Renal osteodystrophy revisited: A didactic review of imaging, pathophysiology, and differential diagnosis

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1 Renal osteodystrophy revisited: A didactic review of imaging, pathophysiology, and differential diagnosis Poster No.: C-2174 Congress: ECR 2010 Type: Educational Exhibit Topic: Musculoskeletal Authors: C. Pierre-Jerome, V. Moncayo, M. R. Terk; Atlanta, GA/US Keywords: renal osteodystrophy, osteomalacia, bone resorption DOI: /ecr2010/C-2174 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 29

2 Learning objectives 1)To illustrate musculoskeletal lesions caused by renal osteodystrophy (ROD). 2) To present the characteristics of these lesions on plain x-ray films and MRI. 3) To discuss the pathophysiology and differential diagnosis of the disease. Background Renal osteodystrophy (ROD) was first introduced in It describes the radiologic findings resulting from chronic renal disease (CRD) [1]. ROD includes findings mainly seen in: (Figure 1) on page 3 -Secondary Hyperparthyroidism -Osteomalacia [1-3] And also: -Osteoporosis -Osteosclerosis [3] ROD develops when the renal function fails to maintain the equilibrium between calcium and phosphorus levels in the blood. It is seen in patients with chronic kidney disease, hemodialysis, peritoneal dialysis, and renal transplantation. End-stage renal disease develops in 0.01% of the US population with 8,000 renal transplantations performed yearly. 85,000 patients undergo hemodyalisis per year [3]. ROD affects about 90% of the patients on dialysis [4]. In children, the disease slows bone growth and causes deformity Page 2 of 29

3 referred to "renal rickets". In adults with kidney disease, the bone changes from ROD can begin many years before symptoms appear. Many of the radiologic manifestations of ROD mimic a variety of different pathologies including inflammatory arthropathies, infection, neoplasm. Another important issue is that in the majority of patients there is a combination of radiographic findings, making it a challenging diagnostic task. Images for this section: Page 3 of 29

4 Fig. 1: ROD Pathophysiology Page 4 of 29

5 Imaging findings OR Procedure details Fig.: Pathophysiology of Secondary Hyperparathyroidism in ROD. References: C. Pierre-Jerome; Radiology, Emory University School of Medicine, Atlanta, UNITED STATES OF AMERICA SECONDARY HYPERPARATHYROIDISM The osseous manifestations of Secondary Hyperparathyroidism include: Bone resorption Brown tumors Periosteal reaction Page 5 of 29

6 Bone Resorption : Reflects increased osteoclastic activity. It is identified in several locations: -Subperiosteal: is pathognomonic of secondary hyperparathyroidism (Fig 3 on page, Fig 4) -Cortical -Subchondral (Fig on page 15 5) -Trabecular -Endosteal -Subligamentous Radiographically it appears as an irregularity of the normal cortical margin, progressing to areas of scalloping and spiculation. Page 6 of 29

7 Fig.: Anteroposterior radiogrpah of the hand of a 29 y/o male with renal osteodystrophy and secondary hyperparathyroidism showing subperiosteal resorption of the terminal tufts. References: C. Pierre-Jerome; Radiology, Emory University School of Medicine, Atlanta, UNITED STATES OF AMERICA Brown Tumors or osteoclastomas: Present as cavities within bone. They are lytic, demarcated, central or excentric expansile lesions (Fig on page 15.6, Fig 7 on page 16, Fig 8 on page ). They are caused by localized replacement of bone by accumulation of necrotic debris, fibrous tissue and liquefaction, due to excessive osteoclastic activity. More frequently seen in: pelvis (Fig 8 on page 17 ), femur, ribs, facial bones. Present always with other signs of hyperparathyroidism. Periosteal reaction: Presents as new bone formation usually in severe and advanced disease. It is caused by osteoblastic stimulation by PTH. Radiographically it presents as: linear new bone paralleling the cortical surface. It could incorporate into adjacent bone with time as increased cortical thickness. There is a radiolucent zone between the periosteal reaction and the underlying cortex. Common sites: pubic rami along the iliopectineal line, femur, humerus, radius, ulna, metacarpals, metatarsals and phalanges. OSTEOPENIA Osteopenia combines the effects of osteomalacia (decreased bone mineralization) and osteoporosis (decrease in bone volume), there also contributes to bone resorption. The osseous manifestations of Osteopenia include: Thinning of the cortices of phalanges, femora, humeri, radii and metacarpals ( on page 18Fig.9 on page 18). Insufficiency fractures due to lack of bone. Page 7 of 29

8 OSTEOMALACIA Osteomalacia and rickets in patients with CRD presents due to lack of active Vitamin D that affects the deposition of bone mineral [4]. The Looser zones (figure), seen as linear radiolucent bands are rare and could be seen in the pubic rami, medial femoral necks, scapulae, ribs, lesser trochanters, long bones [3]. The primary abnormality in children with CRD is the endochondral ossification in the zone of provisional calcification, manifesting radiographically as: Delay in bone age Widening of the growth plate ( on page 19Fig.10 on page 19) Bowing of long bones ( on page 19Fig.10 on page 19) Scoliosis Concave impressions in vertebral endplates Triradiate pelvis Rachitic rosary Ribs Bell shaped thorax [3,4] OSTEOSCLEROSIS Is the abnormal increase in bone density, presumably caused by osteoblastic stimulation by PTH. It may be the sole manifestation of renal osteodystrophy (3). Predilection for axial skeleton, because cancellous bone predominates cortical bone. In vertebral bodies, areas of sclerosis involving superior and inferior end plates. Other axial sites include pelvis ( Fig11 on page 22, on page 21Fig.12 on page 21, on page 21Fig.13 on page 21), ribs, clavicles. SOFT TISSUE AND VASCULAR CALCIFICATION Also called metastatic calcification, occurs by different pathways related to CRD including: increase in the calcium-phosphate product, hypercalcemia, alkalosis [3,4]. Radiographically calcifications can be identified in: Periarticular soft tissues ( on page 23 on page 25Fig. 14 on page 25, on page 23Fig.15 on page 23) Vascular distribution Subcutaneous fat Page 8 of 29

9 Viscerae COMPLICATIONS ASSOCIATED WITH HEMODYALISIS Amyloid deposition occurs almost in all patients who have been on dialysis for 15 years or longer [1]. Can occur in bone, tenosynovium, vertebral disk, articular cartilage, ligament and muscle [3]. The most common site is the carpal tunnel causing carpal tunnel syndrome. Has been associated with the development of carpal cysts. Aluminum toxicity results from aluminum salts used to control hyperphosphatemia, causing osteomalacia. The mechanism is unknown. Radiographic findings overlap with others previously described [3]. Destructive Spondyloarthropathy is also seen in patients undergoing long-term hemodyalisis. Radiographic features are discovertebral junction erosions, vertebral body compression, disk space narrowing. [3] DIFFERENTIAL DIAGNOSIS OF ROD IMAGING FINDINGS Rheumatoid arthritis: Demineralization or subchondral, endosteal, cortical bone resorption in areas such as hands, hips, shoulders can mimic rheumatoid arthritis. Noting other findings related to hyperparathyroidism is the key to diagnosis [2]. (Fig.16 on page 27) Seronegative Arthropaties: Subchondral resorption in the sacro-iliac joint and subligamentous resorption involving the ischialtuberosity may mimic ankylosing spondylitis. Similarly, resorption in the retrocalcaneal bursa or in the insertion of the plantar fascia resembles the finding in Reiter's Syndrome [2]. Neoplasms: Page 9 of 29

10 The findings or pathologies that could be mimicking an agressive neoplasm in patients with ROD are: extensive endosteal or intracortical bone resorption osteosclerosis or osteopenia Brown tumors amyloid deposition Infection: The radiographic appearance of ROD, specially in the spine can mimic infection. The presence of soft tissue swelling, periosteal reaction, bone destruction and joint space narrowing can also be present in osteomyelitis and septic arthritis [2,3]. These entities are commonly seen in patients with CRD, hemodyalisis and renal transplants. Clinical evaluation in cases with suspicion of infection is critical. Bone scintigraphy, CT and MRI are modalities needed for an accurate differentiation between ROD and infection, however these two may coexist. Images for this section: Page 10 of 29

11 Fig. 1: ROD Pathophysiology Page 11 of 29

12 Fig. 2: Pathophysiology of Secondary Hyperparathyroidism in ROD. Page 12 of 29

13 Fig. 3: 57 y/o male with renal transplantation. AP x-rays of the hands showing bone resorption at the distal phalanges bilaterally (acroosteolysis) and diffuse osteopenia. Page 13 of 29

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15 Fig. 4: 52 y/o male with ROD. AP x-rays of the lower extremity showing an area of subperiosteal bone resorption in the proximal tibia (arrow). Fig. 5: AP x-rays of the hands of 43 y/o male with a renal transplant. There is subchondral bone resorption and dislocation of the first metacarpophalangeal joint on the right. Page 15 of 29

16 Fig. 6: 55 y/o female patient with CRD and secondary hyperparathyroidism. Bilateral AP shoulder x-rays, expansile lytic lesions at the lateral aspect of the clavicles (arrows), and at the diaphysis of the left humerus (arrow heads). Cortical thickening and Brown tumor in the right scapula is also seen. Page 16 of 29

17 Fig. 7: MRI of the same patient. MR T2W+Fat Sat sagittal image (upper left corner) showing Brown tumors in the scapula (arrows.) MR T1W coronal image (lower left corner) showing a Brown tumor in the head of the humerus. MR T2W+Fat Sat axial image (lower right corner) showing Brown tumors in the humeral head and in the scapula. Page 17 of 29

18 Fig. 8: 29 y/o male patient with CRD. The X-ray of the lower pelvis and proximal femur shows Brown tumors in the posterior aspect of the acetabulum bilaterally (arrows). Additionally there is protrusio acetabuli and diffuse osteomalacia. Note the post-operative clips on the left following renal transplantation. Page 18 of 29

19 Fig. 9: AP bilateral x-ray of the hands of a 52 y/o male with ROD. There is diffuse osteopenia in both hands with cortical resorption of the radial aspect of the middle phalanges in the second and third digits bilaterally (arrows). Note the bone resorption in the head of the 3rd metacarpal bone in the left hand. Page 19 of 29

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21 Fig. 10: 2 year 8 months old boy with renal rickets presenting deformity and metaphyseal flaring of the femur and tibia, bilaterally. Bowing deformity of the femura more accentuated on the left. Fig. 11: 83 y/o male with ROD. The frontal x-ray of the pelvis (upper left corner) shows bone resorption in the sacrum bilaterally. The lateral view of the lumbar spine (lower right corner) shows osteomalacia and subchondral sclerosis at the vertebral endplates with the "rugger jersey" appearance. The scintigraphy shows uptake in the femora and sternum indicating osteoblastic activity. Page 21 of 29

22 Fig. 12: X-ray Lateral view of the lumbar spine of a 47 y/o male with ROD. There is sclerosis of the endplates in all the lumbar vertebrae. Page 22 of 29

23 Fig. 13: 59 y/o female with ROD. AP X-ray of the pelvis with diffuse sclerosis affecting the iliac bones, the sacrum, pubis, ischium and the proximal femura. Page 23 of 29

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25 Fig. 14: 66 y/o female patient with sickle cell disease and chronic renal failure. A) X-ray of the right hand showing bone resorption in the distal phalanx of the second digit (arrow) and in the head of the third metacarpal (arrow). B) Same patient lateral view of the right elbow shows globular periarticular calcifications of the soft tissues (arrows). Page 25 of 29

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27 Fig. 15: 16 y/o male with renal osteodystrophy. X-ray of the hand illustrating periarticular (arrows) and vascular (arrowhead) calcification. Fig. 16: AP x-ray of the hand of a 62 y/o female with ROD. There is subperiosteal resorption in the chondral surface of the proximal phalanges (arrows), however the erosions are not seen in the bare area commonly seen in rheumatoid arthritis. Page 27 of 29

28 Conclusion This exhibit presents the pathophysiology of ROD and illustrates a large variety of radiological manifestations in the appendicular and axial skeleton. We also discuss the radiological manifestations of ROD that can mimic other entities like inflammatory disorders. Personal Information Claude Pierre-Jerome,M.D.PhD Emory University School of Medicine Department of Radiology/MSK division 59, Executive Park South 4th floor Atlanta, GA USA Tel: (work) (direct) cpierr3@emory.edu Page 28 of 29

29 References 1. Sundaram M. Founders lecture 2007: Metabolic bone disease: what has changed in 30 years? Skeletal Radiol Sep;38(9): Epub 2009 Mar Tigges S, Nance EP, Carpenter WA, ErbRRenalosteodystrophy: imaging findings that mimic those of other diseases. AJR Am J Roentgenol Jul;165(1): MurpheyMD, Sartoris DJ, Quale JL, Pathria MN, Martin NL. Musculoskeletal manifestations of chronic renal insufficiency. Radiographics Mar;13(2): Review. 4. Jevtic V. Imaging of renal osteodystrophy. Eur J Radiol May;46(2): Page 29 of 29