Supracondylar Humeral Osteotomy for Cubitus Varus

Primary Indications

Cosmetic Deformity

• Neutral or negative carrying angle (normally 5-15° valgus)
• Visible gunstock deformity with arm extended
• Parental/patient concern regarding appearance
• Significant asymmetry compared to contralateral side (typically >15° difference)

Timing Requirements

• Minimum 2 years post-injury to assess remodeling potential
• Most perform between ages 6-12 years before skeletal maturity
• No upper age limit if symptoms warrant correction
• Allow time for spontaneous improvement (limited in cubitus varus unlike other deformities)

Functional Prerequisites

• Near full elbow range of motion (functional arc 30-130°)
• No significant stiffness or contracture
• Stable elbow without instability
• Good skin condition at proposed incision site

Relative Indications

• Posterolateral rotatory instability (rare complication)
• Ulnar nerve symptoms from altered cubital tunnel mechanics
• Functional limitation from deformity (unusual)
• Progressive deformity despite skeletal maturity

Contraindications

Absolute

• Active infection at surgical site
• Severe elbow stiffness (arc <60°) - osteotomy will worsen
• Vascular compromise or prior vascular injury
• Skeletal dysplasia with abnormal bone quality

Relative

• Age <5 years (some remodeling potential remains)
• Minimal deformity (<10° varus)
• Patient/family expectations unrealistic
• Medical comorbidities increasing surgical risk
• Poor compliance expected for post-operative rehabilitation

Clinical Evaluation

Deformity Assessment

• Carrying angle measurement with both elbows fully extended (compare to contralateral)
• Assess triplanar components: varus (coronal), internal rotation (axial), hyperextension (sagittal)
• Range of motion documentation (flexion, extension, pronation, supination)
• Cubital tunnel examination for ulnar nerve symptoms (rare but check)
• Skin assessment for scars from prior surgery or injury

Neurovascular Examination

• Radial nerve: wrist extension, thumb extension, finger MCP extension
• Median nerve: thumb opposition, sensation index/middle fingers
• Ulnar nerve: finger abduction/adduction, sensation ring/little fingers
• Anterior interosseous nerve: thumb IP flexion, index DIP flexion (OK sign)
• Posterior interosseous nerve: finger MCP extension with wrist flexed
• Vascular: radial/ulnar pulses, capillary refill, Allen test if concern

Radiographic Planning

Essential Imaging

• Bilateral AP radiographs: long cassette with both elbows fully extended for comparison
• True lateral radiographs: elbow 90° flexion to assess sagittal plane
• Contralateral normal elbow for template comparison
• Consider CT scan for complex three-dimensional deformity planning

Key Measurements

1. Baumann Angle (normal 64-81°)

   • Angle between humeral shaft axis and lateral condyle physis line
   • Decreased in cubitus varus (<64°)
   • Most reliable measurement for varus deformity

2. Carrying Angle (normal 5-15° valgus)

   • Angle between humeral and forearm axes
   • Neutral or negative in cubitus varus (0° to -30°)
   • Clinical correlation important as radiographic measurement variable

3. Humerus-Elbow-Wrist Angle

   • Overall alignment from shoulder to wrist
   • Accounts for combined elbow and wrist alignment

4. Lateral View Assessment

   • Anterior humeral line (normally through middle third of capitellum)
   • Extension deformity component (if line passes posterior to capitellum)

Templating Process

• Trace affected side radiograph on acetate
• Trace contralateral normal for comparison
• Mark proposed osteotomy site (2-3cm proximal to olecranon fossa)
• Calculate wedge size needed: 1mm base width ≈ 1° correction
• Plan for slight overcorrection (5° valgus acceptable)
• Template fixation method (K-wires vs plate position)

Patient Position

• Supine on operating table
• Radiolucent arm board extended at 90° to table
• Affected arm positioned on arm board with shoulder abducted 70-90°
• Ensure C-arm can access for AP and lateral fluoroscopy
• Consider sandbag under ipsilateral shoulder for stability

Preparation and Draping

• Entire upper extremity prepared from shoulder to fingertips
• Include surgical field from axilla to hand circumferentially
• Waterproof drapes isolating operative field
• Limb exsanguinated with elevation (tourniquet optional but helpful)
• Sterile tourniquet on upper arm if used (typically 200-250mmHg)

Surgical Approach Decision

Lateral Approach (Most Common)

• Between brachioradialis (anterior) and triceps (posterior)
• Advantages: familiar anatomy, radial nerve can be identified/protected
• Disadvantages: scar more visible, higher radial nerve risk
• Preferred by most surgeons due to familiarity

Medial Approach (Alternative)

• Anterior to medial intermuscular septum
• Advantages: better cosmetic scar (inner arm), lower radial nerve risk
• Disadvantages: ulnar nerve at risk if technique poor
• Consider in females where cosmesis paramount

Step 1: Skin Incision and Superficial Dissection

Lateral Approach Incision

• 8-10cm longitudinal incision along lateral supracondylar ridge
• Center incision 2-3cm proximal to lateral epicondyle
• Curve slightly posteriorly proximally, anteriorly distally
• Incise skin and subcutaneous tissue with cutting diathermy

Superficial Structures

• Identify and protect lateral antebrachial cutaneous nerve (terminal branch of musculocutaneous)
• Emerges between biceps and brachialis, crosses field superficially
• Gentle retraction preferable to division (prevents lateral forearm numbness)
• Ligate perforating vessels with bipolar cautery

Step 2: Intermuscular Interval and Deep Exposure

Identify Interval

• Develop plane between brachioradialis anteriorly and triceps posteriorly
• Brachioradialis identified by muscle bulk on anterior aspect of lateral supracondylar ridge
• Triceps lateral head inserts on posterior aspect of distal humerus
• Bluntly separate muscles in relatively avascular plane

Deep Dissection

• Radial nerve pierces lateral intermuscular septum 10-12cm proximal to lateral epicondyle
• At osteotomy level (2-3cm proximal to epicondyle) nerve already anterior between brachialis and brachioradialis
• Can identify nerve by palpating between muscles proximal to osteotomy site
• Once identified, protect throughout with gentle retraction

Exposure of Distal Humerus

• Identify lateral supracondylar ridge (bony landmark)
• Elevate brachioradialis origin subperiosteally from lateral ridge
• Elevate triceps lateral head from posterior distal humerus
• Expose circumference of humerus 2-3cm proximal to olecranon fossa

Step 3: Osteotomy Planning and Marking

Identify Osteotomy Level

• 2-3cm proximal to olecranon fossa (supracondylar metaphyseal region)
• Distal enough for good correction leverage, proximal enough to avoid joint
• Use ruler or marking to ensure adequate distance from olecranon fossa
• Confirm level with fluoroscopy (should be entirely metaphyseal, no physis)

Mark Wedge Using Template

• Transfer preoperative template measurements to bone
• Lateral closing wedge: apex medial (intact), base lateral (removed)
• Mark proximal cut line: lateral cortex angling distally-medially toward apex
• Mark distal cut line: lateral cortex angling proximally-medially toward same apex
• Base width (lateral) = correction needed (1mm ≈ 1° correction)
• Typical deformity 15° requires 15mm lateral base width

Reference K-wires

• Insert 2.0mm K-wire parallel to joint line distal to planned osteotomy
• Insert second K-wire proximal to osteotomy aligned with humeral shaft
• These reference wires help assess correction intraoperatively
• Can measure angle between wires before and after osteotomy

Step 4: Perform Lateral Closing Wedge Osteotomy

Protect Soft Tissues

• Place Hohmann retractors subperiosteally around circumference of humerus
• Anterior retractor protects brachialis and neurovascular structures
• Posterior retractor protects triceps
• Medial retractor protects soft tissues from saw blade during osteotomy

Osteotomy Technique

• Oscillating saw with copious irrigation to prevent thermal necrosis
• First cut: proximal limb from lateral cortex angling distally-medially to apex
• Incomplete medial cortex with first cut (leave hinge)
• Second cut: distal limb from lateral cortex angling proximally-medially to same apex
• Again leave medial cortex intact as hinge
• Remove wedge of bone (save for autograft if needed)

Preserve Medial Hinge

• Medial cortex serves as hinge for stable closure
• Complete both saw cuts to within 2-3mm of medial cortex
• Gently complete medial cortex with narrow osteotome if needed
• OR leave as greenstick to compress when closing wedge
• Intact medial hinge provides inherent stability and compression

Step 5: Close Osteotomy and Verify Correction

Wedge Closure

• Apply medial-to-lateral compression force to close wedge
• Hinges on preserved medial cortex (greenstick or incomplete)
• Lateral cortices should approximate with bone-to-bone contact
• Remove any interposed soft tissue preventing closure
• Hold compression manually while checking alignment

Clinical Verification

• Assess carrying angle compared to contralateral elbow
• Should achieve 5-10° valgus (slight overcorrection acceptable)
• Palpate alignment of distal humerus with proximal shaft
• Check for rotational deformity (align distal fragment with proximal)

Fluoroscopic Verification

• AP view: measure Baumann angle (should be 64-81°, symmetric to contralateral)
• AP view: measure carrying angle (target 5-10° valgus)
• Lateral view: check anterior humeral line (through middle third capitellum)
• Oblique views: rule out rotational malalignment
• Compare to preoperative and contralateral radiographs

Step 6: Internal Fixation

Fixation Options

Option 1: Crossed K-wires (Most Common)

• 2-3 smooth 2.0mm K-wires from lateral cortex
• First wire: oblique from lateral epicondylar region across osteotomy into medial proximal cortex
• Second wire: oblique from lateral supracondylar ridge across osteotomy into medial cortex (crosses first wire)
• Optional third wire for additional stability
• Leave wires percutaneous for easy removal (cut and bend outside skin)
• Advantages: simple, adequate stability for metaphyseal bone, easy removal
• Disadvantages: pin site care required, migration risk (1-2%)

Option 2: Plate and Screws

• Small plate (3.5mm reconstruction or 2.7mm paediatric plate)
• Applied to lateral cortex as tension band
• Typically 6-8 hole plate with 3-4 screws proximal, 3-4 screws distal
• Compress osteotomy site with plate application
• Advantages: more stable, allows earlier mobilization, no pin care
• Disadvantages: more soft tissue dissection, requires hardware removal later, more expensive

Fixation Technique

• Maintain compression at osteotomy site during fixation application
• Ensure wires/screws engage far cortex for stability
• Verify fixation position with fluoroscopy (AP and lateral)
• Check no wire/screw penetration into joint
• Assess stability with gentle varus/valgus stress under fluoroscopy

Step 7: Neurovascular Verification

Release Tourniquet

• Release tourniquet (if used) before closure
• Allows vascular assessment and hemostasis
• Minimum 10 minutes for vasospasm to resolve before assessing perfusion

Vascular Assessment

• Palpate radial pulse (should be strong and equal to contralateral)
• Assess capillary refill (should be less than 2 seconds)
• Check overall limb perfusion, color, temperature
• If any concern: ensure no kinking/compression of brachial artery

Neurological Assessment

• Radial nerve: wrist extension, thumb extension (EPL), finger MCP extension
• Posterior interosseous nerve: finger MCP extension with wrist stabilized
• Median nerve: thumb opposition, thenar muscle bulk
• Anterior interosseous nerve: thumb IP flexion and index DIP flexion (OK sign)
• Ulnar nerve (if medial approach): finger abduction/adduction, intrinsic function

Management of Deficit

• Any new deficit: explore nerve to ensure not entrapped or divided
• If nerve intact but in continuity injury: likely neuropraxia, observe
• If nerve divided: primary repair with microsurgical technique
• Document deficit immediately in operative note

Step 8: Wound Closure and Dressing

Hemostasis

• Copious irrigation with normal saline (500-1000mL minimum)
• Bipolar cautery for small bleeding vessels
• Avoid cautery near identified neurovascular structures
• Consider small suction drain if significant ooze (1/8 inch hemovac, remove 24 hours)

Layered Closure

• Close periosteum if possible (2-0 Vicryl) - helps stabilize soft tissue envelope
• Close deep fascia and muscle (2-0 or 3-0 Vicryl interrupted or running)
• Close subcutaneous tissue (3-0 Vicryl buried interrupted)
• Skin closure: subcuticular 4-0 Monocryl (absorbable) or interrupted 4-0 Nylon (removed 10-14 days)
• Skin adhesive (Dermabond) or Steri-Strips for additional skin edge approximation

Dressing

• Non-adherent dressing (Xeroform or Adaptic) over incision
• Sterile gauze padding over wound
• Soft roll gauze circumferentially around elbow (not tight)
• Apply posterior elbow splint over dressing (next step)

Step 9: Splint Application

Posterior Elbow Splint Technique

• Apply with elbow at 90° flexion (comfortable position)
• Forearm in neutral rotation (thumb pointing up)
• Splint extends from upper arm (mid-humeral level) to metacarpal heads
• Leave MCP joints free for finger motion
• Posterior application (not circumferential initially to allow swelling)

Padding and Molding

• Generous padding with cotton cast padding (3-4 layers minimum)
• Extra padding over pressure points: olecranon, medial/lateral epicondyles
• Plaster or fiberglass: 8-10 layers of 4-inch splint material
• Mold carefully: compress anterior and posterior surfaces gently
• Avoid excessive molding pressure over fresh osteotomy site

Secure Splint

• Overwrap with elastic bandage (3-4 inch Ace wrap)
• Moderate compression only, not tight
• Ensure fingertips visible for neurovascular monitoring
• Can apply Velcro straps for security

Recovery Room Protocol

Monitoring

• Neurovascular observations every 15 minutes first hour
• Then hourly for 4 hours minimum
• Check radial pulse, capillary refill, finger color/temperature
• Assess radial nerve function (wrist extension, finger MCP extension)
• Document pain scores and response to analgesia

Warning Signs

• Increasing pain unresponsive to analgesia (compartment syndrome concern)
• Diminished or absent radial pulse
• Capillary refill greater than 3 seconds
• Finger stiffness, swelling, coolness
• New neurological deficit
• Any concern: remove splint immediately and examine

Admission vs Discharge

• Admit overnight if: young child (<5 years), significant swelling, social concerns, distance from hospital greater than 1 hour
• Same day discharge if: older child/adolescent, minimal swelling, reliable family, close to hospital
• Either way: strict neurovascular precautions, written warning signs, clear contact instructions

Pain Management

Multimodal Analgesia

• Regular paracetamol (15mg/kg every 6 hours, maximum 4g/24hr)
• NSAID (ibuprofen 10mg/kg every 8 hours) if no contraindication
• Opioid for breakthrough (oxycodone 0.1-0.2mg/kg every 4-6 hours PRN)
• Ice therapy (20 minutes on, 20 minutes off, protect skin from direct ice contact)

Elevation

• Arm elevated on pillows above heart level
• Reduces swelling and pain
• Encourage hand/finger exercises to pump swelling

Week 1-2: Wound Check and Splint Transition

First Visit (7-10 days)

• Remove dressing, inspect wound
• Remove sutures if non-absorbable used (alternatively 14 days)
• Wound care: keep clean and dry, watch for infection signs
• Radiographs: AP and lateral to assess fixation position
• Remove posterior splint, transition to removable splint or sling for comfort

Begin Active Range of Motion

• Active assisted ROM exercises immediately after splint removal
• Gravity-assisted flexion and extension
• Active supination and pronation
• NO passive stretching (risks fixation failure and loss of correction)
• Gentle active use for activities of daily living

Restrictions

• No heavy lifting (greater than 2kg/5 pounds)
• No contact sports or rough play
• No passive stretching or forced motion
• Removable splint for protection during sleep and outdoor activities

Week 6: Callus Assessment

Clinical Evaluation

• ROM measurement (expect 80-90% normal by 6 weeks)
• Wound healing assessment
• Neurovascular examination

Radiographs

• AP and lateral views
• Assess for callus formation (should be visible by 4-6 weeks in children)
• Verify maintained alignment (no loss of correction)
• If K-wires used: ready for removal if callus adequate

K-wire Removal

• If adequate callus present (bridging 3/4 cortices)
• Can be done in clinic with local anesthesia in older children/adolescents
• Alternatively brief sedation or general anesthesia in younger children
• Cut wires at skin level and remove with needle-nose pliers or wire cutter
• Apply dressing, continue ROM exercises

Week 12: Union Assessment and Return to Activities

Clinical Evaluation

• Should have full or near-full ROM (functional arc minimum)
• Assess carrying angle correction (compare to contralateral)
• No tenderness over osteotomy site

Radiographs

• Solid union expected by 12 weeks (cortical bridging all 4 cortices)
• Maintained correction of carrying angle
• Remodeling of lateral cortex prominence

Activity Progression

• Return to full activities including contact sports if union solid
• Strengthen with progressive resistance exercises
• Unrestricted use

Month 6-12: Hardware Removal (if plate used)

Plate Removal Indications

• Routine: 6-12 months after solid union confirmed
• Earlier if symptomatic (plate prominence, irritation)
• Later if patient asymptomatic and wants to avoid another surgery

Plate Removal Procedure

• Through same incision
• Less dissection than original surgery
• Remove plate and screws under direct vision
• Protect radial nerve (scarred from first surgery)
• Similar post-operative protocol (splint 1-2 weeks, ROM)

Long-term Follow-up to Skeletal Maturity

Annual Visits

• Clinical carrying angle assessment
• Radiographs every 1-2 years
• Monitor for recurrence (rare, typically only if premature physeal closure)
• Monitor for late complications (ulnar nerve symptoms if overcorrected to valgus)

Expected Outcomes

• Excellent cosmetic correction: carrying angle within 5° of contralateral (85-90% patients)
• Full elbow ROM: 95% achieve functional arc (30-130°)
• High satisfaction: 85-95% patients/families satisfied with correction
• Low complication rate: 5-10% overall complications, mostly minor

Alternative Osteotomy Techniques

Lateral Closing Wedge (Most Common - described above)

• Advantages: simple, stable medial hinge, familiar anatomy, reliable correction
• Disadvantages: lateral scar, lateral prominence, shortens humerus slightly (usually insignificant)
• Best for: routine cubitus varus correction in most patients

Medial Closing Wedge

• Remove medial bone wedge, lateral cortex hinge, lateral approach same
• Advantages: corrects valgus deformity, less radial nerve risk (working medially), less lateral prominence
• Disadvantages: ulnar nerve at risk, less familiar anatomy, less stable hinge
• Best for: cubitus valgus correction, revision cases with lateral scarring

Lateral Opening Wedge

• Osteotomy with gap opening laterally, bone graft to fill wedge
• Advantages: no shortening, potentially more precise correction, medial hinge intact
• Disadvantages: requires bone graft (iliac crest donor site), delayed union risk, more complex
• Best for: need to maintain length, combined with other procedures where harvesting graft anyway

Dome (Curved) Osteotomy

• Curved osteotomy rather than wedge, allows multiplanar correction
• Advantages: can address triplanar deformity (varus + rotation + extension) simultaneously, more stable than wedge
• Disadvantages: technically demanding, special instruments helpful, longer surgery time
• Best for: complex three-dimensional deformities, revision cases

Step-Cut Osteotomy

• Multiple small steps creating overall correction
• Advantages: very stable inherently, large contact surface area, can address rotation
• Disadvantages: technically demanding, requires careful planning and execution
• Best for: revision cases, poor bone quality, need for very stable fixation

Medial Approach Technique

When to Consider

• Female patients where cosmesis paramount (medial scar less visible)
• Revision cases with lateral scarring or radial nerve concerns
• Combined procedures requiring medial exposure (e.g., ulnar nerve transposition)

Approach Details

• Incision: 8-10cm over medial supracondylar area anterior to medial epicondyle
• Identify and protect medial antebrachial cutaneous nerve superficially
• Interval: anterior to medial intermuscular septum (stay anterior to avoid ulnar nerve)
• Elevate brachialis and pronator teres origins from medial distal humerus
• Perform lateral closing wedge osteotomy from medial side (working across)
• OR perform medial opening/closing wedge depending on deformity

Advantages of Medial Approach

• Better cosmetic scar (inner arm less visible)
• Lower radial nerve risk (working from medial side)
• Direct access for ulnar nerve assessment/transposition if needed

Disadvantages of Medial Approach

• Less familiar anatomy for most surgeons
• Ulnar nerve at risk if technique poor (go posterior inadvertently)
• More difficult access to lateral cortex for standard lateral closing wedge

Age-Related Factors

Younger Children (5-8 years)

• More remodeling potential (slight residual varus may improve)
• Better bone healing (faster union, usually 6-8 weeks)
• Less cooperation with post-operative protocols (may need longer immobilization)
• Smaller instruments needed (2.7mm plate, 2.0mm K-wires)
• Lower anesthetic risk generally
• Family compliance critical (post-operative care, physiotherapy)

Older Children/Adolescents (9-15 years)

• Less remodeling potential (need accurate correction)
• Still excellent bone healing (8-12 weeks typically)
• Better cooperation with ROM exercises and restrictions
• Can use adult-size instruments (3.5mm plate, 2.0-2.5mm K-wires)
• K-wire removal in clinic with local anesthesia often feasible
• More aware of cosmetic outcome, may have input on scar placement

Growth Plate Considerations

Distal Humeral Physis

• Osteotomy is supracondylar (metaphyseal), proximal to physis
• Should NOT cross physis with osteotomy or fixation
• Verify on fluoroscopy that fixation does not penetrate physis
• Growth disturbance very rare if physis avoided
• If inadvertent physeal injury: monitor for growth arrest

Remodeling Potential

• Cubitus varus does NOT remodel significantly after age 2-3 years
• Unlike other paediatric fractures, spontaneous correction minimal
• Triplanar deformity particularly resistant to remodeling
• Waiting for remodeling is NOT appropriate management
• However slight undercorrection in younger child (age 5-7) may improve slightly

Family Education and Expectations

Preoperative Counseling

• Explain primarily cosmetic procedure (functional ROM usually preserved)
• Realistic expectations: aiming for symmetry within 5° of contralateral
• Discuss risks especially radial nerve injury (2-5% temporary)
• Explain post-operative protocol (splint, ROM, activity restrictions)
• Hardware removal required at 6-12 months (second anesthetic/procedure)
• Small risk residual deformity may need revision

Compliance Requirements

• Strict activity restrictions for 12 weeks (no contact sports, rough play)
• Daily ROM exercises once splint removed (family must supervise)
• Pin site care if K-wires (daily cleaning, watch for infection)
• Multiple follow-up visits required (weeks 1, 6, 12, then longer intervals)
• Long-term follow-up to skeletal maturity recommended

Indications for Revision Osteotomy

Undercorrection (Most Common)

• Significant residual varus (≥10-15° from contralateral)
• Patient/family dissatisfaction with cosmetic result
• Ensure adequate time post-initial surgery (minimum 6 months, ideally 12 months for complete remodeling)

Overcorrection

• Excessive valgus (>20°) causing cosmetic or functional concern
• Tardy ulnar nerve symptoms developing
• Less common than undercorrection but more problematic

Recurrence

• Loss of correction over time (very rare)
• Usually from growth disturbance or premature physeal closure
• Requires investigation for underlying cause

Technical Considerations for Revision

Challenges

• Scar tissue makes dissection more difficult
• Anatomy distorted from prior surgery
• Radial nerve may be scarred in lateral approach zone
• Bone quality at prior osteotomy site may be sclerotic
• Fixation may be more difficult in previously operated area

Solutions

• Consider different approach (medial if lateral used initially, or vice versa)
• Meticulous dissection expecting nerve in scar tissue
• May need osteotomy at different level (more proximal or distal)
• Consider alternative osteotomy type (dome or step-cut for more stable fixation)
• Plan for plate fixation rather than K-wires (more secure in revision)
• Consider bone graft if concern about healing in revision setting

Expected Outcomes

• Generally good if adequate correction achieved
• Higher complication rate than primary (15-20% vs 5-10%)
• Radial nerve injury risk higher in revision (5-10% vs 2-5%)
• Patient/family satisfaction still high if deformity corrected