Understanding common fracture types 🦴

 Fractures are important—not just because they’re common, but because they reveal how bones respond to force, age, and physiology. One way to think about them is as patterns left behind by trauma: each shape tells you something about the mechanism, the anatomy involved, and what might go wrong next.

In this post, we’ll walk through common fracture types and explore how to reason through them. Not just what they look like, but why they happen, how they present, and what they mean for your patient.  

🦴 So What Is a Fracture?

A fracture is a break in the continuity of bone—but that’s just the start. The type of fracture gives you clues about:

• The mechanism of injury (twisting, compression, direct trauma)
• The age and physiology of the patient (kids vs adults)
• The risk of complications (growth arrest, joint damage, nonunion)
• The management plan (surgery, immobilization, follow-up)

Let’s walk through some common types—not just what they look like, but how to reason through them.

🧠 How to Think Through Any Fracture

Here’s a simple framework to use when you see a fracture:

1. Mechanism: What kind of force caused it? Twisting? Compression? Direct blow?
2. Location: Is it near a joint? In a growing bone? In a weight-bearing area?
3. Pattern: What does the fracture line tell you about the direction and energy?
4. Implications: Will it affect growth, joint function, or healing time?
5. Management: Does it need surgery, immobilization, or just watchful waiting?

🧒 Bone, Force, and Age: Why Kids Break Differently

One of the most important things to understand about paediatric fractures is that children’s bones aren’t just smaller versions of adult bones—they’re structurally and physiologically different. As bones grow and calcify, their response to force changes. That’s why the same mechanism of injury can produce very different fracture types depending on the child’s age.

In very young children, especially infants and toddlers, bones are still highly cartilaginous and flexible. When force is applied, they don’t snap—they bend. This is called plastic deformation, and it can be subtle on X-ray. You might not see a clear fracture line, but the bone has bowed under pressure. Always compare sides and look for asymmetry.

Plastic deformation of forearm in a toddler

🩺 Clinical Tip: If you’re seeing a toddler with forearm pain after a fall, and the X-ray looks “normal,” don’t dismiss it—plastic deformation may not show up clearly. Look for subtle bowing and compare sides.

As children get a little older and their bones begin to calcify, they’re still pliable—but now they start to buckle under compressive force. This leads to buckle fractures, also known as torus fractures. These are common in the distal radius after a fall, and they’re usually stable and quick to heal.

Buckle fracture in a wrist

In older children, bones are more mineralized but still not fully rigid. When force is applied, the bone may crack on one side and bend on the other—this is a greenstick fracture. It’s like snapping a fresh twig: one side breaks, the other side holds on. These fractures often need careful immobilization to prevent progression.

Greenstick fracture - one side of the bone is breached, the other is intact

By adolescence, bones have mostly matured. They’re rigid, brittle, and behave more like adult bone. At this stage, the same force that once caused a buckle or greenstick fracture now results in a complete transverse fracture—a clean break across the shaft.

Transverse fracture in a young child

This progression helps explain why fracture classification isn’t just academic—it’s a clue to the child’s developmental stage, the force involved, and the healing potential. It also reminds us that paediatric bones are more forgiving in some ways (rapid healing, remodeling), but more vulnerable in others (growth plate injury, subtle deformities). However, with enough force, transverse fractures can still occur in small children's bones- this is a pattern, but not a rule. 

🧠 Fracture Types 

🔹 Transverse Fracture

• Mechanism: Direct blow or repetitive stress  
• Reasoning: Clean break suggests localized force. Ask: Was this trauma or overuse? Consider stress fractures in athletes or pathologic fractures in older adults.
• Management Insight: Often stable if nondisplaced, but displacement risks malunion.

Transverse fracture tibia

Transverse fracture metacarpal (hand)

🔹 Oblique Fracture

• Mechanism: Angled compression or indirect trauma.
• Reasoning: Diagonal line hints at combined axial and lateral forces. Ask: What direction was the force?
• Clinical Pearl: Can be unstable—watch for shortening or rotation.

Oblique fracture of the humerus (upper arm)

🔹 Spiral Fracture

• Mechanism: Twisting injury (e.g. skiing, child abuse).
• Reasoning: Spiral pattern = rotational force. Ask: Was this accidental or suspicious? In kids, consider non-accidental injury if history doesn’t match.
• Management: Often needs surgical fixation due to instability

Spiral fracture tibia (ankle)

🔹 Comminuted Fracture

• Mechanism: High-energy trauma (e.g. car crash).
• Reasoning: Multiple fragments = massive force. Ask: Is there soft tissue damage?
• Clinical Implication: Healing is slow; surgical fixation often required. Risk of compartment syndrome.

Comminuted fractured femur - high force injury

ORIF (open reduction internal fixation) of a comminuted tibia fracture

🔹 Greenstick Fracture

• Mechanism: Bending force in paediatric bone.
• Reasoning: Incomplete break = pliable bone. Ask: Is this a child? If yes, expect rapid healing—but don’t miss it on X-ray.
• Management: Immobilization; rarely surgical.

Greenstick fracture in the distal radius of a 4 year old child

🔹 Segmental Fracture

• Mechanism: Two separate breaks from severe trauma.
• Reasoning: Floating segment = poor blood supply. Ask: Is this segment viable?
• Clinical Concern: High risk of nonunion and infection.

Segmental fracture in the ulna.

Why segmented and not comminuted?  A comminuted fracture is when a bone shatters into three or more fragments, often from high-impact trauma. In contrast, a segmental fracture involves two or more complete fracture lines in the same bone, creating one or more separate "floating" bone segments that are isolated from the ends of the bone

🔹 Compression Fracture

• Mechanism: Axial load, often in osteoporotic spine.
• Reasoning: Vertebral collapse = bone fragility. Ask: Is this trauma or pathology?
• Management: Pain control, bracing, and osteoporosis workup.

🔹 Avulsion Fracture

• Mechanism: Sudden muscle contraction pulls bone fragment.
• Reasoning: Common in athletes. Ask: Was there a sprint, jump, or kick?
• Management: Conservative unless large displacement.

An avulsion fracture in a finger

🎯 Why Fracture Type Matters

Fractures aren’t just radiographic patterns—they’re reflections of force, age, anatomy, and healing potential. For med students, learning to classify fractures is only the first step. The real skill lies in asking:

• What caused this?
• What structures are involved?
• What are the risks if we miss it?
• How does age change the game?

Let’s explore this through the lens of Salter-Harris fractures, a classification system for physeal (growth plate) injuries in children.

🧒 Salter-Harris Fractures: Growth Plates Under Pressure

The mnemonic SALTER helps remember the five classic types. Personally I hate mnemonics for almost all things- but this is one of the exceptions. It works, because you don't have to remember an additional word ! The mnemonic is in the name. 

Type (Mnemonic)	Pattern	Explanation	Prognosis
Type I S – Straight across / Slipped	Straight through the physis (growth plate)	Often missed on X-ray, suspect in kids with tenderness on growth plate after trauma	Good= growth plate intact
Type II A – Above/Away from the joint	Through physis and metaphysis	Most common; metaphyseal fragment (Thurston-Holland sign) helps identify	Good – epiphysis spared
Type III L - Lower	Through physis and epiphysis	Intra-articular → risk of joint incongruity; surgical fixation often needed	Moderate – growth disturbance risk
Type IV T – Through	Metaphysis, physis, and epiphysis	Crosses all zones → high risk of growth arrest and joint damage	Poorer – needs precise reduction
Type V  ER– Everything Rammed (or ERasure)	Crush injury to physis	Often missed initially; no displacement but high risk of growth arrest	Worst – may cause limb length discrepancy

🩺 Clinical Pearl: A fall on an outstretched hand in a 12-year-old with wrist pain and subtle swelling? Think Salter-Harris II of the distal radius. If it’s intra-articular, you’re in III or IV territory—and that changes everything.

Case: A 10-year-old presents after a trampoline fall. X-ray shows a fracture through the distal femoral metaphysis and physis, sparing the epiphysis.

• Type? Salter-Harris II.
• Mechanism? Axial load with valgus stress.
• Management? Closed reduction and immobilization.
• Why it matters? Femoral physis contributes significantly to leg length—growth arrest here could cause limb discrepancy.

Salter Harris Type 1 - widened and slipped at the growth plate

Salter Harris type II fracture in the finger, the fracture goes through the growth plate and Away (above ) the joint

Salter Harris type III fracture in a toe - the fracture goes Lower (closer to ) the joint

Salter Harris type IV fracture, also in a toe, the fracture line goes Through everything - the epiphysis, the physis and the metaphysis

Type V are rare and difficult to see on Xray - so no pictures for you! 

📝 Wrap-Up

Fractures aren’t just about memorizing shapes—they’re about understanding the forces, the anatomy, and the consequences. As you move through your clinical years, you’ll start seeing these patterns everywhere. So start now: ask why, not just what.

Next time you see a fracture on X-ray, ask: What force caused this? What structures are involved? What could go wrong if we miss it?