Posterior Approach to Humerus: Comprehensive Examination Guide

Introduction and Clinical Context

The posterior approach to the humerus is the WORKHORSE approach for humeral shaft fracture fixation, providing DIRECT visualization of the radial nerve in its spiral groove course and extensile access to the entire humeral shaft from the deltoid insertion proximally to the olecranon distally. This approach is particularly valuable for managing the 12-18% of humeral shaft fractures complicated by radial nerve palsy (highest risk with Holstein-Lewis distal third oblique fracture pattern) and for fractures requiring long segment fixation where anterolateral approaches provide inadequate exposure.

Historical Development and Surgical Evolution

The posterior approach evolved from early 20th century techniques for radial nerve exploration to modern extensile exposure methods. Triceps management remains the key technical controversy - triceps splitting (between long and lateral heads) provides TRUE internervous plane access with minimal denervation risk, triceps-sparing (medial retraction) preserves continuity but limits distal exposure, and triceps reflection (olecranon osteotomy or V-Y lengthening) maximizes distal access at cost of triceps morbidity. Contemporary evidence favors triceps splitting for most humeral shaft fractures, with 95-98% union rates and 2-5% iatrogenic nerve injury rates comparable to other approaches.

The approach's primary advantage is DIRECT radial nerve visualization throughout the spiral groove, allowing safe fracture manipulation and hardware placement without blind nerve retraction. This is particularly critical in primary nerve palsies (12-18% of humeral shaft fractures) where nerve exploration at time of ORIF may identify nerve laceration (5-10% requiring immediate repair) versus nerve contusion/traction (90-95% recovering spontaneously over 3-6 months). The posterior approach also facilitates distal humerus access for complex fracture patterns extending into the metaphysis, where combined posterior and lateral column plating may be required.

Surgical Anatomy and Key Landmarks

Surface Anatomy and Planning

Skin incision landmarks:

• Proximal: Posterior acromion (can extend to deltoid insertion if needed)
• Mid-shaft: Palpable posterior border of humerus (guide for skin incision)
• Distal: Olecranon tip (can extend distally for metaphyseal fractures)

Skin incision placement:

• Standard incision: 10-15cm midline posterior skin incision centered over fracture site
• Extensile option: Olecranon to posterior acromion (20-25cm) for long segment fixation
• Lateral offset: Incision can be placed 1-2cm lateral to true midline to avoid direct plate pressure on skin

Palpable landmarks:

• Acromion: Proximal landmark for approach extension to proximal humerus
• Olecranon: Distal landmark for approach extension to distal humerus/elbow
• Lateral epicondyle: Radial nerve crosses anteriorly 10-12cm proximal to this point
• Posterior humeral border: Palpable through triceps, guides skin incision

Layer-by-Layer Anatomic Dissection

Layer 1 - Skin and Subcutaneous Tissue:

• Midline posterior incision through skin and subcutaneous fat
• Identify and preserve posterior cutaneous nerve of forearm (medial brachial cutaneous nerve terminal branch) - runs along medial border of incision
• Develop full-thickness skin flaps to expose triceps fascia

Layer 2 - Triceps Fascia and Muscle:

• Triceps anatomy: Three heads converge to common tendon
  • Long head: Origin from infraglenoid tubercle (scapula), runs medially
  • Lateral head: Origin from posterior humerus proximal to spiral groove, runs laterally
  • Medial head: Origin from posterior humerus distal to spiral groove, deep to long/lateral heads
• Triceps management options:
  • Splitting technique (PREFERRED): Split between long head (medially) and lateral head (laterally) - TRUE internervous plane
  • Sparing technique: Retract entire triceps medially (preserves continuity but limits distal access)
  • Reflection technique: Olecranon osteotomy or triceps V-Y lengthening (maximizes distal access)

Layer 3 - Radial Nerve Identification:

• Nerve location: Spiral groove on posterior humerus (medial to lateral course)
• Proximal identification: Radial nerve emerges between long head and medial head of triceps 15-20cm distal to acromion
• Distal identification: Nerve passes anterior to lateral intermuscular septum 10-12cm proximal to lateral epicondyle
• Safe dissection: Trace nerve CONTINUOUSLY from proximal to distal (do NOT lose nerve visualization)

Layer 4 - Periosteum:

• Elevate periosteum from posterior humerus in subperiosteal plane (keeps radial nerve in soft tissue envelope)
• Expose fracture site with minimal soft tissue stripping (preserve fracture hematoma and biology)

Neurovascular Anatomy and Relationships

Radial Nerve Course:

• Origin: Posterior cord of brachial plexus (C5-T1)
• Proximal humerus: Runs posteromedially on medial head of triceps
• Spiral groove: Crosses posterior humerus from medial to lateral (spiral course)
  • Accompanied by profunda brachii artery (deep brachial artery)
  • Location: 15-20cm distal to acromion at mid-shaft level
  • Relationship to fracture: Nerve lies DIRECTLY on bone (susceptible to injury with displacement)
• Distal humerus: Pierces lateral intermuscular septum 10-12cm proximal to lateral epicondyle
• Forearm: Divides into superficial branch (sensory to dorsal hand) and posterior interosseous nerve (motor to finger extensors)

Vascular Supply:

• Profunda brachii artery (deep brachial artery): Accompanies radial nerve in spiral groove
  • Origin: Brachial artery proximal humerus
  • Branches: Supplies triceps muscle, contributes to humeral shaft blood supply
• Posterior circumflex humeral artery: Supplies proximal humerus (relevant if proximal extension needed)

Critical Anatomic Relationships:

• Radial nerve is EXTRA-OSSEOUS throughout humerus (runs on bone surface, NOT within bone)
• Nerve-to-bone distance: Approximately 2-3mm (direct contact in spiral groove)
• Distance from lateral epicondyle: 10-12cm to anterior crossing point (variable 8-15cm range)
• Relationship to lateral intermuscular septum: Nerve passes ANTERIOR at distal extent (safe zone ends here)

Indications and Contraindications

Primary Indications (Strong Evidence)

ABSOLUTE Indications:

1. Humeral shaft fracture with radial nerve palsy (12-18% incidence) - allows direct nerve exploration
   • Primary nerve palsy (at time of injury): Exploration indicated if no recovery by 3-4 months
   • Secondary nerve palsy (after manipulation/reduction): IMMEDIATE exploration indicated (may represent nerve interposition)
2. Humeral shaft fracture with vascular injury - requires proximal control of brachial artery
3. Open humeral shaft fracture - requires debridement and stabilization
4. Pathological fracture - requires tumor excision and reconstruction
5. Failed nonoperative management - progressive deformity, neurovascular compromise, or nonunion

RELATIVE Indications:

1. Mid-distal humeral shaft fractures (posterior approach preferred over anterolateral for distal third)
2. Long segment fixation (comminuted fractures requiring long plate)
3. Bilateral humeral shaft fractures (functional bracing not possible)
4. Polytrauma patient (requires early stabilization for mobilization)
5. Floating elbow (ipsilateral forearm fracture - requires humeral stabilization for elbow stability)
6. Patient factors: Obesity (difficult bracing), non-compliance, inability to tolerate prolonged bracing

Contraindications

ABSOLUTE Contraindications:

1. Active infection at surgical site (osteomyelitis, soft tissue abscess)
2. Inadequate soft tissue coverage (requires soft tissue reconstruction FIRST)
3. Medical instability (patient cannot tolerate anesthesia/surgery)

RELATIVE Contraindications:

1. Adequate alignment with nonoperative management (functional bracing successful in 70-90% of shaft fractures)
2. Minimal displacement (less than 20° angulation, less than 3cm shortening - acceptable alignment)
3. Poor bone quality (severe osteoporosis - intramedullary nailing may be preferred)
4. Severe soft tissue injury (may benefit from staged reconstruction)

Preoperative Planning and Patient Positioning

Preoperative Assessment

Clinical Examination:

• Radial nerve function (MANDATORY documentation):
  • Motor: Wrist extension (ECRL/ECRB - radial nerve main trunk), finger extension at MCP joints (EDC - posterior interosseous nerve), thumb extension (EPL/EPB - PIN)
  • Sensory: First dorsal web space sensation (superficial radial nerve)
  • Grading: Full function vs partial vs complete palsy
• Vascular examination: Radial pulse, capillary refill, Doppler signals if pulse absent
• Soft tissue assessment: Open wounds, skin integrity, compartment assessment
• Associated injuries: Ipsilateral forearm fractures (floating elbow), shoulder injuries, chest trauma

Radiographic Planning:

• AP and lateral humerus X-rays: Fracture location, displacement, comminution, fracture length
• CT scan (if needed): Complex fracture patterns, intra-articular extension, bone quality assessment
• Contralateral humerus X-ray: Template for length restoration (if severe comminution)

Implant Selection:

• Plate type: 4.5mm narrow LC-DCP or LCP (low-contact profile)
• Plate length: Minimum 3-4 cortices (6-8 screw holes) proximal and distal to fracture (longer plate for comminution)
• Screw selection: 3.5mm cortical screws for 4.5mm plate, length based on pre-op measurement
• Supplemental options: Lag screws for interfragmentary compression (if large fragments present)

Patient Positioning

LATERAL DECUBITUS position (PREFERRED for posterior approach):

• Position: Patient lateral with affected arm superior
• Advantages:
  • Arm free-draped allows full manipulation and fluoroscopy
  • Gravity assists in triceps retraction (muscle falls anteriorly)
  • Easy conversion to anterolateral approach if needed
  • Stable position for long procedures
• Setup:
  • Axillary roll under dependent axilla (protects brachial plexus)
  • Bean bag or lateral positioners for torso stability
  • All bony prominences padded
  • Upper arm supported on padded arm board or bolsters
• Arm positioning: Elbow flexed 90°, shoulder forward-flexed 20-30°

PRONE position (alternative):

• Position: Patient prone, arm on radiolucent arm board
• Advantages:
  • Excellent posterior access
  • Both arms accessible (if bilateral surgery needed)
  • Good for proximal extension to shoulder
• Disadvantages:
  • Difficult fluoroscopy (C-arm access limited)
  • Longer setup time
  • More physiologic stress on patient (respiratory, cardiovascular)

SUPINE position with cross-body positioning (rarely used):

• Arm across chest with shoulder internally rotated
• Limited access, poor visualization
• Generally NOT recommended for posterior approach

Step-by-Step Surgical Technique

Step 1: Skin Incision and Superficial Dissection

Technique:

1. Mark skin incision: 10-15cm midline posterior incision centered over fracture site
   • Can extend proximally toward posterior acromion (for proximal fractures)
   • Can extend distally toward olecranon (for distal fractures)
   • Lateral offset 1-2cm acceptable to avoid direct plate pressure on skin
2. Incise skin and subcutaneous tissue in line with skin markings
3. Develop skin flaps:
   • Elevate full-thickness flaps medially and laterally
   • Preserve posterior cutaneous nerve of forearm (medial) if visible
   • Expose triceps fascia over 5-7cm width
4. Identify triceps anatomy:
   • Palpate interval between long head (medial) and lateral head (lateral)
   • Identify raphe (white line) between muscle bellies if visible

Step 2: Triceps Management (Splitting Technique - PREFERRED)

Technique (Triceps Splitting):

1. Incise triceps fascia in line with interval between long and lateral heads
   • Start distally at musculotendinous junction (5-7cm proximal to olecranon)
   • Extend proximally along raphe toward deltoid insertion
2. Split triceps muscle bluntly with finger or elevator
   • TRUE internervous plane (radial nerve to both heads, NO motor denervation)
   • Spread muscle fibers along natural cleavage plane
   • Medial head of triceps exposed deep to long/lateral head split
3. Retract long head medially, lateral head laterally
   • Self-retaining retractors placed to hold muscle apart
   • Medial head visible on posterior humerus
4. Incise medial head of triceps (if needed for fracture exposure):
   • Elevate medial head subperiosteally from posterior humerus
   • Split medial head longitudinally if needed for fracture access
   • Radial nerve lies DEEP to medial head (protect during medial head elevation)

Alternative: Triceps-Sparing Technique

• Retract ENTIRE triceps medially (long, lateral, and medial heads together)
• Preserves triceps continuity (no muscle splitting)
• Limited distal exposure (cannot access distal 5-7cm of humerus easily)
• Used for mid-shaft fractures NOT requiring distal fixation

Alternative: Triceps Reflection (Olecranon Osteotomy)

• Reserved for DISTAL humerus fractures requiring wide metaphyseal exposure
• Chevron osteotomy of olecranon, reflect triceps proximally with olecranon fragment
• Maximizes distal exposure but adds olecranon fixation morbidity
• Generally NOT needed for shaft fractures

Step 3: Radial Nerve Identification and Protection

Technique:

1. Identify radial nerve PROXIMALLY first (safest approach):
   • Location: Between long head and medial head of triceps, 15-20cm distal to acromion
   • Palpate nerve as cord-like structure crossing posterior humerus medial to lateral
   • Confirm with gentle nerve stimulator (muscle contraction confirms motor nerve)
2. Trace nerve through spiral groove:
   • Follow nerve distally as it crosses posterior humerus
   • Nerve accompanied by profunda brachii artery (small vessels)
   • Stay in SUBPERIOSTEAL plane when elevating bone (keeps nerve in soft tissue)
3. Identify nerve DISTALLY (confirms continuity):
   • Nerve pierces lateral intermuscular septum 10-12cm proximal to lateral epicondyle
   • Disappears anteriorly (NOT accessible beyond this point via posterior approach)
4. Protect nerve during fracture manipulation:
   • Place vessel loop around nerve for gentle retraction (mark nerve location)
   • Avoid excessive traction (nerve ischemia risk)
   • Keep nerve visible throughout case (do NOT let nerve disappear from field)
5. Document nerve integrity:
   • Visually inspect nerve (laceration vs contusion vs intact)
   • If lacerated: Tag ends with suture, plan delayed repair after fracture fixation
   • If intact: Gentle mobilization to ensure nerve not tethered to fracture

Step 4: Fracture Exposure and Reduction

Technique:

1. Elevate periosteum from fracture site:
   • Minimal soft tissue stripping (preserve fracture hematoma and biology)
   • Subperiosteal elevation only at fracture ends (for plate placement)
   • Avoid circumferential stripping (devascularizes fracture fragments)
2. Irrigate fracture site: Remove hematoma, loose debris, bone chips
3. Assess fracture pattern:
   • Simple transverse/oblique vs comminuted
   • Butterfly fragments (can be lag screw fixed)
   • Fracture length (determines plate length needed)
4. Reduce fracture:
   • Align cortices anatomically (restore length, rotation, alignment)
   • Use bone clamps to hold reduction (no gap at fracture site)
   • Check alignment with fluoroscopy (AP and lateral views)
   • Ensure radial nerve NOT trapped between fracture fragments

Step 5: Plate Application and Fixation

Technique:

1. Select plate:
   • 4.5mm narrow LC-DCP or LCP (low-contact dynamic compression or locking compression plate)
   • Length: Minimum 6-8 holes, spanning 3-4 cortices proximal and distal to fracture
   • Contouring: Pre-bend plate to match posterior humeral curvature (avoid stress risers)
2. Position plate on posterior humerus:
   • Center plate over fracture site
   • Ensure plate does NOT impinge on radial nerve distally (nerve lies anterior to bone distal to spiral groove)
   • Temporarily fix with K-wires or plate-holding forceps
3. Drill and place screws:
   • Proximal screws: 3-4 bicortical screws proximal to fracture
     • Drill, measure, tap (if non-locking), insert 3.5mm cortical screw
     • Engage FAR cortex (bicortical purchase)
   • Distal screws: 3-4 bicortical screws distal to fracture
     • Ensure screws do NOT engage radial nerve anteriorly (palpate anterior cortex before drilling)
   • Compression: If using LC-DCP, load plate eccentrically to compress fracture (optional for simple patterns)
   • Lag screws (if applicable): Place lag screws perpendicular to fracture line for interfragmentary compression (large butterfly fragments)
4. Confirm fixation:
   • Check all screws tight (no toggle)
   • Fluoroscopy: AP and lateral views confirm plate position, screw length, fracture reduction
   • Ensure no intra-articular screw penetration (if distal extension)

Step 6: Closure and Postoperative Care

Technique:

1. Final nerve inspection:
   • Confirm radial nerve NOT compressed by plate or screws
   • Ensure nerve lies freely, not tethered to hardware
   • Document nerve integrity (critical for medicolegal purposes)
2. Irrigate wound: Copious saline lavage (remove debris, blood)
3. Close layers:
   • Triceps: Reapproximate triceps split with interrupted absorbable sutures (0-Vicryl)
     • Do NOT over-tighten (risk of muscle ischemia)
   • Subcutaneous: Close in layers with absorbable sutures (2-0/3-0 Vicryl)
   • Skin: Staples or subcuticular closure (based on surgeon preference)
4. Dressing: Sterile gauze and compressive wrap
5. Splint: Posterior long-arm splint (optional) for first 1-2 weeks (comfort, NOT required for stability)

Postoperative Protocol:

• Immediate: Check radial nerve function on emergence from anesthesia (compare to pre-op)
• First 24-48 hours: Elevate arm, ice, pain control
• Week 1-2: Gentle active ROM elbow/shoulder (pendulums, table slides), NO resistance
• Week 2-6: Progressive ROM, light ADLs, NO lifting
• Week 6-12: Strengthening begins (theraband), progress to functional activities
• Week 12+: Radiographic union, advance to unrestricted activities
• Follow-up: Weeks 2, 6, 12, 24 with X-rays (assess union, hardware position)

Complications and Management

Intraoperative Complications

1. Radial Nerve Iatrogenic Injury (2-5% incidence)

Recognition:

• Visual injury during dissection (laceration, transection, stretch)
• Nerve stimulator no response (if tested)
• Post-op exam (if injury not recognized intra-op)

Management:

• IMMEDIATE recognition:
  • If clean laceration: Primary repair with 8-0 or 9-0 nylon epineurial sutures
  • If nerve contusion/stretch: Observe (most recover spontaneously 3-6 months)
  • If nerve transected: Tag ends with suture, plan delayed nerve grafting 3-6 weeks (allows scarring to demarcate injury zone)
• Prevention:
  • Identify nerve FIRST before manipulating fracture
  • Trace nerve continuously (do NOT lose nerve in field)
  • Subperiosteal dissection (keeps nerve in soft tissue)
  • Check screw length (ensure no anterior cortex penetration where nerve lies)

2. Profunda Brachii Artery Injury

Recognition:

• Pulsatile bleeding from spiral groove
• Bleeding not controlled with electrocautery

Management:

• Ligate vessel with suture ligatures (artery is expendable - collateral circulation adequate)
• Avoid prolonged cautery near radial nerve (thermal injury risk)

3. Inadequate Fracture Reduction

Recognition:

• Fluoroscopy shows malalignment, gap at fracture site, rotation deformity

Management:

• Release clamps, re-reduce fracture
• Consider supplemental lag screws (if large fragments available)
• Accept less than 2mm gap if cortical apposition restored (secondary bone healing acceptable)

4. Hardware Malposition

Recognition:

• Fluoroscopy shows screw penetration of anterior cortex (nerve injury risk)
• Plate not centered on bone (asymmetric fixation)

Management:

• Remove and redirect screws (check screw length calculation)
• Reposition plate if needed

Early Postoperative Complications (0-6 weeks)

1. Wound Infection (2-3% incidence)

Recognition:

• Erythema, warmth, drainage from incision
• Fever, elevated inflammatory markers (WBC, CRP)
• Wound dehiscence

Management:

• Superficial infection: Oral antibiotics (cephalexin or clindamycin), local wound care
• Deep infection: Return to OR for irrigation/debridement, IV antibiotics (cefazolin or vancomycin based on cultures), consider negative pressure wound therapy
• Prevention: Prophylactic antibiotics (cefazolin 2g pre-op), meticulous hemostasis, layered closure

2. Hematoma

Recognition:

• Swelling, ecchymosis, drainage from incision
• Painful, tense wound

Management:

• Small hematoma: Observation (resorbs over 2-4 weeks)
• Large hematoma: Aspiration or open drainage (if infected or under tension)
• Prevention: Meticulous hemostasis, avoid over-anticoagulation

3. Elbow/Shoulder Stiffness (10-15% incidence)

Recognition:

• Limited ROM elbow flexion/extension or shoulder elevation
• Pain with motion

Management:

• Aggressive physical therapy (ROM exercises 3-4x daily)
• NSAIDS for pain/inflammation
• Consider manipulation under anesthesia if no progress by 12 weeks (rare)
• Prevention: Early ROM exercises starting week 1-2 post-op

Late Postoperative Complications (6+ weeks)

1. Nonunion (5-10% incidence)

Recognition:

• Persistent pain at fracture site beyond 4-6 months
• Radiographs: No bridging callus, gap at fracture site, hardware failure/loosening
• CT scan confirms nonunion if X-rays equivocal

Risk factors:

• Inadequate fixation (too-short plate, inadequate screw purchase)
• Excessive soft tissue stripping (devascularizes fracture)
• Infection
• Smoking (impairs healing)
• Distal third fractures (watershed blood supply)

Management:

• Atrophic nonunion (inadequate biology):
  • Revision ORIF with longer plate
  • Bone graft (autograft from iliac crest or allograft)
  • BMP-2 augmentation (consider if smoker or poor bone quality)
• Hypertrophic nonunion (inadequate stability):
  • Revision ORIF with compression plating (dynamize fracture)
  • Consider conversion to intramedullary nail

2. Radial Nerve Palsy (delayed recovery)

Recognition:

• Persistent wrist drop, finger extension weakness beyond 6 months
• EMG shows denervation without reinnervation

Management:

• Conservative management:
  • Wrist cock-up splint (maintains wrist extension, allows finger function)
  • Occupational therapy (adaptive techniques)
  • Wait 12-18 months (nerve regeneration 1mm/day, distance from spiral groove to wrist extensors 20-25cm = 6-8 months expected recovery)
• Surgical options (if no recovery by 12-18 months):
  • Nerve exploration and repair/grafting: If nerve lacerated/neuroma
  • Tendon transfers: Restore wrist/finger extension with expendable flexor tendons
    • PT to ECRB (wrist extension)
    • FCR to EDC (finger extension)
    • PL to EPL (thumb extension)

3. Radial Nerve Painful Neuroma

Recognition:

• Focal tenderness over spiral groove
• Tinel's sign (percussion reproduces dysesthesias)
• Pain with motion

Management:

• Conservative: Desensitization therapy, gabapentin/pregabalin for neuropathic pain
• Surgical: Neurolysis (release scar tissue around nerve), neuroma excision with nerve rerouting

4. Hardware Irritation (5-8% incidence)

Recognition:

• Prominent plate/screws under skin (especially in thin patients)
• Pain with direct pressure
• Skin breakdown over hardware

Management:

• Observation (if asymptomatic and fracture healed)
• Hardware removal after fracture union (12-18 months post-ORIF)
• Prevention: Low-profile plates, adequate soft tissue coverage

Approach Extensions and Modifications

Proximal Extension (for proximal humeral shaft fractures)

Technique:

• Extend skin incision proximally toward posterior acromion
• Split deltoid muscle in line with posterior fibers (parallel to muscle)
  • Identify axillary nerve (exits quadrangular space 5-7cm inferior to acromion) - AVOID nerve injury
  • Limit deltoid split to 5cm distal to acromion (beyond this risks axillary nerve denervation)
• Access proximal humerus and surgical neck if needed
• Close deltoid split with interrupted sutures

Indications:

• Fractures extending into proximal metaphysis/surgical neck
• Long segment fixation required

Distal Extension (for distal metaphyseal fractures)

Technique:

• Extend skin incision distally toward olecranon
• Options for distal access:
  • Triceps V-Y lengthening: Divide triceps tendon in V-shape, reflect proximally, repair in Y-fashion at closure (lengthens triceps, preserves strength)
  • Olecranon osteotomy: Chevron osteotomy through olecranon, reflect triceps/olecranon proximally, fixation with tension band or plate at closure
• Access distal humerus columns for intra-articular fracture fixation
• Close with tendon repair (V-Y) or olecranon fixation (tension band/plate)

Indications:

• Fractures extending into distal metaphysis with intra-articular component
• Distal humerus nonunion

Combined Approaches

Posterior + Lateral approach:

• Separate lateral incision over lateral epicondyle
• Access lateral column for dual plating (posterior and lateral plates for distal humerus fractures)
• Used for complex distal humerus fractures (AO/OTA 13C)

Comparison with Alternative Approaches

Evidence-Based Postoperative Management

Rehabilitation Protocol

Phase 1: Protection Phase (Weeks 0-2)

• Goals: Wound healing, pain control, prevent stiffness
• Restrictions: No lifting, no resistance
• Exercises:
  • Passive/active-assisted ROM elbow (0-90° flexion, progress to full)
  • Shoulder pendulums and table slides
  • Wrist/hand ROM (prevent stiffness, especially if radial nerve palsy)
• Splinting: Optional posterior long-arm splint for comfort (NOT required for fracture stability)

Phase 2: Early Motion Phase (Weeks 2-6)

• Goals: Restore ROM, prevent adhesions, protect healing fracture
• Restrictions: No lifting greater than 5 lbs, no repetitive/resisted activities
• Exercises:
  • Active ROM elbow/shoulder (full motion goals)
  • Gentle stretching if stiffness develops
  • Light ADLs (self-care, eating, typing)
• Radiographs: Week 6 - assess callus formation (expect early bridging callus by 4-6 weeks)

Phase 3: Strengthening Phase (Weeks 6-12)

• Goals: Restore strength, return to functional activities
• Criteria to advance: Radiographic callus (bridging 3/4 cortices), no fracture site pain
• Exercises:
  • Resistance exercises (theraband for shoulder, light dumbbells for elbow)
  • Progressive functional activities (lifting, carrying, pushing)
  • Return to work (non-manual labor week 6-8, manual labor week 10-12)
• Radiographs: Week 12 - confirm union (bridging callus 4/4 cortices, no fracture line visible)

Phase 4: Return to Full Activity (Week 12+)

• Goals: Return to unrestricted activities, sports
• Criteria: Radiographic union (4/4 cortices bridged), full ROM, strength 80%+ of contralateral
• Activities: Sport-specific training, heavy lifting, unrestricted work
• Radiographs: Week 24 - confirm mature union, assess hardware (plan removal if symptomatic)

Radial Nerve Palsy Management

Initial Assessment:

• Distinguish primary palsy (at injury) vs secondary palsy (after manipulation/surgery)
• Secondary palsy: Higher concern for nerve laceration/tethering - consider earlier exploration

Conservative Management (PRIMARY palsy - preferred):

• Natural history: 70-90% spontaneous recovery by 3-6 months
• Splinting: Wrist cock-up splint maintains wrist extension (prevents contracture, allows finger function)
• Monitoring: Serial EMG at 6, 12, 18 weeks (assess for reinnervation)
• Expected recovery timeline:
  • Nerve regeneration rate: 1mm/day (25mm/month)
  • Distance spiral groove to wrist extensors: 15-20cm
  • Expected recovery: 6-8 months (if nerve intact)

Surgical Exploration Indications:

• IMMEDIATE exploration: Secondary palsy (after manipulation), open fracture, vascular injury
• DELAYED exploration (3-4 months): Primary palsy with NO recovery by 3-4 months on serial EMG
• Nerve findings at exploration:
  • Intact nerve with contusion: Neurolysis (release scar tissue), expect recovery 3-6 months post-surgery
  • Neuroma-in-continuity: Nerve conduction studies, resection + grafting if no conduction
  • Complete laceration: Resection + grafting with sural nerve autograft (results variable 60-70% useful recovery)

Australian Clinical Context

Humeral shaft fractures account for approximately 3-5% of all fractures in Australia, with posterior approach ORIF increasingly utilized for specific indications rather than routine management (most uncomplicated fractures still managed nonoperatively with functional bracing). Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) does not track humeral shaft fracture fixation (registry focused on arthroplasty), but institutional data from major trauma centers (Alfred Hospital Melbourne, Royal Perth Hospital) report 20-30% operative rate for humeral shaft fractures (increased from 10-15% in 1990s), with posterior approach representing 60-70% of operative cases.

Radial nerve palsy management follows evidence-based protocols emphasizing nonoperative observation for primary palsies (70-90% spontaneous recovery) and selective exploration for secondary palsies or prolonged palsy (no recovery by 3-4 months). Patients with persistent radial nerve palsy beyond 12-18 months may require tendon transfers for functional restoration - these procedures typically performed at tertiary hand surgery centers (Royal Melbourne Hospital, Flinders Medical Centre, Princess Alexandra Hospital Brisbane) with reported satisfaction rates 80-85% (Grubhofer et al, J Hand Surg Eur Vol 2019: 83% satisfaction with radial nerve palsy tendon transfers at mean 5-year follow-up).

Medicare provides coverage for posterior approach ORIF of humeral shaft fractures under the category of "internal fixation of long bone fractures" - both acute fracture fixation and revision procedures for nonunion are covered. Private health insurance typically covers these procedures with minimal out-of-pocket costs for patients with appropriate coverage levels (hospital/medical cover). Workers' compensation (WorkCover) programs in all Australian states cover operative treatment for work-related humeral shaft fractures, which represent approximately 15-20% of cases (motor vehicle accidents, falls from height, industrial injuries).

Smoking cessation is CRITICAL for fracture healing - smoking increases nonunion risk 2-3 fold in long bone fractures (Patel et al, Acta Orthop 2013: smoking associated with 2.3x nonunion risk in humeral shaft fractures). Australian patients should be referred to Quitline 13 7848 for evidence-based smoking cessation support (free telephone counseling, nicotine replacement therapy coordination). Preoperative smoking cessation counseling and postoperative follow-up significantly improves union rates and reduces complications in operatively managed humeral shaft fractures.

Pearls, Pitfalls, and Expert Tips

Surgical Pearls (What Separates Good from Great)

Pearl 1: Identify radial nerve PROXIMALLY first

• Safest approach: Find nerve between long head and medial head of triceps 15-20cm distal to acromion
• Trace nerve distally through spiral groove (maintains continuous visualization)
• Never proceed with fracture manipulation until nerve identified and protected

Pearl 2: Triceps splitting is TRUE internervous

• Split between long head (medial) and lateral head (lateral) - both innervated by radial nerve, NO motor denervation
• Start distally at musculotendinous junction, extend proximally along raphe
• No triceps strength deficit with proper splitting technique

Pearl 3: Posterior plating is tension-side fixation

• Humerus bends with apex anterior during functional loading (biceps/deltoid pull)
• Posterior plate resists tension forces (superior biomechanics vs anterior/lateral plating)
• Explains 25% higher torsional failure strength vs anterolateral plating (Lin 2006)

Pearl 4: Subperiosteal dissection protects nerve

• Elevate periosteum from bone to expose fracture
• Keeps radial nerve in soft tissue envelope (nerve lies on periosteal surface in spiral groove)
• Avoid circumferential stripping (devascularizes fracture, increases nonunion risk)

Pearl 5: Check screw length before drilling

• Measure both cortices with depth gauge (anterior-posterior thickness)
• Subtract 2-3mm for screw length (avoid anterior cortex penetration)
• Radial nerve lies on anterior cortex distal to spiral groove (screw penetration = nerve injury)

Common Pitfalls (and How to Avoid Them)

Pitfall 1: Losing radial nerve in surgical field

• Problem: Nerve disappears during fracture manipulation, cannot relocate
• Solution: Place vessel loop around nerve after identification (marks location), maintain continuous visualization
• Recovery: If nerve lost, STOP - palpate spiral groove gently, use nerve stimulator to locate (muscle contraction confirms nerve)

Pitfall 2: Excessive nerve retraction

• Problem: Aggressive nerve retraction causes ischemia, neuropraxia (iatrogenic palsy)
• Solution: Gentle mobilization only (just enough to protect from fracture/hardware), avoid tension on nerve
• Prevention: If nerve tethered to fracture, mobilize fracture fragments away from nerve (NOT vice versa)

Pitfall 3: Inadequate plate length

• Problem: Short plate (fewer than 6-8 holes) leads to stress concentration, hardware failure, nonunion
• Solution: Minimum 3-4 cortices (6-8 screw holes) proximal and distal to fracture, longer plate for comminuted fractures
• Evidence: Plates with fewer than 3 cortices each side have 3-4x higher failure rate (Rodriguez-Merchan 2005)

Pitfall 4: Over-stripping soft tissue

• Problem: Circumferential periosteal stripping devascularizes fracture, delays union
• Solution: Minimize soft tissue dissection (expose fracture ends only for plate placement), preserve periosteum and muscle attachments
• Biology principle: Fracture hematoma contains osteogenic cells and growth factors - preserve, don't debride excessively

Pitfall 5: Missing distal intra-articular extension

• Problem: Fracture extends into distal humerus (intra-articular), missed on initial X-rays
• Solution: Obtain quality AP/lateral X-rays including elbow joint, low threshold for CT if suspicious
• Intraoperative: If intra-articular extension discovered, convert to distal humerus approach (triceps reflection or olecranon osteotomy)

Expert Tips (From High-Volume Surgeons)

Tip 1: Lateral decubitus position is superior to prone

• Free-drapes arm (easier manipulation and fluoroscopy)
• Gravity assists triceps retraction (muscle falls anteriorly)
• More comfortable for patient (less physiologic stress)
• Easier conversion to anterolateral approach if needed

Tip 2: Use radial nerve PALSY to your advantage

• If pre-existing radial nerve palsy: Nerve already exposed (easier identification)
• Document nerve integrity at surgery (laceration vs contusion vs intact)
• If lacerated: Tag nerve ends, plan delayed grafting (better outcomes than immediate repair in contaminated field)

Tip 3: Holstein-Lewis pattern warrants early exploration

• Distal third oblique fracture + nerve palsy = higher laceration rate (20-30% vs 5-10% for mid-shaft)
• Consider exploration at 6-8 weeks if no recovery (vs 12-16 weeks for mid-shaft fractures)
• Nerve tethered by lateral intermuscular septum (cannot migrate away from fracture)

Tip 4: Compression plating > bridging plating for simple fractures

• Simple/short oblique fractures: Use LC-DCP with eccentric loading for interfragmentary compression
• Comminuted fractures: Use bridging plate (long plate, no compression) to preserve biology
• Lag screws for large butterfly fragments (perpendicular to fracture line, outside plate)

Tip 5: Plan hardware removal at index procedure

• Discuss with patient: Hardware removal likely at 12-18 months (especially if prominent/symptomatic)
• Use low-profile plates (narrow 4.5mm LC-DCP better than broad 4.5mm DCP)
• Adequate soft tissue coverage (avoid direct plate-on-skin contact)