Skeletal Pathologies

Question 1

Osteoporosis

Answer 1

• generalized loss of bone density caused by an imbalance b/w metabolic bone formation and resorption processes. Associated with excessive resorption and sometimes decreased bone formation. Most common changes are aging and post menopause changes in metabolism
• cone fractures more easily and heal more slowly. Increased risks for anterior wedging or compression fracture of thoracic/lumbar spine
  Treat w/ exercise, hormone replacement, vit D and C may slow disease
• corticol thinning with decreased density in the inner surfaces of bones especially in spine and pelvis. Causes the picture frame appearance, intervertebral disk expand into weakened vertebral bodies. Use lowest kVp practical for these exams

Question 2

Congenital/ developmental hip dysplasia

Answer 2

• incomplete formation of the acetabulum, leg is flexed and abducted the hip may pop out of joint. Tendons/ligaments that hold it in proper alignment are compromised
• if not treated before walking child will waddle like a duck. When diagnosed a pelvic cast or harness is to immobilize the femoral head
• ultrasound is used for detection. AP pelvis and bilateral frog legs (cleaves) projection of hips is taken to visualize pathology. His is usually demonstrated posteriorly and superiorly. Gonadal shielding is important as many images are taken over time

Question 3

Scoliosis

Answer 3

• twisting lateral S shaped curvature of spine caused by idiopathic (no known cause), functional (problem external to the spine such as one leg shorter than the other)
  Neuromuscular (incomplete formation of vertebra), degenerative (commonly associated with arthritis)
• curvature less than 20 degrees is normal, bracing technology is used for curvature exceeding 25-40 degrees. Surgery for rod placement and/or spinal fusion is required
• full spine images of pt standing using their normal stance and weight distribution must include crests. Use breast/gonad shielding many images are taken over time. CT/MRI used to demonstrate more detailed spinal structure

Question 4

Osteomyelitis

Answer 4

• bacterial infection that spreads to bone and bone marrow. Kids is common is metaphsyes of long bone tibia/femur. Adults common in the spine. Could be complication of intravenous drug use, conditions involving vascular insufficiency like diabetes where bacteria can spread from tissue abscesses to adjacent bones
• fever, heat in the affected area, swelling and tenderness. Begins as a bone abscess and then pus from infection spreads down the medullary canal and outwards to periosteum which eventually displaces down the bone length. Ischemia is the bone causes necrosis
• inflammation won’t appear on x-ray for up to 10 days after onset of symptoms. Indications are displacement of fat planes adjacent to and b/w deep muscle bundle unlike skin infections with care more superficial. Eventually bone appears moth eaten. Treat w/ antibiotics, drainage, debridement

Question 5

Osteoarthritis (degenerative joint Disease)

Answer 5

• loss of cartilage and reactive new bone formation, due to gravity and wear and tear of age. Primarily affect hips, shoulder, knees and ankles. May develope secondary to physical, inflammatory, septic or joint pathologies
• loss of articulate cartilage and development of bone spurs (osteophytes) treatment focuses on protecting joints, maintaining mobility and strengthening muscles through rest and exercise
• joint spaces are narrowed and irregular especially in location that bear weight. Demonstration of bone spurs distinguishes this from rheumatoid arthritis

Question 6

Gout

Answer 6

• inherited enzyme disordered characterized by the buildup of uric acid in the blood that causes uric acid crystals to precipitate out in joints, cartilage and kidneys. More common in men
• painful arthritic attack of the 1st MTP but also ears, olecranon bursa, and insertion for Achilles’ tendon. Uric acid crystals cause inflammation, joint effusion, and perarticular swelling. Almost all pt’s experience some renal dysfunction
• joint effusions with deposits of uric acid crystals, joint space narrowing and eventually rate bite erosions

Question 7

spondylolysis

Answer 7

• un displaced cleft defect in the pars interarticularis that pre-disposes the person to the eventual forward displacement of one vertebra on the other (spondylolisthesis) . Occurs in 5% of the population and involves L5
• Lower back pain. Bracing, physical therapy, restricted activity, NSAIDs can be used to manage pain. Surgical laminectomy or spinal fusion may be performed
• lateral lumbar spine will demonstrate spondylolisthesis w/ associated displacement of vertebral body and widened cleft in pars interarticularis. Oblique lumbar spine will show spondylolysis: the Scottie dog with a fractured neck

Question 8

Cystic Bone lesion (unicameral bone cyst)

Answer 8

• fluid filled benign bone cyst most commonly found in humerus or femur
• asymptomatic until tumor is large enough to cause pathologic fracture
• appears as an oval expansile radiolucent well defined lesion with its long axis along the length of the bone