import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Location**: Crosses ANTERIOR to radial neck 6-8cm distal to lateral epicondyle, winds around radius within supinator muscle **Protection**: Avoid direct dissection over radial neck during lateral approach; gentle reduction maneuvers to prevent overstretching; test function before and after reduction **Location**: Posterior to medial epicondyle in cubital tunnel, 2-3cm medial to surgical approach **Protection**: Keep incision on subcutaneous border of ulna (lateral/posterior surface); avoid medial dissection or proximal extension; maintain awareness during proximal ulnar exposure **Location**: Posterolateral vessels enter radial head and neck from surrounding soft tissue envelope **Protection**: Minimize soft tissue stripping around radial head; avoid circumferential exposure; limit periosteal elevation during annular ligament reconstruction **Location**: Wraps around radial head attaching to anterior and posterior margins of radial notch of ulna **Protection**: Assess integrity after radial head reduction; plan reconstruction if unstable (>3 weeks or persistent instability); avoid overly tight reconstruction compromising rotation **Location**: Radial head articulates with capitellum - both surfaces covered with articular cartilage **Protection**: Avoid forceful reduction attempts; no sharp instruments on articular surfaces; remove transarticular K-wire within 3-4 weeks to prevent severe stiffness and cartilage damage **Patient Position**: Supine with arm on radiolucent arm table. Shoulder abducted 70-90°, elbow flexed. Image intensifier for AP and lateral views of elbow and forearm. **Surgical Approach**: Direct lateral or subcutaneous approach to ulnar shaft, open or closed reduction of radial head via annular ligament reconstruction if needed ## Absolute Indications 1. **Acute Monteggia (Bado Type I-IV) with displaced ulnar fracture** - Failed closed reduction of ulna and/or radial head - Open fractures requiring surgical debridement - Associated neurovascular injury requiring exploration - Irreducible radial head (soft tissue interposition) 2. **Chronic/Missed Monteggia (>3 weeks)** - Persistent radial head dislocation with symptomatic instability - Progressive cubitus valgus deformity - Chronic pain or mechanical symptoms - PIN compression from chronic dislocation 3. **Complications of Initial Treatment** - Loss of reduction after closed treatment - Ulnar malunion preventing radial head reduction - Persistent radius plastic deformation - Failed annular ligament healing with instability ## Relative Indications - Bado Type I in adolescent with reliable closed reduction but unstable radial head (consider CRPP ulna first) - Minimally displaced ulnar fracture with radial head subluxation (trial closed reduction first) - Type III lateral dislocation in young child (some treat closed if stable) ## Pre-operative Planning **Imaging Assessment:** - AP and lateral forearm/elbow views - Radiocapitellar line on ALL views (AP/lateral/oblique) - Assess for radius plastic deformation (radial bowing on AP view) - Contralateral comparison for subtle deformity - CT scan if chronic case with bone block or coronoid fracture **Classification:** - Bado Type (I-IV) determines approach and prognosis - Acute (<3 weeks) vs chronic (>3 weeks) - affects need for annular ligament reconstruction - Associated injuries: coronoid fracture, olecranon fracture, proximal radius fracture **Surgical Planning:** - Implant selection: 2.4mm or 2.7mm plate vs intramedullary wire (based on age/fracture pattern) - Plan for radius plastic deformation correction (osteoclasis vs formal osteotomy) - Anticipate annular ligament reconstruction if chronic or known ligament disruption - Consider transarticular K-wire only if reconstruction not feasible (remove 3 weeks maximum) **Special Considerations in Paediatrics:** - Minimal periosteal stripping (excellent periosteal sleeve healing) - Avoid transphyseal screws near proximal ulna physis - Smaller implants (2.4mm often adequate vs 2.7mm in adolescents) - Lower threshold for intramedullary fixation in young children (less soft tissue trauma) ## Surgical Anatomy **Ulnar Shaft:** - Subcutaneous along medial/posterior border (direct approach) - Triangular cross-section: posterior subcutaneous border, anterior interosseous border, lateral border - Ulnar nerve posterior to medial epicondyle in cubital tunnel (2-3cm medial to surgical field) - Proximal ulna physis at coronoid/olecranon (avoid transphyseal fixation) **Radial Head and Neck:** - Articulates with capitellum (radiocapitellar joint) and radial notch of ulna (proximal radioulnar joint) - Annular ligament wraps around radial head, attaches to anterior and posterior margins of radial notch - Blood supply from posterolateral vessels entering radial neck (preserve soft tissue envelope) - Radial head 15° offset from radial shaft axis (creates radiocapitellar line relationship) **Posterior Interosseous Nerve (PIN):** - Radial nerve bifurcates into PIN and superficial sensory branch at level of radiocapitellar joint - PIN enters supinator muscle through arcade of Frohse (4-6cm distal to lateral epicondyle) - Winds around radial neck ANTERIORLY then posteriorly within supinator - Exits supinator 6-8cm distal to lateral epicondyle to innervate wrist/finger extensors - At risk during radial head reduction (stretching), annular ligament reconstruction (direct injury), and radius osteoclasis (traction) **Interosseous Membrane:** - Primary stabilizer of radius-ulna relationship - Central band is strongest component (distal to proximal oblique orientation) - Transmits 80% of axial load from radius to ulna - Disrupted in Monteggia injury contributing to instability ## Bado Classification (Detailed) **Type I (60-70% of cases):** - ANTERIOR radial head dislocation - Apex ANTERIOR angulation of ulnar fracture (usually proximal/middle third) - Mechanism: fall on outstretched hand with forearm pronated, hyperextension force - Associated injuries: coronoid fracture (rare), plastic deformation of radius (common) - Prognosis: BEST outcomes with anatomic reduction **Type II (15% of cases):** - POSTERIOR radial head dislocation - Apex POSTERIOR angulation of ulnar fracture - Mechanism: direct blow to posterior forearm or axial load with elbow flexed - Associated injuries: olecranon fracture, coronoid fracture - Prognosis: Higher risk of stiffness, loss of flexion **Type III (20% of cases):** - LATERAL or anterolateral radial head dislocation - Proximal ulnar METAPHYSEAL fracture (near olecranon, often greenstick) - Mechanism: varus force to elbow with forearm supinated - More common in younger children (2-7 years) - Associated injuries: plastic deformation radius - Prognosis: Good with anatomic reduction, risk of cubitus valgus if malunion **Type IV (Rare <5%):** - ANTERIOR radial head dislocation (like Type I) - BOTH radius AND ulna shaft fractures at same level - High energy injury mechanism - Associated injuries: nerve injury (especially PIN), compartment syndrome - Prognosis: More complications, longer recovery ## Pathoanatomy of Injury **Acute Phase (0-3 weeks):** - Ulnar fracture with apex angulation - Radial head dislocated in direction of ulnar apex - Annular ligament torn or avulsed (Type I especially) - Interosseous membrane disrupted - Radius may have plastic deformation (no visible fracture but permanent bowing) - PIN stretched over displaced radial head (10-20% injury rate) **Chronic Phase (>3 weeks):** - Ulnar fracture begins healing in malunited position - Radial head remains dislocated, annular ligament contracted/healed in elongated position - Radial head cartilage degeneration begins (6-12 weeks) - Radiocapitellar joint incongruent, capitellum may remodel (flattening) - Soft tissue contractures develop - Bone block formation at radial notch (preventing reduction) **Biomechanics:** - Ulnar shortening of 2-3mm creates radial head proximal translation and anterolateral instability - Radius plastic deformation creates bow, preventing radial head reduction even with anatomic ulna reduction - Annular ligament provides 60-70% stability to radial head in rotation - Loss of radiocapitellar contact increases stress on interosseous membrane by 30-40% ### Step 1: Pre-operative Assessment & Classification Pre-operative Assessment & Classification: BADO CLASSIFICATION: Type I (60-70%): anterior radial head dislocation with anterior apex ulnar fracture. Type II (15%): posterior radial head dislocation with posterior apex ulnar fracture. Type III (20%): lateral/anterolateral radial head dislocation with ulnar metaphyseal fracture. Type IV (rare <5%): anterior radial head dislocation with radius AND ulna fracture. ASSESS: (1) Radial nerve function (PIN) - thumb/finger extension, most commonly injured nerve 10-20%, usually neuropraxia. (2) Radiocapitellar relationship - should point to capitellum on ALL views. (3) Associated injuries - plastic deformation radius, coronoid fracture, olecranon fracture. **Technical Tip**: EXAM KEY: 'Monteggia is ulnar fracture with radial head dislocation. I use Bado classification: Type I most common (anterior dislocation, apex anterior ulnar fracture). Critical: check PIN - 10-20% injury rate, usually neuropraxia that recovers. Radiocapitellar line must point to capitellum center on ALL views.' - Missed radial head dislocation on initial X-rays (25% missed initially) - Undetected PIN injury before surgery (document baseline function) - Associated radius plastic deformation causing reduction failure ### Step 2: Reduction Strategy Planning Reduction Strategy Planning: TREATMENT ALGORITHM: (1) ACUTE (<3 weeks): ORIF ulna usually achieves radial head reduction (90% success). (2) Closed reduction ulna attempted first if suitable fracture pattern. (3) Open reduction ulna if: displaced, comminuted, failed closed reduction. (4) Plan for annular ligament reconstruction if chronic or unstable. PLASTIC DEFORMATION: if radius has plastic deformation, MUST straighten radius or radial head will not reduce - can attempt closed bending or osteoclasis. **Technical Tip**: EXAM KEY: 'Key principle: ANATOMIC REDUCTION of ulna length/alignment achieves radial head reduction in 90% acute cases. If radius has plastic deformation, I MUST correct this first - radial head will NOT reduce over bent radius. Plan annular ligament reconstruction if chronic (>3 weeks) or unstable.' - Attempting radial head reduction before correcting ulna = failure - Missing plastic deformation of radius = persistent dislocation - Forcing radial head reduction damaging PIN ### Step 3: Positioning & Draping Positioning & Draping: Supine, arm on radiolucent arm table. Tourniquet on upper arm (typically inflated for visualization). Shoulder abducted 70-90°, elbow flexed to relax soft tissues. Prep and drape entire arm from axilla to hand (may need forearm access). C-arm positioned for AP/lateral elbow and forearm views. **Technical Tip**: EXAM KEY: 'Supine with arm on arm table, tourniquet if needed. I prep entire arm - may need to address radius plastic deformation. C-arm for elbow AND forearm views to assess both ulna reduction and radiocapitellar relationship.' - Inadequate C-arm positioning missing full forearm assessment - Tourniquet pressure on radial nerve proximally - Prep field too small for plastic deformation correction ### Step 4: Ulnar Approach - Subcutaneous Border Ulnar Approach - Subcutaneous Border: Longitudinal incision centered over fracture along subcutaneous border of ulna (medial/posterior surface). Length 5-8cm depending on fracture location. Incise subcutaneous tissue directly to bone - ulna is subcutaneous. PERIOSTEAL ELEVATION: minimal stripping, preserve periosteum for healing, especially in children. Expose fracture adequately for reduction. **Technical Tip**: EXAM KEY: 'Direct approach to ulna subcutaneous border - this is straightforward, ulna is immediately subcutaneous. I minimize periosteal stripping for healing - children have excellent periosteal sleeve. Expose fracture site only.' - Excessive periosteal stripping delays healing and increases synostosis risk - Incision too medial risks ulnar nerve proximally - Inadequate exposure for reduction and plate application ### Step 5: Ulnar Fracture Reduction Ulnar Fracture Reduction: REDUCTION MANEUVERS: (1) Remove interposed periosteum/muscle from fracture site. (2) Achieve ANATOMIC REDUCTION: restore ulnar LENGTH (critical for radial head reduction), correct ANGULATION, restore ROTATION (align subcutaneous border and posterior border). (3) Use reduction forceps to hold. (4) Check with C-arm - must be ANATOMIC, any shortening/angulation prevents radial head reduction. **Technical Tip**: EXAM KEY: 'ANATOMIC ulna reduction is ESSENTIAL - radial head will not reduce if ulna shortened or angulated. I restore length, correct all angulation, check rotation. Critical: even 2-3mm ulnar shortening prevents radial head reduction. Hold with reduction forceps.' - Accepting any ulnar shortening = radial head stays dislocated - Rotational malreduction = angulation on one view - Interposed soft tissue preventing anatomic reduction ### Step 6: Ulnar Fixation - Plate Selection & Application Ulnar Fixation - Plate Selection & Application: IMPLANT: 2.4mm or 2.7mm locking or non-locking plate (depends on bone size/age). 6-8 hole plate for adequate span. TECHNIQUE: (1) Contour plate to ulnar shape (slight bow). (2) Apply to dorsal or lateral surface of ulna. (3) Obtain 3-4 screws (6-8 cortices) on each side of fracture. (4) Lag screw through plate if oblique fracture. (5) Alternative in young children: intramedullary wire if transverse/short oblique. **Technical Tip**: EXAM KEY: 'I use 2.4mm or 2.7mm plate on ulnar shaft, applied to dorsal/lateral surface. Need 3-4 screws each side for stability. Contour plate to match ulnar bow. Alternative in young children: flexible intramedullary wire for transverse fractures - less soft tissue dissection.' - Plate too large for pediatric bone causing stress concentration - Inadequate fixation (<3 screws/side) = loss of reduction - Screws into fracture site = poor purchase and reduction loss ### Step 7: Fluoroscopic Assessment of Ulnar Reduction Fluoroscopic Assessment of Ulnar Reduction: AP AND LATERAL views of forearm: (1) Ulnar length restored - compare to contralateral if needed. (2) No angulation any plane. (3) Hardware appropriate position. (4) Assess RADIAL BOWING - if plastic deformation present, radius will appear bowed on AP view. Must be corrected before radial head reduces. **Technical Tip**: EXAM KEY: 'After ulna fixation, I check AP/lateral forearm views. Ulna must be anatomic. Then I assess RADIUS - if radius shows bowing/plastic deformation on AP, I must correct this or radial head will NOT reduce. Compare forearm to contralateral side.' - Missing radius plastic deformation on fluoroscopy - Accepting residual ulnar angulation (<5° may prevent reduction) - Hardware malposition with screw prominence or cortex penetration ### Step 8: Radial Plastic Deformation Correction (if present) Radial Plastic Deformation Correction (if present): If radius shows plastic deformation (bowing): CLOSED CORRECTION (osteoclasis): (1) Palpate apex of radial bow. (2) Apply three-point bending force - central pressure at apex, counter-pressure at both ends. (3) Hold pressure 2-3 minutes (creep in pediatric bone). (4) AUDIBLE/PALPABLE microfractures as deformation corrects. (5) Check C-arm - radius should be straight on AP. Alternatively: FORMAL OSTEOTOMY if deformation severe or late presentation. **Technical Tip**: EXAM KEY: 'Plastic deformation of radius is common in Monteggia - presents as radial bowing on AP. I correct with closed three-point bending (osteoclasis) - apply central pressure at apex, counter-pressure at ends, hold 2-3 minutes. Feel/hear microfractures. This straightens radius allowing radial head reduction.' - Incomplete correction = persistent radial head dislocation - Fracturing radius cortex completely = need fixation (IM wire) - Neurovascular injury with excessive force (check PIN after) ### Step 9: Assessment of Radial Head Reduction Assessment of Radial Head Reduction: REDUCE RADIAL HEAD: (1) Extend elbow fully - often reduces with ulna correction alone. (2) Supinate forearm and apply direct pressure over radial head. (3) FLUOROSCOPY: radiocapitellar line must point to capitellum center on AP, LATERAL, and OBLIQUE views. (4) Palpate radial head - should be concentric with capitellum, not prominent. (5) Test stability through ROM. **Technical Tip**: EXAM KEY: 'With anatomic ulna reduction and straight radius, radial head USUALLY reduces with elbow extension and direct pressure. I confirm on fluoro - radiocapitellar line to capitellum center in ALL views. Must be concentric and stable. If unstable, consider annular ligament injury.' - Accepting partial reduction = early redislocation - Radiocapitellar line off on one view = not truly reduced - Forcing reduction damaging PIN or articular cartilage ### Step 10: Annular Ligament Reconstruction (if needed) Annular Ligament Reconstruction (if needed): INDICATIONS: (1) Chronic Monteggia (>3-4 weeks), (2) Unstable radial head despite anatomic ulna reduction, (3) Irreparable annular ligament tear. TECHNIQUE: (1) Lateral approach to radial head (Kocher interval: anconeus-ECU). (2) Reduce radial head (may need temporary K-wire). (3) RECONSTRUCT annular ligament: use strip of triceps fascia, lateral collateral ligament, or ECU tendon. (4) Wrap around radial neck 270-360°, secure to periosteum with sutures. (5) Check: radial head stable, rotation maintained (not too tight). **Technical Tip**: EXAM KEY: 'If radial head unstable after ulna fixation, I perform annular ligament reconstruction. Approach via Kocher interval. Use triceps fascia strip wrapped around radial neck. Critical: not too tight - must maintain rotation. This is usually needed in chronic Monteggia >3 weeks.' - Overly tight reconstruction = loss of rotation and stiffness - PIN injury during lateral exposure (runs anterior to radial neck) - Radial head re-dislocation if reconstruction inadequate or too loose ### Step 11: Temporary Radial Head Stabilization (controversial) Temporary Radial Head Stabilization (controversial): For unstable reduction, options: (1) TRANSARTICULAR K-WIRE: from capitellum through radial head, holds reduction, MUST remove at 3-4 weeks maximum (longer = severe stiffness). (2) ANNULAR LIGAMENT repair/reconstruction (preferred). (3) Intramedullary wire down radius providing indirect stability. Most surgeons avoid transarticular pin if possible due to stiffness risk. **Technical Tip**: EXAM KEY: 'If radial head unstable, I prefer annular ligament reconstruction over transarticular pin. Transarticular pin from capitellum causes severe stiffness if left >3-4 weeks. Only use if reconstruction not feasible, remove earliest possible (3 weeks).' - Transarticular pin left >3-4 weeks = severe permanent stiffness - Pin migration causing articular cartilage damage - Cartilage damage with pin placement (avoid central capitellum) ### Step 12: Final Fluoroscopic Confirmation Final Fluoroscopic Confirmation: COMPREHENSIVE ASSESSMENT: (1) AP/LATERAL forearm: ulna anatomic reduction, plate position, no radius deformity. (2) AP/LATERAL/OBLIQUE elbow: radiocapitellar line to capitellum in ALL views, no subluxation. (3) RANGE OF MOTION under fluoro: flexion/extension, pronation/supination - radial head should remain concentrically reduced throughout. (4) Hardware position safe. **Technical Tip**: EXAM KEY: 'Final check: ulna anatomic, radial head concentrically reduced in ALL views, stable through ROM. Radiocapitellar line is critical - must point to capitellum center on every view. If any subluxation with motion, address before closure.' - Dynamic instability missed on static views only - Radiocapitellar alignment perfect on AP but off on lateral - Accepting partial reduction that will redislocate ### Step 13: Post-Reduction Neurovascular Examination Post-Reduction Neurovascular Examination: ESSENTIAL: re-examine PIN function (thumb/finger extension) after radial head reduction. PIN injury can occur FROM reduction maneuvers (overstretching, traction, direct pressure). Document: (1) Radial nerve - wrist/thumb/finger extension. (2) Median nerve (especially AIN). (3) Ulnar nerve. (4) Radial pulse, perfusion. Most PIN injuries are neuropraxias that recover over 3-6 months. **Technical Tip**: EXAM KEY: 'CRITICAL: I re-examine PIN after radial head reduction. PIN can be injured BY the reduction maneuver - overstretching, traction on nerve. If new deficit, nerve is likely stretched but should recover. Document thoroughly. Most recover within 3-6 months with observation.' - Missing new PIN injury from reduction (iatrogenic) - Unrecognized nerve entrapment requiring release - Vascular injury from manipulation (rare but possible) ### Step 14: Closure & Immobilization Closure & Immobilization: Irrigate wound. Close periosteum if possible (enhances healing). Subcutaneous layer with absorbable suture. Skin closure. IMMOBILIZATION: Long arm cast or splint at 90° flexion, forearm in SUPINATION (stabilizes radial head). If transarticular pin: splint only, remove pin at 3 weeks then cast. If stable reconstruction: cast 4-6 weeks. **Technical Tip**: EXAM KEY: 'Close in layers. Long arm cast at 90° flexion, forearm SUPINATED - this is most stable position for radial head. If transarticular pin used, splint only for 3 weeks then cast after pin removal. Cast typically 4-6 weeks total.' - Forearm pronated in cast = radial head re-dislocation risk - Cast too tight = compartment syndrome (especially with tourniquet) - Leaving transarticular pin >3-4 weeks = severe stiffness ### Step 15: Post-operative Protocol & Follow-up Post-operative Protocol & Follow-up: IMMOBILIZATION: 4-6 weeks long arm cast, forearm supinated. X-ray at 1 week (check maintenance reduction), 3 weeks (consider transarticular pin removal if used), 6 weeks (healing assessment). REHABILITATION: gentle active ROM after cast removal, expect full ROM by 3-6 months. LONG-TERM: follow to skeletal maturity - monitor for: (1) late radial head redislocation (rare if anatomic reduction), (2) PIN recovery (3-6 months expected), (3) cubitus valgus from ulnar overgrowth, (4) radioulnar synostosis (rare complication). **Technical Tip**: EXAM KEY: 'Cast 4-6 weeks, supinated. Early follow-up to check maintenance of reduction - redislocation can occur in first 3-6 weeks if inadequate fixation. Start ROM at 6 weeks. Follow long-term: PIN should recover by 6 months if neuropraxia, watch for late complications (cubitus valgus, synostosis). Prognosis excellent if anatomic reduction achieved.' - Early cast removal = re-dislocation before healing - Delayed recognition of redislocation (loss of radiocapitellar line) - PIN injury not recovering by 6 months = possible exploration indicated ## Key Complication Patterns by Bado Type **Type I (Anterior Dislocation):** - Highest PIN injury rate (15-20%) - Best prognosis if anatomic reduction - Annular ligament often torn (may need reconstruction) - Lowest stiffness risk **Type II (Posterior Dislocation):** - Highest risk of elbow stiffness (30-40%) - Loss of flexion most common - Associated olecranon fractures common - Lower PIN injury rate (5-10%) **Type III (Lateral Dislocation):** - Common in young children (2-7 years) - Risk of cubitus valgus from metaphyseal malunion - Often greenstick ulnar fracture (may displace in cast) - Moderate PIN injury rate (10-15%) **Type IV (Both Bones):** - Highest complication rate overall - Compartment syndrome risk (5-10%) - Multiple nerve injuries possible - Longer recovery, more stiffness ## Outcomes by Treatment Type **Acute ORIF (<3 weeks):** - Radial head reduction rate: 90-95% if anatomic ulna reduction achieved - PIN recovery rate: 90% by 6 months (neuropraxia) - ROM: 85-90% patients achieve >120° flexion, >80% pronation/supination by 12 months - Redislocation rate: 5-10% (most within first 6 weeks) - Return to full activity: 3-6 months average **Chronic Reconstruction (>3 weeks):** - Radial head reduction rate: 70-80% (lower than acute) - Requires annular ligament reconstruction: 80-90% of cases - ROM: 70-80% achieve functional motion (some permanent limitation common) - Redislocation rate: 15-25% (higher than acute) - May need radial head excision if failed reconstruction (wait until skeletal maturity) **Plate vs Intramedullary Fixation (Pediatric):** - Plate: more stable, allows earlier mobilization, higher soft tissue trauma - IM wire: less soft tissue dissection, lower infection risk, less stable (requires good bone quality) - Outcomes similar in appropriate cases (transverse/short oblique fractures in younger children good for IM) - Plate preferred for: comminuted fractures, adolescents, revision surgery ## Prognostic Factors **Good Prognosis:** - Bado Type I (anterior dislocation) - Age <10 years - Acute presentation (<3 weeks) - Anatomic ulna reduction achieved - No PIN injury at presentation - Closed injury - Compliant with immobilization **Poor Prognosis:** - Bado Type II (posterior dislocation) - stiffness risk - Age >12 years (approaching skeletal maturity) - Chronic presentation (>3-6 weeks) - Ulnar malunion or persistent shortening - Radius plastic deformation not corrected - High energy injury (Type IV) - Multiple attempts at reduction (increases stiffness) ## Evidence Base **Level I Evidence:** - No randomized trials comparing surgical techniques in pediatric Monteggia (rare injury, heterogeneous populations) **Level III-IV Evidence (Case Series):** - Anatomic ulna reduction achieves radial head reduction in 90% acute cases (multiple series) - PIN injury recovers in 90% by 6 months with observation (neuropraxia) - Chronic Monteggia (>3 weeks) requires annular ligament reconstruction in 80-90% for stability - Transarticular K-wire left >4 weeks causes severe permanent stiffness in 60-80% (historical data) - Plate fixation preferred over IM wire in adolescents and comminuted fractures (biomechanical studies) **Expert Consensus:** - ANATOMIC ulna reduction is essential for radial head reduction (universally accepted) - Radius plastic deformation must be corrected (high consensus) - Annular ligament reconstruction for chronic/unstable cases (high consensus) - Avoid transarticular K-wire if possible, remove by 3-4 weeks maximum if used (high consensus) - Immobilization in supination stabilizes radial head (biomechanical rationale) ## Long-term Outcomes (5-10 year follow-up) **Functional Outcomes:** - 80-85% excellent/good results after acute ORIF with anatomic reduction - 10-15% have minor limitations (slight loss of rotation, minimal pain) - 5-10% have significant limitations (stiffness, chronic pain, recurrent instability) **Radiographic Outcomes:** - 90-95% maintain concentric radial head reduction long-term - 5-10% develop late cubitus valgus (often asymptomatic) - <5% develop radiocapitellar arthritis if anatomic reduction maintained - 20-30% have radiographic changes at radial head if chronic case or redislocation occurred **Return to Activity:** - Non-contact sports: 3 months average - Contact sports: 4-6 months with protective brace initially - Full unrestricted activity: 6 months average (range 4-12 months) - Recurrence of instability: rare (<2%) if anatomic reduction achieved ## Quality of Life - Minimal impact on ADLs if functional ROM achieved (>100° flexion, >70° rotation each direction) - Cosmetic concerns from cubitus valgus deformity in 10-15% - Parental anxiety about nerve recovery (counseling important) - Overall satisfaction: 85-90% in acute cases, 70-75% in chronic cases ## References 1. Bado JL. The Monteggia lesion. Clin Orthop Relat Res. 1967;50:71-86. PMID: 6029027. *Original description of Bado classification system (Types I-IV) based on direction of radial head dislocation - foundational reference for all Monteggia injuries.* 2. Ring D, Waters PM. Operative fixation of Monteggia fractures in children. J Bone Joint Surg Br. 1996;78(5):734-739. PMID: 8836062. *Demonstrates ORIF achieves anatomic reduction and radial head reduction in >90% acute cases - emphasizes importance of ulnar length restoration.* 3. Letts M, Locht R, Wiens J. Monteggia fracture-dislocations in children. J Bone Joint Surg Br. 1985;67(5):724-727. PMID: 4055871. *Comprehensive series showing PIN injury in 10-20% of cases with 90% recovery rate within 6 months - established natural history of nerve injury.* 4. Fowles JV, Sliman N, Kassab MT. The Monteggia lesion in children: fracture of the ulna and dislocation of the radial head. J Bone Joint Surg Am. 1983;65(9):1276-1282. PMID: 6654943. *Long-term outcomes demonstrating importance of anatomic reduction and early intervention - late diagnosis (>3 weeks) requires complex reconstruction.* 5. Stoll TM, Willis RB, Paterson DC. Treatment of the missed Monteggia fracture in the child. J Bone Joint Surg Br. 1992;74(3):436-440. PMID: 1587896. *Chronic Monteggia reconstruction techniques - annular ligament reconstruction required in 80-90% for stability, outcomes inferior to acute treatment.* 6. Wilkins KE. Changes in the management of Monteggia fractures. J Pediatr Orthop. 2002;22(4):548-554. PMID: 12131457. *Modern treatment algorithm emphasizing anatomic ulna reduction as primary goal, correction of radius plastic deformation, role of annular ligament reconstruction.* 7. Eygendaal D, Verdegaal SH, Obermann WR, van Vugt AB. Posterolateral dislocation of the elbow joint: relationship to medial instability. J Bone Joint Surg Am. 2000;82(4):555-560. PMID: 10761946. *Detailed anatomy of annular ligament and lateral collateral ligament complex - surgical approach and reconstruction techniques.* 8. Reckling FW. Unstable fracture-dislocations of the forearm (Monteggia and Galeazzi lesions). J Bone Joint Surg Am. 1982;64(6):857-863. PMID: 7085713. *Biomechanics of forearm instability - explains why ulnar shortening prevents radial head reduction and role of interosseous membrane.* 9. Thompson GH, Wilber JH, Marcus RE. Internal fixation of fractures in children and adolescents: a comparative analysis. Clin Orthop Relat Res. 1984;(188):10-20. PMID: 6467711. *Pediatric-specific fixation techniques comparing plate vs intramedullary wire - minimal periosteal stripping importance in children.* 10. Dormans JP, Rang M. The problem of Monteggia fracture-dislocations in children. Orthop Clin North Am. 1990;21(2):251-256. PMID: 2183130. *Comprehensive review of diagnosis pitfalls (25% missed initially), radiocapitellar line assessment technique, prevention strategies for missed diagnosis.*

Paediatric Monteggia Fracture Dislocation - ORIF Ulna & Radial Head Reduction

Paediatric Monteggia Fracture Dislocation - ORIF Ulna & Radial Head Reduction