What are the different types of fractures?

Types of Fractures

Fractures are classified into four primary categories based on their underlying etiology: osteoporotic (fragility) fractures, traumatic fractures, pathologic fractures, and stress fractures, each with distinct mechanisms, clinical implications, and management considerations. 1

Primary Fracture Classifications

Osteoporotic (Fragility) Fractures

These fractures occur from low-impact mechanisms (fall from standing height or less) and are associated with impaired bone strength, representing a critical indicator of underlying skeletal fragility. 1, 2

Major Osteoporotic Fractures

• Include clinical vertebral, hip, humerus, and forearm fractures 1
• The European Medicines Agency additionally designates pelvis, distal femur, proximal tibia, and multiple ribs as major osteoporotic fracture sites 1
• Vertebral fractures are the most common fragility fractures in adults aged 50+ years, yet often go unrecognized clinically, representing a major gap in identifying high-risk individuals 1
• Hip and clinical vertebral fractures carry the highest postfracture mortality, particularly in the first year following injury 1

Minor Osteoporotic Fractures

• Include all other fractures except those of the face, hands, skull, feet, and ankles 1

Critical Clinical Pitfall: Fragility fractures are neither normal nor benign events—they signal significantly increased "imminent fracture risk" in the 1-2 years following the index fracture, with approximately 2-fold increased risk of subsequent fractures. 1

Traumatic Fractures

• Caused by significant external impact force or injury exceeding a fall from standing height 1
• Represent high-energy mechanisms that distinguish them from fragility fractures 1
• Both high-trauma and low-trauma fractures should be included in clinical osteoporosis assessments, as prior fractures of either type increase subsequent fracture risk 1

Pathologic Fractures

• Occur secondary to altered skeletal physiology and mechanics in the setting of benign or malignant lesions 1
• Examples include fractures in bones affected by malignancy, multiple myeloma, or other skeletal pathology 1
• These fractures reflect underlying disease processes that compromise bone structural integrity 1

Stress Fractures

• Associated with major recent increase in physical activity or repeated excessive activity with limited rest 1
• Common sites include tibia, tarsal navicular, metatarsals (in runners), fibula, femur, pelvis, and spine 1
• Result from repetitive microtrauma exceeding bone's capacity for repair 1

Anatomic and Mechanical Fracture Patterns

Proximal Femoral Fractures (Hip Fractures)

Intracapsular Fractures (50% of hip fractures)

• Include subcapital, transcervical, and basicervical fractures 1
• May be displaced or undisplaced 1
• Blood loss at time of injury is minimal due to poor vascular supply and capsular tamponade 1
• Undisplaced fractures carry 30-50% risk of subsequent displacement if treated conservatively 1
• Displaced intracapsular fractures disrupt capsular blood supply, leading to avascular necrosis risk, necessitating hemiarthroplasty or total hip arthroplasty 1

Extracapsular Fractures (50% of hip fractures)

• Include intertrochanteric and subtrochanteric fractures 1
• Blood loss from cancellous bone can exceed one liter, with greater loss correlating with increased comminution 1
• More painful than intracapsular fractures due to greater periosteal disruption 1
• Treated surgically with sliding hip screw (intertrochanteric) or intramedullary nail (subtrochanteric) 1

Rib Fractures

Rib fractures are characterized by number, displacement, and anatomical zone (anterior/lateral/posterior), with specific ribs contributing differently to respiratory mechanics and clinical outcomes. 1

Fracture Types by Complexity

• Simple: Single fracture line across the rib without fragmentation 1
• Wedge: Second fracture line not spanning full rib width, creating butterfly fragment 1
• Complex: At least two fracture lines with one or more fragments spanning rib width 1

Anatomical Considerations

• Ribs 3-8 are most commonly plated and contribute most significantly to thoracic volumes 1
• First rib repair rarely indicated due to depth, vascular proximity, and minimal respiratory contribution 1
• Ribs 11-12 (floating ribs) repair considered only for marked displacement causing organ damage or herniation 1

Long Bone Fracture Patterns

By Mechanism

• Transverse fractures: Caused by bending load perpendicular to bone 1
• Spiral fractures: Result from torsion or twisting along long axis 1
• Oblique fractures: Combination of bending and torsion loads 1
• Torus (buckle) fractures: Result from axial compression loading 1

Important Caveat: While spiral fractures were historically considered highly suspicious for abuse, recent evidence shows no single fracture pattern can distinguish abuse from non-abuse with absolute certainty. 1

Pediatric-Specific Fracture Patterns

High Specificity for Abuse

• Classic metaphyseal lesions (CMLs): Appear as corner or bucket-handle fractures depending on radiographic projection 1
• Rib fractures, especially posteromedial 1
• Scapular, sternal, and spinous process fractures 1

Moderate Specificity for Abuse

• Multiple fractures, especially bilateral 1
• Fractures of different ages 1
• Epiphyseal separations and vertebral body fractures 1

Low Specificity (Common in Both Abuse and Accidental Injury)

• Long bone shaft fractures 1
• Linear skull fractures 1
• Clavicular fractures 1

Critical Age-Related Factor: Femoral and humeral fractures in non-ambulatory children have higher abuse specificity compared to ambulatory children, where these fractures are most commonly non-inflicted. 1

Dental Fractures

Luxation Injuries

• Concussion: Tender to touch, no mobility or displacement, no sulcular bleeding 1
• Subluxation: Abnormal mobility without displacement, sulcular bleeding present 1
• Lateral luxation: Displaced laterally (often palatal/lingual), may be mobile or locked 1
• Extrusive luxation: Partial vertical displacement from socket 1
• Intrusive luxation: Tooth forced into alveolus 1

Crown Fractures

• Enamel only (uncomplicated): Limited sensitivity unless rough edge present 1
• Enamel and dentin (uncomplicated): Frequently sensitive to air, food, beverages 1
• With exposed pulp (complicated): Increased infection risk from oral flora exposure 1

Open Fractures

• Any fracture communicating with external environment via skin wound 3
• May result from external penetration, laceration by fracture fragments, or shearing/degloving forces 3
• Require specific management principles regardless of mechanism 3

Clinical Significance and Morbidity

Fragility fractures require surgical intervention in many cases, with associated risks including anesthetic complications, postoperative pain, bleeding, infection, and thromboembolic complications. 1

• Postfracture mortality is highest in the first year, particularly following clinical vertebral or hip fractures 1
• More than 4 million fractures occur annually in Europe, with direct costs approaching €57 billion per year 1
• By 2050,50% of the world's hip fractures are expected to occur in Asia 1