# CIM Case: Paediatric Forearm Fracture ## Clinical Scenario **Patient:** 13-year-old boy **Presentation:** Fall at football 2 hours ago, landed on outstretched right arm, obvious deformity of forearm, immediate pain and swelling **Relevant history:** No previous fractures, right-hand dominant, otherwise healthy, normal growth and development, competitive footballer **Examination findings:** - Obvious angular deformity of right mid-forearm - Swelling and tenderness over both radius and ulna - Unable to rotate forearm due to pain - Fingers warm, pink, moving freely - Radial pulse palpable - No compartment tension - Full finger flexion and extension - Sensation intact to light touch all digits - Elbow and wrist joints above and below appear stable --- ## Investigations Provided ### Laboratory Results | Test | Result | Normal Range | Interpretation | |------|--------|--------------|----------------| | N/A | - | - | Bloods not routinely required for closed fracture | ### Imaging **Image 1: AP and Lateral Radiographs of Right Forearm** **Radiological features:** - Both bone midshaft forearm fracture - Radius: Complete transverse fracture at junction of middle and distal thirds - 25° apex dorsal angulation - 80% cortical contact - Mild rotational displacement - Ulna: Complete oblique fracture at mid-diaphysis - 20° apex volar angulation - Bayonet apposition (no overlap) - No extension to wrist or elbow joints - No plastic deformation of either bone - Radial head in normal position (not Monteggia) - Open physes - approaching skeletal maturity **Classification:** Diaphyseal both bone forearm fracture, displaced, closed ## Questions & Model Answers **Acceptable Angulation Limits:** The key principle is **age-dependent remodelling potential**. Younger children remodel more because: - More growth remaining - Greater periosteal activity - Physeal contribution to correction **Acceptable Limits by Age:** | Age Group | Location | Angulation | Rotation | Apposition | |-----------|----------|------------|----------|------------| | **<10 years** | Distal third | <15-20° | <45° | Bayonet OK | | **<10 years** | Middle third | <10-15° | <30° | Bayonet OK | | **<10 years** | Proximal third | <10° | <30° | Bayonet OK | | **10+ years** | Distal third | <10-15° | <30° | No bayonet | | **10+ years** | Middle third | <10° | <15-20° | >50% contact | | **10+ years** | Proximal third | <10° | <10° | >50% contact | | **Skeletally mature** | All | <5° | None | Anatomic | **This Patient (13 years old, midshaft):** - Current angulation: 25° radius, 20° ulna - Current apposition: 80% radius, bayonet ulna - **UNACCEPTABLE** - exceeds limits for age **Key Considerations:** **Rotation is Poorly Tolerated:** - Does NOT remodel well at any age - Causes functional limitation (can't supinate/pronate fully) - Assess clinically and radiographically **Angulation in Plane of Motion Remodels Best:** - AP angulation (flexion/extension plane) remodels better - Lateral angulation (pronation/supination plane) remodels less **Bayonet Apposition:** - Shortening up to 1cm acceptable in young children - Remodels with growth - Not acceptable near skeletal maturity > **Consultant Tip:** Older children (>10 years) have limited remodelling. Proximal fractures tolerate less angulation because less growth contribution from proximal radius physis. **Immediate Management:** **Emergency Department:** 1. Analgesia (intranasal fentanyl, IV morphine) 2. Splint in position of comfort (sugar tong or backslab) 3. Elevate limb 4. Neurovascular documentation 5. Nil by mouth (anticipate theatre) **Decision: Manipulation vs Direct Fixation:** **This Patient (13 years, midshaft, 25° angulation):** - Close to skeletal maturity - Limited remodelling potential - Unacceptable angulation - Two options: 1. Attempt closed reduction and casting 2. Proceed directly to ORIF **Closed Reduction Attempt (MUA):** - Reasonable to try once in ED or theatre - Under sedation or general anaesthesia - If satisfactory reduction achievable, cast - Likelihood of success: moderate (complete fractures harder to reduce and hold) **When to Proceed Directly to Fixation:** - Age >10 with complete displaced fracture - Failed closed reduction attempt - Unstable fracture pattern - Open fracture - Compartment syndrome - Polytrauma - Ipsilateral upper limb injury **This Patient's Recommendation:** - Attempt MUA under GA (single attempt) - If reduction achievable (<10° angulation), above-elbow cast - If reduction not achievable or unstable, proceed to ORIF **If MUA Successful:** - Above-elbow cast in neutral rotation - Slight flexion at elbow (90°) - Three-point moulding over fracture - X-ray in cast before leaving theatre - Close follow-up (1 week) > **Consultant Tip:** In older children with complete both bone fractures, set realistic expectations. MUA often fails to achieve or maintain reduction. Have consent for ORIF ready. **Closed Reduction Technique:** **Anaesthesia:** - Procedural sedation (ketamine) OR general anaesthesia - Muscle relaxation crucial for reduction **Reduction Manoeuvre:** **Step 1 - Increase Deformity:** - Recreate mechanism to unlock fragments - Increases angulation initially **Step 2 - Apply Traction:** - Longitudinal traction along forearm - Correct length - Assistant provides counter-traction at elbow **Step 3 - Reduce Angulation:** - Apply correcting force opposite to angulation - For apex dorsal (common): pressure on apex while pushing distal fragment volarly - Three-point fixation principle **Step 4 - Correct Rotation:** - Most difficult to assess and correct - Match bicipital tuberosity position to contralateral side - Proximal fragment follows proximal muscle insertions **Rotation Assessment:** | Fracture Level | Proximal Fragment Position | Rotation Needed | |----------------|---------------------------|-----------------| | **Proximal 1/3** | Full supination (biceps) | Supinate distal fragment | | **Middle 1/3** | Neutral (supinator + pronators balance) | Neutral | | **Distal 1/3** | Pronated (pronator teres) | Pronate distal fragment | **Step 5 - Apply Cast:** - Above-elbow backslab initially (can complete later) - Well-moulded, three-point fixation - Interosseous mould to maintain radial bow - Neutral rotation typically **Post-Reduction X-ray Checklist:** - [ ] Angulation <10° both bones - [ ] Rotation corrected (bicipital tuberosity orientation) - [ ] Adequate apposition (>50%) - [ ] Radial bow preserved - [ ] Cast well-moulded **If Reduction Inadequate:** - Single re-manipulation attempt reasonable - Then proceed to fixation if still inadequate > **Consultant Tip:** Interosseous mould is key. Flatten the interosseous space and you get loss of rotation. Preserve the radial bow. **Operative Fixation Options:** **1. Elastic Stable Intramedullary Nailing (ESIN/TEN):** **Technique:** - Two titanium elastic nails per bone - Entry points: radius - distal, Lister's tubercle level; ulna - proximal olecranon - Prebend nails (3x canal diameter apex) - Retrograde in radius, antegrade in ulna - Stack or single nail technique **Advantages:** - Percutaneous/minimal incision - Preserves periosteal blood supply - Allows fracture site compression - Good for simple transverse/short oblique patterns - Hardware removal under local possible **Disadvantages:** - Less rotational control - Hardware prominence (nail ends) - Not ideal for proximal or distal metaphyseal fractures - Learning curve **2. Open Reduction Internal Fixation (Plate and Screws):** **Technique:** - Henry approach (anterior) for radius - Direct approach for ulna - 3.5mm LC-DCP or LCP (8-10 hole plate) - Minimum 6 cortices each side of fracture - Lag screw for oblique patterns **Advantages:** - Anatomic reduction - Rigid fixation - Good rotational control - Can address comminution **Disadvantages:** - Larger incisions, more dissection - Risk to posterior interosseous nerve (proximal radius) - May need plate removal later (20-30%) - Refracture after removal **3. K-Wire Fixation:** - Rarely used alone for forearm fractures - May augment other fixation - Risk of pin tract infection **This Patient (13 years, midshaft both bone):** - Age near maturity favours plating - Could consider ESIN if simple transverse pattern - **Recommendation: ORIF with plates and screws** **Why Plating for This Patient:** - Near skeletal maturity - needs anatomic reduction - Complete both bone fracture - needs stable fixation - Competitive athlete - faster return to sport with rigid fixation > **Consultant Tip:** ESIN works well in younger children (6-12 years). Older adolescents near maturity often do better with adult-type fixation (plates). **Surgical Technique - ORIF Both Bone Forearm:** **Positioning:** - Supine on radiolucent table - Arm on arm board - Tourniquet applied (inflate after prep) **Approach Order:** - Fix the simpler fracture first (often ulna) - This restores length and aids radius reduction **Ulna Fixation:** **Approach:** Direct subcutaneous approach - Incision along subcutaneous border - Elevate ECU and FCU off bone - Protect ulnar nerve distally **Fixation:** - 3.5mm LC-DCP or LCP (6+ cortices each side) - Lag screw if oblique pattern - Contour plate to bone **Radius Fixation:** **Approach:** Henry (volar) approach - Incision along line from biceps tendon to radial styloid - Develop interval between FCR and brachioradialis - Ligate leash of Henry (radial artery branches) - Supinate forearm to expose radius volarly - Protect superficial radial nerve proximally **Critical Structures:** - **Posterior interosseous nerve:** at risk in proximal 1/3 (supinator) - **Superficial radial nerve:** emerges from under brachioradialis distally **Fixation:** - 3.5mm LC-DCP or LCP - Volar surface preferred (biomechanically) - 6+ cortices each side **Intraoperative Checks:** - Full supination and pronation - Radial bow restored - No hardware impingement **Closure:** - Tourniquet down, haemostasis - Layered closure - Backslab or splint for comfort (optional in rigid fixation) **Postoperative:** - Elevation - Sling for 1-2 weeks - Early ROM (forearm rotation, elbow, wrist) - Serial X-rays at 2, 6, 12 weeks > **Consultant Tip:** Henry approach - the key is the leash of Henry. Ligate it cleanly. Keep forearm supinated to swing radius volarly and away from the posterior interosseous nerve. **Complications:** **Early Complications:** | Complication | Incidence | Prevention/Management | |--------------|-----------|----------------------| | **Compartment syndrome** | 1-3% | High index of suspicion, fasciotomy if present | | **Neurovascular injury** | <1% | Careful dissection, protect PIN and SRN | | **Infection** | 1-2% | Prophylactic antibiotics, sterile technique | | **Malreduction** | Variable | Intraoperative fluoroscopy, clinical rotation check | **Late Complications:** | Complication | Incidence | Management | |--------------|-----------|------------| | **Malunion** | 5-10% | Corrective osteotomy if functional limitation | | **Loss of rotation** | 10-20% | May improve with therapy, osteotomy if severe | | **Nonunion** | <5% | Rare in children, revision fixation + bone graft | | **Refracture** | 5-10% (after plate removal) | Gradual return to sport, protect for 6-8 weeks | | **Synostosis** | 1-2% | Risk with high energy, resection when mature | | **Hardware prominence** | Variable | Plate removal if symptomatic | **Plate Removal:** **Indications:** - Patient/parent request (common in children) - Hardware prominence/irritation - Planned for competitive athlete - Before physeal closure (theoretical) **Timing:** - Minimum 12-18 months post fixation - After radiographic union (usually by 3-6 months) - Before return to high-risk sport **Technique:** - Same approaches - All screws must be removed - Protect against refracture: 6-8 weeks protected activity **Refracture After Plate Removal:** **Risk Factors:** - Early removal (<12 months) - Large plates (stress shielding) - Return to sport too soon - Comminuted original fracture **Prevention:** - Wait adequate time - Gradual return to activity - Consider forearm guard initially **Return to Sport (This Patient):** | Milestone | Timing | |-----------|--------| | Range of motion exercises | 2 weeks | | Light activity | 6 weeks | | Non-contact sport | 8-12 weeks | | Contact sport (football) | 12-16 weeks | | Plate removal (if desired) | 12-18 months | | Full sport after plate removal | 6-8 weeks post-removal | > **Consultant Tip:** Discuss plate removal at the outset. Many families expect it. Explain refracture risk and that it's not mandatory if asymptomatic. --- ## Key Teaching Points ### Pattern Recognition **This pattern suggests paediatric forearm fracture requiring intervention:** - Older child/adolescent (>10 years) - Complete both bone fracture - Angulation exceeding age-appropriate limits - Midshaft location (limited remodelling) **Distinguish from Monteggia/Galeazzi:** | Injury | Features | Key Finding | |--------|----------|-------------| | **Both bone forearm** | Radius and ulna diaphyseal | Both bones fractured, no dislocation | | **Monteggia** | Ulna fracture + radial head dislocation | Radial head not pointing at capitellum | | **Galeazzi** | Radius fracture + DRUJ disruption | DRUJ widening, ulna head prominent | **Always get elbow and wrist X-rays** to exclude associated injury. ### Critical Management Points 1. **Age determines acceptable angulation** - <10 years more forgiving, >10 years stricter 2. **Rotation does not remodel** - must be corrected at initial reduction 3. **MUA is reasonable first attempt** - but set expectations for older children 4. **ESIN for younger children, plates for adolescents** - near skeletal maturity = adult fixation 5. **Henry approach for radius** - protect PIN proximally, ligate leash of Henry 6. **Plate removal is optional** - not mandatory if asymptomatic, refracture risk exists --- ## Common Examiner Follow-ups **Q: "This child is 6 years old with the same fracture. How would your management differ?"** For a 6-year-old: - **Greater remodelling potential** - more growth remaining - **More forgiving limits** - up to 15° acceptable at midshaft - **MUA more likely to succeed** - greenstick patterns common - **If MUA fails, consider ESIN** - works well in this age group - **Plate removal almost always done** - avoid permanent hardware in growing child The 6-year-old would likely be managed with MUA and cast, with ESIN reserved for failure. --- **Q: "The fracture is plastic deformation of the ulna with a radius fracture. How do you manage this?"** Plastic deformation (bowing) management: - **Recognise on X-ray:** Curved bone without clear fracture line - **Remodelling is limited** for plastic deformation - **Correction needed if >10-15° bow** - **Technique:** Apply 3-point bending force under GA for 2-3 minutes - May feel/hear cortical microcracking - Cast in corrected position - More difficult to correct than complete fracture --- **Q: "At 1-week follow-up, the fracture has displaced in cast. What are your options?"** Re-displacement in cast: - **Common** - up to 30% of both bone fractures - **If still within acceptable limits** - continue cast, close follow-up - **If outside limits:** - Re-manipulation (if within 2 weeks, single attempt) - ORIF if re-manipulation fails or already attempted once - **Prevention:** Good initial moulding, close early follow-up, above-elbow cast After 2 weeks, callus formation makes closed reduction difficult. Proceed to ORIF if unacceptable alignment at that point. --- **Q: "What is the role of ESIN in paediatric forearm fractures?"** ESIN (Elastic Stable Intramedullary Nailing): - **Ideal age:** 6-12 years - **Ideal fracture:** Simple transverse or short oblique, midshaft - **Contraindications:** Comminuted, very proximal/distal, open - **Technique:** Retrograde radius, antegrade ulna, prebent nails - **Outcomes:** 90%+ union, good functional results - **Complications:** Hardware prominence, delayed union, loss of reduction - **Removal:** At 6-12 months, often under local anaesthesia ESIN offers a minimally invasive option between casting and plating. --- ## Related Topics - Monteggia Fracture-Dislocation - Galeazzi Fracture - Paediatric Elbow Fractures - Forearm Compartment Syndrome - ESIN Technique - Paediatric Fracture Principles