Age / Sex : 62 / M

Chief complaint : Lower back pain for several months. End-stage renal disease

Discussion

Answer: Destructive spondyloarthropathy

Findings:

Marked narrowing of intervertebral disc space at L3-4 level on plain radiography

MR images show destruction of intervertebral disc space at L3-4 level with irregularity of adjacent endplates and prominent erosions.

T2-weighted image shows lesions of predominantly low signal intensity.

Heterogeneous enhancement on Gd-enhanced images.

No significant paravertebral inflammation or edema

Differential Diagnosis:

Infectious spondylitis

Neuropathic spondyloarthropathy

Gout

CPPD deposition disease

Discussion:

Patients with chronic renal disease and on hemodialysis may develop many different musculoskeletal abnormalities, including secondary hyperparathyroidism, osteomalacia, osteosclerosis, osteoporosis, amyloidosis, a variety of crystal deposition diseases, destructive osteoarthropathy, and destructive spondyloarthropathy.

Destructive spondyloarthropathy is considered a serious complication of chronic hemodialysis, and is characterized by rapidly progressive radiographic abnormalities, including loss of intervertebral disk space, erosion of subchondral bone in the adjacent vertebral bodies, and new bone formation.

Destructive spondyloarthropathy affects middle-aged and elderly patients with chronic renal disease who have been undergoing maintenance hemodialysis. The prevalence of the condition has been reported to range from 5 to 25.3% in different series, and it depends on age and the duration of hemodialysis. Destructive spondyloarthropathy shows a predilection for the lower portion of the cervical spine, although the craniocervical junction, and occasionally the thoracic and lumbar spine may also be affected.

Beta2-microglobulin amyloidosis is a major cause of destructive spondyloarthropathy. Amyloid deposits accumulate at intervertebral discs, facet joints, and the ligamentum flavum in spine lesions

Destructive spondyloarthropathy is characterized by erosions of the anterosuperior and/or anteroinferior corners of the vertebral body, severe narrowing of the intervertebral disk space, and erosions and cysts of adjacent vertebral plates with minimal osteophyte formation. As the disease progresses, vertebral body collapse, subluxation, or listhesis may occur.

Single, or usually multiple, spinal levels are involved. But destructive changes are limited in one or sometimes two disc levels. It was thought that once the destructive changes had occurred, axial and shearing loads were concentrated to the involved level and destruction progressed in limited disc levels.

MRI findings include low signal intensity in the affected intervertebral discs and adjacent vertebral endplates on both T1- and T2-weighted MR images. Enhancement of the affected spinal segments is seen and may be due to reactive inflammation around deposits of beta-2 microglobulin amyloid.

Early vertebral abnormalities may simulate those of early ankylosing spondylitis, with erosions of the anterosuperior or anteroinferior corners of the vertebral bodies involved. As the disease progresses, destructive lesions may simulate infection.

It may be difficult to differentiate changes secondary to destructive spondyloarthropathy from infectious spondylitis. In infectious spondylitis, structures that are involved show increased signal intensity on T2-weighted and STIR images. But, other studies of destructive spondyloarthropathy have reported abnormal high signal intensity in the affected structures on T2-weighted MR images. In most cases, however, low signal is present in T2-weighted images and allows exclusion of an infection. And absence of paraspinal inflammatory change and no clinical or laboratory evidence of infection may be helpful to its differentiation.

References:

1. J. TD, J. TS, Donald R. Imaging in the Dialysis Patient: Imaging in Dialysis Spondyloarthropathy. Seminars in Dialysis 2002;15(4):290-6


2. Kiss E, Keusch G, Zanetti M, Jung T, Schwarz A, Schocke M, et al. Dialysis-Related Amyloidosis Revisited. AJR American Journal of Roentgenology 2005;185(6):1460-1467


3. Kaplan P, Resnick D, Murphey M, Heck L, Phalen J, Egan D, et al. Destructive noninfectious spondyloarthropathy in hemodialysis patients: A report of four cases. Radiology 1987;162:241-244


4. Hayami N, Hoshino J, Suwabe T, Sumida K, Mise K, Hamanoue S, et al. Destructive spondyloarthropathy in patients on long-term peritoneal dialysis or hemodialysis. Ther Apher Dial 2015;19:393-398