Posterior Approach to the Elbow

The posterior approach to the elbow provides access for distal humerus fractures and total elbow arthroplasty (TEA) via three main techniques: triceps-splitting (Van Gorder) preserves insertion but limits exposure; triceps-reflecting (Bryan-Morrey) elevates triceps with anconeus as a continuous sleeve and is most popular for TEA; olecranon osteotomy (chevron with apex distal) provides maximum articular visualization but requires secure fixation and delays rehabilitation. The ulnar nerve must be identified in the cubital tunnel and protected throughout—injury rate is 8%, higher if not mobilized. Anterior transposition is performed in 60-80% of cases. Anatomic triceps repair through drill holes in the olecranon (at 30° flexion) is critical to prevent extension lag and 15% strength loss.

The posterior approach to the elbow is the workhorse approach for complex distal humerus fractures, total elbow arthroplasty, and posterior elbow pathology. Multiple variations exist to balance exposure against morbidity to the triceps mechanism.

Historical development:

• 1933: Van Gorder described triceps-splitting approach preserving insertion
• 1982: Bryan and Morrey described triceps-reflecting technique with anconeus sleeve
• Classic: Olecranon osteotomy described by multiple surgeons for maximum articular exposure
• Modern: Paratricipital approaches attempt to spare triceps entirely for simple fractures

Current indications for posterior approach:

This approach provides the best exposure for:

• Distal humerus fractures (intra-articular and extra-articular)
• Total elbow arthroplasty (primary and revision)
• Elbow arthrodesis
• Heterotopic ossification excision
• Posterior elbow impingement lesions
• Olecranon fractures requiring distal fixation
• Triceps repair after rupture

Epidemiology:

Distal humerus fractures account for approximately 2% of all fractures in adults, with bimodal distribution (young males and elderly females). In Australia, approximately 300-400 total elbow arthroplasties are performed annually according to the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). The posterior approach is used in over 90% of complex distal humerus fracture fixations.

Outcomes by approach:

Studies comparing approaches show:

• Triceps-splitting: 5% extension lag, excellent for simple fractures
• Bryan-Morrey reflecting: 10% extension lag if poor repair, gold standard for TEA
• Olecranon osteotomy: 15% nonunion/malunion rate, best visualization
• Paratricipital: minimal morbidity but inadequate for complex fractures

The choice of approach represents a balance between adequate exposure for the surgical goal and minimizing morbidity to the extensor mechanism.

Surface Anatomy and Landmarks

Patient positioned - prone or lateral decubitus:

• Prone: patient face down, arm over bolster or arm table
• Lateral: injured side up, arm draped free over bolster
• Both allow gravity-assisted soft tissue retraction
• Elbow flexed 90 degrees opens posterior compartment

Surface landmarks:

• Olecranon tip (palpable subcutaneously)
• Medial epicondyle (prominent medial landmark)
• Lateral epicondyle (less prominent laterally)
• Ulnar nerve palpable in cubital tunnel (medial epicondyle to olecranon)
• Triceps insertion to olecranon

Incision:

• Midline posterior over triceps and olecranon
• Begins 10cm proximal to olecranon tip
• Extends distally 8-10cm along subcutaneous border of ulna
• Curves slightly medial or lateral around olecranon tip
• Total length 15-20cm for adequate exposure

Deep Anatomy and Structures at Risk

Triceps muscle anatomy:

The triceps has three heads converging to a common tendon:

1. Long head - origin from infraglenoid tubercle of scapula
2. Lateral head - origin from posterior humerus (lateral to radial groove)
3. Medial head - origin from posterior humerus (medial to radial groove)

All three insert on the olecranon via a common tendon approximately 4cm wide.

Anconeus muscle:

Small triangular muscle lateral to triceps:

• Origin: lateral epicondyle
• Insertion: lateral olecranon and proximal ulna
• Innervation: radial nerve
• Function: assists elbow extension, stabilizes elbow

In Bryan-Morrey approach, anconeus is elevated with triceps as continuous sleeve.

Ulnar nerve anatomy:

The ulnar nerve is THE critical structure at risk:

• Descends medial intermuscular septum in arm
• Passes through arcade of Struthers (medial head triceps)
• Lies in cubital tunnel (between medial epicondyle and olecranon)
• Covered by Osborne ligament (arcuate ligament)
• Enters flexor carpi ulnaris between two heads
• Recurrent motor branch to FCU given immediately distal to epicondyle

The nerve is vulnerable throughout posterior approaches and must be identified early.

Radial nerve anatomy:

Less commonly injured but important:

• Lies in spiral groove on posterior humerus
• Passes anterior between brachialis and brachioradialis
• Gives posterior interosseous nerve distal to elbow
• At risk with proximal extension of approach or vigorous retraction

Blood supply:

Important vessels include:

• Brachial artery: anterior, at risk if dissection carried too far medially
• Radial collateral artery: anastomoses with radial recurrent, lateral side
• Medial collateral artery: accompanies ulnar nerve, preserve during transposition
• Posterior ulnar recurrent artery: runs with ulnar nerve, may need ligation

Safe zones:

• Ulnar nerve identified early prevents injury
• Midline dissection avoids radial nerve laterally
• Subperiosteal elevation protects neurovascular structures
• Anterior dissection limited to avoid brachial vessels

The posterior approach to the elbow does NOT use a true internervous plane. Instead, it splits or elevates the triceps muscle (innervated by radial nerve) to access the posterior distal humerus and elbow joint.

Triceps innervation:

The entire triceps muscle is innervated by the radial nerve (C7-C8):

• Long head: branch from radial nerve in axilla
• Lateral head: branches from radial nerve in spiral groove
• Medial head: branches from radial nerve in spiral groove

Approach variations:

1. Triceps-splitting (Van Gorder):

   • Splits triceps in midline longitudinally
   • Preserves insertion on olecranon
   • Does NOT denervate muscle (splits between fascicles)
   • Minimal morbidity if split closed properly

2. Triceps-reflecting (Bryan-Morrey):

   • Elevates triceps insertion from olecranon
   • Raises triceps and anconeus as continuous sleeve
   • Temporarily denervates insertion region
   • Requires anatomic repair for function

3. Olecranon osteotomy:

   • Osteotomizes olecranon with triceps attached
   • Preserves triceps insertion entirely
   • Maximizes articular exposure
   • Requires secure osteotomy fixation

Clinical implications:

Because this is NOT an internervous approach, anatomic repair is essential for all approaches that detach or split the triceps. The triceps provides the only active elbow extension, and injury or poor repair results in significant functional impairment.

Anconeus anatomy:

The anconeus (radial nerve innervation) is elevated with triceps in Bryan-Morrey approach, creating a continuous sleeve of extensor tissue. This provides broader lateral exposure and facilitates repair.

Correct positioning optimizes exposure and facilitates surgical technique in posterior elbow approaches.

Position options:

Prone Position

Advantages:

• Both arms accessible (bilateral cases)
• Gravity assists soft tissue retraction
• Stable, secure position
• Easy C-arm access from either side

Setup:

1. Patient prone on chest rolls or Wilson frame
2. Arm abducted 90 degrees on arm table or bolster
3. Elbow flexed 90 degrees hanging off bolster
4. Forearm hanging dependent or supported
5. Head turned away from operative side

Padding critical:

• Chest and iliac crest on supports
• Genitals (male) protected
• Knees and toes padded
• Elbows (opposite side) padded

Lateral Decubitus Position

Advantages:

• Easier for anesthesia (airway access)
• More familiar to shoulder surgeons
• Easy conversion if approach extended

Setup:

1. Lateral position with operative side up
2. Beanbag or supports for stability
3. Arm draped free over bolster or Mayo stand
4. Elbow flexed 90 degrees
5. Dependent axilla protected with roll

Padding critical:

• Axillary roll (two finger-breadths)
• Lateral knee and fibular head
• Dependent arm and shoulder

Supine Position (Less Common)

Can be used with arm across chest on folded towels:

• Allows anterior access if needed
• Less stable for fracture work
• Difficult assistant positioning

Tourniquet:

• Applied to proximal arm after exsanguination
• Pressure 250-300 mmHg for adults
• Limit time to under 120 minutes
• Release for TEA implantation (cement interdigitation)

Fluoroscopy:

• C-arm from contralateral side or over patient
• Obtain AP and lateral views before draping
• Ensure perfect lateral (anterior humeral line through capitellum)
• Check position of arm allows full elbow extension for intraoperative views

Common positioning errors:

• Excessive abduction (brachial plexus stretch)
• Inadequate padding (pressure injuries)
• Arm position preventing full elbow motion
• C-arm position inadequate for intraoperative imaging

Neurovascular Injuries

Ulnar nerve injury (8% incidence):

Mechanisms:

• Direct injury during dissection or retraction
• Stretch injury during elbow manipulation
• Compression from postoperative hematoma or swelling
• Inadequate decompression with scarring

Prevention:

• Early identification and mobilization
• Gentle handling with soft loops
• Anterior transposition for most cases
• Avoid excessive traction during manipulation
• Document baseline function preoperatively

Recognition:

• Preoperative examination critical (fracture may cause injury)
• Postoperative examination in recovery room
• Motor: weakness of FCU, FDP (ring/small), intrinsics
• Sensory: numbness small finger and ulnar half ring finger

Management if injury occurs:

• Document examination findings
• Observe for 3-6 months (most recover)
• Nerve conduction studies at 6-12 weeks
• Consider exploration if no recovery at 6 months
• Occupational therapy for hand function

Radial nerve injury (less than 2%):

Rare but devastating:

• Injury during proximal triceps elevation
• Excessive lateral retraction
• Results in wrist drop and hand weakness

Median nerve injury (rare):

Usually from excessive medial dissection or anterior retraction.

Triceps Complications

Extension lag (10-15% with poor repair):

Causes:

• Inadequate triceps repair
• Repair under insufficient tension
• Sutures pulling through bone (osteoporotic bone)
• Repair failure during rehabilitation

Prevention:

• Anatomic repair through drill holes
• Heavy nonabsorbable suture
• Adequate number of drill holes (3-4 minimum)
• Repair at appropriate tension (30 degrees flexion)
• Protected rehabilitation first 6 weeks

Management:

• Observation for 6-12 months (may improve with therapy)
• Triceps advancement if persistent lag over 30 degrees
• Consider allograft reconstruction for severe cases

Triceps rupture (less than 5%):

Complete failure of repair:

• Usually technical failure (inadequate fixation)
• More common in revision surgery
• Requires surgical repair or reconstruction

Osteotomy Complications

Nonunion (5-10%):

Risk factors:

• Transverse osteotomy (less stable than chevron)
• Inadequate fixation
• Early aggressive motion
• Smoking, diabetes, NSAIDs

Prevention:

• Chevron osteotomy preferred (more stable)
• Rigid fixation (plate better than tension band)
• Protected rehabilitation first 6 weeks
• Avoid NSAIDs for HO prophylaxis if possible

Management:

• Revision fixation with bone graft if symptomatic
• Hardware removal if asymptomatic but painful

Prominent hardware (50% removal rate):

Very common with olecranon fixation:

• K-wires and tension band prominent subcutaneously
• Plate less prominent but still noticeable
• Removal common after fracture/osteotomy union

Elbow Stiffness

Incidence: 30-50% have some limitation of motion

Risk factors:

• Severe initial trauma
• Prolonged immobilization (osteotomy)
• Heterotopic ossification
• Inadequate physiotherapy

Prevention:

• Early motion (soft tissue approaches)
• Indomethacin for HO prophylaxis (75mg daily for 6 weeks per Australian eTG)
• Aggressive physiotherapy
• Avoid prolonged immobilization

Management:

• Physiotherapy and stretching program
• Consider manipulation under anesthesia at 3-6 months
• Arthroscopic or open contracture release if persistent

Infection

Risk: 2-5% superficial, 1-3% deep

Prevention:

• Cefazolin 2g IV pre-incision (Australian eTG guidelines)
• Redose every 4 hours if case over 4 hours
• Meticulous soft tissue handling
• Consider drain for dead space
• Layered closure

Management:

• Superficial: oral antibiotics, local wound care
• Deep early (under 3 weeks): irrigation and debridement, retain hardware
• Deep late: hardware removal after union, long-term antibiotics

Heterotopic Ossification

Incidence: 10-30% radiographic, 5-10% clinically significant

Risk factors:

• High-energy trauma
• Head injury
• Delayed surgery
• Extensive soft tissue dissection

Prevention:

• Indomethacin 75mg daily for 6 weeks (eTG guideline)
• Single-dose radiation (700-800 cGy within 72 hours postop) alternative
• Gentle soft tissue handling
• Early motion

Management:

• Observation for 12-18 months (maturation)
• Excision if mature and limiting function
• Restart prophylaxis after excision

Immediate Postoperative (0-48 hours)

Recovery room:

• Document neurovascular examination (ulnar nerve especially)
• Check motor function: wrist/finger extension (radial), intrinsics (ulnar)
• Check sensory function: all nerve distributions
• AP and lateral elbow radiographs to confirm reduction/fixation

Splinting:

• Posterior splint at 90 degrees flexion
• Forearm neutral rotation
• Well-padded to allow for swelling
• Avoid circumferential cast initially (compartment syndrome risk)

Pain management:

• Multimodal analgesia (reduce opioid use)
• Regional nerve block if available (interscalene or peripheral)
• NSAIDs cautious if osteotomy performed (nonunion risk)
• Ice and elevation

DVT prophylaxis:

• Low molecular weight heparin (Australian eTG guidelines) or
• Rivaroxaban 10mg daily for upper extremity high risk patients
• Consider prophylaxis for inpatient stay

Early Postoperative (Week 1-6)

Mobilization protocol depends on approach:

Soft tissue approach (triceps-split or reflecting):

• Begin gentle active-assisted ROM at 2-7 days
• Gravity-assisted extension
• Active flexion allowed
• Avoid active resisted extension for 6 weeks (triceps repair protection)
• Target: 30-130 degrees by 6 weeks

Olecranon osteotomy:

• Protected motion for 6 weeks until osteotomy heals
• Passive ROM only for first 3 weeks
• Active-assisted ROM weeks 3-6
• Active ROM after radiographic union at 6 weeks
• More conservative to protect osteotomy

Physiotherapy:

• Critical for preventing stiffness
• Supervised therapy 2-3 times weekly
• Home exercise program daily
• Focus on terminal flexion and extension
• Gentle passive stretching

Radiographic follow-up:

• 2 weeks: check reduction maintained
• 6 weeks: assess fracture/osteotomy healing
• 12 weeks: confirm union

Intermediate (6 weeks to 3 months)

Progression:

• Remove splint at 6 weeks (if fracture/osteotomy stable)
• Begin active resisted extension (triceps strengthening)
• Progressive resistance exercises
• Continue ROM exercises
• Goal: functional arc 30-130 degrees

Strengthening program:

• Isometric exercises initially
• Progressive resistance with bands/weights
• Eccentric triceps exercises
• Functional activities (lifting, carrying)

Return to activities:

• Light activities at 6-8 weeks
• Lifting restrictions under 5kg until 12 weeks
• Progressive increase in demands

Long-term (3-6 months and beyond)

Advanced strengthening:

• Heavy resistance exercises
• Sport-specific training if applicable
• Return to manual labor 4-6 months

Return to sport:

• Non-contact sports: 3-4 months
• Contact sports: 6 months minimum
• Individualized based on fracture healing and strength

Expected outcomes:

ROM:

• 90% achieve functional arc (30-130 degrees)
• 10-20% have some limitation
• Terminal extension loss common (10-20 degrees)

Strength:

• 80-90% of contralateral strength at 1 year
• Triceps-splitting: 95% strength
• Bryan-Morrey: 85-90% strength if good repair
• Osteotomy: 85% strength

Function:

• Most achieve good to excellent function
• Simple fractures better than comminuted
• TEA outcomes depend on indication and bone quality

AOANJRR data for total elbow arthroplasty: According to the Australian Orthopaedic Association National Joint Replacement Registry 2023 report, 300-400 total elbow arthroplasties are performed annually in Australia. The Bryan-Morrey triceps-reflecting approach is used in over 80% of cases, with the posterior approach being universal for TEA. Indications include rheumatoid arthritis (40%), trauma (30%), and osteoarthritis (20%). Linked cemented TEA demonstrates 88% survival at 10 years, compared to 85% for uncemented implants. Revision rates are higher for trauma indication (35% at 10 years) compared to rheumatoid arthritis (15% at 10 years).

PBS and pharmaceutical guidelines: Indomethacin is PBS-listed for heterotopic ossification prophylaxis after major joint surgery. The Australian eTG guideline recommends indomethacin 75mg daily (modified release) or 25mg three times daily for 6 weeks as first-line prophylaxis in high-risk cases. Single-dose radiation therapy (700-800 cGy within 72 hours postoperatively) is available at major centers as an alternative, particularly when there is concern about NSAID effects on bone healing.

eTG antibiotic guidelines: Australian eTG guidelines for surgical prophylaxis in elbow surgery recommend cefazolin 2g IV at induction (within 60 minutes of incision), with redosing every 4 hours if the procedure exceeds 4 hours. Duration is typically a single dose, or maximum 24 hours for complex cases. For penicillin allergy, vancomycin 25-30 mg/kg IV is recommended, infused over 60-120 minutes starting within 120 minutes of incision. High-risk patients (diabetes, immunosuppression, revision surgery) may require extended prophylaxis to 24 hours postoperatively based on individual risk assessment.

Australian injury epidemiology: Distal humerus fractures demonstrate a bimodal distribution in Australia, affecting young males through high-energy trauma and elderly females through falls. The incidence is approximately 5-6 per 100,000 population per year. Falls account for 60% of cases in the elderly population, while motor vehicle accidents account for 30% in young adults. Work-related injuries account for 10% and are covered by WorkCover schemes. Return to work timing varies from 6-8 weeks for office work to 4-6 months for manual labor. Functional outcome scores such as QuickDASH are used for impairment assessment in compensation claims.

Medicare and healthcare delivery: Posterior elbow approaches for fracture fixation and arthroplasty are covered under Medicare for both public and private hospital settings. These procedures are typically performed in public hospitals for acute trauma cases or private hospitals for elective arthroplasty, with funding arrangements varying based on insurance status and indication. Multidisciplinary team involvement including hand therapy and occupational therapy is essential for optimal outcomes, particularly given the high rate of stiffness complications requiring intensive rehabilitation.