• Fractures account for a significant proportion of Emergency Department presentations worldwide. In Hong Kong, the ageing population means a dual burden:
  • Young adults: high-energy trauma (road traffic accidents [RTAs], sports injuries, falls from height) — these tend to cause complex fractures and fracture-dislocations.
  • Elderly: low-energy trauma (simple falls from standing height) — these are fragility fractures in osteoporotic bone.
• The most common fractures overall include: distal radius (Colles'), hip (neck of femur), ankle, proximal humerus, and vertebral compression fractures ^[2].
• Fracture is more common than dislocation in children because the paediatric bone is weaker than the ligaments and growth plates are mechanically vulnerable ^[3].

• Hong Kong has one of the world's most rapidly ageing populations. Osteoporotic hip fractures are a major public health burden — prevalence in HK women: 1 in 6 aged 60–69, 1 in 5 aged 70–79, 1 in 4 aged ≥ 80 ^[6].
• Road traffic accidents remain a significant cause of high-energy fractures and dislocations, particularly motorcyclists and pedestrians.
• High-energy trauma (e.g. fall from height, RTA) is a common mechanism for pelvic fractures, tibial plateau fractures, and fracture-dislocations ^[4][5].

• Three-column model (Denis):
  • Anterior column: anterior longitudinal ligament + anterior half of vertebral body
  • Middle column: posterior half of vertebral body + posterior longitudinal ligament
  • Posterior column: pedicles, lamina, facets, spinous processes, posterior ligamentous complex
• Instability = involvement of ≥ 2 columns.

The immature skeleton differs from the adult skeleton in several critical ways ^[3]:

Unique paediatric fracture patterns ^[3]:

• Greenstick fracture: one cortex breaks, the other bends (like breaking a green twig)
• Plastic deformation (bowing): bone bends without a visible fracture line
• Torus (buckle) fracture: compression of one cortex causing a "buckle" — stable, treated with splint
• Physeal (growth plate) injuries: classified by the Salter-Harris classification (see Classification section)

Because ligaments are stronger than the growth plate in children, fracture is more common than dislocation, and physeal injury is more common than ligament injury ^[3].

This is one of the most important classifications in paediatric orthopaedics. The mnemonic is SALTR:

Why does crossing the physis matter? The physis (growth plate) is responsible for longitudinal bone growth. Damage to the germinal layer of chondrocytes can cause premature physeal closure → limb length discrepancy or angular deformity. Types III, IV, and V carry the highest risk.

The differential diagnosis of knee pain is extensive and location-dependent ^[7]:

The differential diagnosis of back pain is broad ^[12]:

For vertebral compression fractures specifically, distinguish:

• Osteoporotic fragility fracture: low-energy, elderly, known risk factors ^[2]
• Pathological fracture from metastasis: suspect if above T5, constitutional symptoms, night pain, weight loss ^[2]
• Traumatic fracture: adequate mechanism (fall from height, RTA)
• Chance fracture (seatbelt fracture): horizontal fracture of upper lumbar spine, distraction injury of posterior column in passenger with lap belt only ^[5]

These rules were developed to reduce unnecessary X-rays for ankle injuries. An ankle X-ray is indicated if there is:

• Any pain in the malleolar zone AND any one of:
  1. Bone tenderness at distal 6 cm of posterior edge of tibia or tip of medial malleolus
  2. Bone tenderness at distal 6 cm of posterior edge of fibula or tip of lateral malleolus
  3. Inability to bear weight immediately after injury AND in the Emergency Department for 4 steps

Why posterior edge? Because the most clinically significant malleolar fractures involve the posterior cortex of the distal tibia and fibula. Tenderness over the anterior border is more likely to represent a ligament injury.

A foot X-ray is indicated if there is:

• Midfoot pain AND any one of:
  1. Bone tenderness at the base of the 5th metatarsal
  2. Bone tenderness at the navicular
  3. Inability to bear weight immediately and in the Emergency Department for 4 steps

The Ottawa rules have a sensitivity of ~98–100% for significant fractures (very few false negatives) but moderate specificity (~40%) — meaning they effectively rule out fracture when negative but still lead to many normal X-rays when positive.

A knee X-ray is indicated if any of:

1. Age ≥ 55
2. Isolated patella tenderness
3. Tenderness at fibular head
4. Inability to flex knee to 90°
5. Inability to bear weight immediately and in the Emergency Department for 4 steps

Used to decide whether cervical spine imaging is needed after trauma (addressed in spine-specific notes but important in polytrauma context).

Why do these measurements matter? The distal radius articulates with the carpus and the ulna at the DRUJ. Any loss of radial height, inclination, or tilt changes the load distribution across the wrist joint → accelerates degenerative change and causes mechanical dysfunction. The threshold values represent the point beyond which functional outcomes significantly worsen if not corrected.

• On AP pelvis X-ray: a smooth curving line formed by the medial edge of the femoral neck and the inferior edge of the superior pubic ramus
• Disrupted Shenton's line = femoral neck fracture until proven otherwise
• Also look for: prominent lesser trochanter (external rotation), higher lesser trochanter (shortening)

• Garden I–II = undisplaced → internal fixation
• Garden III–IV = displaced → arthroplasty (elderly) or ORIF (young)

• Measured on lateral X-ray foot: angle between a line from the posterior tuberosity to the highest point of the posterior facet, and a line from this point to the highest point of the anterior process
• Normal: 25–40°
• Flattened (< 25°) = calcaneal compression fracture

• On any elbow X-ray view: a line through the centre of the radial shaft should always pass through the centre of the capitellum
• Disrupted line → radial head dislocation (key finding in Monteggia fracture-dislocation)

• On lateral elbow X-ray: a line along the anterior cortex of the humerus should pass through the middle third of the capitellum
• Displaced anteriorly or posteriorly → supracondylar fracture (especially important in children)

• C1 level: prevertebral soft tissue ≤ 10 mm
• C3 level: ≤ 7 mm (the "3×7=21 rule")
• C7 level: ≤ 21 mm
• Widening suggests haematoma from occult fracture

• 4 lines on lateral X-ray should be smooth: anterior vertebral line, posterior vertebral line, spinolaminar line, tips of spinous processes
• 3 lines on AP view should be smooth: spinous processes (midline), lateral masses, vertebral body margins
• Malalignment of any line → fracture or ligamentous injury until proven otherwise

Plain X-ray is the first-line investigation because it requires no patient movement, is readily available, fast, inexpensive, and has the highest spatial resolution for detecting fractures ^[5][13].

Principles:

• Most films require ≥ 2 views because fractures may be detected only in one view ^[13] — typically AP + lateral as minimum
• X-ray can only distinguish between four densities: calcium (bone), water (soft tissue), fat, and air ^[13]
• 2-D representation of 3-D structures → overlapping may be present → use different angles to remedy ^[13]
• Always request imaging of the entire bone (including the joint above and below) — fractures can propagate, and associated injuries at distant sites can be missed

Standard Views by Region:

Key X-ray Findings and Their Interpretation:

Systematic X-ray Interpretation — The ABCS Approach:

Fracture X-ray Interpretation — Systematic Description ^[2]:

Paediatric X-ray interpretation requires additional attention ^[2]:

• Specific morphology due to more active periosteum: bowing (plastic deformation), greenstick (one cortex breaks), buckled/torus (impacted cortex)
• Epiphyseal injury: physis is the weakest part → susceptible to fracture → Salter-Harris classification
• Comparison views of the contralateral limb may be needed to distinguish a physis from a fracture line (secondary ossification centres in children can mimic fractures)

CT is the best modality for organ/vascular injury and provides superior bony detail compared to plain X-ray ^[5].

Indications in fractures/dislocations:

Key CT Findings:

MRI excels at soft tissue assessment — it shows things that CT and X-ray cannot.

Indications:

Key MRI Findings:

USG advantages: fast. Disadvantages: operator dependent, often obscured by bowel gas ^[5]

Not used for fracture diagnosis per se, but essential in the work-up of fragility fractures to diagnose and quantify osteoporosis ^[6]:

• T-score ≥ –1.0: Normal
• T-score between –1.0 and –2.5: Osteopenia
• T-score ≤ –2.5: Osteoporosis
• T-score ≤ –2.5 with fragility fracture: Established osteoporosis

T-score = (Patient's BMD – mean BMD of young adult women) / SD. Each 1 SD decrease in BMD = 2× increased risk of hip fracture ^[6].

Lab tests are not used to diagnose fractures themselves but are essential for:

1. Clinical features present (snuffbox tenderness, scaphoid tubercle tenderness, pain on thumb telescoping)
2. Initial X-ray (AP, lateral, scaphoid view) → normal
3. Treat as scaphoid fracture: thumb spica cast immobilisation
4. Repeat X-ray at 10–14 days (bone resorption at fracture site → fracture line becomes visible)
5. If still equivocal → MRI wrist (gold standard for occult scaphoid fracture)

1. Elderly patient, fall, groin pain, unable to weight-bear, pain on internal rotation
2. AP + lateral X-ray hip → normal
3. MRI hip (within 24h if available) → bone marrow oedema confirms fracture
4. If MRI unavailable → CT hip or bone scan (less sensitive than MRI for undisplaced fractures)

1. Pelvic XR in primary survey → identify obvious fractures
2. CT pelvis with contrast → assess for:
   • Fracture extent and classification
   • Haematoma / contrast extravasation (vascular injury → may need angiographic embolisation)
   • Visceral injury (gas in bladder = bladder rupture)
3. If haemodynamically unstable → pelvic binder → CT when stabilised → interventional radiology if active bleeding

1. AP + lateral X-ray tibia/fibula → spiral fracture identified
2. CT scan indicated to:
   • Rule out fracture extension to posterior malleolus (intra-articular extension to the ankle)
   • Assess for any other fracture lines

1. Plain X-ray: readily available, shows obvious fracture and malalignment, can miss subtle fracture, cannot exclude ligamentous instability, cannot exclude soft-tissue compressive lesion (e.g., haematoma) ^[14]
2. CT spine: reasonably available, still cannot show soft-tissue injury — but superior for bony detail ^[14]
3. MRI spine: difficult to arrange but shows soft-tissue lesion, cord oedema — essential for detecting disc herniation, epidural haematoma, ligamentous injury, cord compression ^[14]

Definition: restoring the fracture fragments to acceptable alignment.

Aims ^[2]:

• Tamponade bleeding (realigned bone ± splint compresses the fracture haematoma)
• Restore blood supply (displaced fragments can kink or stretch vessels)
• Reduce traction on nerves (displacement stretches nerves → neuropraxia)
• Reduce traction on soft tissue (displaced fragments increase compartment pressure)

When is reduction NOT indicated? ^[2]:

• No or little displacement (already in acceptable alignment)
• Reduction unlikely to succeed (e.g., compression fracture of vertebrae — you cannot "uncrush" cancellous bone)

Methods:

Post-reduction: ALWAYS check neurovascular status + obtain post-reduction X-ray to confirm alignment ^[2].

Purpose: Hold the reduced fracture in position while it heals. Immobilisation also serves as the best analgesic.

Types of Internal Fixation ^[2]:

Why does the choice of fixation matter? Different fractures have different biomechanical demands. A femoral shaft fracture needs a load-sharing device (IMN) that allows early weight-bearing. A tibial plateau fracture needs anatomical reduction of the joint surface (ORIF with plates/screws) to prevent post-traumatic arthritis. An olecranon fracture needs tension band wiring to convert the tensile pull of the triceps into a compressive force that promotes healing ^[2].

Rehabilitation begins from day 1, not after the cast comes off. The goals are:

• Prevent stiffness (immobilisation causes joint capsule contracture and muscle wasting)
• Restore ROM (physiotherapy)
• Strengthen muscles (progressive resistance exercises)
• Restore function (occupational therapy, return to activity)
• Prevent complications (DVT prophylaxis, pressure sore prevention, chest physiotherapy)

Shoulder Dislocation — Anterior ^[2]:

1. Closed reduction under sedation (multiple techniques: Hippocratic, Kocher, Stimson, traction-countertraction)
2. Post-reduction: neurovascular check (axillary nerve — regimental badge area) + post-reduction X-ray
3. Broad arm sling immobilisation × 2–3 weeks
4. Physiotherapy: rotator cuff and periscapular strengthening
5. Recurrent instability (especially in young patients): consider arthroscopic Bankart repair or Latarjet procedure (coracoid transfer for bone loss)

Clavicle Fracture ^[2]:

• Conservative (mainstay): sling immobilisation (e.g., figure-of-eight brace), physiotherapy (ROM exercise, muscle strengthening). Usually heal within 4–6 weeks.
• Operative indications: threatened skin (tented, tethered, non-blanching), open fracture, bilateral fracture (to permit weight-bearing) ^[2]
• Operative modalities: closed reduction with IM fixation, ORIF (plate and screws if unable to unite)

Proximal Humerus Fracture ^[2]:

• Non-operative (if no displacement): sling immobilisation then rehabilitation
• Operative (displaced, open, neurovascular compromise):
  • Closed reduction with percutaneous pinning: preferred for surgical neck fractures
  • ORIF: preferred for head-splitting fractures
  • Hemiarthroplasty / Reverse shoulder arthroplasty (RSA): rare, for severely comminuted fractures in elderly

Humeral Shaft Fracture ^[2]:

• Non-operative (1st line): coaptation splint → functional bracing
  • Acceptable limits: < 20° anterior angulation, < 30° varus/valgus, < 3 cm shortening
• Operative indications: open fracture, vascular injury, brachial plexus injury, pathologic fracture
  • ORIF (plate and screws or IMN)
• Usually heal in 8–12 weeks
• Watch for Holstein-Lewis fracture (spiral fracture of distal third → radial nerve entrapment → wrist drop) ^[2]

Radial Head Fracture — Mason Classification and Management ^[2]:

• Type 1 (non-displaced / < 2 mm): elbow sling × 1 week in flexion → early mobilisation
• Type 2 (displaced > 2 mm / angulated): ORIF
• Type 3 (comminuted): ORIF ± LCL reconstruction; if ORIF not feasible → radial head excision with replacement

Olecranon Fracture ^[2]:

• Non-operative: minimally displaced < 2 mm / unfit for surgery → elbow sling × 1 week in flexion → early mobilisation
• Operative:
  • Tension band wiring: if fracture is proximal to coronoid process → converts tensile force of triceps into compression at fracture site
  • Olecranon plating: if fracture is at or distal to coronoid process

Elbow Dislocation ^[2]:

• Simple (no fracture): closed reduction (in-line traction or manipulation of olecranon) + splinting
• Complex (with fracture, e.g., terrible triad): ORIF of coronoid process and radial head + LCL/MCL reconstruction

Supracondylar Fracture (Children) ^[2]:

• Non-displaced: above-elbow backslab
• Displaced: closed reduction + percutaneous K-wire fixation (usually 2–3 lateral pins)
• Open reduction if closed reduction fails or if vascular compromise (brachial artery)
• Monitor closely for Volkmann's ischaemic contracture (compartment syndrome of forearm)

Forearm Shaft Fractures (including Galeazzi and Monteggia) ^[2]:

• Acute: RICE, analgesics, immobilisation by slab
• Definitive: Open reduction internal fixation (ORIF) is preferred because forearm fractures affect motion (supination, pronation) — you need anatomical reduction to restore the interosseous space and rotational axis ^[2]
• Nightstick fracture (isolated ulnar shaft): may be managed conservatively with cast if non-displaced

Colles' / Smith Fracture ^[2]:

• Stable extra-articular fracture: Closed reduction + short arm cast immobilisation × 6 weeks
  • Closed reduction technique: traction + recreation of the deformity then reversal → mould the cast (3-point fixation)
• Unstable fracture (based on radiographic criteria — > 5 mm shortening, > 5° angulation change, > 2 mm step-off, comminution, associated ulnar fracture [NOT ulnar styloid]): ORIF with plating / K-wire fixation
• Open fracture: external fixation

Scaphoid Fracture ^[2]:

• Non-operative (undisplaced fracture, or normal XR but high clinical suspicion): thumb spica cast immobilisation + repeat XR at 14 days ± MRI
• Operative (displaced or proximal pole fracture): percutaneous screw fixation — needed because the proximal pole has the poorest blood supply and highest AVN risk

• Mallet finger ^[2]: DIP extension splint × 6–8 weeks; surgery if Type III (joint subluxation / > 50% articular surface)
• Boxer's fracture (5th MC neck): closed reduction + ulnar gutter splint; rarely needs surgery unless significant rotational deformity
• Bennett's fracture (1st MC base, intra-articular): ORIF or closed reduction with percutaneous K-wire fixation — must restore articular surface of the CMC joint
• Skier's thumb (UCL rupture): partial tear → thumb spica; complete tear (Stener lesion) → surgical repair

Salter-Harris Fractures (Paediatric Epiphyseal Injuries) ^[2]:

This is one of the most important management algorithms in orthopaedic surgery:

Key principles ^[2]:

• Intracapsular displaced → high AVN risk ( > 95%) because retinacular vessels are disrupted → in elderly patients, replacing the head (arthroplasty) is better than trying to fix it and risking AVN/non-union
• Extracapsular → blood supply preserved → fix the fracture (DHS or IMN) and let it heal
• Young patients with displaced intracapsular fractures → attempt ORIF urgently (within 6 hours ideally) to try to preserve the native hip — AVN risk is accepted because joint replacement in the young has limited lifespan
• Post-operative: DVT prophylaxis, early mobilisation, fall prevention measures, treatment of osteoporosis (bisphosphonates + lifestyle modifications) ^[2]

• Immediate: traction splinting (Kendrick traction device → change to skin traction ASAP)
  • Contraindicated in hip or pelvic fracture ^[2]
• Operative (within 24–48h): antegrade intramedullary nail (with closed or open reduction) — the gold standard
• Non-operative (rare): long leg cast only if non-displaced with multiple comorbidities making surgery too high-risk

• Immediate: skin traction
• Operative (mainstay): retrograde IMN (simple) / ORIF (complex) / external fixation (open fracture)
• Peri-prosthetic fractures may require ORIF or distal femoral replacement

• Pelvic binder is usually NOT indicated (unlike pelvic ring fractures)
• Undisplaced: conservative management × 6–8 weeks (protected weight-bearing)
• Displaced:
  • Young: ORIF (restore joint surface anatomy)
  • Old: fracture fixation + total hip replacement

• Unstable pelvic fracture is a life-threatening injury — massive haemorrhage potential ^[15]
• Immediate: pelvic binder (reduces pelvic volume → tamponades venous bleeding)
• Haemodynamic instability: resuscitation, massive transfusion protocol, pelvic external fixation, angiographic embolisation if arterial bleeding on CT
• Definitive: ORIF once patient is stable

• Uncomplicated lateral plateau fracture: hinged knee brace × 8–12 weeks, physiotherapy, analgesics
• Complicated / Medial plateau fracture: ORIF + post-op hinged knee brace × 8–12 weeks
• Open fracture: external fixation → delayed definitive surgery

• Non-displaced: straight leg immobilisation by hinged knee brace → early weight-bearing in extension, quadriceps strengthening
• Significantly displaced / disrupted extensor mechanism: ORIF with tension band wiring — converts tensile force of the extensor mechanism into compression force to assist fracture healing
• Comminuted: partial/total patellectomy

• Acute: RICE, analgesics, reduction + above-knee backslab (anatomical reduction not necessary for shaft fractures — some overlap/shortening is acceptable). Monitor for compartment syndrome.
• Uncomplicated: closed reduction + intramedullary nail for early weight-bearing
• Proximal/distal with intra-articular extension: ORIF
• Open fracture: external fixation before definitive surgery

• Non-operative indications: non-displaced fracture, Weber A, Weber B without talar shift
  • Closed reduction + below-knee backslab, repeat neurovascular exam + XR
• Operative indications: bimalleolar/trimalleolar fracture, Weber B with talar shift, Weber C, open fracture
  • ORIF ± syndesmotic screw / tightrope fixation

Why does talar shift matter? Even 1 mm of lateral talar shift reduces tibiotalar contact area by ~40%, dramatically accelerating degenerative change. That's why Weber B fractures are only stable if the talus hasn't shifted — once it shifts, the syndesmosis is disrupted and surgical fixation is needed.

• Non-operative: closed reduction + below-knee backslab
• Operative (mainstay): staged approach — temporary external fixator → ORIF after 7–14 days (allowing soft tissue swelling to settle) ± ankle fixation by hindfoot nail

• Usually operative: closed reduction with percutaneous pinning or ORIF
• Assess posterior heel skin integrity — may require emergency surgery

• Type I (undisplaced): conservative (below-knee cast)
• Type II–IV (displaced): closed reduction + cast in A&E → urgent ORIF

The urgency here is because of the tenuous blood supply. Every hour of displacement further compromises the already precarious vascular supply → increases AVN risk.

• Non-displaced, ligamentous only: weight-bearing cast × 6 weeks + close follow-up with repeat imaging
• Displaced / bony Lisfranc: ORIF (anatomical reduction of the tarsometatarsal alignment is critical) or primary arthrodesis

• Medical: ABC support, DVT prophylaxis, stress ulcer prophylaxis, analgesics, urinary catheter ^[16]
• Non-surgical immobilisation only in stable injuries: spinal orthoses × 2–3 months ^[16]
  • Problems: pressure sores, weakening of muscles, soft tissue contractures, decreased pulmonary function, chronic pain syndrome ^[16]
• Surgical treatment in unstable injuries ^[16]:
  • Surgical decompression if a patient with normal cord function or incomplete cord lesion progressively deteriorates
  • Reduction of fractures or dislocations
  • Fixation of unstable spinal elements
• Methylprednisolone is associated with higher risk of morbidity and complications and should NOT be used ^[16]

Pathophysiology: Displaced fracture fragments or dislocated joints can stretch, compress, or lacerate adjacent nerves and vessels. The severity depends on the type of force:

Key fracture-nerve associations (revisited here because they are complications):

Vascular injury: displaced fracture fragments or dislocated joints can cause intimal tears → thrombus formation → acute limb ischaemia. Key associations:

• Supracondylar fracture (children): brachial artery injury → Volkmann's contracture (see below)
• Knee dislocation: popliteal artery injury (~40% incidence — the artery is tethered behind the knee) — must always get CT angiography
• Tibial plateau fracture: popliteal artery
• Fractures/dislocations → arterial stretching → intimal tear → thrombus formation ^[10]
• Proximal humerus: axillary artery injury — may be masked by extensive collateral circulation preserving distal pulse ^[2]

Definition: elevated pressure within a closed fascial compartment that compromises perfusion to the muscles and nerves within it.

Pathophysiology ^[2][10][17]:

• Fracture haematoma + tissue oedema within a non-distensible fascial compartment → ↑intracompartmental pressure → exceeds capillary perfusion pressure → muscle and nerve ischaemia → cell membrane damage → more fluid leaks into interstitial space → further ↑pressure (vicious cycle)
• Prolonged ischaemia ( ≥ 6 hours) + delayed revascularisation → fluid leaks out via damaged cell membrane → oedema → secondary ischaemia when pressure ≥ 30 mmHg or within 30 mmHg of diastolic BP ^[10]
• More common in legs (4 compartments) than thigh (3 compartments) ^[2]
• Anterior compartment is most commonly affected whereas involvement of posterior compartment is the most functionally devastating ^[17]

Clinical Features — The 6 Ps ^[2]:

Diagnosis: Primarily clinical. If physical examination is unreliable (e.g., obtunded patient), measure intracompartmental pressure with a Stryker monitor ^[2]:

• Absolute pressure > 30 mmHg, OR
• Delta pressure (diastolic BP minus compartment pressure) < 30 mmHg → fasciotomy indicated

Management ^[2]:

1. Remove all constrictive dressings (cast, bandages)
2. Limb elevation at the level of the heart (NOT above — this reduces perfusion pressure)
3. Analgesia, O₂, IV fluids
4. Emergency fasciotomy of all compartments ^[2]
5. Leave skin incisions open for re-inspection after 48h ± remove necrotic tissue
6. Post-op: monitor RFT, CK (rhabdomyolysis)

High-risk fractures for compartment syndrome ^[2]:

• Tibial shaft fracture (most common)
• Supracondylar fracture (children) — forearm compartment syndrome
• Forearm fractures (both-bone)
• High-energy fractures with significant soft tissue injury

Definition: the end result of untreated/inadequately treated compartment syndrome of the forearm.

Pathophysiology ^[2]:

• Commonly found in supracondylar fracture in children ^[2]
• Brachial artery injury (or sustained compartment syndrome) → ischaemic necrosis of the forearm flexors → necrotic muscle is replaced by fibrous tissue → shortening and contracture → claw-like deformity of the hand
• The flexors are affected more than the extensors because the flexor compartment is deeper and has higher metabolic demands

Clinical features: wrist flexion, MCP hyperextension, IP flexion (flexed, clawed hand). Passive extension of the fingers is limited and worsened by wrist extension (tightens the fibrosed flexors further).

Prevention: early recognition and treatment of compartment syndrome is the ONLY way to prevent Volkmann's contracture. Once established, it is devastating and largely irreversible.

The most likely serious complication of an open fracture is infection ^[15].

This was specifically tested in the lecture slide: a 46-year-old male with a Grade II open tibia fracture — the most likely serious complication is infection (not compartment syndrome, malunion, or non-union) ^[15].

Why? The breach in skin exposes bone to environmental bacteria. Bone, once infected (osteomyelitis), is extremely difficult to treat because:

• Bone has relatively poor vascularity compared to soft tissue → antibiotics struggle to penetrate
• Dead bone (sequestrum) acts as a nidus for persistent infection
• Biofilm formation on dead bone/implants makes eradication very difficult

Prevention (as covered in the management section): urgent antibiotics (within 1 hour), tetanus prophylaxis, surgical debridement, staged wound closure.

Fracture blisters ^[2]:

• Formed by elevation of the epidermal layer from the dermis
• Indicate severe soft tissue injury
• Do NOT puncture — may lead to local infection

Pathophysiology: fractures disrupt intramedullary and periosteal vessels → bleeding into the fracture haematoma and surrounding soft tissues.

Estimated blood loss by fracture site:

Pelvic fractures deserve special mention ^[5]: the pelvic retroperitoneum can accommodate massive blood volumes. The venous plexus (presacral, internal iliac) is the primary source. Management includes pelvic binder, resuscitation, angiographic embolisation for arterial bleeding.

Pathophysiology:

• Long bone fractures (especially femoral shaft) → fat globules from bone marrow enter the venous circulation → lodge in the pulmonary and cerebral microcirculation
• Two theories: (1) mechanical: physical obstruction of capillaries, (2) biochemical: free fatty acids released from fat globules cause endothelial damage → inflammation → capillary leak
• Results in a clinical triad: respiratory distress + neurological deterioration + petechial rash

Clinical features (classically 24–72 hours after long bone fracture):

• Respiratory: tachypnoea, hypoxia, ARDS
• Neurological: confusion, agitation, decreased GCS
• Dermatological: petechial rash (classically over chest, axillae, conjunctivae) — pathognomonic but often transient

Prevention: early fracture stabilisation (especially femoral shaft — IMN within 24–48h reduces FES risk).

Pathophysiology: Virchow's triad — (1) stasis (immobilisation), (2) endothelial injury (fracture, surgery), (3) hypercoagulability (acute phase response, post-operative state) → venous thrombosis → embolism to pulmonary vasculature.

Prevention: LMWH prophylaxis, mechanical prophylaxis (TED stockings, intermittent pneumatic compression), early mobilisation.

High-risk fractures: #NOF (prolonged immobility in elderly), pelvic fractures, femoral shaft fractures, spinal cord injury (loss of muscle pump).

Cubitus varus — the most common complication of supracondylar fractures in children ^[3]:

• Resulted from mal-reduction/malunion or physeal damage
• Cosmetic deformity but little functional deficit ^[3]
• Also known as "gunstock deformity" ^[2]

Definition: death of bone tissue due to interruption of its blood supply.

Pathophysiology: fracture disrupts the articular/nutrient vessels → bone distal to the disruption dies → if not revascularised → collapse of the articular surface → secondary osteoarthritis.

High-risk fractures for AVN:

Definition: formation of bone in abnormal locations, e.g., within muscle — also called myositis ossificans ^[2].

Pathophysiology: traumatised soft tissue (especially muscle around the elbow and hip) → pluripotent mesenchymal stem cells → metaplastic bone formation. The precise trigger is not fully understood but relates to the release of bone morphogenetic proteins (BMPs) from the fracture haematoma into adjacent soft tissues.

Common sites: elbow (most common), hip (especially after acetabular fractures, THA)

Prevention (in high-risk patients): indomethacin (NSAIDs inhibit prostaglandin-mediated osteogenesis) or low-dose radiation therapy.

Pathophysiology: any intra-articular fracture that heals with residual incongruity (articular step-off) → abnormal load distribution across the joint surface → accelerated cartilage wear → OA.

This is why intra-articular fractures demand anatomical reduction — even 2 mm of articular step-off significantly increases OA risk. Key examples:

• Tibial plateau fracture → OA knee ^[2]
• Distal radius fracture (if intra-articular with step-off) → radiocarpal OA ^[2]
• Calcaneal fracture → subtalar joint OA ^[2]
• Patella fracture → patellofemoral OA ^[2]
• Acetabular fracture → OA hip ^[2]
• Lisfranc injury → midfoot OA ^[2]

Previously called "reflex sympathetic dystrophy" or "Sudeck's atrophy."

Definition: a chronic pain syndrome characterised by pain disproportionate to the initial injury, associated with autonomic dysfunction (vasomotor and sudomotor changes), oedema, and trophic changes.

Pathophysiology: not fully understood — likely involves peripheral and central sensitisation, neurogenic inflammation, and sympathetic nervous system dysfunction. Occurs most commonly after distal radius fractures and tibial fractures.

Clinical features (Budapest criteria):

• Continuing pain disproportionate to the inciting event
• Sensory changes (allodynia/hyperalgesia)
• Vasomotor changes (temperature/colour asymmetry)
• Sudomotor/oedema changes (sweating, oedema)
• Motor/trophic changes (decreased ROM, weakness, hair/nail/skin changes)

Management: multidisciplinary — physiotherapy (most important), pharmacological (gabapentinoids, bisphosphonates, calcitonin), psychological support.

Pathophysiology: damage to the physis (growth plate), particularly the germinal layer of chondrocytes → premature physeal closure (physeal bar/bridge formation) → limb length discrepancy and/or angular deformity.

Salter-Harris classification predicts growth arrest risk ^[3]:

• Type I–II: Good prognosis ^[3]
• Type III: Poor prognosis — fracture through the germinal layer ^[3]
• Type IV: Poor prognosis — fracture crosses entire physis ^[3]
• Type V: Crush fracture of physis → worst prognosis ^[3]

Management of growth arrest: physeal bar resection (if < 50% of physis involved), corrective osteotomy, limb lengthening procedures, or contralateral epiphysiodesis (if approaching skeletal maturity).