Imaging in dialysis spondyloarthropathy

Factors Associated with Retro-Odontoid Pseudotumor in Long-Term Hemodialysis Patients

OBJECTIVE

Hemodialysis has been reported to be associated with retro-odontoid pseudotumor (ROP), but its clinical characteristics have not been well described. The purpose of the present study was to investigate the factors associated with ROP in hemodialysis patients.

METHODS

A retrospective clinical study of hemodialysis patients was conducted with the evaluation of computed tomography and magnetic resonance imaging of cervical spinal lesions at a single institution from 2012 to 2020. The patients' characteristics and radiographic findings were assessed. A case-control analysis was performed between patients with ROP (ROP group) and patients without ROP (control group).

RESULTS

We analyzed 46 patients. The mean duration of hemodialysis (± standard deviation) was 21.5 ± 11.8 years. The mean retro-odontoid soft tissue thickness was 4.3 ± 0.3 mm and was correlated with the duration of hemodialysis (r = 0.46, P < 0.01). Thirty patients (65.2%) were included in the ROP group. The ROP group showed a significantly longer duration of hemodialysis (24.9 ± 11.2 years vs. 15.2 ± 10.3 years, P < 0.01) and a higher incidence of osteolytic lesions in the atlantoaxial joint compared with the control group (60.0% vs. 18.8%, P < 0.01). Logistic regression analysis revealed the atlantoaxial osteolytic lesions are associated with retro-odontoid pseudotumor in hemodialysis patients (odds ratio, 5.1; 95% confidence interval, 1.1-24.2; P = 0.04).

CONCLUSIONS

The existence of ROP in hemodialysis patients was associated with osteolytic lesions in the atlantoaxial joint. The finding of atlantoaxial erosive lesions in long-term hemodialysis patients requires spine surgeons to carefully evaluate the presence of ROP.

A Novel Grading System of Destructive Lumbar Spondyloarthropathy Based on Evaluation of the Facet Joints

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To develop and evaluate a new grading system for destructive lumbar spondyloarthropathy (DLSA) by assessing bony destruction of the facet joints; to evaluate interrater reliability; and to determine the association between anteroposterior (AP) dural sac diameter at the lumbar level and the new grading.

SUMMARY OF BACKGROUND DATA

The characteristics of DLSA are unknown, hindering clinical care and research. Imaging to determine the cause of DLSA may positively contribute to patient outcome or well-being by providing prognostic information.

PATIENTS AND METHODS

In the magnetic resonance images (MRIs), we measured an axial midline AP dural sac diameter and evaluated bone destruction caused by amyloidosis at the level of the center of each lumbar disk of the lumbar spine. Two orthopedic surgeons independently evaluated each case at two-month intervals and assigned the grade by rating bone destruction at each lumbar level. Weighted κ and intraclass correlation coefficients for interrater reliability were calculated. In addition, the correlation between the AP diameter of the spinal dural sac at the lumbar level and the new MRI-based DLSA grade was examined.

RESULTS

The sample size of 82 patients was reached by examining records of 118 consecutive patients. The mean (SD) age of the included patients was 65 (7.2) years, and 36 (43.9%) were women. The grading of DLSA showed moderate to good interrater reliability at both assessments (κ, 0.59-0.78). Intraclass correlation coefficient showed substantial to excellent agreement (intraclass correlation coefficient, 0.63-0.86). The AP diameter of the spinal dural sac at the lumbar level showed a significant correlation with the new grading ( P <0.001).

CONCLUSIONS

The new MRI-based grading system for DLSA has good interrater reliability, although the strength of agreement varies somewhat. The new grading system correlates with AP dural sac diameter. Thus, this classification focused on facet erosion, which leads to functional incompetence may be helpful in surgical decision-making.

Imaging of Spine Infections

The incidence of spondylodiskitis has increased over the last 20 years worldwide, especially in the immunodepressed population, and it remains a complex pathology, both in terms of diagnosis and treatment. Because clinical symptoms are often nonspecific and blood culture negative, imaging plays an essential role in the diagnostic process. Magnetic resonance imaging, in particular, is the gold standard technique because it can show essential findings such as vertebral bone marrow, disk signal alteration, a paravertebral or epidural abscess, and, in the advanced stage of disease, fusion or collapse of the vertebral elements. However, many noninfectious spine diseases can simulate spinal infection. In this article, we present imaging features of specific infectious spine diseases that help radiologists make the distinction between infectious and noninfectious processes.

Differentiation between infectious spondylodiscitis versus inflammatory or degenerative spinal changes: How can magnetic resonance imaging help the clinician?

Spondylodiscitis is a complex disease whose diagnosis and management are still challenging. The differentiation between infectious and non-infectious aetiology is mandatory to avoid delays in the treatment of life-threatening infectious conditions. Imaging methods, in particular magnetic resonance imaging (MRI), play a key role in differential diagnosis. MRI provides detailed anatomical information, especially regarding the epidural space and spinal cord, and may allow differential diagnosis by assessing the characteristics of certain infectious and inflammatory/degenerative lesions. In this article, we provide an overview of the radiological characteristics and differentiating features of non-infectious inflammatory spinal disorders and infectious spondylodiscitis, focussing on MRI results and presenting relevant clinical and pathological features that help early diagnosis.

A Rare Case of Cervical Charcot After Spinal Cord Injury: A Case Report

CASE

We present a rare case of cervical Charcot disease that was diagnosed in a paraplegic patient by loss of function caudal to the original level of spinal cord injury. Clinical imaging, diagnosis, differentials, and operative management are discussed.

CONCLUSIONS

Charcot disease of the cervical spine is rare and very difficult to diagnose in the paraplegic patient population. High clinical suspicion should be maintained in these patients who demonstrate any form of neurologic deterioration, mechanical instability, or change in spinal alignment. It is often necessary to rule out infection. Spinal decompression and surgical stabilization is the treatment of choice.

Spinal Manifestations of Systemic Disease

The spine is frequently involved in systemic diseases, including those with neuropathic, infectious, inflammatory, rheumatologic, metabolic, and neoplastic etiologies. This article provides an overview of systemic disorders that may affect the spine, which can be subdivided into disorders predominantly involving the musculoskeletal system (including bones, joints, disks, muscles, and tendons) versus those predominantly involving the nervous system. By identifying the predominant pattern of spine involvement, a succinct, appropriate differential diagnosis can be generated. The importance of reviewing the medical record, as well as prior medical imaging (including nonspine imaging), which may confer greater specificity to the differential diagnosis, is stressed.

Tendon thickening in dialysis-related joint arthritis is due to amyloid deposits at the surface of the tendon

OBJECTIVES

Beta-2-microglobulin (β2M) dialysis-related amyloidosis (DRA), a disabiliting joint disease, has been initially reported in patients under long-term dialysis. The incidence and prevalence has significantly decreased with the improvement in dialysis techniques. Here, we attempted to clarify the clinical and MRI features to improve the diagnosis.

METHODS

We retrospectively reviewed the files of 19 patients under dialysis treatment referred for suspicion of β2M DRA. The diagnosis was based on MRI criteria (low signal intensity on both T1- and T2-weighted MR sequences). MRI analysis included a scoring of the several joint lesions. Scores were quantified according to a severity scale (0 to 3).

RESULTS

Patients had a mean age of 66.0 ± 10.5 years and mean dialysis duration of 23.7 ± 10.5 years. DRA affected mainly large joints (shoulder in 73.7%, hip in 47.3%) and spine (36.8%). MRI images for 8 shoulders, 8 hips, and 3 spines were analysed. Amyloid synovitis was present in all cases, with high mean scores in the three sites. In all joints, the most common lesions were tendon thickening (68.4%) and bone erosions (68.4%). The mean tendon thickening score was high, particularly at the shoulders and also at the spine. Bone erosions were most frequent in the shoulder and pelvis.

CONCLUSION

In patients under long-term dialysis, β2M DRA involves large joints but also the spine. Special awareness should be drawn by the thickening of the tendon. MRI is required to characterize the pattern of the lesions and to achieve the diagnosis.

Beyond ulcers and osteomyelitis: imaging of less common musculoskeletal complications in diabetes mellitus

Metabolic perturbations in diabetes mellitus affect various organ systems and can lead to end-organ failure. Though most musculoskeletal (MSK) complications of diabetes mellitus are usually not life-threatening, they are often the cause of significant morbidity. While some of the MSK complications have a proven association with diabetes mellitus, others have been loosely associated because of their frequent coexistence, as are the rheumatologic complications. While many of these conditions are well-known, some are overlooked in routine clinical practice. This article focuses on highlighting key imaging features of less common MSK complications and associations of diabetes mellitus.

Cross-Sectional Imaging for Inflammatory Arthropathy of the Pelvis

Inflammatory arthropathy predominantly affecting the axial skeleton can cause pain, stiffness, disability, and ankylosis. This article discusses the use of cross-sectional imaging in the domain of inflammatory pelvic and axial arthropathy highlighting the key distinguishing features of common known diseases and their differential diagnoses.

Magnetic resonance imaging of bacterial and tuberculous spondylodiscitis with associated complications and non-infectious spinal pathology mimicking infections: a pictorial review

Magnetic resonance (MR) imaging plays an important role in the evaluation of bacterial and tuberculous spondylodiscitis and associated complications. Owing to its high sensitivity and specificity, it is a powerful diagnostic tool in the early diagnosis of ongoing infections, and thus provides help in prompt initiation of appropriate, therapy which may be medical or surgical, by defining the extent of involvement and detection of complications such as epidural and paraspinal abscesses. More specifically, MR imaging helps in differentiating bacterial from tuberculous infections and enables follow up of progression or resolution after appropriate treatment. However, other non-infectious pathology can demonstrate similar MR imaging appearances and one should be aware of these potential mimickers when interpreting MR images. Radiologists and other clinicians need to be aware of these potential mimics, which include such pathologies as Modic type I degenerative changes, trauma, metastatic disease and amyloidosis. In this pictorial review, we will describe and illustrate imaging findings of bacterial and tuberculous spondylodiscitis, their complications and non-infectious pathologies that mimic these spinal infections.

Surgical Management for Destructive Atlantoaxial Spondyloarthropathy in Long-Term Hemodialysis Patients

BACKGROUND

Atlantoaxial spondyloarthropathy most often results from rheumatoid arthritis, cancer metastasis, or basilar invagination. Dialysis-related spondyloarthropathy is a rare cause of spinal deformity and cervical myelopathy at the atlantoaxial joint. We report 2 patients on long-term hemodialysis who presented with atlantoaxial spondyloarthropathy.

CASE DESCRIPTION

Two patients with end-stage renal failure presented with a history of progressively worsening neck pain, motion limitation, and gait disturbance. In both patients, radiologic findings showed a bone-destroying soft tissue mass lateral to C1 and C2, compressing the spinal cord and causing atlantoaxial instability. We performed a C1 laminectomy and C12 transarticular screw fixation and biopsied the osteolytic mass. The neck pain, hand numbness, and gait disturbance improved.

CONCLUSIONS

Although the surgical management of these patients involves many challenges, appropriate decompression and fusion surgery is an effective treatment option.

Destructive Spondyloarthropathy in Patients on Long-Term Peritoneal Dialysis or Hemodialysis

Destructive spondyloarthropathy (DSA) is the most serious spinal complication of dialysis-related amyloidosis in patients on long-term hemodialysis (HD), but we could not find any information about DSA in patients on peritoneal dialysis (PD) for over 10 years. We retrospectively evaluated factors contributing to DSA in HD and PD patients. Sixty-seven patients on dialysis for 10 to 19 years were compared between a PD group (n = 23) or a HD group (n = 44). In the PD group, nine patients (39%) developed DSA. The mean age of DSA patients was significantly higher than that of non-DSA patients (66.2 ± 10.0 vs. 51.0 ± 12.8 years, P = 0.03). The frequency of cervical spine DSA did not show any difference between the PD and HD groups, but the frequency of lumbar spine DSA showed a significant difference (22% vs. 5%, P = 0.04). The serum beta-2 microglobulin (B2MG) level was significantly higher in PD patients than in HD patients (38.4 mg/L vs. 27.4 mg/L, P = 0.0025). Mechanical stress such as elevation of the intra-abdominal pressure due to infusion of PD fluid (1500 mL to 2000 mL) for over 10 years might contribute to lumbar DSA in patients on long-term PD.

Imaging of haemodialysis: renal and extrarenal findings

Electrolyte alterations and extra-renal disorders are quite frequent in patients undergoing haemodialysis or peritoneal dialysis. The native kidneys may be the site of important pathologies in patients undergoing dialysis, especially in the form of acquired renal cystic disease with frequent malignant transformation. Renal neoplasms represents an important complication of haemodialysis-associated acquired cystic kidney disease and imaging surveillance is suggested. Extra-renal complications include renal osteodistrophy, brown tumours, and thoracic and cardiovascular complications. Other important fields in which imaging techniques may provide important informations are arteriovenous fistula and graft complications.

Teaching points

• Renal neoplasms represent a dreaded complication of haemodialysis.

• In renal osteodystrophy bone resorption typically manifests along the middle phalanges.

• Brown tumours are well-defined lytic lesions radiographically, possibly causing bone expansion.

• Vascular calcifications are very common in patients undergoing haemodialysis.

• Principal complications of the AV fistula consist of thrombosis, aneurysms and pseudoaneurysms.

Diabetic musculoskeletal complications and their imaging mimics

Diabetes mellitus is increasingly prevalent and results in various clinically important musculoskeletal disorders affecting the limbs, feet, and spine as well as in widely recognized end-organ complications such as neuropathy, nephropathy, and retinopathy. Diabetic muscle ischemia-a self-limited disorder-may be confused with infectious or inflammatory myositis, venous thrombosis, or compartment syndrome. The absence of fever and leukocytosis, combined with the presence of bilaterally distributed lesions in multiple and often noncontiguous muscles in the legs, including the thighs, is suggestive of ischemia; by contrast, the presence of well-defined intramuscular abscesses with rimlike enhancement favors a diagnosis of infectious pyomyositis. In the diabetic foot, an ulcer, sinus tract, or abscess with an adjacent region of abnormal signal intensity in bone marrow favors the diagnosis of pedal osteomyelitis over that of neuropathic arthropathy. Contrast material-enhanced magnetic resonance imaging is important when planning the treatment of foot infections in diabetic patients because it allows the differentiation of viable tissue from necrotic regions that require surgical débridement in addition to antibiotic therapy. Subtraction images are particularly useful for visualizing nonviable tissue. Dialysis-associated spondyloarthropathy characteristically occurs in diabetic patients with a long history of hemodialysis. Intervertebral disk space narrowing without T2 signal hyperintensity, extensive endplate erosions without endplate remodeling, and facet joint involvement are suggestive of spondyloarthropathy instead of infectious diskitis or degenerative disk disease. Although the clinical features of these conditions may overlap, knowledge of the patient's medical history, coupled with recognition of key imaging characteristics, allows the radiologist to make a prompt and correct diagnosis that leads to appropriate management.

Various musculoskeletal manifestations of chronic renal insufficiency

Musculoskeletal manifestations in chronic renal insufficiency are caused by complex bone metabolism alterations, now described under the umbrella term of chronic kidney disease mineral- and bone-related disorder (CKD-MBD), as well as iatrogenic processes related to renal replacement treatment. Radiological imaging remains the mainstay of disease assessment. This review aims to illustrate the radiological features of CKD-MBD, such as secondary hyperparathyroidism, osteomalacia, adynamic bone disease, soft-tissue calcifications; as well as features associated with renal replacement therapy, such as aluminium toxicity, secondary amyloidosis, destructive spondyloarthropathy, haemodialysis-related erosive arthropathy, tendon rupture, osteonecrosis, and infection.

Uremic tumoral calcinosis causing atlantoaxial subluxation and spinal cord compression in a patient on continuous ambulatory peritoneal dialysis

Uremic tumoral calcinosis (UTC) is a form of metastatic tissue calcification unique to dialysis patients, manifesting with amorphous and cystic masses containing calcium phosphate deposits in periarticular soft tissue. An involvement of the cervical spine with bone destruction is extremely rare in UTC. We describe a 44-year-old uremic female on long-term continuous ambulatory peritoneal dialysis who developed UTC in the peri-odontoid region with consequent atlantoaxial subluxation and spinal cord compression, featuring severe neck soreness, headache, and hypertension. Surgical removal of the destructive cervical spine lesion, showing typical tumoral calcinosis on histology, completely resolved the clinical symptoms. To date, the patient maintains uneventful postoperative course with tight control of serum phosphorus, calcium, and secondary hyperparathyroidism by medical treatment. We also review other reported unusual cases of UTC involving the cervical spine and discuss the differential diagnosis of destructive spinal lesions in uremic patients, such as UTC, dialysis-related amyloidosis, and brown tumors.

Lumbar stenosis and systemic diseases: is there any relevance?

STUDY DESIGN

A retrospective study of spinal stenosis patients admitted to Assaf Harofeh Medical Center Orthopedic Departments.

OBJECTIVE

To assess any correlation between systemic disease and spinal stenosis.

SUMMARY OF BACKGROUND DATA

Lumbar stenosis is a common spinal disease with various etiologies. No findings have been reported correlating spinal stenosis incidence with background diseases, although diabetes mellitus (DM) has been found to play a role in intervertebral disc degeneration and spondylolisthesis.

METHODS

Hospitalization records of patients with spinal stenosis admitted to Assaf Harofeh Medical Center Orthopedic Departments between 1984 and 1993 were checked for background diseases, age, and sex. The data collected were statistically evaluated for any correlation between spinal stenosis and chronic diseases and compared with the data published by the "Israeli Bureau of Statistics" and Israel's largest Health Maintenance Organization's chronic disease survey.

RESULTS

Of 537 patients with spinal stenosis 57% (308) were males and (229) 43% females with an average age of 60+/-14 years. Diseases occurring with a high incidence were hypertension (HTN)-23.2% (compared with 7.8% in the general population), DM-13.6% (5.9%), ischemic heart disease (IHD)-11.9%, and hyperlipidemia-4.4%. Patients with spinal stenosis had no significant age and sex distribution difference compared with the general population and no such difference was found for patients suffering from HTN, IHD, or DM. Isolating the effect of DM on HTN and IHD revealed that HTN was a primary disease whereas IHD was secondary to DM with significant statistical validation (P=0.003).

CONCLUSIONS

To the best of our knowledge this is the first study linking spinal stenosis and DM or HTN. It was found that chronic diseases do not alter the natural age and sex distribution of spinal stenosis. The major question remaining concerns the biologic mechanism linking spinal stenosis and DM or HTN.

Sonographic evaluation of entheseal sites of the lower extremity in patients undergoing hemodialysis

PURPOSE

To evaluate the entheseal sites of the lower extremities in patients on hemodialysis using the Glasgow Ultrasound Enthesitis Scoring System (GUESS) and to correlate the findings with the duration of hemodialysis and patient scores.

METHODS

Forty-nine patients who were on hemodialysis for at least 2 years were grouped according to duration of hemodialysis. Total GUESS scores; total enthesophyte, erosion, and bursitis scores; and tendon thicknesses were calculated, compared between groups, and correlated with duration of dialysis.

RESULTS

There was a statistically significant correlation between duration of hemodialysis and total GUESS score (p < 0.001, r = 0.81) and also between the total enthesophyte and erosion scores (p < 0.001). If severe enthesitis was defined as a total GUESS score of more than 18, receiver operating characteristic (ROC) curve analysis revealed that a cutoff point of 10 years for the duration of hemodialysis would predict severe enthesal damage with 83% sensitivity and 93% specificity (area under the ROC curve, 0.92; 95% confidence interval, 0.83-1.00).

CONCLUSION

Hemodialysis results in entheseal site changes that worsen with extended duration of hemodialysis, especially after 10 years.

Dialysis-related amyloidosis revisited

OBJECTIVE

Dialysis-related amyloidosis occurs secondarily to the deposition of beta(2)-microglobulin. Dialysis-related amyloidosis predominantly involves the osteoarticular system and is clinically manifested by erosive and destructive osteoarthropathies, destructive spondyloarthropathy, and carpal tunnel syndrome. This article illustrates the radiographic, sonographic, CT, and MRI findings of dialysis-related amyloid arthropathies.

CONCLUSION

Dialysis-related amyloidosis is characterized by various imaging appearances. In evaluating amyloidosis, MRI provides considerably more information than that obtained from conventional radiographic, CT, and sonographic studies.

[Dialysis-associated spondyloarthropathy. Case report and literature review]

Hemodialysis has considerably prolonged the life of patients suffering from terminal renal failure. However, long-term hemodialysis leads to new bone complications and spinal disorders such as destructive spondyloarthropathy (DSA). At the present time DSA is reported in 8% to 18% of the dialysed patients. Diagnosis is based on severe narrowing of the intervertebral disk, erosions and geodes of the adjacent vertebral plates simulating infectious spondylitis. Lesions progressively involve posterior joints and may lead to severe destruction of the spine. The pathogenesis of this syndrome is still unknown. Several factors have been implicated, including microcrystal deposition, amyloidosis, inflammatory and foreign body reactions and suggest that the pathogenesis of erosive spondyloarthropathies of hemodialysed patients is multifactorial. Spinal instability inducing myelopathy and radiculopathy were observed in 8% of the cases. Treatment must be accorded to the natural disease course and to the quality of the bone. We report the case of a chronic dialysed patient with destructive spondyloarthropathy involving the cervical and thoracic spine. Pathogenesis, radiological datas and therapeutic approach are discussed.

Surgical Treatment with Instrumentation for Severely Destructive Spondyloarthropathy of Cervical Spine

Nine patients with severely destructive spondyloarthropathy and marked neurologic deficits associated with dialysis-related amyloidosis underwent posterior decompression and fusion by means of instrumentation at our institute. All patients showed segmental kyphosis, six patients vertebral ankylosis, and eight patients spondylolisthesis. Spondylolisthesis at two levels was noted in three patients. Of the 11 levels of spondylolisthesis in all, 9 were proximally adjacent and 2 were distally adjacent to vertebral ankylosis. All patients underwent posterior decompression and multisegment fusion with autogenous iliac bone. From three to five spinal segments were fixed. Seven patients underwent posterior fusion by means of a pedicle or lateral mass screw between levels C3 and C7, one patient between C3 and C6, and one between C3 and T1. The clinical rate of improvement at the final follow-up was 74.3%. Though complete stability could not be achieved in three patients, the results were rated as good. No postoperative neurologic deterioration has been observed in this series, nor did any patients die immediately after surgery or during the postoperative follow-up period. As anterior long-span surgery might be too invasive for hemodialysis patients, we think that posterior decompression and fusion may well be a reasonable and effective strategy for severe hemodialysis-associated cervical spondyloarthropathy with neurologic deficits. To achieve complete stability, 360 degrees fusion with both anterior and posterior fixation with instrumentation may be required for these patients.

Imaging of the Lumbar Spine Neoplasms

The most common lumbar spine tumors are metastatic disease, myeloma, and hemangioma. Primary osseous lesions of the lumbar spine are unusual. When encountered, they often exhibit characteristic imaging properties, aiding the radiologist to provide a short list of differential diagnoses. We provide a discussion of imaging appearance of lumbar spine neoplasms. Emphasis of this review is on osseous lesions. Few common neurogenic intradural, extraaxial lesions are also discussed.