Learning Radiology xray montage

Renal Osteodystrophy
Rugger-Jersey Spine

·        Constellation of musculoskeletal abnormalities occurring with chronic renal failure featuring some combination of

o       Osteomalacia (adults)

o       Rickets (children)

o       2° hyperparathyroidism

o       Soft-tissue calcifications

o       Osteosclerosis

o       Soft-tissue + vascular calcifications

·        Low calcium levels lead to osteomalacia

o       Additional factors responsible for osteomalacia are

§         Inhibitors to calcification produced in the uremic state

§         Aluminum toxicity

§         Dysfunction of hepatic enzyme system A

§         Renal insufficiency with diminished filtration results in phosphate retention

·        Maintenance of Ca x P product lowers serum calcium directly, which in turn increases parathyroid hormone production (2°hyperparathyroidism)

·        Osteopenia

o       Combined effect of

§         Osteomalacia (reduced bone mineralization due to acquired insensitivity to vitamin D / antivitamin D factor)

§         Osteitis fibrosa cystica (bone resorption)

§         Osteoporosis (decrease in bone quantity)

o       Complications

§         Fracture predisposition (lessened structural strength) with minor trauma

·        Spontaneously

§         Fracture prevalence increases with duration of hemodialysis + remains unchanged after renal transplantation

·        Sites of fractures

o       Vertebral body (3-25%)

o       Pubic ramus, rib (5-25%)

o       Milkman fracture / Looser zones (in 1%)

o       Metaphyseal fractures

o       Prognosis

§         Osteopenia may remain unchanged / worsen after renal transplantation + during hemodialysis

·        Secondary hyperparathyroidism

o       Cause

§         Inability of kidneys to adequately excrete phosphate leads to hyperplasia of parathyroid chief cells (2° hyperparathyroidism)

§         Excess parathyroid hormone affects the development of osteoclasts, osteoblasts, osteocytes

o       Hyperphosphatemia

o       Hypocalcemia

o       Increased PTH levels

o       Subperiosteal, cortical, subchondral, trabecular, endosteal, subligamentous bone resorption

o       Osteoclastoma = brown tumor = osteitis fibrosa cystica (due to parathyroid hormone -stimulated osteoclastic activity

§         More common in 1° hyperparathyroidism

o       Periosteal new-bone formation (8-25%)

o       Chondrocalcinosis

§         More common in 1° hyperparathyroidism)

·        Osteosclerosis (9-34%)

o       One of the most common radiologic manifestations

§         Most common with chronic glomerulonephritis

o       May be the sole manifestation of renal osteodystrophy

o       Diffuse chalky density

o       Thoracolumbar spine in 60% with dense end-plates produce appearance of rugger-jersey (rugger jersey spine)



Rugger-jersey spine in

Renal osteodystrophy

o       Also in pelvis, ribs, long bones, facial bones, base of skull (children)

o       Prognosis

§         May increase/regress after renal transplantation

·        Soft-tissue calcifications

o       Metastatic secondary to hyperphosphatemia (solubility product for calcium + phosphate exceeds 60-75 mg/dL in extracellular fluid)

§         Hypercalcemia

§         Alkalosis with precipitation of calcium salts

o       Dystrophic secondary to local tissue injury

§         Location

·        Arterial (27-83%)

o       In medial + intimal elastic tissue

§         Dorsalis pedis a., forearm, hand, wrist, leg

o       Pipestem appearance without prominent luminal involvement

·        Periarticular (0-52%)

o       Multifocal

o       Frequently symmetric

o       May extend into adjacent joint

o       Chalky fluid / pastelike material

o       Inflammatory response in surrounding tenosynovial tissue

o       Discrete cloudlike dense areas

§         Fluid-fluid level in tumoral calcinosis

o       Prognosis

§         Often regresses with treatment

·        Treatment

o       Decrease of phosphorus absorption in bowel

o       Vitamin D3 administration (if vitamin D resistance predominates)

o       Parathyroidectomy for 3° hyperparathyroidism (= autonomous hyperparathyroidism)


rugger jersey spine ct

Rugger Jersey Spine in Renal Osteodystrophy. Sagittal CT reconstruction of spine shows alternating bands of increased density at the endplates of vertebral bodies and less dense central portions.