import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Branches from profunda femoris** traverse vastus lateralis from posterior to anterior. Location: Throughout vastus muscle belly. Protection: Careful vastus splitting with coagulation of perforators as encountered. **Motor supply to gluteus medius/minimus**. Location: 3-5cm proximal to greater trochanter tip (safe zone below GT). Protection: Limit proximal dissection, avoid retractors above GT. **Major nerve posterior to hip**. Location: 5cm posterior to greater trochanter, emerges below piriformis. Protection: No posterior retractor placement, avoid posterior dissection. **Femoral artery and vein anteriorly**. Location: Femoral triangle, anteromedial to femur. Protection: Strictly lateral approach, no anterior dissection beyond femoral shaft. **Absolute Indications:** - Stable intertrochanteric fractures (AO/OTA 31-A1) - the ideal DHS fracture pattern - Simple pertrochanteric fractures (AO/OTA 31-A2.1) with intact medial cortex and lateral wall - Lateral wall thickness >20mm on pre-reduction imaging (Palm criteria) - Basicervical femoral neck fractures in elderly with osteoporotic bone (selected cases) **Relative Indications:** - Selected A2.2 patterns with reconstructable medial cortex - Patients where intramedullary device contraindicated (severe femoral bowing, narrow canal) - Surgeon expertise with DHS for borderline patterns **Australian Context:** - ANZHFR 2023: 48% of intertrochanteric fractures receive DHS, 52% receive cephalomedullary nail - Medicare MBS item 47528: Internal fixation of intertrochanteric fracture - $1,247.55 - LMWH or DOAC for VTE prophylaxis (enoxaparin 40mg daily or rivaroxaban 10mg daily for 35 days) **Absolute Contraindications:** - Reverse obliquity patterns (AO 31-A3) - fracture line runs superomedial to inferolateral, DHS cannot resist varus collapse - Lateral wall thickness <20mm or comminuted - lateral wall required for barrel plate stability - Subtrochanteric extension - DHS cannot control long lever arm of distal fragment - Pathological fractures with metastatic bone disease - inadequate bone for screw purchase **Relative Contraindications:** - Severe osteoporosis with eggshell cortex - high cut-out risk - Combined neck-shaft fractures - complex pattern better suited to reconstruction nail - Fracture in young patient (<50 years) - consider anatomic reduction ORIF if fit for longer surgery - Morbid obesity (BMI >40) - increased mechanical demands **Bony Landmarks:** - Greater trochanter (GT) - most prominent lateral hip landmark, entry point for guide wire - Lesser trochanter - level of neck cut reference, attachment of iliopsoas - Intertrochanteric crest - joins GT to LT posteriorly, defines fracture region - Calcar femorale - dense medial cortex, critical for load-bearing in DHS **Femoral Neck Anatomy:** - Normal neck-shaft angle: 125-135° (average 130°) - Femoral neck anteversion: 10-15° (affects guide wire rotation) - Trabecular architecture: Compressive trabeculae (medial), tensile trabeculae (lateral), Ward's triangle (central deficiency) - Cortical thickness: Medial cortex thickest (calcar), lateral thinnest **Vascular Anatomy:** - Profunda femoris artery: Runs posterior to femur in adductor canal, gives off perforating branches - Perforating arteries: 3-4 branches traverse vastus lateralis from posterior to anterior - Medial femoral circumflex artery (MFCA): Main blood supply to femoral head - runs along posterior neck, protected by leaving quadratus femoris intact - Lateral femoral circumflex artery: Supplies anterolateral thigh, branches encountered during approach **Neural Anatomy:** - Sciatic nerve: Exits pelvis below piriformis, runs posterior to hip 5cm posterior to GT, at risk with posterior retractor placement - Superior gluteal nerve: Exits above piriformis, 3-5cm proximal to GT tip - safe zone below GT - Femoral nerve: Lies anteromedial in femoral triangle, protected by strictly lateral approach - Lateral femoral cutaneous nerve: Exits lateral to ASIS, can be injured with anterior extension **Surface Landmarks:** - Palpate greater trochanter - most prominent lateral bony point - Femoral shaft axis - line from GT to lateral femoral condyle - Vastus ridge - palpable ridge on lateral femur distal to GT **Incision:** - Start just distal to GT tip, extend distally along lateral femoral shaft - Length: 8-12cm (adjust for body habitus and plate length) - Orientation: Straight, parallel to femoral shaft axis **Superficial Dissection:** 1. Incise skin and subcutaneous fat to fascia lata 2. Identify and incise fascia lata (iliotibial band) in line with skin incision 3. Fascia lata is thick, strong layer - incise carefully to avoid muscle 4. Retract edges to expose vastus lateralis muscle belly **Deep Dissection:** Two options for vastus lateralis: 1. **SPLIT technique** (preferred): Split muscle in line with fibers running obliquely from superolateral to inferomedial. Less bleeding, preserves muscle function. 2. **ELEVATE technique**: Elevate muscle anteriorly off lateral intermuscular septum. More bleeding, but may give better exposure. Control perforating vessels from profunda femoris with electrocautery as encountered. **Internervous Plane:** - This approach is NOT a true internervous plane - Vastus lateralis is supplied by femoral nerve throughout its belly - The approach works by SPLITTING vastus lateralis in line with muscle fibers - This is an INTRAmuscular plane, not INTERnervous - Safe because splitting in fiber direction minimizes denervation **Comparison to Other Hip Approaches:** - Posterior approach: Gluteus maximus (inf. gluteal) vs gluteus medius (sup. gluteal) - true internervous superficially - Anterior approach: Sartorius (femoral) vs TFL (sup. gluteal) - true internervous - Anterolateral (Watson-Jones): TFL vs gluteus medius - NOT internervous (both sup. gluteal) - Lateral (Hardinge): Splits gluteus medius - NOT internervous - Direct lateral (DHS): Splits vastus lateralis - NOT internervous (all femoral) **Standard Imaging:** - AP pelvis - shows both hips for comparison, measures neck-shaft angle - Lateral hip (cross-table or shoot-through) - essential for assessing posterior comminution - Traction view if fracture severely displaced (reduces fracture, better pattern assessment) **Advanced Imaging (When Indicated):** - CT scan if: - Complex pattern or concern for lateral wall integrity - Occult femoral neck fracture suspected (5% have concomitant intracapsular fracture) - Pathological fracture requiring assessment of bone stock - MRI rarely indicated in elderly trauma **AO/OTA 31-A Classification:** - **31-A1**: Simple pertrochanteric (2 fragments) - A1.1: Along intertrochanteric line - IDEAL for DHS - A1.2: Through greater trochanter - A1.3: Below lesser trochanter - **31-A2**: Multifragmentary pertrochanteric (>2 fragments) - A2.1: One intermediate fragment - DHS suitable if lateral wall intact - A2.2: Several intermediate fragments - NAIL preferred - A2.3: Extending more than 1cm below lesser trochanter - NAIL preferred - **31-A3**: Intertrochanteric/reverse obliquity - A3.1: Simple oblique - NAIL MANDATORY - A3.2: Simple transverse - NAIL MANDATORY - A3.3: Wedge or comminuted - NAIL MANDATORY **Palm Criteria (Palm et al. JBJS 2007):** - Measure lateral wall thickness on AP radiograph - Distance from lateral cortex to level where lag screw will sit - **>20mm = Intact lateral wall** → DHS appropriate - **<20mm = Deficient lateral wall** → High failure risk, NAIL preferred **Why Lateral Wall Matters:** - DHS barrel plate sits on lateral cortex - If lateral wall fractures during surgery → implant loses buttress - Lateral wall fracture converts stable to unstable pattern - Failure rate increases from 5% to 40% with lateral wall fracture **Plate Angle Selection:** - 135° angle (standard): Most common, suits most patients - 150° angle: For high neck-shaft angle (>135°), or coxa valga - Match angle guide to plate angle selected **Plate Length:** - 4-hole barrel plate: Standard for most fractures - 6-hole or longer: Consider for osteoporosis, subtrochanteric extension, comminution **Lag Screw Length:** - Typically 85-105mm in adults - Measure intraoperatively to confirm (should end 5-10mm from subchondral bone) - Select based on guide wire measurement minus 5-10mm **Procedure-Specific Risks:** - Cut-out (5-15%): Lag screw migration through femoral head - most common mechanical complication - Non-union (<5%): Higher with varus malalignment, poor medial cortex contact - Malunion: Varus, shortening, rotational deformity - AVN (<2% in extracapsular fractures - rare because blood supply preserved) - Infection (1-3%): Superficial or deep - DVT/PE (10-20% without prophylaxis, <5% with prophylaxis) - Need for revision surgery (5-10%) **General Risks:** - Bleeding requiring transfusion (20-30%) - elderly patients often anemic at baseline - Medical complications (cardiac 5%, respiratory 5%, renal 3%, delirium 10-30%) - Mortality: 30-day 5-10%, 1-year 20-30% in elderly with hip fracture **Functional Outcome:** - Most patients mobilise weight-bearing as tolerated (WBAT) - 50% return to pre-injury function at 1 year - 30% remain below baseline function at 1 year - Many require ongoing mobility aids (frame, stick) ### Step 1: Anaesthesia and Patient Positioning Patient under general or spinal anaesthesia on fracture table. Affected leg in traction boot with longitudinal traction applied. Internal rotation 10-15 degrees to correct typical external rotation deformity of distal fragment. Perineal post well-padded and positioned lateral to genitals. Contralateral leg abducted in hemilithotomy or extended. Confirm C-arm can obtain clear AP and lateral views BEFORE draping. **Technical Tip**: EXAM KEY: 'I position the patient supine on a fracture table. Longitudinal traction corrects shortening. Internal rotation 10-15° corrects the external rotation deformity typical of intertrochanteric fractures. The perineal post is well-padded and positioned LATERAL to the genitals to prevent pudendal nerve compression. I CONFIRM imaging views before prepping.' - Perineal post too medial → pudendal nerve compression (numbness, impotence) - Excessive traction → sciatic nerve stretch, compartment syndrome - Lateral pelvic tilt → difficulty obtaining true AP/lateral views - Inadequate C-arm access → suboptimal imaging during fixation ### Step 2: Closed Reduction Apply gentle longitudinal traction and internal rotation. Check reduction on AP and lateral C-arm views. **ACCEPTABLE REDUCTION CRITERIA:** - Anatomic or slight valgus alignment (5-10°) - valgus preferred over varus - Restoration of medial cortical continuity (CRITICAL for DHS biomechanics) - No posterior sag on lateral view (common pitfall) - Normal or slightly increased neck-shaft angle (125-135°) - Rotation corrected (patella facing ceiling) If closed reduction inadequate, use Schanz pin joystick in greater trochanter to manipulate proximal fragment. DO NOT proceed until reduction acceptable. **Technical Tip**: EXAM KEY: 'I accept ANATOMIC or SLIGHT VALGUS alignment (5-10°) with restoration of medial cortical support - this is CRITICAL as DHS is a LOAD-BEARING device. The medial cortex must be in contact to share load with the implant. VARUS malalignment is NEVER acceptable as it predicts biomechanical failure. I verify NO posterior sag on lateral view.' - VARUS malalignment is NEVER acceptable - causes DHS failure in 40% vs 5% - Persistent posterior sag on lateral → leads to apex posterior deformity - Over-distraction → prevents fracture impaction and healing - Loss of medial cortical contact → removes weight-bearing buttress - Malrotation → affects hip ROM and gait postoperatively ### Step 3: Skin Incision and Superficial Dissection Palpate greater trochanter. Make longitudinal incision 8-12cm, starting just distal to GT, extending distally along lateral femoral shaft. Incise skin and subcutaneous tissue to fascia lata. Identify and incise fascia lata (iliotibial band) in line with skin incision. Retract edges with self-retaining retractor to expose vastus lateralis muscle. **Technical Tip**: EXAM KEY: 'Direct lateral approach with 8-12cm incision starting just BELOW the greater trochanter tip, extending distally. I incise through fascia lata (iliotibial band) to expose vastus lateralis. Incision length adjusted for body habitus - longer in obese patients.' - Incision too proximal → enters gluteus medius (abductor weakness) - Incision too anterior → lateral femoral cutaneous nerve injury - Inadequate length → poor exposure, instrument crowding, errors ### Step 4: Deep Dissection and Femoral Exposure Two options for vastus lateralis management: 1. **SPLIT** along muscle fibres (preferred - less bleeding) 2. **ELEVATE** anteriorly off lateral intermuscular septum Expose lateral femoral cortex for plate length required (minimum 8-10cm). Identify and coagulate perforating vessels from profunda femoris as encountered. Clear periosteum ONLY where plate will sit - minimize periosteal stripping. **Technical Tip**: EXAM KEY: 'I prefer to SPLIT vastus lateralis in line with its muscle fibers - this minimizes bleeding and preserves motor function. I expose the lateral femoral cortex for the planned plate length. Perforating vessels from profunda femoris traverse the muscle - I control these with electrocautery before they bleed.' - Perforating vessels cause significant bleeding if not controlled proactively - Excessive periosteal stripping devascularises bone → delayed union - Posterior dissection risks profunda femoris artery - Sharp posterior retractor placement → sciatic nerve injury ### Step 5: Guide Wire Insertion and Positioning Attach angle guide (135° standard) to lateral femoral cortex at level of lesser trochanter. Entry point: junction of proximal and middle thirds of femur, at or just above lesser trochanter level. Advance guide wire under fluoroscopy toward femoral head centre. **TARGET POSITION (CRITICAL):** - Centre-centre position in femoral head on AP view - Centre-centre OR inferior-centre on lateral view - NEVER superior position - increases cut-out 3-4 fold Advance wire to within 5-10mm of subchondral bone. Calculate Tip-Apex Distance (TAD) at this point. **Technical Tip**: EXAM KEY: 'I insert the guide wire through a 135° angle guide, aiming for CENTRE-CENTRE position in the femoral head on BOTH AP AND lateral views. INFERIOR-CENTRE on lateral is also acceptable. SUPERIOR position is NEVER acceptable as it increases cut-out risk 3-4 fold. Baumgaertner's classic paper showed TAD predicts failure - I calculate TAD at guide wire insertion and adjust before proceeding.' - Superior placement → cut-out risk increases 3-4 fold - NEVER acceptable - Posterior placement → posterior perforation, AVN if damages MFCA - Wire too long → joint penetration - Wire too short → inadequate lag screw depth, poor purchase - Wrong angle → varus stem, malposition ### Step 6: Tip-Apex Distance Calculation Calculate TAD to confirm acceptable wire position: 1. Measure tip-to-apex distance on AP view (in mm) 2. Measure tip-to-apex distance on lateral view (in mm) 3. Correct for magnification using known wire/screw diameter 4. Sum both measurements: TAD = AP distance + Lateral distance **TARGET: TAD <25mm** - TAD <25mm: Cut-out risk 2-5% - TAD 25-30mm: Cut-out risk increases - TAD >30mm: Cut-out risk 6-fold higher (30%+) If TAD >25mm, REPOSITION guide wire before proceeding. **Technical Tip**: EXAM KEY: 'Baumgaertner's Tip-Apex Distance is the SINGLE MOST IMPORTANT predictor of DHS success. I calculate TAD by summing the tip-to-apex distance on AP plus lateral views, correcting for magnification. TAD MUST be less than 25mm. If above 25mm, I REPOSITION the guide wire - do NOT accept suboptimal position.' - TAD >25mm is UNACCEPTABLE - reposition wire, do not proceed - Magnification error → calculate using known screw diameter as reference - Measuring to head apex, NOT to subchondral bone edge - TAD >30mm → cut-out risk 6-fold higher ### Step 7: Triple Reaming Perform triple reaming over guide wire to measured depth (5-10mm short of subchondral bone). Triple reaming creates a smooth, three-part channel: - Outer diameter for barrel plate seating - Middle diameter for lag screw threads - Inner diameter for lag screw core This allows: - Easy lag screw insertion without resistance - Lag screw SLIDING for dynamic compression as fracture settles Irrigate during reaming to prevent thermal necrosis. Confirm depth with gauge. **Technical Tip**: EXAM KEY: 'Triple reaming is ESSENTIAL for DHS function. The three-diameter channel allows the lag screw to SLIDE within the barrel, enabling dynamic compression as the patient bears weight and the fracture impacts. This is the "dynamic" in Dynamic Hip Screw. Without proper reaming, the screw cannot slide and static load leads to failure.' - Reaming too deep → subchondral perforation, joint penetration - Reaming too shallow → lag screw threads proud, cannot slide - Thermal necrosis (no irrigation) → bone death, loosening - Eccentric reaming → screw malposition ### Step 8: Lag Screw Insertion Select lag screw length based on measurement (typically 85-100mm). Insert over guide wire through reamed channel. Advance to within 5-10mm of subchondral bone - check with fluoroscopy. **CONFIRM FINAL POSITION:** - Centre-centre or inferior-centre on AP view - Centre-centre or inferior-centre on lateral view - Calculate and DOCUMENT final TAD - MUST be <25mm - Screw threads fully within femoral head **Technical Tip**: EXAM KEY: 'I insert the lag screw to within 5-10mm of subchondral bone with optimal position being CENTRE-CENTRE on both views, or INFERIOR-CENTRE on lateral. I calculate and DOCUMENT Tip-Apex Distance which MUST be less than 25mm - this is recorded in the operative note for medicolegal protection. TAD >25mm is unacceptable and requires repositioning BEFORE plate application.' - Joint penetration → catastrophic articular damage, requires removal - TAD >25mm → cut-out risk unacceptable - REPOSITION before plate - Superior placement → cut-out 3-4x more likely - Screw too short → inadequate purchase, pullout ### Step 9: Barrel Plate Application Slide barrel plate over lag screw. CRITICAL: Seat plate FLUSH against lateral femoral cortex - plate must NOT be proud. Ensure plate aligned with femoral shaft axis without flexion/extension or rotation. Apply provisional fixation with one distal cortical screw. **PLATE SEATING CHECK:** - No gap between plate and cortex - Plate parallel to femoral shaft - No rotation of plate - Barrel fully engaged on lag screw **Technical Tip**: EXAM KEY: 'The barrel plate MUST seat FLUSH on the lateral femoral cortex. If the plate is proud (not seated), the lag screw cannot slide within the barrel - losing the "dynamic" function. I apply provisional fixation with ONE screw first, then check position on fluoroscopy before definitive fixation.' - Plate proud → lag screw cannot slide, static loading → failure - Plate malrotated → screw angulation, impingement - Plate too proximal → screws in fracture zone - Plate too distal → inadequate proximal fragment fixation ### Step 10: Cortical Screw Fixation Insert cortical screws through remaining plate holes achieving BICORTICAL purchase. Minimum 4 cortices of fixation distally (2 screws × 2 cortices). Consider anti-rotation screw in proximal hole above barrel for added rotational stability of femoral head. Confirm ALL screws bicortical on fluoroscopy. **SCREW PLACEMENT GOALS:** - Bicortical purchase (30-44mm screws typical) - Perpendicular to plate and cortex - All screw tips visible on lateral view - No screws in fracture zone **Technical Tip**: EXAM KEY: 'I achieve BICORTICAL purchase with all cortical screws - this provides maximum pullout resistance. In osteoporotic bone, I may use longer screws to engage far cortex firmly. I avoid placing screws in the fracture zone. An anti-rotation screw superiorly can improve rotational control of the femoral head fragment.' - Unicortical screws → inadequate fixation, plate pullout - Screws in fracture zone → interferes with healing, stress riser - Screws too long → soft tissue impingement, vessel injury - Stripped cortex → no purchase, consider rescue techniques ### Step 11: Compression and Final Fluoroscopic Check Remove guide wire from lag screw. Apply compression through barrel plate compression screw mechanism to engage dynamic lag effect. Release traction gradually and observe for stability. **COMPREHENSIVE FINAL CHECK:** 1. Reduction maintained (valgus acceptable, medial cortex intact) 2. Lag screw centre-centre or inferior-centre on BOTH views 3. TAD <25mm DOCUMENTED in operative note 4. Screw 5-10mm from subchondral bone, NO joint penetration 5. Plate FLUSH on lateral cortex 6. ALL screws bicortical 7. Rotation and length correct (compare to contralateral leg) 8. Compression applied - fracture impacted **Technical Tip**: EXAM KEY: 'My final check includes: 1) Reduction maintained - valgus acceptable, medial cortex contact. 2) Lag screw position centre-centre or inferior-centre on BOTH views. 3) TAD documented and less than 25mm. 4) No joint penetration. 5) Plate flush. 6) All screws bicortical. 7) Rotation and length satisfactory. 8) Fracture compressed. I document TAD in the operative note for medicolegal purposes.' - TAD >25mm requires repositioning - do NOT accept - Joint penetration requires screw exchange - Unrecognised malrotation causes functional impairment - Persistent varus predicts failure - consider conversion to nail - Loss of reduction at traction release → fixation inadequate ### Step 12: Wound Closure and Post-operative Management Copious irrigation with saline. Meticulous haemostasis with electrocautery. Consider drain for high-risk patients (anticoagulation, large haematoma anticipated). Repair vastus lateralis muscle if elevated. Close fascia lata with strong absorbable suture (0 or 1 Vicryl) - provides soft tissue coverage of implant. Subcutaneous closure with 2-0 absorbable. Skin with staples or subcuticular suture. Sterile dressing. **Technical Tip**: EXAM KEY: 'I irrigate copiously, achieve haemostasis, and close fascia lata carefully - this layer provides important soft tissue coverage over the implant. I document blood loss and neurovascular status at closure. Post-operatively, I mobilise WBAT from Day 1 for stable fixation - early mobilisation reduces medical complications and mortality in elderly hip fracture patients.' - Inadequate haemostasis → haematoma → infection risk - Poor fascial closure → implant exposure, wound complications - Missed neurovascular injury → delay in management **Avascular Necrosis (<2% for extracapsular fractures):** - Rare in intertrochanteric fractures because blood supply preserved - Medial femoral circumflex artery runs along posterior neck - protected by leaving quadratus femoris intact - May occur if lag screw damages MFCA or with posterior perforation - Management: If symptomatic, consider arthroplasty **Nerve Injury (<1%):** - Sciatic nerve: Posterior retractor placement, excessive traction - Superior gluteal nerve: Proximal dissection above GT - Pudendal nerve: Perineal post malposition - Prevention: Careful retractor placement, padded post lateral to genitals, limit traction - Management: Document, EMG at 3 weeks, observation (most neuropraxia recover) **Heterotopic Ossification (5-10% radiographic, 1-2% symptomatic):** - Less common than in THA - Risk factors: Head injury, burns, prolonged immobilisation - Prevention: Not routine - consider indomethacin if high risk - Management: Observation if asymptomatic, excision if severe restriction **Hip Fracture Epidemiology:** - 26,000+ hip fractures annually in Australia - 50% intertrochanteric, 45% intracapsular, 5% subtrochanteric - Mean age: 84 years for women, 80 years for men - Female:Male ratio 3:1 **Implant Selection Trends:** - Intertrochanteric fractures: 48% DHS, 52% cephalomedullary nail - Trend toward increasing nail use for all patterns - DHS use declining but remains appropriate for stable patterns **Timing of Surgery:** - ANZHFR target: Surgery within 48 hours for 80% of patients - Current performance: 72% achieve this target - Delay beyond 48 hours associated with 10% increased mortality per day **30-Day Outcomes:** - Mortality: 7-10% - Medical complications: Cardiac 5%, Pneumonia 6%, UTI 10%, Delirium 25% - Return to theatre: 2-3% **1-Year Outcomes:** - Mortality: 20-30% (highest in first 3 months) - Residential care admission: 25% (previously community-dwelling) - Return to pre-injury function: 50% - Mobility aids required: 70% **Tip-Apex Distance (Baumgaertner et al. JBJS 1995):** - Landmark paper defining TAD - Cut-out rate: 2% if TAD <25mm vs 16% if TAD >25mm - Superior screw position increased cut-out 3-4 fold - MUST KNOW for exam - cite this paper **Lateral Wall Importance (Palm et al. JBJS 2007):** - Lateral wall thickness <20mm → failure rate 40% - Lateral wall thickness >20mm → failure rate 5% - Pre-operative CT can assess wall integrity - Lateral wall fracture converts stable to unstable pattern **DHS vs Nail for Stable Fractures (Cochrane Review 2010, updated 2017):** - No significant difference in outcomes for stable A1/A2.1 fractures - Similar mortality, function, reoperation rates - DHS slightly shorter operative time and less blood loss - Nail has theoretical advantage of load-sharing but not borne out in stable fractures **DHS vs Nail for Unstable Fractures (Multiple RCTs):** - Nail superior for A2.3 and A3 patterns - Lower failure rate with nail for unstable fractures - Parker 2012, Reindl 2015, Zhang 2017 meta-analyses support nail for unstable patterns **Early Surgery (Moran et al. JBJS 2005):** - Delay beyond 48 hours increases mortality 10% per day - Complications increase with delay - Surgery within 36 hours optimal if medically cleared - Supports current ANZHFR 48-hour target **Orthogeriatric Co-management (Grigoryan et al. BMC Geriatr 2014):** - Orthogeriatric care reduces mortality 20-30% - Reduces length of stay - Reduces complications (delirium, pressure injuries, infections) - Cost-effective intervention - standard of care in Australia **VTE Prophylaxis (NHMRC Guidelines):** - LMWH (enoxaparin 40mg daily) or DOAC (rivaroxaban 10mg daily) for 35 days - Start 6-12 hours postoperatively (balance bleeding vs VTE risk) - Mechanical prophylaxis: TED stockings, foot pumps, early mobilisation - High-risk (previous VTE): Extended prophylaxis, consider IVC filter **Antibiotic Prophylaxis (eTG - Therapeutic Guidelines):** - Cefazolin 2g IV within 60 minutes of incision - 4g if >120kg body weight - Penicillin allergy: Vancomycin 15-20mg/kg IV (max 2g) - Single dose sufficient - no benefit to extended prophylaxis **Medicare MBS Item Numbers:** - 47528: Internal fixation of intertrochanteric fracture - $1,247.55 - Includes DHS, cephalomedullary nail, or other fixation devices **ANZHFR Quality Standards:** - Surgery within 48 hours (target 80%) - Orthogeriatric care (target 100%) - Pressure injury prevention - Delirium screening and prevention - Falls prevention and bone health assessment **Fracture Table Setup:** - Radiolucent fracture table (Maquet, Hana, or similar) - Boot traction attachment for affected limb - Well-padded perineal post (lateral to genitals to avoid pudendal nerve) - Unaffected leg in hemilithotomy or extended and abducted **C-arm Positioning:** - C-arm enters from contralateral side, between patient's legs - Must obtain clear AP and lateral views of hip and proximal femur - Confirm imaging BEFORE prepping patient **Instrumentation:** - DHS instrument set with guide wire, triple reamer, tap - 135° and 150° angle guide/jig - Lag screws (85-105mm range) - 4-hole barrel plate (135° or 150°) - Cortical screws (32-44mm typical) - Depth gauge, calibrated measuring device **Reduction Aids:** - Schanz pin for joystick manipulation if needed - Bone hooks, ball spike pusher - Traction table controls for length and rotation ### Step 1: Anaesthesia and Positioning Patient under general or spinal anaesthesia on fracture table. Affected leg in traction boot with longitudinal traction applied. Internal rotation 10-15 degrees to correct typical external rotation deformity of distal fragment. Perineal post well-padded and positioned lateral to genitals. Contralateral leg abducted in hemilithotomy or extended. Confirm C-arm can obtain clear AP and lateral views. **Exam Key**: "I use a fracture table with the patient supine. Longitudinal traction corrects shortening, and internal rotation 10-15 degrees corrects the external rotation deformity of the distal fragment. The perineal post is well-padded and positioned lateral to the genitals to prevent pudendal nerve compression." ### Step 2: Closed Reduction Apply gentle longitudinal traction and internal rotation. Check reduction on AP and lateral C-arm views. **ACCEPTABLE REDUCTION CRITERIA:** - Anatomic or slight valgus alignment (5-10 degrees) - Restoration of medial cortical continuity (CRITICAL for DHS) - No posterior sag on lateral view - Normal or slightly increased neck-shaft angle (125-135 degrees) If closed reduction inadequate, use Schanz pin joystick in greater trochanter to manipulate proximal fragment. Accept reduction before proceeding. **Exam Key**: "I accept anatomic or slight valgus alignment with restoration of medial cortical support - this is CRITICAL as DHS is a load-bearing device. Varus malalignment is biomechanically doomed to failure. I verify no posterior sag on lateral view." - Varus malalignment is NEVER acceptable - causes DHS failure - Persistent posterior sag leads to apex posterior deformity - Over-distraction prevents impaction and healing - Loss of medial cortical contact removes weight-bearing support ### Step 3: Incision and Superficial Dissection Palpate greater trochanter. Make longitudinal incision 8-12cm centred just distal to GT, extending along lateral femoral shaft. Incise skin and subcutaneous tissue. Identify and incise fascia lata (iliotibial band) in line with skin incision. Retract to expose vastus lateralis muscle. **Exam Key**: "Direct lateral approach with 8-12cm incision starting just below the greater trochanter tip extending distally. I incise through fascia lata to expose vastus lateralis." ### Step 4: Deep Dissection Two options for vastus lateralis: 1. **Split** along muscle fibres (less bleeding) 2. **Elevate** anteriorly off lateral intermuscular septum Expose lateral femoral cortex for plate length required. Identify and coagulate perforating vessels from profunda femoris as encountered. Clear periosteum only where plate will sit. - Perforating vessels cause significant bleeding if not controlled - Excessive periosteal stripping devascularises bone - Posterior dissection risks profunda femoris vessels ### Step 5: Guide Wire Insertion Attach angle guide (135° standard) to lateral femoral cortex at level of lesser trochanter. Entry point: junction of proximal and middle thirds of femur, at or just above lesser trochanter level. Advance guide wire under fluoroscopy toward femoral head. **TARGET POSITION:** - Centre-centre OR inferior-centre on BOTH AP and lateral views - NEVER superior - increases cut-out 3-4 fold Advance wire to within 5-10mm of subchondral bone. Measure and calculate Tip-Apex Distance. **Exam Key**: "I insert the guide wire through a 135-degree angle guide, aiming for centre-centre or inferior-centre position in the femoral head on BOTH AP and lateral views. Superior position is NEVER acceptable as it increases cut-out risk 3-4 fold. I calculate TAD at this point." ### Step 6: Triple Reaming Perform triple reaming over guide wire to measured depth (5-10mm short of subchondral bone). Triple reaming creates smooth channel allowing: - Easy lag screw insertion - Lag screw sliding for dynamic compression Irrigate during reaming to prevent thermal necrosis. Confirm depth with gauge. ### Step 7: Lag Screw Insertion Select lag screw length based on measurement (typically 85-100mm). Insert over guide wire through reamed channel. Advance to within 5-10mm of subchondral bone. **CONFIRM:** - Centre-centre or inferior-centre position on AP and lateral - Calculate final TAD - MUST be <25mm **Exam Key**: "I insert the lag screw to within 5-10mm of subchondral bone with optimal position being centre-centre or inferior-centre. I calculate and document Tip-Apex Distance which MUST be less than 25mm - this is the single most important predictor of DHS success. TAD greater than 25mm is unacceptable and requires repositioning." ### Step 8: Barrel Plate Application Slide barrel plate over lag screw. Seat plate **FLUSH** against lateral femoral cortex - must not be proud. Ensure plate aligned with femoral shaft axis without flexion/extension or rotation. Apply provisional fixation with one distal cortical screw. ### Step 9: Screw Fixation Insert cortical screws through remaining plate holes achieving **bicortical purchase**. Minimum 4 cortices of fixation distally (2 screws x 2 cortices). Consider anti-rotation screw in proximal hole above barrel for added rotational stability. Confirm all screws bicortical on fluoroscopy. ### Step 10: Compression and Final Check Remove guide wire. Apply compression through barrel plate mechanism to engage dynamic lag effect. **COMPREHENSIVE FINAL CHECK:** 1. Reduction maintained (valgus acceptable, medial cortex intact) 2. Lag screw centre-centre or inferior-centre 3. TAD <25mm documented 4. Screw 5-10mm from subchondral bone, no joint penetration 5. Plate flush on lateral cortex 6. All screws bicortical 7. Rotation and length correct (compare to contralateral) Release traction gradually and observe for stability. - TAD >25mm requires repositioning - do NOT accept - Joint penetration requires screw exchange - Unrecognised malrotation causes functional impairment - Persistent varus predicts failure ### Step 11: Closure Copious irrigation with saline. Meticulous haemostasis. Consider drain for high-risk patients (anticoagulation, large haematoma). Repair vastus lateralis. Close fascia lata with strong absorbable suture (0 or 1 Vicryl) - provides soft tissue coverage of implant. Subcutaneous closure with 2-0 absorbable. Skin with staples or subcuticular suture. Sterile dressing. **Immediate Post-operative:** - DVT prophylaxis: LMWH or NOAC (Australian standard: enoxaparin 40mg daily or rivaroxaban 10mg daily for 14-35 days) - Tranexamic acid reduces transfusion requirement - Orthogeriatric co-management for medical optimisation **Mobilisation Protocol:** - Weight-bearing as tolerated (WBAT) from Day 1 for stable fixation - Sit out of bed Day 0-1 - Stand with frame Day 1 - Physiotherapy for gait training, transfers, ROM **Follow-up:** - Radiographs at 2 weeks, 6 weeks, 12 weeks - Monitor for cut-out (typically occurs within first 3 months) - Fracture union expected 8-12 weeks **Hardware Removal:** - Not routinely required - Consider if symptomatic (lateral thigh pain, trochanteric bursitis) 1. Baumgaertner MR, Curtin SL, Lindskog DM, Keggi JM. The value of the tip-apex distance in predicting failure of fixation of peritrochanteric fractures of the hip. *J Bone Joint Surg Am*. 1995;77(7):1058-1064. 2. Palm H, Jacobsen S, Sonne-Holm S, Gebuhr P. Integrity of the lateral femoral wall in intertrochanteric hip fractures: an important predictor of reoperation. *J Bone Joint Surg Am*. 2007;89(3):470-475. 3. Parker MJ, Handoll HH. Gamma and other cephalocondylic intramedullary nails versus extramedullary implants for extracapsular hip fractures in adults. *Cochrane Database Syst Rev*. 2010;(9):CD000093. 4. Anglen JO, Weinstein JN. Nail or plate fixation of intertrochanteric hip fractures: changing pattern of practice. A review of the American Board of Orthopaedic Surgery database. *J Bone Joint Surg Am*. 2008;90(4):700-707. 5. Australian and New Zealand Hip Fracture Registry (ANZHFR). Annual Report 2023. Hip fracture care in Australia and New Zealand. 6. NICE Guideline NG124. Hip fracture: management. National Institute for Health and Care Excellence. 2017 (updated 2023). 7. Moran CG, Wenn RT, Sikand M, Taylor AM. Early mortality after hip fracture: is delay before surgery important? *J Bone Joint Surg Am*. 2005;87(3):483-489. 8. Kanis JA, Johnell O, Oden A, et al. The risk and burden of vertebral fractures in Sweden. *Osteoporos Int*. 2004;15(1):20-26. 9. Simmermacher RK, Ljungqvist J, Bail H, et al. The new proximal femoral nail antirotation (PFNA) in daily practice: results of a multicentre clinical study. *Injury*. 2008;39(8):932-939. 10. Griffin XL, Parsons N, Achten J, et al. Recovery of health-related quality of life in a United Kingdom hip fracture population. *Bone Joint J*. 2015;97-B(3):372-382.

Dynamic Hip Screw (DHS) for Intertrochanteric Fracture

Dynamic Hip Screw (DHS) for Intertrochanteric Fracture