Neck of Femur Fractures - Dynamic Hip Screw and Cannulated Screws

Indications for Fixation vs Arthroplasty

Intracapsular Fractures (Femoral Neck)

Cannulated Screws:

• Undisplaced fractures (Garden I-II) in ANY age if anatomically reduced
• Young patients (under 60-65) with displaced fractures IF anatomical closed reduction achievable
• Physiologically young patients (60-75) with good bone quality and minimal comorbidities
• Contraindications: displaced fractures in elderly (high AVN/nonunion risk), failed closed reduction, pathologic fractures

Arthroplasty (Hemiarthroplasty or THR):

• Displaced fractures (Garden III-IV) in elderly patients (over 65-70)
• Displaced fractures in patients with pre-existing hip arthritis
• Displaced fractures with failed closed reduction attempts
• Pathologic fractures through femoral neck
• Choose THR if: independent ambulators, no cognitive impairment, life expectancy over 5 years, acetabulum healthy
• Choose hemiarthroplasty if: limited mobility, cognitive impairment, significant comorbidities, life expectancy under 5 years

Extracapsular Fractures (Intertrochanteric/Subtrochanteric)

Dynamic Hip Screw (DHS):

• Stable intertrochanteric fractures (AO/OTA 31-A1, intact medial cortex/lesser trochanter)
• Some A2 patterns with minimal medial comminution (under 2cm medial cortex gap)
• Adequate bone quality for lag screw purchase
• No significant subtrochanteric extension

Cephalomedullary Nail:

• Unstable intertrochanteric fractures (AO 31-A2 with large posteromedial fragment, A3 with reverse obliquity)
• Subtrochanteric fractures (AO 32-A, B, C)
• Any intertrochanteric fracture with subtrochanteric extension
• Bilateral hip fractures (faster surgery, earlier mobilization)
• Very osteoporotic bone with medial comminution (better load sharing)

Age and Functional Considerations

Young Patients (Under 60):

• Preserve native femoral head whenever possible
• Accept risk of AVN/nonunion with fixation over arthroplasty
• Demand anatomical reduction (under 2mm displacement, normal Garden alignment)
• Consider open reduction if closed inadequate
• Long-term: revision arthroplasty easier after failed fixation than revision arthroplasty after primary arthroplasty at young age

Elderly Patients (Over 75):

• Lower threshold for arthroplasty in displaced intracapsular fractures
• Balance surgical risk vs functional outcome
• Consider medical comorbidities: ASA 4 patients may benefit from faster surgery (cannulated screws under 30min vs hemiarthroplasty 90min)
• Assess pre-fracture function: community ambulators with good cognition may benefit from THR over hemiarthroplasty
• Quote NHFD data: 30-day mortality 6.7%, 1-year mortality 30% - realistic expectations

Medical Optimization Pre-operatively

• Anemia: transfuse if Hb under 80 g/L (JBI guidelines), correct if time permits
• Anticoagulation: reverse warfarin (vitamin K, PCC), hold DOACs per half-life, assess bleeding risk
• Cardiovascular: cardiology input if unstable, optimize rate/rhythm, continue beta-blockers
• Fluids: resuscitate if hypovolemic, monitor urine output
• Timing: NICE guidelines recommend surgery within 36 hours of admission (improves outcomes, reduces complications)
• Consent: discuss fixation vs arthroplasty, AVN/nonunion risk if fixing, mobility expectations, mortality risk

Surgical Anatomy

Osseous Anatomy of Proximal Femur

Femoral Head:

• Spherical articular surface (40-50mm diameter)
• Covered with hyaline cartilage except fovea centralis (ligamentum teres attachment)
• Subchondral bone: thickest superolaterally (weight-bearing), thinnest at fovea
• Trabecular pattern: medial (compressive) and lateral (tensile) trabecular systems converge at femoral neck
• Ward's triangle: area of relative weakness inferior to femoral head

Femoral Neck:

• Connects head to shaft at 125-135° (neck-shaft angle, reduces with age)
• Anteversion 10-15° (version of neck relative to transepicondylar axis)
• Intracapsular: fractures here disrupt retinacular blood supply
• Cortical thickness: anterior and posterior cortices thick, superior and inferior thin
• Calcar femorale: dense vertical bone medial femoral neck, critical for medial support

Greater Trochanter:

• Lateral prominence, insertion of abductors (gluteus medius/minimus anterosuperior, piriformis/obturators posterior)
• Vastus lateralis originates from vastus ridge (anterior GT extending distally)
• Vulnerable to avulsion with abductor muscle pull
• Key landmark for incision (palpable even in obese patients)

Lesser Trochanter:

• Posteromedial prominence, insertion of iliopsoas
• Integrity indicates fracture stability (intact = stable, comminuted/displaced = unstable)
• Useful fluoroscopic landmark for guide wire trajectory (wires should enter 2cm distal to avoid lesser trochanter)

Intertrochanteric Region:

• Between greater and lesser trochanters, entirely extracapsular
• Cortical bone shell with cancellous interior (good healing potential, rich blood supply)
• Fractures here have lower AVN/nonunion risk than intracapsular

Vascular Anatomy and Blood Supply

Arterial Supply to Femoral Head:

• Medial femoral circumflex artery (MFCA): dominant supply (80%), branch of profunda femoris (or femoral artery), courses posteriorly, gives off retinacular arteries
• Lateral femoral circumflex artery (LFCA): minor contribution (20%), branch of profunda femoris, runs laterally, also contributes retinacular vessels
• Retinacular arteries: run along femoral neck within hip capsule, enter head at head-neck junction (4-6 vessels), disrupted by displaced intracapsular fractures
• Artery of ligamentum teres: branch of obturator or medial femoral circumflex, minor contribution in adults (more important in children)
• Femoral diaphyseal nutrient artery: supplies femoral shaft, contributes to extracapsular region

Clinical Significance:

• Displaced intracapsular fractures: tear capsule and retinacular vessels → AVN risk 15-33%
• Undisplaced intracapsular: capsule intact, vessels kinked/stretched → AVN risk 5-10%
• Extracapsular fractures: extracapsular blood supply intact → AVN risk near 0%
• Capsular tamponade: hematoma within capsule may compress retinacular vessels (theoretical, controversial whether capsulotomy helps)

Muscular Anatomy and Lateral Approach

Superficial Structures:

• Skin and subcutaneous tissue: generous in elderly patients
• Fascia lata: dense lateral thigh fascia, continuous with iliotibial band, requires incision
• Tensor fascia lata: anterior muscle, avoid (denervated if damaged)

Lateral Femur:

• Vastus lateralis: covers anterolateral femur, origin from vastus ridge (anterior GT) and lateral femoral shaft
• Lateral intermuscular septum: separates vastus lateralis (anterior compartment) from biceps femoris (posterior compartment)
• Technique: elevate vastus anteriorly off lateral septum and lateral femur (preserves muscle, exposes lateral cortex for implant)

Abductors (Proximal):

• Gluteus medius: superficial abductor, inserts on lateral/superior GT
• Gluteus minimus: deep abductor, inserts on anterior GT
• Superior gluteal nerve: innervates both muscles, enters 3-5cm superior to GT tip (avoid dissection proximal to GT to protect)

Neurovascular Structures at Risk

Anterior Structures:

• Femoral neurovascular bundle: 3-4cm medial to femoral neck, protected by staying lateral
• Lateral femoral cutaneous nerve: runs lateral to ASIS, courses distally in superficial fascia, can be injured by anterior skin incision (causes meralgia paresthetica - anterolateral thigh numbness)

Posterior Structures:

• Sciatic nerve: 1-2cm posterior to posterior femoral cortex at lesser trochanter level, avoid posterior dissection
• Superior gluteal neurovascular bundle: 3-5cm superior to GT tip, avoid proximal dissection

Lateral Structures:

• Perforating vessels from lateral femoral circumflex: penetrate vastus lateralis along lateral intermuscular septum, control bleeding with bipolar (not blind clamping)

Patient Positioning

Fracture Table Technique (Standard for DHS)

Table Setup:

• Patient supine on fracture table with radiolucent top
• Perineal post between legs (well-padded with foam, prevents pudendal nerve injury)
• Injured leg in traction boot (padded boot around ankle/foot)
• Uninjured leg: hemilithotomy position (abducted 45°, flexed at hip/knee, leg support) OR extended on lateral leg support (if hemilithotomy limits C-arm access)

Traction Application:

• Initial traction 20-30 lbs (10-15 kg) via traction boot
• Adjust based on fracture reduction quality
• Excessive traction (over 40 lbs): can distract fracture excessively, impede reduction
• Maintain traction throughout surgery until final hardware in place

Image Intensifier Positioning:

• C-arm on opposite side from surgeon (e.g., surgeon on left, C-arm on right for right hip)
• Allows lateral view (C-arm beam horizontal, parallel to floor)
• Ensure ability to obtain: AP pelvis, AP hip, lateral hip (cross-table lateral or frog-leg if cross-table difficult)
• Test ALL views before prepping (common error: discover inadequate lateral access after draped)

Advantages:

• Stable platform for reduction maneuvers
• Consistent traction maintains reduction during surgery
• Both hands free for surgeon (not holding leg)

Disadvantages:

• Risk of pudendal nerve injury (well-padded post essential)
• Risk of perineal skin breakdown (prolonged pressure)
• Limited ability to manipulate limb rotation during case
• Risk of foot/ankle compartment syndrome (excessive traction time)

Free Leg Technique (Alternative for Cannulated Screws)

Setup:

• Standard radiolucent operating table (no fracture table)
• Patient supine, both legs extended on table
• No perineal post, no traction boot

Reduction Technique:

• Assistant applies manual traction to injured leg (holds foot/ankle)
• Surgeon can manipulate limb freely (flexion, rotation, abduction/adduction)
• More dynamic reduction maneuvers possible (Leadbetter, Flynn techniques)

Advantages:

• No perineal post complications
• Easier to manipulate rotation (key for intracapsular fracture reduction)
• Faster setup and patient positioning
• Can convert to fracture table if reduction fails

Disadvantages:

• Requires skilled assistant to maintain traction
• Surgeon only has one hand free (other holds leg or directs assistant)
• Traction may fatigue assistant during long case
• Harder to maintain reduction for DHS plate application

Best For:

• Cannulated screw fixation (percutaneous, don't need plate application)
• Intracapsular fractures requiring rotation manipulation
• Short cases (under 60 minutes)
• Patients with contraindication to fracture table (e.g., bilateral hip fractures, ipsilateral femoral shaft fracture)

Closed Reduction Techniques

Intracapsular Fractures

Leadbetter Maneuver:

1. Flex hip to 90° (relaxes capsule, disengages fragments)
2. Apply traction (10-15 lbs, pulls distal fragment distally)
3. Internally rotate leg 15-20° (reduces posterior displacement, aligns fragments)
4. Circumduct leg while maintaining traction (gentle circular motion, engages head into acetabulum)
5. Extend hip to neutral while maintaining traction and internal rotation
6. Check reduction on AP and lateral fluoroscopy

Flynn Maneuver:

1. Flex hip to 90° and knee to 90°
2. Apply longitudinal traction along femoral shaft (assistant pulls on leg)
3. Apply lateral traction (assistant pulls leg laterally, away from midline)
4. Internally rotate leg 15-20°
5. Extend hip to neutral while maintaining traction
6. Check reduction on fluoroscopy

Key Principles:

• Flexion relaxes capsule and iliofemoral ligament (allows manipulation)
• Traction disengages fragments (overcomes muscle forces)
• Internal rotation corrects external rotation deformity (femoral head typically externally rotated after fracture)
• Extension locks reduction (tightens anterior capsule)

Assessing Reduction Quality:

• AP view: Garden alignment index 160±10° (angle between femoral head axis and medial femoral neck cortex), medial cortex continuity, displacement under 5mm in elderly (under 2mm in young)
• Lateral view: Garden alignment 180±10° (normal is 180° = collinear), no posterior sag (posterior cortex angulation under 20°), no anterior translation
• Both views: concentric reduction of femoral head in acetabulum, fracture line visible but minimal gap

Failed Closed Reduction:

• Young patients: consider open reduction via anterior (Smith-Petersen) or posterior approach, achieve anatomical reduction under direct vision
• Elderly patients: convert to hemiarthroplasty or THR (closed reduction attempt under 10-15 minutes, don't persist if clearly failing)

Extracapsular Fractures

Reduction Technique:

• Longitudinal traction with limb in neutral rotation (NOT internal rotation)
• Assess medial cortex reduction: need continuity or minimal gap (under 2cm acceptable if stable)
• Correct varus deformity: may need abduction force (assistant abducts leg while traction maintained)
• Correct valgus deformity: adduction force (rare, usually varus is problem)

Acceptable Reduction:

• Neck-shaft angle: 125-135° (varus under 10° acceptable, valgus preferred over varus)
• Anterior/posterior cortex: alignment within 5mm, no excessive posterior sag (under 20°)
• Rotation: neutral (avoid internal rotation, avoid external rotation)
• Medial cortex: continuity ideal, gap under 2cm acceptable if lateral cortex reduced and fixed

Unstable Patterns:

• Posteromedial comminution (large posterior/medial fragment): difficult to reduce medial cortex, accept gap, ensure lag screw in good bone
• Reverse obliquity: fracture line runs from superomedial to inferolateral, inherently unstable to axial loading, consider nail over DHS

Dynamic Hip Screw Operative Steps

1. Skin Incision and Superficial Dissection

Incision:

• Longitudinal incision centered over lateral femur
• Proximal extent: 2cm distal to greater trochanter tip (palpate GT before incision)
• Length: 8-12cm depending on plate length (4-hole plate = 8-10cm, 6-hole = 10-12cm)
• Direction: parallel to femoral shaft axis

Technique:

• Incise skin and subcutaneous tissue with knife
• Control bleeding with diathermy (generous in elderly patients)
• Identify fascia lata (white glistening strong fascia)

2. Deep Dissection - Vastus Lateralis Elevation

Fascial Incision:

• Incise fascia lata in line with skin incision using heavy scissors or knife
• Full length of incision

Vastus Lateralis Elevation:

• Identify anterior edge of vastus lateralis muscle
• Using periosteal elevator, elevate vastus anteriorly off lateral femoral shaft
• Start distally (easier) and work proximally
• Elevate in subperiosteal plane where possible (preserves muscle blood supply)
• Expose lateral femoral cortex from GT region distally for plate length

Retractor Placement:

• Anterior Hohmann retractor: retracts vastus anteriorly, tip on anterior femoral cortex
• Posterior Hohmann retractor: protects posterior soft tissues, tip on posterior femoral cortex
• Ensure retractors on bone (not soft tissue - prevents neurovascular injury)

Hemostasis:

• Control perforating vessels from lateral intermuscular septum with bipolar cautery
• Bone bleeding from osteoporotic bone: bone wax sparingly, thrombin-soaked gelfoam

3. Guide Wire Insertion for Lag Screw

Guide/Jig Placement:

• Attach DHS guide to lateral femoral cortex using positioning pins
• Guide angle: 135° or 150° (match to selected plate barrel angle)
• Position on femur: guide barrel should align with femoral neck axis on AP and lateral views
• Confirm position with fluoroscopy before inserting wire

Wire Insertion:

• Use 2.0-2.5mm smooth guide wire through guide sleeve
• Entry point on lateral cortex: anterior third of lateral cortex, 1-2cm distal to vastus ridge (ensures anterior position in neck)
• Trajectory: aim for center of femoral head on AP view (or slightly inferior = center-inferior)
• Lateral view: aim for center of head (or slightly inferior = center-inferior)
• Advance wire across fracture into femoral head (check reduction maintained)
• Final position: 5-10mm from subchondral bone (check on AP and lateral)

Tip-Apex Distance Measurement:

• Measure distance from wire tip to apex of femoral head on AP fluoroscopy image (in mm)
• Measure distance from wire tip to apex on lateral fluoroscopy image (in mm)
• Add the two measurements (normalize for magnification if calibration marker used)
• Target: sum under 25mm (Baumgaertner: TAD over 25mm = 6x increased cut-out risk)
• If TAD over 25mm: reposition wire more inferior and/or posterior before proceeding

Optimal Wire Position:

• AP view: center or inferior-third of femoral head (avoids superior head where bone weaker)
• Lateral view: center or inferior-third (avoids anterior where bone weaker)
• Overall: "center-inferior" position ideal (central on AP, inferior on lateral)

4. Reaming for Lag Screw

Reamer Selection:

• Cannulated triple reamer matching planned lag screw diameter (typically 10-12.5mm)
• Three cutting flutes, hollow center (passes over guide wire)

Reaming Technique:

• Place reamer over guide wire
• Ream lateral cortex entry site first (hard cortical bone)
• Advance reamer incrementally, checking depth frequently on fluoroscopy
• Clear bone debris from reamer flutes every 2-3cm (prevents jamming)
• Ream to depth 5-10mm shorter than measured wire depth (leaves tip within head, avoids joint penetration)

Pitfalls:

• Over-reaming (penetrating femoral head): check depth frequently, stop if any crunching sensation
• Wire advancement during reaming: wires can advance or toggle, re-check wire position after reaming
• Reamer binding: clear bone debris frequently, ensure adequate entry hole in lateral cortex

5. Lag Screw Insertion

Screw Length:

• Measure guide wire depth with depth gauge (or use pre-measured depth from wire insertion)
• Select lag screw 5-10mm shorter than measured depth (tip should be 5-10mm from subchondral bone)

Insertion Technique:

• Place lag screw over guide wire
• Advance screw using mallet (gentle tapping, not forceful hammering)
• Partially-threaded screw: threads engage femoral head only, smooth shaft traverses fracture (creates lag effect)
• Check depth on fluoroscopy every few taps (avoid advancing too far)
• Final position: tip 5-10mm from subchondral bone on both AP and lateral views

Assessing Lag Screw Sliding:

• Test that screw slides freely (not yet attached to barrel-plate)
• Screw should move with gentle push/pull (if binds, may be too long)
• Remove guide wire after screw positioned

6. Barrel-Plate Application

Plate Selection:

• Standard 4-hole plate for most fractures (provides 4 screws distal to fracture)
• 6-8 hole plate for subtrochanteric extension or osteoporotic bone
• Barrel angle matches lag screw angle (135° or 150°)

Plate Positioning:

• Slide barrel over lag screw (barrel has internal threads/sleeve that engages lag screw)
• Seat barrel-plate against lateral femoral cortex
• Check plate position: flush against lateral cortex (no anterior/posterior gapping), centered on lateral femur (not rotated anteriorly/posteriorly)
• May need gentle plate contouring to match femoral anatomy (modern pre-contoured plates usually fit well)

Temporary Fixation:

• Hold plate with reduction clamp or insert K-wire through distal hole (maintains position during screw insertion)

Checking Compression Mechanism:

• Ensure lag screw can slide into barrel (compression mechanism of DHS)
• Should see 10-15mm of threaded lag screw shaft visible outside barrel (on lateral fluoroscopy)
• This "collapse space" allows fracture impaction during healing
• If lag screw bottomed out in barrel: remove and use shorter screw

7. Distal Screw Insertion

Screw Holes:

• Typically 4 screws distal to fracture (4-hole plate)
• Insert screws sequentially from distal to proximal

Technique for Each Screw:

1. Drill: 3.2mm drill bit through plate hole, bicortical (feel far cortex penetration)
2. Measure: depth gauge in drill hole, measure to far cortex
3. Tap: 4.5mm cortical tap (in young bone with hard cortex, may skip in elderly osteoporotic bone)
4. Insert: 4.5mm cortical screw, length measured +2-4mm (ensure bicortical purchase)

Screw Length:

• Bicortical fixation essential (screw tip just through far cortex)
• Avoid excessive medial cortex penetration (over 10mm past far cortex risks iliopsoas irritation or pelvic penetration)
• Check all screw lengths on fluoroscopy after insertion

Screw Tightening:

• Tighten screws to secure plate firmly to femoral shaft
• Avoid over-tightening (can strip threads in osteoporotic bone)
• Compression between plate and bone should be firm but not excessive

8. Final Assessment

Fluoroscopy:

• AP view: fracture reduction maintained, lag screw position (center-inferior), tip-apex distance under 25mm, plate flush laterally, distal screws bicortical
• Lateral view: fracture reduction (no posterior sag), lag screw position (center-inferior), lag screw collapse space visible (10-15mm threaded shaft outside barrel), distal screws bicortical

Collapse Space:

• Critical to verify adequate collapse space
• Measure on lateral fluoroscopy: distance from lag screw thread sleeve to barrel end should be 10-15mm
• Allows controlled impaction and compression during healing
• If inadequate (under 5mm): fracture can't compress, increased cut-out risk

Release Traction:

• Slowly release traction while observing fracture on fluoroscopy
• Fracture should remain reduced (if displaces, fixation inadequate)
• Slight impaction normal (fracture gaps close as load transfers to implant)

Cannulated Screw Fixation Technique

Indications Specific to Screws

Ideal Candidates:

• Undisplaced intracapsular fractures (Garden I-II)
• Young patients (under 60) with displaced fractures achieving anatomical closed reduction
• Vertical fracture patterns (Pauwels II-III) in young patients (screws better resist shear than single lag screw)

Advantages over DHS:

• Percutaneous insertion (minimal soft tissue dissection)
• Preserves blood supply better (less periosteal stripping)
• Shorter operative time (30-45 min vs 60-90 min for DHS)
• Less blood loss
• Smaller incisions (cosmetic)

Biomechanics:

• Three screws provide better rotational stability than single large lag screw
• Parallel configuration resists rotation
• Spread at fracture site (over 15mm) resists rotation and shear
• Partially-threaded screws create compression (lag effect)

Guide Wire Insertion Strategy

Configuration:

• Inverted triangle: most common (inferior wire, two superior wires forming triangle apex distally)
• Alternative: horizontal triangle (three wires at same level vertically, spread medial-lateral)

Wire Positions:

1. Inferior Wire (First):

   • Entry: 2cm distal to vastus ridge on anterior cortex
   • Avoids lesser trochanter (posterior-medial)
   • Trajectory: toward inferior-central femoral head
   • This wire determines minimum screw length

2. Posterior-Superior Wire (Second):

   • Entry: 2cm distal to GT tip on posterior cortex
   • Trajectory: toward posterior-superior head
   • Parallel to inferior wire (within 10°)

3. Anterior-Superior Wire (Third):

   • Entry: 2cm distal to GT tip on anterior cortex
   • Trajectory: toward anterior-superior head
   • Parallel to other wires (within 10° of both)

Key Principles:

• Parallelism: wires within 10° of parallel (maximizes compression, prevents divergence)
• Spread: wires separated by over 15mm at fracture site (resists rotation)
• Depth: all wires 5mm from subchondral bone (measured on AP and lateral - wire tip should NOT penetrate head on either view)
• Avoid convergence: if wires converge at fracture, inadequate spread (poor fixation)

Drilling Technique

Lag Screw Concept:

• Only NEAR cortex should be threaded
• Drill creates glide hole in near (lateral) cortex
• Screw threads engage FAR (medial) cortex and femoral head only
• As screw tightens, compression generated across fracture

Technique:

• Use cannulated drill bit OVER wire (not through wire)
• Drill near cortex only (1-2cm depth, just through lateral cortex)
• Check drilling does not advance or damage wire
• Repeat for all three wires

Screw Length Measurement:

• Measure each wire separately with depth gauge
• Use shortest measurement (typically inferior wire) as minimum screw length
• Select screws: measured depth minus 5-10mm (keeps tip within head, short of subchondral bone)

Screw Insertion and Compression

Screw Selection:

• Partially-threaded 6.5mm or 7.0mm cannulated screws (most common)
• Thread length typically 16mm or 32mm (choose based on bone quality and fracture location)
• Ensure threads will cross fracture line (threads engage head fragment, smooth shaft in neck)

Insertion Sequence:

1. Insert all three screws PARTIALLY over wires (advance to near cortex, not fully seated)
2. Check positions on fluoroscopy (all three screws visible on AP and lateral)
3. Tighten screws in ALTERNATING fashion:
   • Tighten inferior screw 5 turns
   • Tighten posterior screw 5 turns
   • Tighten anterior screw 5 turns
   • Repeat until all screws fully seated
4. This alternating technique ensures even compression (prevents one screw from fully compressing before others engage)

Assessing Compression:

• Watch fracture gap on fluoroscopy during final tightening
• Should see gap close as compression applied
• Avoid over-tightening (threads can strip in osteoporotic bone, OR if all threads engage both fragments, continued tightening distracts fracture)

Remove Wires:

• Once screws fully inserted and compression achieved, remove guide wires
• Wires prevent screw backing out if left in place (controversial whether to leave or remove)

Final Fluoroscopic Assessment

AP View:

• Three screws visible, parallel configuration
• Spread at fracture site over 15mm (measure on fluoroscopy)
• Tips 5mm from subchondral bone
• Threads crossing fracture line
• No screw penetration of femoral head

Lateral View:

• Three screws visible (may overlap if parallel, spread them slightly in AP direction to see all three on lateral)
• Tips 5mm from subchondral bone
• No anterior or posterior penetration
• Reduction maintained

Release Traction:

• Slowly release traction while watching fracture on fluoroscopy
• Fracture should remain reduced and compressed
• Slight impaction acceptable

Wound Closure

• Three small stab incisions (2-3cm each)
• Close fascia lata if opened (2-0 Vicryl)
• Close skin with 3-0 nylon or subcuticular Monocryl
• Simple dressings (no drain needed for percutaneous screws)