Rheumatoid Elbow Synovectomy & Radial Head Excision

Primary Indications:

• Persistent elbow synovitis despite 6 months optimal medical management (DMARDs, biologics)
• Painful limited range of motion interfering with ADLs
• Larsen Grade I-III disease (preserved joint space on radiographs)
• Painful radial head involvement with crepitus, erosions, or cystic changes
• Radiocapitellar impingement causing mechanical symptoms
• Palpable synovial thickening with effusion

Contraindications:

• Larsen Grade IV-V disease (advanced joint destruction) - consider arthroplasty
• Active infection or recent septic arthritis
• Severe medical comorbidities precluding surgery
• Poor bone quality with fracture risk
• Combined MCL and radial head insufficiency (causes severe valgus instability)
• Unrealistic patient expectations

Larsen Classification System:

• Grade 0: Normal radiographs, no abnormalities
• Grade I: Soft tissue swelling, periarticular osteopenia, NO erosions present
• Grade II: Erosions present, joint space preserved (normal width)
• Grade III: Joint space narrowing with less than 50% loss
• Grade IV: Joint space narrowing with more than 50% loss
• Grade V: Complete joint destruction, ankylosis, or complete obliteration

Surgical Decision Algorithm:

• Grades I-II: Synovectomy alone, preserve radial head if possible
• Grade III: Synovectomy + radial head excision if symptomatic
• Grades IV-V: Total elbow arthroplasty or interposition arthroplasty

Expected Outcomes:

• Pain relief in 70-80% at 5 years
• Improved ROM by 20-30 degrees average
• Recurrent synovitis in 30-50% at 5-10 years
• Buys 5-10 years before arthroplasty consideration
• Patient satisfaction 75-85%

Clinical Examination:

• ROM measurement: Normal elbow flexion 0-150°, pronation/supination 80°/80°
• Flexion contracture quantification (common in RA)
• Valgus/varus stability testing (MCL/LCL integrity)
• Ulnar nerve assessment (Tinel's, subluxation, motor/sensory function)
• Radial head palpation with forearm rotation (crepitus, pain, synovitis)

Imaging:

• AP/Lateral radiographs: Larsen grading, joint space preservation, erosions
• Oblique views: Better visualization of radial head, radiocapitellar joint
• MRI (optional): Synovial hypertrophy quantification, cartilage assessment
• CT (if arthroplasty considered): Bone stock assessment, deformity evaluation

Medical Optimization:

• Rheumatology coordination for medication management
• DMARDs: Continue methotrexate (low infection risk), consider holding biologics 1-2 weeks perioperatively
• Steroids: Continue physiologic doses, stress dose coverage if prolonged use
• Anticoagulation: Manage per guidelines (aspirin continue, warfarin bridge if needed)
• Nutritional status: RA patients often malnourished, optimize protein intake

Lateral Elbow Anatomy:

Kocher Interval (TRUE Internervous Plane):

• Posterior: Anconeus muscle (supplied by radial nerve main trunk)
• Anterior: Extensor carpi ulnaris (supplied by posterior interosseous nerve)
• This is a TRUE internervous plane - different nerve supply to muscles
• Deep to interval: Joint capsule, radiocapitellar joint, lateral collateral ligament complex

Lateral Collateral Ligament Complex:

1. Radial Collateral Ligament (RCL): Lateral epicondyle to annular ligament, provides varus stability
2. Lateral Ulnar Collateral Ligament (LUCL): MOST IMPORTANT - lateral epicondyle to supinator crest of ulna, prevents PLRI
3. Annular Ligament: Encircles radial head, allows rotation, blends with RCL
4. Accessory LCL: Variable, blends with annular ligament

Posterior Interosseous Nerve (PIN) Course:

• Branches from radial nerve 6cm proximal to radiocapitellar joint
• Radial nerve divides into superficial (sensory) and deep (motor = PIN) branches
• PIN dives posteriorly through supinator muscle
• Enters supinator at Arcade of Frohse (fibrous arch at proximal supinator edge)
• Winds around radial neck from posterior to ANTERIOR
• At radial neck level (4-6cm distal to joint), PIN lies ANTERIOR to bone
• Supplies all finger/thumb extensors: EPL, EPB, EIP, EDC, EDM, ECU proximally

Radial Nerve Main Trunk:

• Travels in spiral groove posterolateral humerus
• 10-12cm proximal to lateral epicondyle
• Pierces lateral intermuscular septum
• Travels anterior to lateral epicondyle between brachialis and brachioradialis
• Divides into superficial and deep (PIN) branches at radiocapitellar joint level

Ulnar Nerve:

• Posterior to medial epicondyle, 2-3cm from palpable prominence
• Travels in cubital tunnel (bony floor: medial epicondyle and olecranon)
• Osborne's ligament (arcuate ligament) forms roof of tunnel
• Passes between two heads of FCU distally
• Commonly compressed or subluxing in RA patients

Median Nerve and Brachial Artery:

• Medial to biceps tendon in antecubital fossa
• Deep to lacertus fibrosus (bicipital aponeurosis)
• Median nerve crosses anterior to brachialis
• Passes between two heads of pronator teres
• Stay lateral and on bone to avoid these structures

Patient Positioning:

• Supine with arm across chest: Arm rests on bolster, exposes lateral elbow, comfortable for patient
• Lateral decubitus: Alternative position, arm supported on arm board
• Prone: Rarely used for elbow, limits anterior access
• General or regional anesthesia (interscalene or axillary block)
• Tourniquet high on arm (250-300 mmHg), exsanguinate with elevation

Landmarks:

• Lateral epicondyle: Most prominent lateral bony landmark
• Radial head: Palpate 2cm distal to lateral epicondyle, rotates with forearm
• Olecranon: Posterior prominence, tip easily palpable
• Ulnar nerve: 2-3cm posterior to medial epicondyle (palpable, rolls under finger)

Skin Incision:

• 8-10cm longitudinal incision from lateral epicondyle distally
• Centered over radial head
• Extends proximally over lateral epicondyle, distally over proximal radius
• Can curve posteriorly if posterior access needed

Superficial Dissection:

• Incise subcutaneous tissue in line with skin
• Identify fascia between anconeus (posterior) and ECU (anterior)
• Anconeus fibers run obliquely from lateral epicondyle to ulna
• ECU fibers run longitudinally along posterior forearm
• Develop interval by blunt dissection (finger or scissors)

Deep Dissection:

• Split fascia between muscles
• Anconeus retracts posteriorly, ECU anteriorly
• Visualize joint capsule deep to muscles
• Identify lateral collateral ligament complex (preserve)
• Make longitudinal capsulotomy ANTERIOR to LCL complex

Internervous Plane Advantage:

• No motor nerves crossed during dissection
• Anconeus (radial nerve), ECU (PIN) have different innervation
• Safe approach with minimal denervation risk
• Direct access to radiocapitellar joint and lateral compartment

Step 1: Assessment & Planning

Assessment & Planning: Clinical assessment of ROM (normal flexion 0-150°, pronation/supination 80°/80°), stability testing, neurovascular examination. Review imaging: AP/lateral radiographs for Larsen classification, assess articular cartilage preservation. LARSEN grading: 0 equals normal, I equals soft tissue swelling only, II equals erosions present, III equals less than 50% joint space loss, IV equals more than 50% loss, V equals complete destruction. Surgery appropriate for Grades I-III with preserved joint space.

Step 2: Positioning & Landmarks

Positioning: Supine with arm across chest on bolster (best exposure of lateral elbow). Alternatively lateral decubitus with arm supported. Tourniquet high on arm (250-300 mmHg). Mark bony landmarks: LATERAL EPICONDYLE (most prominent), RADIAL HEAD (palpate with forearm rotation, 2cm distal to epicondyle), OLECRANON (posterior tip). Plan incision along lateral epicondyle-radial head axis.

Step 3: Lateral (Kocher) Incision

Incision: 8-10cm longitudinal incision from lateral epicondyle distally over radial head. Extend proximally 3-4cm above epicondyle, distally 5-6cm below. Divide subcutaneous tissue in line with skin. Identify fascial interval between ANCONEUS (posterior) and ECU (anterior). TRUE INTERNERVOUS PLANE: Anconeus supplied by radial nerve main trunk, ECU by posterior interosseous nerve (PIN).

Step 4: Superficial Dissection

Superficial dissection: Divide fascia between anconeus and ECU sharply with knife. Develop interval by blunt dissection (finger or Mayo scissors). Anconeus fibers run obliquely posteriorly, ECU fibers longitudinal. Retract anconeus posteriorly, ECU anteriorly. Visualize lateral collateral ligament complex deep - PRESERVE intact for stability. Identify joint capsule deep to LCL.

Step 5: Capsulotomy & Synovectomy

Capsulotomy: Longitudinal capsular incision ANTERIOR to LCL complex. Extend proximally and distally along joint line. Preserve LCL complex posteriorly. SYNOVECTOMY: Remove hypertrophic inflamed synovium using rongeurs, shavers, small curettes. Clear anterior compartment thoroughly. Remove pannus from articular surfaces of capitellum and radial head. Access posterior compartment by extending capsulotomy posteromedially (be aware of ulnar nerve location).

Step 6: Radial Head Assessment

Assessment: Inspect radial head for erosions, cystic changes, cartilage loss. Palpate for crepitus with passive pronation/supination. Assess radiocapitellar articulation - capitellum erosions, joint space narrowing. If radial head painful, eroded, cystic, or causing impingement, proceed with excision. If intact cartilage and pain-free, preserve radial head (contributes to valgus stability, longitudinal forearm stability).

Step 7: Radial Head Excision

Excision technique: CRITICAL STEP - Protect PIN by placing forearm in FULL SUPINATION (moves PIN anteriorly away from radial neck). Circumferentially expose radial neck with subperiosteal dissection using periosteal elevator. Stay on bone. Divide annular ligament circumferentially with knife. Use oscillating saw to perform osteotomy of radial neck 2-3mm distal to radiocapitellar joint (just below articular surface). Remove radial head specimen. Smooth bony edges with rongeur. PRESERVE 2-3cm of proximal radius distal to osteotomy - excessive excision causes proximal radial migration and DRUJ instability.

Step 8: Anterior Capsular Release (if flexion contracture)

Release for contracture: If flexion contracture exceeds 30°: Perform anterior capsular release. Excise thickened anterior capsule sharply. Release adhesions in coronoid fossa using curette. Elevate brachialis muscle fibers off anterior distal humerus. Extend release proximally if needed. Goal: achieve less than 30° flexion contracture intraoperatively (some loss expected postoperatively).

Step 9: Posterior Compartment Access (if needed)

Posterior access: For posterior synovitis or olecranon impingement: Extend interval posteromedially between anconeus and FCU. Develop plane carefully (ulnar nerve nearby). Access posterior elbow compartment. Remove posterior synovium from olecranon fossa. Excise olecranon osteophytes if causing impingement (blocking flexion). Remove loose bodies if present.

Step 10: Ulnar Nerve Assessment & Decompression

Ulnar nerve management: If preoperative ulnar nerve symptoms (numbness, tingling, weakness in ulnar distribution): Identify ulnar nerve posterior to medial epicondyle. Assess for subluxation (with elbow flexion), compression, synovial compression. Perform IN-SITU DECOMPRESSION: Release Osborne's ligament (arcuate ligament over cubital tunnel). Divide arcade of Struthers proximally (medial intermuscular septum). Divide FCU fascia distally. Neurolysis if perineural scarring present. Anterior transposition if severe symptoms, instability, or failed in-situ decompression.

Step 11: Range of Motion Assessment

ROM testing: Release tourniquet temporarily. Passively assess ROM: Flexion (goal 130-140°), Extension (goal less than 30° flexion contracture), Pronation/supination (goal 70°/70° each direction). Test stability: Valgus stress (MCL integrity), Varus stress (LCL integrity), Posterolateral rotatory instability (lateral pivot shift test). If unstable, consider ligament repair (rare in synovectomy, more common if ligament injured iatrogenically).

Step 12: Hemostasis & Drain Placement

Hemostasis: Release tourniquet definitively. Achieve meticulous hemostasis with bipolar electrocautery. RA patients often on anticoagulation (aspirin, warfarin), DMARDs, steroids - all impair hemostasis. Irrigate thoroughly. Place small drain (10Fr round or 7mm flat drain) - exit posteriorly to avoid radial nerve. Avoid large bore drains (increase bleeding). Consider fibrin sealant or tranexamic acid if oozy field.

Step 13: Closure

Layered closure: Attempt capsular closure if tissue adequate (often thin and deficient in RA). Use 2-0 absorbable suture. Close ECU-anconeus interval with 2-0 Vicryl interrupted sutures. Subcutaneous layer with 3-0 Vicryl. Skin closure with 3-0 or 4-0 nylon interrupted vertical mattress sutures (allows drainage) OR subcuticular 4-0 Monocryl. Interrupted sutures preferred in RA (easier to remove if wound issues, allows drainage between sutures).

Step 14: Dressing & Splinting

Postoperative dressing: Apply bulky soft dressing with fluffed gauze. Posterior splint in 90° flexion, neutral forearm rotation (mid pronation-supination). Splint for comfort only, NOT rigid immobilization. Remove drain at 24-48hrs when output less than 30mL per 8hrs. Early ROM critical - begin at 48-72hrs.

Step 15: Postoperative Rehabilitation

Rehabilitation protocol: Remove drain 24-48hrs. Begin gentle active ROM at 48-72hrs (avoid passive stretching initially - increases inflammation). Frequency: 5-10 minutes every 1-2 hours. Progress to active-assisted ROM at 1-2 weeks. Therapist-supervised therapy at 2 weeks. Full active ROM by 3-4 weeks. Strengthening at 6-8 weeks (light resistance, progressive). Monitor for recurrent synovitis (warmth, swelling, loss of motion). Coordinate with rheumatology for optimal medical management (DMARDs, biologics) to slow disease progression.