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KMTC Orthopedics & Trauma Exam - Full Explanation of All Questions

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PAPER 1: KMTC/QP-08/EPS - Section 1: Multiple Choice Questions

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Q1. A patient falls from two-storey height with isolated abdominal pain and stable vitals. Which mechanism should prompt focused imaging for hollow viscus injury?

• Option B (low-energy fall) would not warrant aggressive imaging
• Option C (isolated extremity impact) does not involve the torso
• Option D (blunt head trauma) focuses on a different system

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Q2. High-speed MVC with restrained driver and improperly positioned lap belt - most likely injury pattern?

• The upper body flexes forcefully over the belt
• The lumbar spine is distracted (pulled apart) horizontally through L1-L3
• Simultaneously, the bowel is compressed between the anterior abdominal wall and the spine, causing mesenteric tears or bowel perforation

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Q3. Smoker with mid-shaft tibial fracture shows delayed callus at 16 weeks. Which mechanism explains delayed healing?

1. Causes vasoconstriction of periosteal and endosteal blood vessels
2. Inhibits angiogenesis (new blood vessel formation) - directly reducing the vascular ingrowth needed for callus formation
3. Impairs osteoblast differentiation and function
4. Reduces chondrocyte proliferation in the cartilaginous callus phase

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Q4. Osteoporosis patient with fragility fracture and impaired healing. Which systemic factor reduces healing capacity?

• Reduced osteoprogenitor (stem) cell pool - fewer cells available to differentiate into osteoblasts
• Altered trabecular microarchitecture - the scaffold on which new bone forms is already compromised
• Poor mechanical stability - osteoporotic bone cannot hold fixation devices as well
• Reduced growth factor reservoir - bone matrix contains growth factors (TGF-β, BMP) that are released on fracture; osteoporotic bone has less of these

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Q5. High-energy open tibial fracture: why does early soft-tissue coverage improve healing?

1. Angiogenesis - new blood vessels must grow in from surrounding tissue; vascularized flaps bring their own blood supply
2. Immune defense - the soft-tissue envelope brings macrophages, neutrophils, and antibodies that fight contaminating bacteria
3. Biological scaffold - the periosteum and surrounding tissue contain osteoprogenitor cells
4. Reduces dead space - eliminating cavity where bacteria can colonize

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Q6. Elderly patient with minimal trauma sustains proximal humerus fracture. Best aetiology?

1. Distal radius (Colles' fracture)
2. Vertebral body
3. Proximal humerus
4. Hip (femoral neck)

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Q7. Teenage athlete develops tibial fracture after months of increasing training load. Most likely aetiological mechanism?

• Runners (medial tibial stress syndrome → tibial stress fracture)
• Military recruits
• Basketball/volleyball players

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Q8. Child with greenstick fracture of forearm. Which property of pediatric bone explains this?

• Higher organic content (collagen) relative to mineral content → bone is more flexible/plastic
• Thick, strong periosteum → acts like a hinge on the tension side, holding fragments together
• Greater elasticity → bone can bend beyond its yield point on one cortex while the opposite cortex buckles rather than fracturing completely

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Q9. Farmer with open tibial fracture contaminated with soil. Which aetiologic factor increases infection and nonunion risk most?

1. High-energy mechanism - extensive bone comminution, poor vascularity, large dead space
2. Soft-tissue loss - loss of the protective biological envelope
3. Gross contamination (soil contains Clostridium, gram-negative organisms, fungi)

• Grade I: wound < 1cm, clean
• Grade II: wound 1-10cm, moderate contamination
• Grade III: wound > 10cm, extensive soft-tissue loss; IIIC includes vascular injury

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Q10. Patient with metastatic prostate cancer has femoral fracture following minimal movement. Aetiologic classification?

• Disproportionately minor force
• Known malignancy or systemic disease
• Radiographic evidence of bony lesion at fracture site
• Often preceded by pain at the site (herald pain)

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Q11. Radiographs show tibial fracture in a twisting injury. Most appropriate fracture pattern descriptor?

• Twisting/torsion → Spiral fracture - the fracture line spirals around the long axis of the bone like a corkscrew
• Direct blow → Transverse fracture (perpendicular to shaft)
• Axial loading/compression → Comminuted or burst fracture
• Bending → Oblique or transverse fracture, often with a butterfly fragment

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Q12. Transverse femoral fracture after direct lateral blow. What differentiates transverse from oblique patterns?

• Transverse fracture: fracture line runs at 90° to the long axis of the bone. Results from a direct blow, bending force, or tension stress. The bone is literally snapped in half.
• Oblique fracture: fracture line runs at an angle (typically 30-45°) to the long axis. Results from a combination of compression and bending forces.

• Transverse fractures are more stable after reduction (flat surfaces oppose each other)
• Oblique fractures tend to shorten because muscle pull causes the fragments to slide along the oblique plane

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Q13. Mid-shaft clavicle fracture with superior displacement of the medial fragment. Which muscular forces explain this?

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Q14. Displaced humeral head fracture with rotation deformity on axial imaging. Why is rotational displacement clinically important?

1. Glenohumeral incongruency - the humeral head no longer sits properly in the glenoid fossa, predisposing to early arthritis
2. Altered muscle mechanics - the rotator cuff tendons (subscapularis, supraspinatus, infraspinatus, teres minor) insert on the greater and lesser tuberosities; malrotation changes their moment arm and pulling direction
3. Neurovascular impingement - the axillary nerve and anterior circumflex humeral artery lie close to the surgical neck; malrotation can stretch or compress these structures
4. Impingement - rotational deformity can cause the greater tuberosity to impinge under the acromion during arm elevation

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Q15. Distal radius fracture with numbness in lateral 3.5 fingers. Best explanation?

• Fracture displacement or dorsal angulation (Colles' fracture) can compress the median nerve within the carpal tunnel
• Acute swelling increases carpal tunnel pressure
• Haematoma at the fracture site exerts direct pressure on the nerve

• Option A (radial artery laceration) would cause vascular signs, not numbness in specific digits
• Option C (ulnar nerve) would cause numbness in the little finger and medial half of ring finger
• Option D is trivially incorrect

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Q16. High-energy tibial fracture with tense limb, painful on passive stretch, paresthesia. Most time-sensitive action?

• Pain out of proportion to injury
• Pain on passive stretch of muscles in that compartment (most sensitive early sign)
• Paresthesia (nerve ischemia)
• Pressure (tense compartment)
• Paralysis (late sign)
• Pallor/Pulselessness (very late - limb may be lost by this point)

• Nerves: ~30 minutes
• Muscle: 6-8 hours before irreversible damage

• Volkmann's ischemic contracture
• Permanent neurological deficit
• Renal failure from myoglobinuria (rhabdomyolysis)
• Death

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Q17. Child with forearm deformity, minimal pain, preserved motion after a fall. What differentiates greenstick from complete fracture?

• Cortical disruption on only one side (the tension side breaks; the compression side buckles or bends)
• Intact periosteum on the compression side acts as a hinge - this is why there is relative stability and preserved motion
• Minimal displacement - the intact periosteal hinge prevents the fragments from separating completely
• Less pain than complete fractures because there is no gross instability or crepitus

• Full cortical disruption on both sides
• No periosteal hinge
• Gross instability and crepitus (abnormal movement)
• More pain and swelling

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Q18. Radiograph shows transverse femoral shaft fracture with sharp margins and minimal sclerosis. Which sign suggests ACUTE fracture?

• Option A (callus) indicates healing/old fracture
• Option C (smooth rounded edges) indicates remodeling
• Option D (cortical thickening) indicates chronic stress reaction or healing

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Q19. Long-bone fracture with limb deformity and absent distal pulses after resuscitation. Which priority decision optimizes limb salvage?

1. Urgent closed reduction of the fracture - restores alignment and may relieve vessel kinking/compression
2. Reassess pulses - if pulses return, the vessel was kinked (not transected); proceed with definitive fracture fixation
3. If pulses remain absent → urgent vascular imaging (CT angiogram or operative angiogram) to identify the injury
4. Vascular repair (embolectomy, bypass, or direct repair) within 6 hours of ischemia onset

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Q20. Persistent wrist stiffness after distal radius fixation and immobilization. Best rehabilitation strategy?

• Capsular and ligamentous contracture
• Tendon adhesion formation
• Loss of synovial fluid circulation
• Periarticular fibrosis and scar tissue

1. Early supervised mobilization - gentle active and passive range-of-motion exercises, begun as early as safely possible
2. Targeted stretching - flexion, extension, pronation, supination of the wrist
3. Scar management - silicone gel sheets, scar massage to soften periarticular adhesions
4. Graded strengthening - progressive resistance once range of motion is improving
5. Occupational therapy for functional tasks

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PAPER 1: Section 2 - Short Answer Questions

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Q21. Highlight the difference between pathological and stress fractures in terms of etiology and radiographic features (3 marks)

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Q22. Clinical and radiographic features that help identify a displaced fracture (6 marks)

1. Visible deformity - abnormal angulation, shortening, or rotation of the limb
2. Shortening - the limb appears shorter (e.g., shortened leg in femoral fracture)
3. Abnormal rotation - foot/limb rotated externally or internally beyond normal range
4. Crepitus - grating sensation on palpation from bone fragments rubbing
5. Abnormal mobility - movement at a site that should be immobile
6. Neurovascular compromise - absent pulses, paresthesia indicating fragment has injured vessels/nerves

1. Loss of cortical continuity - the cortical lines are interrupted and offset
2. Overlap of fragments on X-ray indicating shortening
3. Angulation - change in the normal axis of the bone visible on X-ray
4. Soft-tissue swelling - hematoma shadow around the fracture
5. Two views mandatory - displacement is often only visible on one plane (AP and lateral required)

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Q23. Explain why greenstick fractures are unique to children and how they are managed (5 marks)

1. Higher organic content - children's bone contains proportionally more collagen (organic matrix) than adults, making it more flexible and less brittle
2. Thick periosteum - the pediatric periosteum is thicker and stronger, acting as a hinge that prevents complete fracture
3. Greater bone elasticity - pediatric bone can deform beyond its yield point without complete failure
4. Active bone growth - the metabolic activity of growing bone allows bending without brittle fracture
5. In adults, bone mineral (inorganic) content predominates → bone is stiffer and brittle → complete fractures, not greenstick

• Incomplete/undisplaced: simple immobilization in a plaster cast (3-4 weeks)
• Angulated greenstick: completion of the fracture is sometimes performed - deliberately completing the fracture releases the "spring" tension from the bent cortex, allowing proper reduction and preventing re-angulation
• Following reduction, apply a well-moulded plaster cast
• Follow-up X-rays at 1-2 weeks to check for re-angulation
• Excellent remodeling potential means near-perfect long-term outcomes expected

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Q24. Outline the principles of fracture classification based on pattern and location (6 marks)

1. Transverse - fracture line perpendicular (90°) to long axis; caused by direct blow or bending; stable after reduction
2. Oblique - fracture line at 30-45° angle; caused by combination of compression and bending; tendency to shorten
3. Spiral - fracture line winds around the bone; caused by torsional (twisting) forces; long fracture line
4. Comminuted - more than 2 fragments; caused by high-energy crush or burst; most unstable
5. Butterfly/wedge - triangular fragment between two main fragments; caused by high-energy 3-point bending
6. Compression/impaction - bone crushed together; caused by axial loading; common in vertebrae and cancellous bone

1. Diaphyseal (shaft fractures) - proximal, middle, or distal third
2. Metaphyseal - near the expanded ends of long bones
3. Epiphyseal - involving the growth plate in children (Salter-Harris classification)
4. Intra-articular - extending into the joint surface; requires anatomical reduction to prevent post-traumatic arthritis
5. Periarticular - near but not involving the joint

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Q25. Explain why early fluid resuscitation is critical in long-bone fractures and outline the preferred approach (5 marks)

1. Significant hidden blood loss - a closed femoral shaft fracture can lose 1,000-2,000 mL of blood into the thigh; tibial fracture ~500 mL; pelvic fracture potentially > 3,000 mL - all invisible externally
2. Risk of hypovolaemic shock - without replacement, patients progress through Class I→IV hemorrhagic shock
3. Multiple fractures compound losses - polytrauma patients can exsanguinate from fractures alone
4. Tissue hypoperfusion impairs fracture healing, promotes infection, and risks multi-organ failure
5. Compartment syndrome risk - hypoperfusion followed by reperfusion can worsen compartment pressures

1. IV access - two large-bore (16G or larger) peripheral IV cannulae
2. Initial bolus - 1 liter of warmed crystalloid (Normal Saline or Hartmann's/Ringer's Lactate) in adults
3. Blood transfusion early if not responding to crystalloid (type O negative blood if crossmatch not yet available)
4. Damage Control Resuscitation (DCR): 1:1:1 ratio of packed RBCs:FFP:platelets in massive hemorrhage
5. Permissive hypotension in penetrating trauma (target SBP 80-90 mmHg until hemorrhage controlled) - slightly different approach in blunt trauma
6. Definitive hemorrhage control - fracture stabilization (splinting, external fixation, packing for pelvis) reduces bleeding

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Q26. What factors determine the choice of immobilization method in pediatric fractures? (5 marks)

1. Age and growth plate proximity - fractures near growth plates (Salter-Harris) may need more careful anatomical reduction; younger children have more remodeling potential allowing acceptance of greater malignment
2. Fracture pattern and stability - stable (greenstick, torus/buckle) fractures → simple splint/cast; unstable or displaced fractures → operative fixation
3. Degree of displacement and angulation - acceptable angulation varies by age, bone, and plane (more accepted in younger children and in the sagittal plane)
4. Location - diaphyseal vs. periarticular vs. intra-articular; intra-articular fractures need anatomical reduction regardless of age
5. Neurovascular status - vascular compromise demands urgent reduction (e.g., supracondylar humerus fracture in children)
6. Soft tissue condition - open fractures require external fixation or irrigation/debridement
7. Patient cooperation and compliance - toddlers may need different cast types than adolescents
8. Type of bone - cancellous (metaphyseal) vs. cortical (diaphyseal) heals differently

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Q27. Clinical features and emergency management of vascular injury following a fracture (4 marks)

1. Pain - severe, out of proportion, especially on passive movement
2. Pallor - limb appears pale or white compared to the other side
3. Pulselessness - absent or diminished distal pulse (dorsalis pedis, posterior tibial, radial, ulnar)
4. Paresthesia - numbness, tingling in the distribution of nerves in the ischemic limb
5. Paralysis - inability to move distal muscles (late sign indicating severe ischemia)
6. Perishing cold - the affected limb is cold to touch compared to the contralateral limb

1. Urgent fracture reduction - to relieve pressure/kinking on the vessel; reassess pulses
2. Vascular surgery consultation immediately
3. CT angiography or operative angiogram to define the injury
4. Vascular repair within 6 hours - options include: embolectomy, end-to-end anastomosis, vein graft bypass, or intraluminal shunt (temporary) in damage-control situations
5. Fasciotomy - may be required after reperfusion (reperfusion injury causes swelling)
6. Limb fasciotomy should not be delayed while awaiting imaging if ischemia is clear

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Q28. Define nonunion and differentiate between hypertrophic and atrophic types (6 marks)

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PAPER 1: Section 3 - Long Answer Questions

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Q29. Principles of reduction and immobilization in fracture management; how these vary between adults and children (20 marks)

1. Restore length - prevent shortening
2. Correct angulation - restore normal bone axis
3. Correct rotation - even small rotational errors cause significant functional deficit

• Manipulation under anesthesia (MUA) or sedation/analgesia
• Technique: traction → disimpaction → reverse the mechanism of injury
• Applied for most fractures as first-line

• Failed closed reduction
• Intra-articular fractures requiring anatomical alignment
• Fractures with interposed soft tissue preventing reduction
• Vascular injury requiring operative exploration
• Open fractures requiring debridement
• Pathological fractures

1. Plaster of Paris (POP) or fiberglass cast - for stable fractures; applied after swelling settles
2. Traction (skin or skeletal) - for femoral shaft fractures, unstable pelvic fractures; maintains length while healing begins
3. External fixation - for open fractures, severely comminuted fractures, fractures with significant soft-tissue injury, damage control
4. Internal fixation:
   • Intramedullary (IM) nail - for long bone diaphyseal fractures (femur, tibia, humerus)
   • Dynamic Hip Screw (DHS) - for intertrochanteric femur fractures
   • Plating - for metaphyseal, periarticular, and intra-articular fractures
5. Functional bracing - allows controlled motion during healing

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Q30. Role of rehabilitation in fracture management; how early mobilization influences long-term outcomes (20 marks)

1. Restore range of motion (ROM)
2. Regain muscle strength
3. Restore proprioception and coordination
4. Return to full functional activity and work
5. Prevent complications of immobilization

• Elevation to reduce swelling
• Isometric exercises (muscle contractions without joint movement) - prevent muscle atrophy
• Active movement of joints above and below the fracture
• Pain management to enable participation
• Ice therapy for swelling

• Active-assisted range of motion (AAROM) → progress to active ROM → passive ROM
• Hydrotherapy - water buoyancy reduces weight bearing while allowing movement
• Scar tissue mobilization and massage
• Proprioception re-training (balance boards, functional movements)

• Progressive resistance exercises
• Closed kinetic chain exercises (functional weight-bearing)
• Sport-specific training if applicable

• Progressive loading
• Work hardening for manual laborers

1. Prevents joint stiffness and contractures - immobilization causes capsular shrinkage, fibrosis, and cartilage degeneration within weeks; early movement maintains joint fluid circulation and cartilage nutrition
2. Prevents muscle atrophy - disuse atrophy begins within 24-48 hours of immobilization; early exercises preserve muscle mass and strength
3. Promotes fracture healing - controlled cyclic loading stimulates callus formation (Wolff's Law - bone responds to mechanical stress); absolute immobility is NOT necessary and may paradoxically impair healing
4. Reduces DVT risk - muscle pump action in the calf returns venous blood; immobility → stasis → DVT → pulmonary embolism
5. Improves proprioception - early weight-bearing and joint movement prevents loss of joint position sense
6. Reduces psychological impact - early functional return reduces depression, anxiety, and loss of independence
7. Reduces heterotopic ossification - early gentle movement of periarticular fractures (e.g., elbow) reduces abnormal bone formation in soft tissues
8. Cost-effective - reduces hospital stay, reduces need for prolonged physiotherapy

• Lower 30-day mortality
• Shorter hospital stays
• Better functional outcomes at 1 year
• Lower rates of pneumonia and pressure sores

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PAPER 2: KMTC/QP-08/EPP - Questions 1-14

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Q1 (from the older KMTC paper) - MCQs on femur fracture anatomy:

• Flexion - by iliopsoas (attaches to lesser trochanter)
• Abduction - by gluteus medius/minimus (attach to greater trochanter)
• External rotation - NOT internal rotation

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Q8. Fracture of the proximal femur includes:

1. Femoral head - subcapital/intracapsular fractures
2. Femoral neck - subcapital, transcervical, basicervical
3. Intertrochanteric region - between the trochanters; intratrochanteric = intertrochanteric
4. Subtrochanteric - below the lesser trochanter

• Option A (2/3 shaft fracture) is a diaphyseal, not proximal fracture
• Option B (subtrochanteric fracture) - the prefix is "sub" meaning below the trochanter, which is borderline proximal but typically classified separately
• Option D (compartment syndrome) is a complication, not a fracture type

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Q9. Typical features of compartment syndrome:

• Warmth (Option A) is NOT a typical feature - the limb may actually be cool in late compartment syndrome due to vascular compromise
• Tenderness (Option B) is present but non-specific
• Paresthesia (Option C) indicates nerve ischemia - an early sensitive sign
• Loss of function (Option D) is a late sign of established ischemia

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Q10. Bones of the foot:

• 7 tarsal bones: calcaneus, talus, navicular, cuboid, and 3 cuneiforms (not 28 - Option A is wrong)
• 5 metatarsals
• 14 phalanges (2 in hallux, 3 in each lesser toe)
• Total: 26 bones in the foot (not 28)

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Q11 (KMTC EPP - Section 2). Complications of fracture shaft fibula (5 marks)

1. Peroneal nerve injury (common peroneal nerve winds around the fibular neck) → foot drop, loss of dorsiflexion and eversion
2. Compartment syndrome - especially anterior and lateral compartments of the leg
3. Delayed union/nonunion - especially in middle-third fibula fractures with poor blood supply
4. Malunion - particularly in fibular fractures associated with ankle fractures; affects ankle stability
5. Peroneal artery injury - the peroneal artery runs near the fibula
6. Ankle instability - the fibula provides lateral support to the ankle mortise; if the distal fibula is fractured and malunited, lateral ankle instability results
7. Chronic pain and disability at the fracture site

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Q12. Mechanical stability in fractures - what is provided? (5 marks)

1. Absolute stability (no interfragmentary movement) - provided by:
   • Rigid plate and screw fixation with compression
   • Lag screw fixation
   • Results in primary bone healing (direct remodeling across fracture without callus)
2. Relative stability (controlled interfragmentary movement) - provided by:
   • Intramedullary nail
   • Bridge plating
   • Functional bracing
   • External fixator (some)
   • Results in secondary bone healing (callus formation, endochondral ossification)
3. Cast/splint - provides relative stability by preventing gross movement
4. Traction - provides distraction/alignment stability
5. External fixator - provides rigid stability for open fractures, unstable pelvis

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Q13(A). KMTC EPP - Open fracture tibia/fibula: Primary investigations (5 marks)

1. Plain X-rays (2 views minimum):
   • AP and lateral of the tibia/fibula
   • Must include the joint above (knee) and below (ankle) to identify associated injuries
   • Identifies fracture pattern, level, degree of comminution, contaminating foreign bodies
2. Full Blood Count (FBC/CBC):
   • Baseline haemoglobin (degree of blood loss)
   • White cell count (infection, inflammatory response)
   • Platelet count (coagulopathy)
3. Blood grouping and cross-matching - for surgical preparation and possible transfusion
4. Coagulation profile (PT, PTT, INR) - for surgical planning
5. Urea and Electrolytes (U&E) / Renal Function Tests - baseline before surgery and anesthesia; rhabdomyolysis can cause AKI
6. Blood glucose - especially in diabetic patients who have higher infection risk
7. Wound swab for culture and sensitivity - to identify contaminating organisms before empirical antibiotics are started
8. Blood cultures if systemic sepsis is suspected

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Q13(B). State the treatment plan (5 marks)

1. ABCDE approach (airway, breathing, circulation, disability, exposure) - manage life-threatening injuries first
2. IV antibiotics immediately - cephalosporin (e.g., cefazolin 2g IV) + metronidazole for heavily contaminated wounds; aminoglycoside (gentamicin) for farm injuries
3. Tetanus prophylaxis - tetanus toxoid or immunoglobulin based on vaccination status
4. Wound management: cover with sterile saline-soaked dressing; do NOT repeatedly expose the wound
5. Temporary splintage - back slab to prevent further injury and reduce pain

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Q14. Discuss the process of bone healing (10 marks)

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• Disruption of blood vessels in the periosteum, cortex, and medullary canal
• A hematoma forms at the fracture site
• This is NOT just "blood clot" - it is biologically active, containing:
  • Growth factors: TGF-β, PDGF, FGF, BMP
  • Inflammatory mediators
  • Osteoprogenitor cells
• The hematoma provides the initial scaffold and biological signals for healing

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• Vasodilation and increased permeability → swelling, pain, heat
• Neutrophils then macrophages arrive to debride dead tissue
• Macrophages release cytokines (IL-1, IL-6, TNF-α) that recruit mesenchymal stem cells
• Granulation tissue begins to replace the hematoma
• Angiogenesis begins - new blood vessels ingrow to supply the repair zone

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• Mesenchymal stem cells differentiate into chondroblasts (cartilage-forming cells)
• A cartilaginous callus (soft callus) forms around the fracture ends
• This provides temporary mechanical stability ("rubbery callus")
• Not visible on plain X-ray at this stage
• Periosteal reaction may be just becoming visible at 2-3 weeks

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• The cartilaginous callus undergoes endochondral ossification (same process as bone formation in the fetal growth plate)
• Osteoblasts replace cartilage with woven bone (immature bone)
• The callus progressively mineralizes and becomes hard callus
• Visible on X-ray as "callus bridging" the fracture
• The fracture becomes progressively more rigid

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• Woven bone (disorganized) is replaced by lamellar bone (organized along lines of stress - Wolff's Law)
• Osteoclasts resorb excess callus
• The medullary canal is restored
• The bone eventually returns to nearly normal shape and strength
• In children, this process can correct angular deformity; in adults, it only improves mechanical properties

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• Secondary (indirect) healing: the process described above; involves hematoma → cartilage → bone; requires some interfragmentary movement; most common in clinical practice
• Primary (direct) healing: occurs when fracture surfaces are in absolute contact with rigid compression fixation (no interfragmentary gap); osteoclasts tunnel directly across the fracture line (cutting cones) followed by osteoblasts laying lamellar bone; NO callus formation; much slower but anatomically precise

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PAPER 2: Section B - Short Answer Questions

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SB1. Process of healing of cancellous bone (5 marks)

1. Rich blood supply - cancellous bone is highly vascular; the large surface area and interconnecting trabeculae allow rapid revascularization
2. Hematoma formation - as in all fractures, a hematoma forms
3. Trabecular bridging - the trabecular scaffolding of cancellous bone allows rapid ossification directly along trabecular surfaces without the need for extensive cartilaginous callus
4. Direct ossification - mesenchymal stem cells differentiate directly into osteoblasts (less cartilaginous callus than cortical fractures) → intramembranous ossification
5. Faster union - cancellous fractures heal 3-4x faster than cortical (e.g., distal radius metaphysis heals in 4-6 weeks vs. tibial shaft 12-16 weeks)
6. Remodeling - the trabeculae reorganize along stress lines
7. Minimal callus visible on X-ray compared to diaphyseal fractures

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SB2. Five clinical features that should always arouse suspicion of a fracture (5 marks)

1. Pain and tenderness at the site - especially point tenderness directly over bone
2. Swelling - hematoma formation causes localized swelling within hours
3. Deformity - visible angulation, shortening, or rotational abnormality
4. Loss of function - patient unable to use the affected limb normally (inability to weight-bear, reduced range of motion)
5. Crepitus - grating or crunching sensation on gentle palpation or attempted movement (do NOT elicit deliberately)
6. Abnormal mobility - movement occurring at a site that should be immobile
7. Bruising (ecchymosis) - appears within 24-48 hours; may track distally due to gravity

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SB3. Five tests of union of a fracture (5 marks)

1. Absence of pain at the fracture site on palpation and weight-bearing
2. Absence of abnormal mobility at the fracture site - clinician applies gentle stress across the fracture; united fracture shows no movement
3. Ability to weight-bear without pain (for lower limb fractures)
4. Return of function - patient can use the limb normally

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SB4. Five stages of repair of a fractured tubular (long cortical) bone (5 marks)

1. Hematoma stage - fracture hematoma forms from ruptured vessels; biological signals (growth factors) released
2. Inflammatory stage - phagocytic debridement; granulation tissue; angiogenesis begins; mesenchymal cell recruitment
3. Soft callus (fibrocartilaginous callus) stage - chondroblasts form cartilage around the fracture; temporary stability
4. Hard callus (bony callus) stage - endochondral ossification converts cartilage to woven bone; callus visible on X-ray; fracture becomes rigid
5. Remodeling stage - woven bone converted to lamellar bone; medullary canal re-established; callus gradually resorbed; bone returns to near-normal shape

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SB5. Differentiate primary and secondary bone healing (5 marks)

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SB6. Five factors influencing the speed of fracture union (5 marks)

1. Blood supply - fractures in well-vascularized areas (metaphysis) heal faster than those in poorly vascularized areas (mid-shaft femoral neck, navicular, scaphoid waist)
2. Degree of displacement/soft tissue damage - greater displacement = more periosteal stripping = poorer blood supply = slower healing
3. Fracture type - cancellous heals faster than cortical; oblique/spiral (more surface area contact) heal faster than transverse
4. Infection - suppurative infection prevents union (produces hyaluronidase, bacterial enzymes that destroy callus)
5. Immobilization quality - inadequate immobilization causes excessive interfragmentary motion, converting callus to fibrous tissue (fibrous nonunion)

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SB7. Five absolute indications for open reduction (5 marks)

1. Failed closed reduction - when satisfactory alignment cannot be achieved by closed means (due to interposed muscle, tendon, or periosteum blocking reduction)
2. Intra-articular fractures - displaced fractures involving joint surfaces require anatomical reduction to restore joint congruency and prevent post-traumatic arthritis
3. Vascular injury requiring operative exploration - fracture must be stabilized during vascular repair
4. Fracture with nerve injury - where nerve is trapped in the fracture site (e.g., radial nerve in humeral shaft fracture requiring exploration)
5. Open fractures - the wound already provides surgical access; debridement and stabilization are performed together
6. Multiple fractures (polytrauma) - damage control orthopaedics (DCO) - early total care (ETC) with ORIF reduces mortality and morbidity
7. Pathological fractures - require stabilization plus treatment of underlying disease (e.g., prophylactic nailing + cement for metastatic lesions)
8. Fractures with compartment syndrome - fasciotomy + fracture fixation performed together

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SB8. Five systemic complications of fractures (5 marks)

1. Hypovolaemic shock - major blood loss (femoral shaft loses 1-2 L, pelvic fracture 2-4 L); leads to multi-organ failure if not treated
2. Fat embolism syndrome (FES) - fat droplets released from medullary cavity enter circulation; classic triad: hypoxemia, neurological changes, petechial rash; occurs 24-72 hours post-injury
3. Venous thromboembolism (DVT/PE) - immobility + hypercoagulable state + vessel injury (Virchow's triad); pulmonary embolism is a leading cause of death in trauma patients

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PAPER 2: Section C - Long Answer Questions

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SC1. Compartment Syndrome - full discussion

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1. Acute compartment syndrome - surgical emergency; occurs within hours of injury; irreversible damage within 6-8 hours if untreated
2. Chronic exertional compartment syndrome (CECS) - occurs in athletes during exercise; pressure rises temporarily during activity → pain and paresthesia → resolves with rest; not immediately limb-threatening; treated conservatively initially (activity modification) or surgically with elective fasciotomy

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1. Fractures - hematoma formation within the compartment (most common cause in the leg)
2. Crush injury - massive swelling and edema of crushed muscle
3. Burns - circumferential burns cause eschar formation and constrict compartments
4. Prolonged limb compression (e.g., patient found unconscious lying on their limb)
5. Reperfusion injury - after vascular repair, reperfusion of ischemic muscle causes massive swelling
6. Bleeding disorders/anticoagulation - hematoma formation in already tight compartments
7. Intravenous infiltration - inadvertent injection of fluids into compartment

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1. Pain - severe, disproportionate to injury; constant, burning quality
2. Pain on Passive stretch - THE most sensitive early sign; passively extending the fingers/toes causes severe pain in the forearm/leg compartments
3. Paresthesia - tingling, numbness in the distribution of nerves passing through the compartment; indicates nerve ischemia
4. Pressure - tense, woody/board-like compartment on palpation; compartment feels rigid rather than soft
5. Pallor - the limb becomes pale due to reduced perfusion (later sign)
6. Pulselessness - absent distal pulses (VERY LATE sign; implies complete vascular occlusion; limb is likely unsalvageable by this point)
7. Paralysis - inability to move muscles in the compartment (late sign; indicates irreversible muscle ischemia)

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1. Remove all constrictive dressings, split casts bivalve completely down to skin
2. Position limb at heart level (do NOT elevate excessively - reduces arterial perfusion pressure)
3. Optimize systemic blood pressure to maintain perfusion pressure
4. Oxygen supplementation
5. If compartment pressure measurement available: measure and document

• Lateral incision: releases anterior + lateral compartments
• Medial incision: releases superficial + deep posterior compartments

1. In the forearm (3 compartments): volar forearm fasciotomy ± dorsal
2. In the thigh (3 compartments): lateral incision
3. Wound management: fasciotomy wounds are left open, covered with non-adherent dressings, and closed at 48-72 hours when swelling has resolved (delayed primary closure or split-thickness skin graft if needed)

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SC2. Classification of Fractures

1. Traumatic fractures - caused by a force greater than the bone's strength:
   • High-energy (RTA, falls from height, industrial injuries) → comminuted, open fractures
   • Low-energy (fall from standing height) → depends on bone quality
2. Stress fractures - repetitive submaximal loading exceeding the bone's repair capacity:
   • Fatigue fractures: abnormal load on normal bone (athletes, military)
   • Insufficiency fractures: normal load on abnormal bone (osteoporosis) - sometimes classified separately
3. Pathological fractures - fracture through bone weakened by disease:
   • Primary bone tumors (osteosarcoma, Ewing's)
   • Metastatic bone disease (prostate, breast, lung, kidney, thyroid - "Pb KTL")
   • Metabolic bone disease (osteoporosis, Paget's disease, osteomalacia)
   • Infection (chronic osteomyelitis weakens cortex)
   • Bone cysts (unicameral bone cyst, aneurysmal bone cyst)

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1. Simple (closed) fractures - skin intact; lower infection risk; amenable to conservative management
2. Open (compound) fractures - bone communicates with external environment through a wound; higher infection risk; require urgent irrigation, debridement, antibiotics; classified by Gustilo-Anderson:
   • Grade I: < 1cm clean wound
   • Grade II: 1-10cm moderate contamination
   • Grade III: > 10cm, extensive soft tissue loss; IIIA (adequate soft tissue), IIIB (requires flap), IIIC (vascular injury requiring repair)
3. Comminuted fractures - more than 2 fragments; difficult to reduce and hold; often require operative fixation
4. Intra-articular fractures - involve joint surfaces; require anatomical reduction (within 2mm) and stable fixation; non-anatomical union leads to post-traumatic arthritis
5. Pathological fractures - require treatment of underlying condition plus fracture stabilization; healing may not occur without treating the primary disease

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