DHANALAKSHMI SRINIVASAN UNIVERSITY - BPT III Year

Clinical Orthopaedics - Model Exam Answer Key

I. LONG ESSAY (20 marks each)

Q1. Total Hip Arthroplasty (THA) - Indications, Contraindications, Procedure and Complications

Definition

INDICATIONS

• Severe osteoarthritis of the hip (Grade III/IV) with disabling pain and loss of function
• Rheumatoid arthritis with hip involvement
• Avascular necrosis (AVN) of femoral head - late stage
• Failed previous hip surgeries (failed hemiarthroplasty, failed ORIF)
• Ankylosing spondylitis with hip ankylosis
• Post-traumatic arthritis
• Femoral neck fractures in elderly patients (as primary arthroplasty)
• Congenital hip dysplasia with secondary arthritis

1. Severe hip pain affecting daily activities
2. Significant radiological changes
3. Failure of conservative management (physiotherapy, analgesics, walking aids) for at least 3-6 months

CONTRAINDICATIONS

• Active infection (local or systemic) - especially active hip sepsis
• Neuropathic (Charcot's) joint
• Absent or non-functional abductor musculature
• Progressive neurological disease (e.g., severe Parkinson's)
• Medically unfit for anesthesia

• Young, highly active patients (<50 years) - due to implant longevity concerns
• Morbid obesity (BMI >40)
• Poor skin/soft tissue coverage
• Osteoporosis
• Uncontrolled diabetes mellitus
• Immunosuppressed states
• Vascular insufficiency of the limb
• Psychiatric illness or inability to comply with rehabilitation

PROCEDURE

• Full medical workup, blood investigations, X-ray hip AP and lateral, templating
• Correction of anemia, cessation of anticoagulants
• Pre-operative physiotherapy counselling
• DVT prophylaxis planning

• Posterolateral (most common) - best acetabular exposure
• Anterolateral (Hardinge) - less dislocation risk
• Direct anterior approach - minimally invasive

1. Incision over greater trochanter (posterolateral approach)
2. Division of short external rotators (piriformis, obturator internus, gemelli)
3. Posterior capsulotomy and hip dislocation
4. Femoral neck cut at appropriate level and angle
5. Acetabular preparation: Reaming of acetabulum to correct size; press-fit or cemented acetabular cup (polyethylene/metal/ceramic) placed at 40-45° abduction and 15-20° anteversion
6. Femoral preparation: Canal broaching; femoral stem insertion (cemented or cementless); femoral head trial and definitive head placement
7. Trial reduction - check stability, leg length, range of motion
8. Final reduction, repair of capsule and short rotators
9. Wound closure with drain

• Cemented (older patients, osteoporotic bone)
• Cementless/press-fit (younger patients, good bone stock)
• Hybrid (cementless cup + cemented stem)

COMPLICATIONS

• Fracture of femur or acetabulum
• Neurovascular injury (sciatic nerve most common)
• Excessive blood loss

• Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE) - most common serious complication
• Wound infection
• Hip dislocation (posterior dislocation most common, especially with posterolateral approach)
• Leg length discrepancy
• Urinary retention

• Aseptic loosening (most common long-term complication) - cement-bone or implant-bone interface failure
• Periprosthetic joint infection (PJI)
• Periprosthetic fracture
• Polyethylene wear and osteolysis
• Heterotopic ossification (Brooker classification)
• Implant failure
• Trochanteric bursitis/non-union (if trochanteric osteotomy done)

• Day 1: Bed exercises, deep breathing, ankle pumps
• Day 2: Sitting at edge, standing with support
• Hip precautions (avoid flexion >90°, adduction across midline, internal rotation)
• Progressive weight-bearing and gait training
• Return to functional activities by 6-12 weeks

Q2. Colles' Fracture - Clinical Features and Management

Definition

CLINICAL FEATURES

• Fall on outstretched hand
• Immediate pain and swelling at wrist
• Common in women >50 years (osteoporosis)

• Severe pain at wrist
• Swelling and tenderness over distal radius
• Inability to use the hand

• "Dinner fork deformity" (or "silver fork deformity") - the most characteristic sign
  • Dorsal prominence of distal fragment + anterior step = resembles a dinner fork
• "Bayonet deformity" - radial displacement causing radial deviation
• Swelling and bruising over dorsum of wrist
• Tenderness on palpation of distal radius
• Restricted wrist movements (painful)
• Possible neurovascular deficit - median nerve most commonly compressed (carpal tunnel syndrome-like symptoms: numbness in thumb, index, middle fingers)

• Transverse fracture of distal radial metaphysis within 2.5 cm of wrist
• Dorsal displacement of distal fragment
• Dorsal angulation (loss of normal 11° volar tilt - becomes dorsal tilt)
• Radial shortening (normal radial length 11-12 mm reduced)
• Radial angulation (normal radial inclination 22° - reduced)
• Associated ulnar styloid fracture in 50-60% cases
• Possible intraarticular extension (Smith, Barton variants)

MANAGEMENT

• Check neurovascular status - median nerve, radial/ulnar pulses
• X-ray wrist AP and lateral views
• Rule out scaphoid/carpal injuries

A. Conservative Management (for stable, undisplaced or minimally displaced fractures)

• Anesthesia: Hematoma block (most common), Bier's block, or IV sedation
• Steps of reduction (Charnley's technique):
  1. Traction and disimpaction in line with deformity
  2. Flex and pronate wrist (to correct dorsal angulation)
  3. Ulnar deviation (to correct radial shift)
  4. Apply moulded plaster of Paris (POP) cast

• Below-elbow POP cast/backslab with wrist in slight flexion and ulnar deviation (Cotton-Loder position)
• Duration: 6 weeks
• Re-X-ray at 1 week to check position

• Radial length within 2 mm of opposite side
• Dorsal tilt <10°, or restoration of volar tilt
• Radial inclination >15°
• Articular step-off <2 mm

B. Surgical Management (for unstable/comminuted/intraarticular fractures)

• Failed closed reduction
• Intraarticular fractures with step-off >2 mm
• Comminuted fractures (especially in young patients)
• Bilateral fractures
• Associated carpal instability
• Neurovascular compromise

1. Percutaneous K-wire fixation (Kapandji technique) - for reducible but unstable fractures
2. External fixation - for comminuted, osteoporotic bone
3. Volar locking plate (ORIF) - gold standard for displaced intraarticular fractures; allows early mobilization
4. Fragment-specific fixation - for complex intraarticular patterns

C. Post-reduction / Physiotherapy Management

• Elevation of limb to reduce edema
• Finger exercises (full fist, composite fist)
• Shoulder and elbow range of motion
• Grip strengthening within cast

• Active assisted wrist flexion/extension, radial/ulnar deviation
• Forearm pronation/supination
• Hot wax bath / paraffin wax
• TENS for pain relief

• Progressive strengthening (putty, resistance bands)
• Fine motor activities
• ADL retraining
• Return to work/sport activities

Complications of Colles' Fracture:

• Malunion (most common) - residual dorsal angulation, radial shortening
• Median nerve injury - acute carpal tunnel syndrome
• Sudeck's atrophy (Complex Regional Pain Syndrome / CRPS Type I)
• Rupture of extensor pollicis longus (EPL) tendon
• Stiffness of wrist and fingers
• Distal radioulnar joint (DRUJ) instability
• Osteoarthritis of wrist (if intraarticular)
• Carpal tunnel syndrome (late)

II. SHORT ESSAYS (5 marks each)

Q3. Stages of Fracture Healing

Stages of Secondary Fracture Healing:

• Disruption of blood vessels forms a fracture hematoma
• Clot forms between fracture ends
• Inflammatory mediators released (PGE2, cytokines, growth factors)
• Acts as scaffold for subsequent repair

• Acute inflammatory response
• Recruitment of macrophages, neutrophils
• Angiogenesis begins
• Undifferentiated mesenchymal cells migrate into hematoma

• Fibrovascular tissue replaces hematoma
• Fibroblasts and chondroblasts produce Type I and Type II collagen
• Woven bone and cartilage form = soft callus (visible on X-ray around 3 weeks)
• Fracture still mobile but pain decreases

• Enchondral ossification converts cartilage to woven bone
• Callus becomes hard (seen on X-ray)
• Fracture site becomes rigid

• Woven bone replaced by lamellar bone
• Medullary cavity restored (Wolff's law - bone remodels along lines of stress)
• Cortical continuity restored
• Fracture line disappears on X-ray

• Local: Blood supply, type of bone, degree of displacement, infection
• Systemic: Age, nutrition, hormones (PTH, growth hormone), smoking, diabetes

Q4. Anterior Dislocation of Shoulder

Definition

• Subcoracoid (most common - 85%)
• Subglenoid
• Subclavicular
• Intrathoracic (rare)

• Indirect force: Abduction + external rotation + extension
• Direct posterior blow to shoulder

Clinical Features:

• Severe pain with shoulder held in slight abduction and external rotation
• "Square shoulder" / "Epaulette sign" - loss of normal rounded contour, deltoid prominence disappears
• Humeral head palpable anteriorly/below coracoid
• Calloway's sign - increased circumference of shoulder
• Loss of all shoulder movements
• Hamilton ruler test positive - straight edge ruler bridges acromion to lateral epicondyle
• Neurovascular exam: Axillary nerve most commonly injured (numbness over regimental badge area, deltoid weakness)

Management:

1. Kocher's method (levering technique - risk of fracture, less used now)
2. Hippocratic method (traction-countertraction)
3. Stimson's technique (prone position with hanging weight)
4. Cunningham technique (seated, muscle massage)
5. FARES method (Fast, Reliable, Safe)

• X-ray to confirm reduction
• Immobilization in shoulder sling: 3 weeks (<30 years), 1-2 weeks (>40 years)
• Physiotherapy: Pendulum exercises, followed by active ROM, rotator cuff strengthening
• Recurrence rate is high (90% in young patients <20 years)

• Bankart repair (labral reconstruction - gold standard arthroscopic)
• Latarjet procedure (for bony deficiency)
• Remplissage (for Hill-Sachs)

Q5. Principles of Tendon Transfer

Definition

Indications:

• Irreparable nerve injuries (brachial plexus, radial nerve palsy, ulnar nerve palsy)
• Polio paralysis
• Tendon ruptures (EPL rupture after Colles' fracture)
• Cerebral palsy with spastic deformities

Principles (Mnemonic: PASTA-BEST):

Q6. Amputation - Definition, Indications, Types and Ideal Stump

Definition

Indications (5D's + V):

1. Dead limb - irreversible gangrene (dry or wet), Buerger's disease, severe frostbite
2. Dangerous limb - malignant tumor (sarcoma), gas gangrene (clostridial)
3. Damaged beyond repair - crush injury, devascularized limb after failed vascular reconstruction
4. Diseased limb - chronic osteomyelitis, chronic non-healing ulcers with bone involvement
5. Dysfunctional limb - severe, useless, painful paralysis (spastic limb)
6. Vascular - severe peripheral vascular disease (diabetes mellitus, PAOD), critical limb ischemia

Types:

• By technique:
  • Open/Guillotine amputation (emergency, dirty wounds - closed later)
  • Closed/Flap amputation (elective, clean - primary closure)
• By level (lower limb, most common):
  • Toe/ray amputation
  • Transmetatarsal
  • Syme's (ankle disarticulation) - best distal stump
  • Below-knee (BK/transtibial) - preferred level
  • Through-knee (knee disarticulation)
  • Above-knee (AK/transfemoral)
  • Hip disarticulation
  • Hemipelvectomy

Ideal Stump Characteristics:

1. Adequate length - sufficient to fit prosthesis and provide leverage (BK: 12-15 cm from knee joint)
2. Conical/cylindrical shape - tapered end for prosthetic fitting
3. Painless - no neuroma, no phantom limb pain
4. Stable skin cover - healthy, non-adherent scar; scar not at end/weight-bearing area
5. Good circulation - well-vascularized flap; no trophic changes
6. Muscle cover - myodesis (muscle to bone) or myoplasty (muscle to muscle) for padding
7. Bony end - smooth, rounded, beveled end; no bony spurs
8. Sensate skin - preferably sensate skin for better prosthetic feedback
9. No joint contracture - full range of the proximal joint

Q7. Spondylolisthesis

Definition

Classification (Wiltse):

1. Type I - Dysplastic (Congenital): Congenital defect of superior sacral facets
2. Type II - Isthmic (most common): Defect in pars interarticularis (spondylolysis) - common in gymnasts/athletes
3. Type III - Degenerative: Due to degenerative facet joint arthritis (common in elderly women)
4. Type IV - Traumatic: Acute fracture other than pars
5. Type V - Pathological: Due to bone disease (Paget's, tumor)

Grading (Meyerding's):

• Grade I: 0-25% slip
• Grade II: 25-50% slip
• Grade III: 50-75% slip
• Grade IV: 75-100% slip
• Grade V (Spondyloptosis): >100% - complete fall-off

Clinical Features:

• Low back pain (worse with activity, relieved by rest)
• Tight hamstrings (classic)
• Short trunk, protruding abdomen, flattened buttocks
• Lumbar hyperlordosis
• "Step deformity" palpable at L4-L5 in severe cases
• Neurological symptoms: Sciatica, L5/S1 root compression
• In severe cases: Cauda equina syndrome (bladder/bowel dysfunction)

Investigations:

• X-ray lumbar AP + lateral + oblique views
• Oblique view: "Scottie dog sign" with collar = pars defect
• MRI: Neural compression, disc pathology
• CT: Best for bony anatomy, pars defect

Management:

Q8. Principle Types and Methods of Internal Fixation

Definition

Principles (AO Principles):

1. Anatomical reduction of fracture fragments
2. Stable fixation - absolute stability (compression) or relative stability (bridging)
3. Preservation of blood supply - to bone and soft tissues (biological fixation)
4. Early, active, pain-free mobilization of muscles and joints

Types of Internal Fixation:

• Cortical screw (fine threads)
• Cancellous screw (coarse threads) - used in metaphysis/epiphysis
• Lag screw - produces compression by "lagging" fragments
• Cannulated screws - for femoral neck, scaphoid

• Dynamic Compression Plate (DCP) - most commonly used; compresses fracture
• Locking Compression Plate (LCP) - locking screws into plate; for osteoporotic/periarticular fractures; acts as internal fixator
• Buttress/Anti-glide plate - prevents displacement in metaphyseal fractures (tibial plateau)
• Blade plate - for intertrochanteric/femoral fractures
• DHS (Dynamic Hip Screw) - for intertrochanteric fractures; controlled collapse allowed

• Most biomechanically ideal for long bone diaphyseal fractures
• Types: Kuntscher nail, PFN (Proximal Femoral Nail), Tibial IM nail
• Locked nails (proximal and distal locking screws) for length/rotation control
• Advantages: Weight bearing early, closed technique, minimal periosteal damage

• Kirschner wires (K-wires) - temporary fixation, pediatric fractures
• Cerclage wires - periprosthetic fractures, olecranon
• Tension band wiring - converts tension force to compression (olecranon, patella)

• Converts distracting tension forces on the convex side to compressive forces at the fracture
• Used in: Patella, olecranon, medial malleolus fractures

Q9. Osteoarthritis

Definition

Classification:

• Primary OA - no identifiable cause; age-related, idiopathic; common in elderly women
• Secondary OA - due to known cause (fractures, septic arthritis, AVN, dysplasia, metabolic disorders)

Pathophysiology:

• Cartilage degradation: Imbalance between matrix synthesis and breakdown
• Chondrocytes produce MMPs (matrix metalloproteinases), IL-1, TNF-α
• Progressive fibrillation → fissuring → cartilage loss → subchondral bone exposed (eburnation)
• Subchondral changes: Sclerosis, cysts, osteophyte formation at margins

Clinical Features:

• Pain: Deep, aching; worse with activity, relieved by rest (cf. RA: worst in morning); later becomes constant
• Stiffness: Short morning stiffness (<30 min, cf. RA >1 hour)
• Crepitus on movement
• Bony swelling (osteophytes) - Heberden's nodes (DIP), Bouchard's nodes (PIP) in hands
• Joint deformity and restricted range of motion
• No systemic features (cf. RA)

X-ray Features (LOSS mnemonic):

• L - Loss of joint space (narrowing)
• O - Osteophytes (bony spurs)
• S - Subchondral sclerosis
• S - Subchondral cysts

Management:

• Weight reduction (most important for knee OA)
• Physiotherapy: Quadriceps strengthening, range of motion exercises, hydrotherapy
• Walking aids (stick, walker)
• Patient education
• Thermal modalities (heat/cold), TENS

• Paracetamol (first line)
• Topical NSAIDs (diclofenac gel)
• Oral NSAIDs (with PPI cover)
• Intraarticular corticosteroid injection (short-term relief)
• Intraarticular hyaluronic acid (viscosupplementation)
• Duloxetine (for widespread pain)

• Arthroscopic debridement and lavage (limited benefit)
• Osteotomy (realignment - unicompartmental OA in young)
• Hemiarthroplasty / Unicompartmental knee arthroplasty
• Total Joint Replacement (THA/TKA) - for severe disease, failed conservative treatment

Q10. Neck of Femur Fracture

Definition

Classification:

• Type I: <30° (compression force - stable, good prognosis)
• Type II: 30-50° (shear force)
• Type III: >50° (severe shear - most unstable, worst prognosis)

• Grade I: Incomplete (impacted/valgus)
• Grade II: Complete, undisplaced
• Grade III: Complete, partially displaced
• Grade IV: Complete, fully displaced

• Subcapital (at head-neck junction) - most common
• Transcervical (midcervical)
• Basal (at base of neck)

Clinical Features:

• Common in elderly women with osteoporosis after trivial fall
• Severe pain in groin/hip, referred to knee
• Limb shortened and externally rotated (for displaced fractures; undisplaced - minimal signs)
• Patient unable to stand or walk
• Tenderness over femoral triangle
• Telescoping positive
• Impacted fracture: Patient may be able to walk with pain (diagnostic trap)

Complications:

• Avascular Necrosis (AVN) of femoral head - most important; blood supply (medial and lateral circumflex femoral arteries, retinacular vessels) disrupted
• Non-union - poor blood supply, shear forces
• Malunion
• DVT/PE
• Urinary tract infections in elderly

Management:

• Internal fixation: 2-3 cannulated cancellous screws (parallel) or dynamic hip screw (DHS)
• Early weight bearing

• Young patients (<65 years): ORIF with cannulated screws - attempt to preserve femoral head
• Elderly patients (>65 years):
  • Hemiarthroplasty (Austin Moore / Thompson prosthesis) - unipolar or bipolar
  • Total Hip Arthroplasty (for active elderly, pre-existing OA)

• Early mobilization (Day 1-2)
• Bed exercises, deep breathing
• Progressive weight-bearing
• Hip precautions (for hemiarthroplasty/THA)

III. SHORT ANSWERS (2 marks each)

Q11. Boxer Fracture

Q12. Student's Elbow (Olecranon Bursitis)

Q13. Complications of Fracture

• Blood loss and shock
• Neurovascular injury
• Visceral injury (lung, bowel)

• Fat embolism (24-72 hours - triad: dyspnea, petechiae, confusion)
• DVT/Pulmonary embolism
• Compartment syndrome (6 P's: Pain, Pallor, Pulselessness, Paraesthesia, Paralysis, Pressure)
• Wound infection
• Tetanus (open fractures)

• Malunion - fracture heals in poor position
• Delayed union - fracture not united in expected time
• Non-union - fracture fails to unite (atrophic/hypertrophic)
• Avascular necrosis
• Joint stiffness
• Post-traumatic arthritis
• Osteomyelitis (open fractures)
• Complex Regional Pain Syndrome (Sudeck's atrophy)
• Myositis ossificans

Q14. Stages of PIVD (Prolapsed Intervertebral Disc)

1. Nuclear Prolapse (Protrusion): Nucleus pulposus pushes into weakened annulus fibrosus but annulus remains intact. Pain only.
2. Disc Prolapse (Extrusion): Nucleus ruptures through annulus but still connected to disc. Nerve root compression begins.
3. Disc Sequestration: Free fragment of nucleus pulposus separates and lies free in spinal canal. Severe neurological deficit.
4. Disc Herniation with Migration: Sequestrated fragment migrates up or down the spinal canal.

Q15. Hoffa Syndrome (Infrapatellar Fat Pad Syndrome)

Q16. Difference between Osteotomy and Arthrodesis

Q17. Denis Browne Splint

Q18. Bamboo Spine

Q19. Hangman's Fracture

Q20. SLR Test (Straight Leg Raise Test / Lasegue's Test)

1. Patient lies supine, relaxed.
2. Examiner passively raises the straight (extended) leg at the hip while keeping the knee extended.
3. Test is positive if the patient's sciatica (radicular pain below the knee) is reproduced between 30°-70° of elevation.
4. Braggard's sign: At the angle of pain, dorsiflex the ankle - increases tension on sciatic nerve, worsens pain = confirms radiculopathy.

• Positive (30-70°): L4-L5 or L5-S1 disc herniation with nerve root compression
• Pain only in back (not radiating) = not positive; hamstring tightness is not a positive SLR

• 70°: Usually lumbar/sacroiliac pathology rather than disc