Orthopedics Quiz

Radiographic Examination of Bones and Soft Tissues

• Cortical Fracture: A fracture of the neck of the fifth metacarpal bone, also known as a Boxer's fracture.

• Surgical Sites: Visible radiolucent lines and drill holes from past surgical interventions.

• Position of Bones: Assess normal bone alignment and positioning, identifying any fractures, dislocations, or subluxations.

  • Example: Compare the humerus position in relation to the glenoid for a normal shoulder versus a posterior shoulder dislocation.
  • Dislocated Hip: A rare condition, often caused by trauma like road accidents.

Bone Density (ABCs of Bone Remodeling)

Skeletal Architecture

• General Bone Density: Assessed visually by observing the shade of gray, indicating sufficient radiographic contrast between bone and soft tissue.
  • Adequate contrast ensures clear differentiation between bone and surrounding tissues.
  • Example: A dense cortical shell (brighter) with a less dense cancerous bone (less bright).

Textural Abnormalities

• Trabeculae: Evaluate the appearance of trabeculae, as changes in their structure can indicate alterations in mineralization and disease processes.

  • Descriptors: Use terms like thin, delicate, smudge, or fluffy to describe the trabeculae.

  • Examples:

    • Hyperparathyroidism: Decalcification of bones, erosion of the cortex, and a characteristic squiggly appearance of the tibia.
    • Coley’s Anemia: An inherited blood disorder that causes destruction of red blood cells, leading to cortical thickening, osteopenia, and marrow proliferation in metacarpals and phalanges. Fingers may appear square or sausage-like due to a loss of normal tubulation.
    • Lacy Appearance: Coley's anemia can also cause a lacy appearance of the bone's interior.

Local Density Changes

• Sclerosis: Assess for localized increases in bone density, particularly in weight-bearing (WB) areas, indicating a repair process.
  • Increased bone density strengthens the area to withstand WB forces.
• Excessive Sclerosis:
  • Normal: Can be seen in bone healing with callus formation.
  • Degenerative: Occurs in arthritis or as a reactive response to tumors or cancer.
  • Example: In osteoarthritis, excessive sclerosis (bright white) can be seen alongside narrowed medial joint space and osteophyte formation.

Cartilage Spaces

Joint Spaces

• Joint Space Width: Assess the width of joint spaces to identify if it is well-preserved and contains a normal thickness of cartilage, disc, or tissue.
  • Narrowed Joint Space: Indicates degenerative changes.

Subchondral Bone

• Subchondral Bone Density and Irregularities: Observe for changes in subchondral bone density (e.g., sclerosis) or irregularities.
  • Osteoarthritis (OA): Sclerotic subchondral bone occurs as new bone forms to assist with weight-bearing.
  • Rheumatoid Arthritis (RA) or Gout: Shows little reactive sclerosis, instead exhibiting radiolucencies (transparent areas) on the joint margin.

Epiphyseal Plates

• Epiphyseal Plate Changes: Examine the epiphysis for alterations in growth plate position, size, smoothness of borders, or presence of disruptions or gaps.
  • Smooth Margin and Increased Bone Activity: Indicates increased bone activity associated with linear growth.
  • Disruptions: Can occur due to trauma or metabolic disorders.
  • Comparison with Contralateral Side: Necessary for accurate interpretation.

Soft Tissues

Muscles

• Muscle Girth: Assess muscle girth for changes that may indicate muscle wasting (atrophy) or gross swelling.
  • Muscle Wasting: Caused by muscular disease, paralysis, severe illness, or disuse atrophy following trauma.
  • Gross Swelling: Indicates inflammation, edema, hemorrhage, or a tumor.

Fat Pads

• Fat Pad Position: Assess fat pad position for any changes that may indicate swelling or injury to an adjacent structure.
  • Compare fat pad size and location to the contralateral extremity.

Joint Capsule

• Joint Capsule Visibility: Normally, the capsule is not easily visualized, but it becomes visible when swelling is present.
  • Causes of Joint Swelling: Exacerbations of arthritic conditions, infection, hemophilia, acute joint trauma, or effusion from trauma and intraarticular fractures can produce swelling.

Periosteum

• Periosteal Reactions: Examine the periosteum for reactive processes that indicate different pathologies.
  • Four Types of Periosteal Reactions:
    • Solid: Slow-rolling process (e.g., fracture healing, chronic osteomyelitis).
    • Laminated/Onion Skin: Indicates repetitive injury.
    • Sunburst/Speculated: Seen in malignant bone lesions, metastatic squamous cell tumors.
    • Codman's Triangle: A triangular elevation of the periosteum caused by tumors, subperiosteal hemorrhage, or other trauma.

Miscellaneous Soft Tissues

• Gas in Soft Tissues: Indicates the presence of gas-forming organisms, typically due to gangrene or trauma.
• Calcifications in Soft Tissues: Can be a result of old trauma where hemorrhage has coagulated and calcified.
  • Examples: Renal calculi, gallstones, or calcifications in abdominal organs.
• Foreign Bodies: Occasionally, metal shards can be identified in soft tissue radiographs.

Skeletal Pathology

• Radiographic Diagnosis: Includes identification of pathology category, distribution of the lesion, and predictor variables that characterize disease features.

Identify Category

• Congenital: Example: Cervical rib.
• Inflammatory: Examples: Osteomyelitis, rheumatoid arthritis, gout.
• Metabolic: Examples: Paget's disease, fibrous dysplasia.
• Neoplastic: Example: Primary bone tumor.
• Traumatic: Example: Fractures.
• Vascular: Example: Avascular necrosis.
• Miscellaneous or Other: Examples: Musculoskeletal injuries, infection, osteoarthritis.

Identify Distribution

• Monoarticular: Example: Fracture.
• Polyarticular: Example: Rheumatoid arthritis.
• Diffuse: Examples: Osteoporosis, metastases.

Identify Predictor Variables

• Behavior of Lesion: Osteolytic (bone-destroying), osteoblastic (bone-forming), or mixed.
• Bone or Joint Involved: Specific locations of the lesion.
• Locus (Location) within the Bone: The exact site of the lesion.
• Patient's Age, Gender, and Race: Certain factors can influence the risk of specific conditions.
• Margin of Lesion: Sharp margins often indicate a slower-growing lesion, while poorly defined margins suggest a more aggressive process.
• Shape of Lesion: Longer lesions tend to be slower-growing, while wider lesions may be more aggressive.
• Joint Space: Assess if the joint space is narrowed or preserved.
• Bony Reaction: Periosteal reaction: An interrupted pattern is often associated with malignancy or an aggressive process, while an uninterrupted pattern suggests a benign process.
• Matrix Production: Matrix is the tissue produced by primary bone and neoplasms.
  • Osteoid: Appearance of white clouds.
  • Conjoined: Popcorn-like appearance.
• Soft Tissue Changes: Edema, hemorrhage, joint effusion.
• History of Trauma or Surgery: Important information for interpreting radiographic findings.

Radiologic Report

• Purposes:
  • Link radiographic findings with patient history and exam results.
  • Provide comparison with previous or subsequent radiologic examinations.
  • Create a permanent record.
  • Support treatment by identifying indications and contraindications for intervention.
  • Facilitate research and communication.
• Typical Information:
  • Patient demographics, imaging findings, conclusions, name of radiologist.

The 4 Ds

• Detect: The initial step, often enhanced by knowledge of patient history and exam findings.
• Describe: Clear and concise description of findings using medical terminology. Ensure clarity for another radiologist to arrive at the same conclusion.
• Diagnosis or Differential Diagnosis: The core of the report, addressing the clinical question posed by the referring provider. Differential diagnoses are usually listed in order of probability (maximum of 3).
• Decision: Recommendations for next steps, urgency of communication, and any further required tests.

Errors in Diagnostic Radiology

• Types of Errors (Renfrew Classification)
  • Type 1 (Complacency): Finding identified but attributed to the wrong cause
  • Type 2 (Faulty Reasoning): Finding identified as abnormal but attributed to the wrong cause
  • Type 3 (Lack of Knowledge): Finding identified but attributed to the wrong cause due to lack of knowledge
  • Type 4 (Under-Reading): Missed abnormality that was noticeable in retrospect
  • Type 5 (Poor Communication): Finding identified as abnormal but poor communication to the relevant clinician
  • Type 6 (Technique): Abnormality was not identifiable due to poor imaging technique
  • Type 7 (Prior Exam): Failure to review previous imaging results which led to missed finding
  • Type 8 (History): Finding missed due to incomplete clinical information
  • Type 9 (Location): Finding missed because it was outside of the region of interest
  • Type 10 (Satisfaction of Search): Failure to find a subsequent abnormality after an initial abnormality was detected
  • Type 11 (Complication): Most often associated with interventional procedures
  • Type 12 (Satisfaction of Report): Over-reliance on a prior report
• Brooks Classification
  • Latent Errors: 'Inbuilt' system or technical faults that predispose to errors
  • Active Failures or Human Error: Diagnostic errors or misinterpretation
    • Complications from procedures
    • Can involve more than one person or be secondary to latent errors
  • External Causes: Factors beyond the control of the radiologist
  • Customer Causes: Related to the patient and non-radiology staff