Medications, imaging, and fractures
Imaging
There are several types of medical imaging used to assess different tissues and structures in the body. Below are the main types.
X-ray (radiography)
- Best for: Bones, fractures, joint alignment, lung conditions
- How it works: Uses ionizing radiation to create images of dense structures
- Common uses:
- Fractures & dislocations
- Arthritis
- Lung infections (e.g., pneumonia)
- Foreign objects
- Limitations: limited soft tissue visibility, radiation exposure
- Interpreting an X-ray
- High-density tissue (e.g., bone) - absorbs x-rays to a greater degree, and appears white on the film.
- Low-density tissue (e.g., the lungs) - absorbs X-rays to a lesser degree, and appears black on the film
- Intermediate density tissue (e.g., muscle and fat) - appears as shades of grey on the x-ray film
Computed tomography (CT scan)
- Best for: Bones, soft tissues, internal bleeding, internal organs, and the brain.
- How it works: Combines multiple X-rays to create cross-sectional images
- Common uses:
- Bone fractures and complex injuries
- Internal bleeding (trauma)
- Stroke
- Tumors
- Lung and abdominal conditions
- Limitations: higher radiation exposure than X-rays
- Interpreting CT scan
- Dense structures (like bone and calcifications) appear lighter (white).
- Lucent structures (like air and fat) appear darker (black).
Magnetic resonance imaging (MRI)
- Best for: Soft tissues, brain, muscles, ligaments, and nerves
- How it works: Uses strong magnets and radio waves to generate detailed images
- Common uses:
- Ligament and tendon injuries
- Brain and spinal cord conditions
- Tumors
- Disc herniations
- Limitations: expensive, time-consuming, may be contraindicated with certain ferromagnetic metal implants and devices (e.g., some pacemakers, aneurysm clips) - safety depends on the specific implant
- Interpreting MRI
- T1 MRI highlights anatomy, provides crisp images, and shows fluids as dark
- T2 MRI focuses on pathology, making fluids bright, which is ideal for visualizing inflammation, edema
Ultrasound
- Best for: Soft tissues, pregnancy, blood flow
- How it works: Uses high-frequency sound waves to create real-time images.
- Common uses:
- Pregnancy monitoring
- Soft tissue injuries (e.g., muscle tears)
- Blood clots (Doppler ultrasound)
- Organ imaging (e.g., liver, kidneys)
- Limitations: poor image quality for bones and deep structures
Nuclear medicine imaging (e.g., PET scan, bone scan)
- Best for: Organ function, cancer detection, metabolic activity
- How it works: Uses radioactive tracers to highlight metabolic activity
- Common uses:
- Cancer detection (PET scan)
- Bone metastases (bone scan)
- Stress fracture/microfracture (bone scan)
- Thyroid and kidney function
- Limitations: radiation exposure, high cost
Fluoroscopy
- Best for: Real-time imaging of movement (e.g., swallowing, joint motion)
- How it works: Continuous X-ray imaging allows real-time assessment
- Common uses:
- Barium swallow for digestive tract
- Cardiac catheterization
- Joint injections
- Limitations: higher radiation exposure than standard X-rays
Example: Choosing the right imaging study
A patient reports a popping sensation and knee instability after twisting the joint during sports. The supervising PT suspects a ligament tear. Which imaging modality is best suited to visualize this soft-tissue injury?
Answer: MRI - it provides the soft-tissue detail needed to visualize ligaments, tendons, and cartilage. X-ray is best for bone, and CT is best for bone and internal bleeding, so neither shows a ligament tear as clearly.
Medications
Medications for musculoskeletal conditions target pain, inflammation, and muscle spasms, encompassing analgesics, anti-inflammatories, muscle relaxants, and any other relevant musculoskeletal symptoms.
- Non-steroidal anti-inflammatory drugs (NSAIDs)
- Mechanism of action: decrease inflammation, fever, and pain
- Key adverse effects to monitor: GI ulcers, indigestion, and increased bleeding risk
- Opioids
- Mechanism of action: decreases pain in the musculoskeletal system
- Key adverse effects to monitor: decreased respiration rate (respiratory depression), constipation, and addiction risk with long-term use
- Corticosteroids
- Mechanism of action: decrease inflammation in the musculoskeletal system
- Key adverse effects to monitor: osteoporosis (increased fracture risk with long-term use), high blood pressure, and weight gain/diabetes
- Baclofen
- Mechanism of action: decrease spasticity
- Key adverse effects to monitor: drowsiness, dizziness, fatigue, and muscle weakness; abrupt withdrawal can cause seizures, hallucinations, and rebound spasticity
- Muscle relaxants
- Mechanism of action: acts on the central nervous system (CNS) to interfere with the transmission of nerve impulses to muscles, reducing muscle spasms and tension
- Key adverse effects to monitor: drowsiness, dizziness, muscle weakness, and nausea
Fractures
A fracture is a partial or complete break in the bone. There are many different types of fractures. Bone fractures are often caused by falls, injury, or a direct hit or kick to the body. Overuse or repetitive motions can cause stress fractures.
Types of fractures
- Open (compound): The bone breaks through the skin, exposing it to the environment
- Closed (simple): The bone breaks but does not penetrate the skin.
- Transverse: A straight break across the bone
- Oblique: A diagonal break at an angle to the bone
- Spiral: A twisting break that spirals around the bone
- Greenstick: A partial break that occurs in children’s flexible bones
- Comminuted: The bone breaks into multiple fragments
- Stress fracture: A small, hairline crack caused by repetitive stress
- Impacted fracture: The broken ends of the bone are driven into each other
- Avulsion fracture: A small piece of bone is pulled away by a tendon or ligament
Salter-Harris fracture
A Salter-Harris fracture is a type of bone fracture that occurs in children and adolescents, involving the growth plate (physis).
Salter-Harris fractures are classified into five types based on the location and extent of the fracture:
-
S - Straight across (Type I) Fracture through the growth plate (physis) only → No bone involvement
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A - Above (Type II) Fracture through the physis and metaphysis (above) → Most common type
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L - Lower (Type III) Fracture through the physis and epiphysis (below) → Involves joint surface
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TE - Through everything (Type IV) Fracture through metaphysis, physis, and epiphysis → Crosses entire bone
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R - Crush (Type V) Crush injury to the growth plate → Often not visible initially, worst prognosis



