenesis of destructive spondyloarthropathy remains unclear, the disorder is thought to relate to a hemodialysis-associated amyloidosis. It appears that the disease correlates with the duration of hemodialysis, although it has been reported in patients with chronic renal insufficiency not associated with hemodialysis. Radiographic features simulate those of an infectious process, encompassing a range of abnormalities from superficial erosions to large bony defects. Computed tomography (CT) images reveal osteolytic areas, with bone sclerosis of adjacent vertebral endplates, and minimal osteophytosis. The intervertebral spaces appear narrow or obliterated. On magnetic resonance imaging (MRI), the disorder may show the imaging characteristics of spondylodiskitis. The absence of high signal intensity on T2-weighted images generally helps to eliminate the diagnosis of an infection. With progression of the disease, collapse of a vertebral body and spinal instability may occur. Severe complications of destructive spondyloarthropathy in long-term dialysis patients may include spinal cord compromise, necessitating surgical decompression, with or without spinal stabilization.

Calcium crystal-induced inflammation

Recent studies have added to our knowledge regarding the mechanisms of calcium crystal deposition. Calcium pyrophosphate dihydrate (CPPD) crystal deposition is associated with elevated levels of PPi in joints. Cyclic compression of cartilage transiently elevated ATP levels in culture media. Extracellular ATP may be hydrolyzed by nucleoside triphosphate pyrophosphohydrolase (NTPPPH), yielding an elevated PPi concentration. CPPD crystal deposition increases with age. Nitric oxide may alter cartilage matrix by interfering with chondrocyte mitochondrial function and ATP production. Transglutaminase in adult, but not young, porcine articular chondrocytes was able to activate latent transforming growth factor beta, a potent stimulus to PPi production. Basic calcium phosphate crystals are more likely to form in a milieu of reduced PPi concentration. The ank gene mutation results in higher intracellular PPi concentration and lower extracellular concentration. The ANK protein is thought to be a transmembrane protein necessary for transport of PPi out of cells. A mutation that results in reduced synthesis of NTPPPH PC-1 caused infantile wrist and ankle periarticular calcification and vascular calcification.