The hand consists of:

• 8 carpal bones​ - proximal row (scaphoid, lunate, triquetrum, pisiform); distal row (trapezium, trapezoid, capitate, hamate)

• 5 metacarpals

• 14 phalanges

Diaphysis: main shaft of bone​

Metaphysis: flared end of bone, usually proximal

Physis: growth plate

Epiphysis: Rounded end of long bone

Bone healing - Infllammation, repair, remodelling

• Primary bone healing (direct)

  • occurs under conditions of absolute stability​

  • cortical contact exists across very small gaps

  • blood vessels infiltrate gap followed by mesenchymal cells that differentiate into osteoblasts and lay down new woven bone

  • Haversian remodeling in which osteoclasts in cutting cones resorb the necrotic fracture ends and replace the woven bone with new osteons

• Secondary bone healing​ (indirect)

  • occurs under conditions of relative stability​

  • depends on periosteal blood supply leading to the formation of radiographically visible callus​​

  • 4 stages:

    • inflammation​ (0 weeks) - haematoma and generalised inflammatory response

    • soft callus (3 weeks) - mesenchymal cells differentiate into chondroblasts and fibroblasts. Chondroblasts lay down hyaline cartilage

    • hard callus (12 weeks) - enchondral and intramembranous ossification

    • remodelling - original bone geometry is recreated over the course of months to years

Fracture stability

• Absolute stability

  • fixation in which motion is reduced nearly completely, with interfragmentary compression

  • eg compression plates and lag screws

• Relative stability​​​​

  • allows motion at fracture site​

  • depending on motion, can stimulate callus or inhibit bony bridging and union

  • eg casts, intramedullary nails, external fixators

Open/ compound: wound allows interaction between fracture and environment

Closed: Intact skin over fracture and haematoma

Simple: Two bone fragments

Comminuted: More than two bone fragments

Transverse: Fracture perpendicular to the long axis of the bone

Oblique: Fracture tangential to long axis of the bone

Spiral: Fracutre plane oblique and rotated

Impaction: End-on stress force causing compression without displacement

Longitudinal: Parallel to long axis of bone

Pathological: Fracture in tumour-laden or osteoporotic bone

Stress: Fracture in normal bone caused by cyclic loading

Greenstick: Incomplete fracture involving only one cortex

Intra-articular: Through articular surface

History: Age, hand dominance and occupation, mechanism of injury

Examination: Areas of tenderness, deformities, malrotation

Neurovascular status: Needs to be checked and documented before anaesthetisation

Soft tissue injury: Open or closed

Radiographs: AP and lateral minimum, may require oblique or specialised views

Decision on management plan depends on

• Age, handedness, occupation/hobbies, health and likely compliance with therapy​

• Open or closed fracture

• Stability of fracture

• Rotation or significant shortening

• Intra-articular

• Bone loss

• Neurovascular status and other structural injuries

• Preferred duration of rehabilitation (early mobilisation vs splinting)

• Surgeon expertise and available equipment

Complex fractures should always be discussed with a senior team member​

Metacarpal head fractures

• Operative​

  • ORIF​

  • External fixation

  • MCP arthroplasty

Metacarpal shaft fractures

• Operative​

  • ORIF​ with plate and/or lag screw

  • K-wire fixation (cross)

• Non-operative​

  • Splinting​

Metacarpal neck fractures​​

• Operative​

  • ORIF​

  • Intramedullary K-wire fixation ("Bouquet" technique)

• Non-operative​

  • Reduction and splinting​

Proximal and middle phalanges

• Operative​

  • K-wire fixation​ vs ORIF​​

  • 90-90 dental wires

• Non-operative​

  • Splinting vs buddy strapping​

Distal phalanx​​

• Tuft fractures usually conservatively managed unless very displaced​

• Operative

  • K-wire ​​​(axial)

Seymour fracture​​ - Physeal (Salter-Harris) fracture associated with nailbed injury

• Operative​

  • Closed or open reduction with K-wire fixation (axial)​

• Non-operative​

  • Closed reduction and splinting​

Infection

Malunion, malrotation, angulation, shortening

Nonunion

Loss of motion