import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: 2-5mm posterior to medial epicondyle in cubital tunnel, 3-4mm deep to subcutaneous tissue **Protection**: For medial pin insertion - extend elbow 45-60° (moves nerve posteriorly), mini-open 1cm incision preferred, palpate/visualize nerve, insert pin anterior to nerve under direct vision. Lateral-entry only technique avoids this risk entirely. **Injury Risk**: 2-4% iatrogenic injury with percutaneous medial pin, less than 1% with mini-open visualization, 0% with lateral-entry only technique **Location**: Branch of median nerve passing deep to pronator teres 4-6cm distal to medial epicondyle, courses on interosseous membrane between FPL and FDP **Protection**: No direct surgical risk (injured at presentation from stretching over fracture spike). Check preoperatively: OK sign (FPL), FDP index flexion, pronator quadratus function. Document carefully for medicolegal purposes. **Injury Risk**: 10-20% at presentation (most common nerve injury), usually neurapraxia recovering spontaneously in 3-6 months, pure motor deficit (no sensory loss) **Location**: Crosses antecubital fossa 10-15mm anterior to distal humerus, tethered proximally by lacertus fibrosus and distally by deep head of pronator teres **Protection**: Gentle reduction technique (avoid multiple attempts), assess pulse pre- and post-reduction, backslab elbow flexion less than 90° (70-80°) to avoid kinking artery at fracture site, especially with residual swelling. **Injury Risk**: Kinked or compressed (pink pulseless) in 10-15% Gartland III (observe if pink hand), rarely lacerated less than 2% (requires exploration if white/pulseless) **Location**: Runs medial to brachial artery 8-12mm anterior to distal humerus in antecubital fossa, proximal fragment can impale nerve with anterior displacement **Protection**: Check preoperatively: thumb-index pinch strength, thenar muscle bulk/strength, sensation radial 3.5 fingers. Gentle reduction technique. Document pre/post-reduction status. **Injury Risk**: 3-5% at presentation from direct injury by anterior displacement of proximal fragment, usually recovers with reduction **Location**: Posterior interosseous nerve branch passes around radial neck 15-20mm anterior to lateral epicondyle, superficial radial nerve courses anterolateral to elbow **Protection**: Entry point for lateral pins should be on lateral epicondyle or posterior to avoid nerve (15-20mm anterior is danger zone). Check preoperatively: wrist/thumb extension, first webspace sensation. **Injury Risk**: 3-5% at presentation (usually radial nerve), less than 1% iatrogenic with lateral pins if entry point chosen correctly ## Gartland Classification System **Type I - Nondisplaced** - Anterior humeral line intersects capitellum on lateral radiograph - No angulation or rotation - Posterior fat pad sign may be only finding - Treatment: Above-elbow backslab, elbow 90° flexion - Outcome: Excellent, remodels completely **Type IIA - Angulated, Posterior Cortex Intact** - Anterior humeral line passes anterior to capitellum - Extension angulation present - Posterior cortex intact (serves as hinge) - No rotation (medial/lateral columns aligned) - Baumann angle maintained within 5° of contralateral - Treatment: May attempt closed reduction and casting (controversial), many surgeons pin for reliability **Type IIB - Angulated and Rotated** - Angulation in extension (anterior humeral line anterior to capitellum) - Rotation present (medial or lateral column malalignment) - Posterior cortex may appear intact on one view but disrupted on other - Loss of Baumann angle (varus or valgus tilt) - Treatment: CRPP mandatory - unstable fracture **Type III - Completely Displaced** - No cortical contact between fragments - Periosteal hinge may be intact (usually posterior) or completely disrupted - High neurovascular injury risk (15-20% nerve injury, 10-15% vascular) - Treatment: Urgent CRPP within 6-8 hours - Compartment syndrome risk: 0.5-1% **Critical Distinction**: Type IIA versus IIB - examiners focus here. IIA has angulation but NO rotation and intact posterior cortex on BOTH views. IIB has rotation (medial/lateral column malalignment) making it unstable despite appearing aligned on single view. IIB always requires surgery. ## Neurovascular Examination Protocol **Document Pre-Reduction (Medicolegal Essential)** **Anterior Interosseous Nerve (AIN)** - Most common (10-20%) - Motor: FPL weak (thumb IP flexion) - OK sign lost - Motor: FDP index weak (index DIP flexion) - unable to flex DIP in isolation - Motor: Pronator quadratus weak (resisted pronation with elbow flexed) - Sensory: NONE (pure motor nerve) - Mechanism: Stretching over anterior spike of proximal fragment - Prognosis: 90% recovery over 3-6 months (neurapraxia) **Median Nerve** - 3-5% at presentation - Motor: Thumb-index pinch weakness, thenar muscle atrophy (chronic) - Motor: FPL, FDP index/middle (overlap with AIN) - Sensory: Radial 3.5 fingers, thenar eminence - Mechanism: Direct injury from anterior displacement of proximal fragment - Prognosis: Usually recovers with reduction **Radial Nerve** - 3-5% at presentation - Motor: Wrist extension weak (wrist drop), thumb extension weak - Motor: Finger MCP extension weak - Sensory: First webspace (superficial radial nerve) - Mechanism: Traction or direct injury - Prognosis: Usually recovers **Ulnar Nerve** - 1% at presentation, 2-4% iatrogenic with medial pin - Motor: Finger abduction weak (interossei), Froment sign - Motor: Small finger abduction weak (ADM) - Sensory: Small finger ulnar half, ring finger ulnar half - Mechanism: Iatrogenic injury with medial pin insertion - Prognosis: Usually neurapraxia, recovers 3-6 months **Vascular Assessment** - Radial pulse: Present, diminished, or absent - Capillary refill: Normal less than 2 seconds - Hand color: Pink versus white/pale - Hand temperature: Warm versus cool/cold - Pink pulseless hand (10-15%): Brachial artery kinked, adequate collaterals (radial/ulnar), safe to observe after reduction - White/pulseless hand: Brachial artery lacerated or severely compressed, requires urgent exploration if persists post-reduction 90% of pink pulseless hands develop adequate collaterals and do not require exploration. After reduction, if hand remains pink and warm with good capillary refill, observe closely. If hand becomes white, cold, or compartment syndrome develops, urgent exploration and possible fasciotomy required. Document pulse status meticulously pre- and post-reduction. ## Radiographic Assessment Criteria **Lateral View - Anterior Humeral Line** - Draw line along anterior cortex of humerus extending distally - Normal: Bisects middle third of capitellum - Abnormal: Passes through anterior third or entirely anterior to capitellum (extension deformity) - Post-reduction: MUST bisect middle third (essential quality indicator) **AP View - Baumann Angle** - Angle between long axis of humerus shaft and line through capitellum physis - Normal: 70-75° (range 64-81°) - Compare to contralateral side (within 5° acceptable) - Less than 65°: Varus malreduction (medial tilt) - Greater than 80°: Valgus malreduction (lateral tilt) - Baumann angle less than 64° correlates with cubitus varus deformity **AP View - Medial and Lateral Columns** - Medial column: Medial metaphyseal cortex should align with medial epicondyle - Lateral column: Lateral metaphyseal cortex should align with capitellum - Disruption indicates rotation (IIB or III fracture) **Gordon Line (AP View)** - Line along anterior cortex of distal humerus - Should point toward capitellum ossification center - Disruption indicates rotation ## Closed Reduction Sequence (Step-by-Step) ### Step 1: Longitudinal Traction (2-3 minutes) **Technique** - Elbow extended initially - Surgeon applies gentle steady traction at forearm/wrist - Assistant provides counter-traction at upper arm (proximally) - Maintain traction for 2-3 minutes (allows muscle relaxation) **Purpose** - Disimpacts fracture fragments - Corrects shortening - Unlocks fragment overlap **Key Points** - Gentle traction (avoid excessive force - myositis ossificans risk) - Muscle relaxation essential (inadequate anesthesia prevents reduction) - Extension initially unlocks fragments (flexion locks them before reduction) ### Step 2: Coronal Plane Correction (Varus/Valgus) **Technique for Varus Deformity (Most Common)** - Apply valgus stress to elbow - Direct pressure with thumb on lateral condyle pushing medially - Index finger stabilizes medial epicondyle - "Milking maneuver" - massage lateral fragment medially **Purpose** - Corrects medial tilt (varus angulation) - Restores Baumann angle - Aligns medial and lateral columns **Fluoroscopy Check** - AP view: Medial/lateral columns should align - Baumann angle approaching 70-75° ### Step 3: Sagittal Plane Correction (Extension Deformity) **Technique** - Flex elbow to 90° while maintaining traction and coronal correction - Place both thumbs on olecranon posteriorly - Apply direct posterior-to-anterior pressure on olecranon - Translates distal fragment anteriorly - Continue to flex elbow **Purpose** - Corrects posterior displacement (extension deformity) - Anterior humeral line repositioned to bisect capitellum **Feel/Audible "Clunk"** - Reduction often feels clunk as fragments engage - Indicates periosteal hinge engagement **Fluoroscopy Check** - Lateral view: Anterior humeral line bisects middle third capitellum ### Step 4: Hyperflexion to Lock Reduction **Technique** - Hyperflex elbow 120-140° (maximum flexion comfortable) - Posterior periosteal hinge tightens - Fracture stabilized by soft tissue tension **Vascular Check CRITICAL** - Check radial pulse with hyperflexion - If pulse disappears: reduce flexion to 90° (artery kinked) - Pink hand acceptable, white hand requires less flexion **Purpose** - Intact posterior periosteal hinge (extension injury) tightens with hyperflexion - Locks reduction preventing displacement during pinning **Mechanism**: Extension-type supracondylar fractures (98%) disrupt anterior periosteum but preserve posterior periosteum. Hyperflexion tightens this posterior hinge like closing a book, stabilizing reduction. Flexion-type fractures (2%) have opposite pattern - posterior periosteum disrupted, anterior intact, require extension to lock. ### Step 5: Final Fluoroscopic Confirmation **Acceptable Reduction Criteria** - Lateral: Anterior humeral line bisects middle third capitellum - AP: Baumann angle 70-75° (within 5° of contralateral) - AP: Medial and lateral columns aligned - No intra-articular extension **Unacceptable Reduction - Do Not Pin** - Anterior humeral line through anterior third capitellum or anterior - Baumann angle differs greater than 10° from contralateral - Medial/lateral column malalignment (rotation) - Repeat reduction attempt or consider open reduction if irreducible ## Lateral-Entry Only Technique (Preferred by Many) ### Advantages - NO ulnar nerve injury risk (safest technique) - Biomechanically adequate if 2-3 divergent pins used - Easier to perform (single approach) - Fewer skin incisions ### Disadvantages - Slightly less rotational stability than crossed pins (if only 2 pins) - Requires 3 pins for optimal stability (versus 2-3 with crossed) ### Technique **Entry Point** - Lateral epicondyle region - Avoid 15-20mm anterior (radial nerve territory) - Palpate lateral epicondyle, enter at or just posterior **First Pin** - 1.6mm smooth K-wire (1.8mm in larger children) - Aim medially and proximally - Engage medial column cortex above fracture - Confirm AP/lateral fluoroscopy **Second Pin** - Maximally divergent from first pin (greater than 30° angle) - Enter lateral epicondyle 5-10mm from first pin - Aim medially/proximally engaging medial cortex - Wide spread at fracture site (greater than 2cm) **Third Pin (Recommended)** - Further divergence - Maximizes rotational stability - Some surgeons use 2 pins if excellent divergence achieved **Fluoroscopy Confirmation** - AP: All pins cross fracture, engage medial cortex, spread at fracture greater than 2cm - Lateral: Pins anterior to posterior cortex, avoid perpendicular physis crossing - No joint penetration (tips 2-3mm from joint line) **Biomechanics**: Divergent pins provide rotational stability through triangulation. Parallel pins provide NO rotational control - loss of reduction inevitable. Minimum 30° divergence required. Three pins better than two for lateral-entry only. ## Crossed Pin Configuration (Stronger Rotational Control) ### Advantages - Superior biomechanical stability (rotational and varus/valgus) - May use only 2 pins total (1 lateral + 1 medial) - Better for highly unstable fractures (medial comminution, flexion-type) ### Disadvantages - Ulnar nerve injury risk 2-4% (percutaneous) or less than 1% (mini-open) - Technically more demanding - Requires elbow extension (changes position mid-case) ### Technique - Lateral Pin First - Insert 1-2 lateral pins as described above - Confirm reduction maintained on fluoroscopy ### Technique - Medial Pin **Elbow Extension Critical** - Extend elbow to 45-60° - Moves ulnar nerve posteriorly away from pin trajectory - NEVER insert medial pin with elbow flexed (nerve directly in path) **Mini-Open Technique (Preferred)** - 1cm incision over medial epicondyle - Dissect to bone carefully - Palpate ulnar nerve in cubital tunnel (posterior to epicondyle) - Visualize nerve or protect with small retractor - Insert 1.6mm K-wire under direct vision anterior to nerve - Aim laterally/proximally engaging lateral cortex **Percutaneous Technique (Higher Risk)** - No incision, direct pin insertion - Palpate ulnar nerve position - Insert pin anterior to nerve path (assumed) - 2-4% iatrogenic injury rate - NOT recommended by most experts **Fluoroscopy Confirmation** - AP: Medial pin crosses lateral pin at fracture site - AP: Both pins cross fracture, engage far cortices - Lateral: Pins diverge, anterior to posterior cortex ## Pin Specifications and Biomechanics **Pin Size** - 1.6mm smooth K-wires (most common) - 1.8mm for larger children (greater than 12 years) - 2.0mm rarely needed **Pin Number and Stability** - 1 pin: INADEQUATE (no rotational control) - 2 pins divergent: Adequate IF good divergence (greater than 30°) - 3 lateral pins: Equivalent or superior to crossed configuration - Lateral + medial: Strongest but ulnar nerve risk **Spread at Fracture Site** - Greater than 2cm separation critical - Increases lever arm for rotational control - Closer pins = less stability **Cortical Engagement** - All pins MUST engage far cortex (bicortical) - Unicortical purchase inadequate - Pin tips should extend 2-3mm beyond far cortex (confirmed on orthogonal views) **Avoiding Physis Injury** - Lateral condyle physis: Tangential crossing acceptable, avoid perpendicular - Trochlear physis: Stay anterior on lateral view - AVN trochlea (rare less than 1%) if pin crosses physis perpendicular ## Immobilization Protocol **Above-Elbow Posterior Backslab** - Critical elbow flexion LESS THAN 90° (optimal 70-80°) - Forearm neutral rotation (not pronated/supinated) - Well-molded to prevent rotation **Rationale for Flexion Less Than 90°** - Hyperflexion (greater than 100°) kinks brachial artery at fracture site - Especially dangerous with residual swelling - Volkmann ischemic contracture risk - Pins provide stability - hyperflexion not needed **Collar and Cuff** - Added for comfort - Elevation reduces swelling - Remove for neurovascular checks **Duration** - Backslab for 3-4 weeks until pin removal - May convert to removable brace at 2 weeks if minimal swelling ## Neurovascular Monitoring (First 24-48 Hours) **Hourly Checks (First 12 Hours)** - Radial pulse - Capillary refill (less than 2 seconds normal) - Hand color (pink versus white) - Hand temperature (warm versus cool) - Pain assessment (severe progressive pain = compartment syndrome) **Nerve Function (Every 2-4 Hours)** - AIN: OK sign, FDP index flexion - Median: Thumb-index pinch, thenar sensation - Radial: Wrist/thumb extension, first webspace sensation - Ulnar: Finger abduction, small finger sensation **Compartment Syndrome Signs (Urgent Re-Exploration)** - Progressive severe pain out of proportion - Pain with passive finger extension (earliest reliable sign) - Tense forearm compartments (anterior and/or posterior) - Progressive nerve deficits - Loss of pulses (late sign) **White/Pulseless Hand Management** - If persists after reduction: Urgent exploration - Brachial artery laceration or entrapped in fracture - May require fasciotomy if compartment syndrome - Vascular surgery consultation **Pink Pulseless Hand Management** - Observe closely (90% develop adequate collaterals) - Hourly vascular checks first 12 hours - If hand remains pink/warm/good capillary refill: Acceptable - Doppler ultrasound to confirm radial/ulnar artery flow - Most recover radial pulse over weeks-months ## Pin Removal Protocol **Timing** - 3-4 weeks post-surgery - Radiographic union not required (fracture heals 4-6 weeks) - Pins maintain alignment until early callus forms **Technique** - Clinic procedure (no anesthesia needed if pins left proud) - Clean pin sites with chlorhexidine - Unbend pins with needle holders/pliers - Remove with steady gentle pull - No sedation required in most children **If Pins Buried** - Local anesthetic infiltration - Small incision over pin ends - May require brief sedation or general anesthetic **Post-Removal** - Range of motion exercises immediately - Expect stiffness initially (common) - Most regain full motion over 6-12 months ## Range of Motion Recovery **Early Phase (Weeks 1-4)** - Immobilized in backslab - No formal therapy needed - Pins prevent motion **Intermediate Phase (Weeks 4-8)** - Active ROM exercises after pin removal - Expect 30-40° flexion-extension arc initially - Gradual improvement - NO passive stretching (myositis ossificans risk) **Late Phase (Months 2-6)** - Progressive active motion - 80-90% regain full extension by 6 months - 5-10% permanent loss greater than 10° extension (cosmetic, non-functional) - Flexion usually returns to normal **Cubital Tunnel Syndrome (Delayed)** - Ulnar nerve symptoms develop months-years later (5-10%) - From cubitus varus deformity stretching nerve - May require cubital tunnel release or corrective osteotomy ## Troubleshooting Difficult Cases **Irreducible Fracture (Soft Tissue Interposition)** - Brachialis muscle entrapped most common - Median nerve entrapped (rare, but documented) - Periosteum buttonholed preventing reduction - Recognition: Repeated reduction attempts fail, unstable despite pinning - Management: Open reduction (anterior approach), remove interposed tissue, reduce, pin **Flexion-Type Fracture (2% of Cases)** - Opposite pattern: Anterior periosteum intact, posterior disrupted - Distal fragment displaced anteriorly (flexion mechanism) - Higher ulnar nerve injury at presentation (crosses anterior to medial epicondyle) - Reduction: Extension (not flexion) locks fracture - Immobilization: Extension (not flexion) **Open Fracture (Rare 1-2%)** - Usually medial skin penetration (spike of proximal fragment) - Treatment: Urgent debridement, CRPP or K-wire fixation if stable reduction - External fixation if highly contaminated (Gustilo III) - IV antibiotics (cefazolin + gentamicin if Gustilo III) **Delayed Presentation (Greater Than 7-10 Days)** - CRPP contraindicated (callus prevents reduction, fracture planes adherent) - Options: Accept position (remodels significantly less than 5 years age), skin or skeletal traction (controversial), open reduction (high stiffness risk) - Most surgeons observe if Baumann angle within 10-15° of normal **Floating Elbow (Ipsilateral Forearm Fracture)** - 5-10% have both radius/ulna and supracondylar fractures - Higher compartment syndrome risk (dual-level swelling) - Management: Fix supracondylar first (CRPP), then forearm (intramedullary flexible nails preferred) - Avoid casting both fractures (compartment risk) ## References 1. **Gartland JJ**. Management of supracondylar fractures of the humerus in children. *Surg Gynecol Obstet*. 1959;109(2):145-154. [Original description of Gartland classification system, foundational paper for supracondylar fracture management, defines Type I-III based on displacement pattern] 2. **Skaggs DL, Cluck MW, Mostofi A, Flynn JM, Kay RM**. Lateral-entry pin fixation in the management of supracondylar fractures in children. *J Bone Joint Surg Am*. 2004;86(4):702-707. doi:10.2106/00004623-200404000-00006 [Demonstrates biomechanical adequacy of lateral-entry only pinning with 2-3 divergent pins, safety advantage avoiding ulnar nerve] 3. **Brauer CA, Lee BM, Bae DS, Waters PM, Kocher MS**. A systematic review of medial and lateral entry pinning versus lateral entry pinning for supracondylar fractures of the humerus. *J Pediatr Orthop*. 2007;27(2):181-186. doi:10.1097/bpo.0b013e3180316cf2 [Meta-analysis showing crossed pins superior biomechanical stability but 2-4% iatrogenic ulnar nerve injury versus 0% lateral-entry only] 4. **Shaw BA, Kasser JR, Emans JB, Rand FF**. Management of vascular injuries in displaced supracondylar humerus fractures without arteriography. *J Orthop Trauma*. 1990;4(1):25-29. doi:10.1097/00005131-199003000-00005 [Landmark paper establishing safety of observing pink pulseless hand after reduction, 90% develop adequate collaterals, arteriography/exploration not routinely needed] 5. **Choi PD, Melikian R, Skaggs DL**. Risk factors for vascular repair and compartment syndrome in the pulseless supracondylar humerus fracture in children. *J Pediatr Orthop*. 2010;30(1):50-56. doi:10.1097/BPO.0b013e3181c6b3a8 [Analysis of 165 pulseless hands: pink hand observe (90% good outcome), white hand 70% require exploration, compartment syndrome 0.5-1%] 6. **Ramachandran M, Skaggs DL, Crawford HA, et al**. Delaying treatment of supracondylar fractures in children: has the pendulum swung too far? *J Bone Joint Surg Br*. 2008;90(9):1228-1233. doi:10.1302/0301-620X.90B9.20728 [Study demonstrating increased complications with surgical delay greater than 8 hours, recommends urgent surgery within 6-8 hours for Gartland III] 7. **Valencia M, Moraleda L, Díez-Sebastián J**. Long-term functional results of neurological complications of pediatric supracondylar humeral fractures. *J Pediatr Orthop*. 2015;35(6):606-610. doi:10.1097/BPO.0000000000000333 [Natural history of nerve injuries: AIN recovers 90% by 6 months, median 80%, radial 85%, ulnar 75%, most neurapraxia not requiring exploration] 8. **Wilkins KE, Beaty JH, Chambers HG, Toniolo RM**. Fractures and dislocations of the elbow region. In: Rockwood CA, Wilkins KE, Beaty JH, eds. *Fractures in Children*. 4th ed. Philadelphia: Lippincott-Raven; 1996:653-904. [Comprehensive textbook chapter detailing anterior humeral line, Baumann angle measurement, acceptable reduction criteria, historical evolution of treatment] 9. **Omid R, Choi PD, Skaggs DL**. Supracondylar humeral fractures in children. *J Bone Joint Surg Am*. 2008;90(5):1121-1132. doi:10.2106/JBJS.G.01354 [Current concepts review covering classification, neurovascular assessment, reduction techniques, pinning configurations, complications including cubitus varus prevention] 10. **Gottschalk HP, Sagoo D, Glaser D, Doan J, Edmonds EW, Schlechter J**. Biomechanical analysis of pin placement for pediatric supracondylar humerus fractures: does starting point, pin size, and number matter? *J Pediatr Orthop*. 2012;32(5):445-451. doi:10.1097/BPO.0b013e318257d1cd [Biomechanical study showing 3 lateral pins equivalent to crossed configuration, pin divergence greater than 30° and spread greater than 2cm at fracture critical for rotational stability]

Supracondylar Humerus Fracture - Closed Reduction Percutaneous Pinning

Supracondylar Humerus Fracture - Closed Reduction Percutaneous Pinning