import { OnePagerSummary, ExamWarning, InfoCardGrid, InfoCard, MnemonicCard, EvidenceCard, VivaScenarioSection, VivaScenario, ExamCheatSheet, ContentSection, ExamPearl, SafetyAlert, NumberHighlightRow, NumberHighlight, Tabs, Tab, ComparisonTable } from '@/components/mdx' **Ulnar nerve**. Location: Passes behind medial epicondyle in cubital tunnel, then between two heads of FCU. Protection: Identify FIRST in approach, mobilize with vessel loop, transpose anteriorly if needed. NEVER leave compressed under plates. **Radial nerve**. Location: Posterior arm in spiral groove, then anterior at lateral intermuscular septum ~10cm proximal to lateral epicondyle. Protection: Limit proximal dissection, palpate if extending approach proximally, protect during plate application. **Posterior interosseous nerve (PIN)**. Location: Within supinator muscle, vulnerable if extending laterally. Protection: Maintain forearm in supination if lateral exposure needed, avoid retraction beyond radial head. **Triceps tendon and olecranon articular cartilage**. Location: Olecranon osteotomy site. Protection: Chevron osteotomy at bare area (apex of trochlear notch), score with saw, complete with osteotome. Precise anatomical reduction required. **Brachial artery and median nerve**. Location: Anterior to elbow in cubital fossa. Protection: Avoid anterior penetration during fixation, confirm no anterior screw/K-wire penetration on fluoroscopy, flex elbow during posterior dissection. ## AO/OTA Classification of Distal Humerus Fractures (13) **Type A: Extra-articular** - A1: Avulsion - A2: Simple metaphyseal - A3: Metaphyseal comminuted - Treatment: Usually lateral or medial approach sufficient **Type B: Partial Articular (single column)** - B1: Lateral sagittal (capitellum) - B2: Medial sagittal (trochlea) - B3: Coronal (Dubberley classification for capitellum) - Treatment: Approach matched to fracture pattern **Type C: Complete Articular (bicolumnar)** - C1: Articular simple, metaphyseal simple - C2: Articular simple, metaphyseal comminuted - C3: Articular comminuted - Treatment: Posterior approach with olecranon osteotomy optimal **Exam Key Points:** - Type C fractures are most common adult pattern - C3 fractures have worst prognosis - Bimodal distribution: young males (high energy), elderly females (osteoporotic) - 90% are extra-articular in children (supracondylar) ## Plate Configuration Debate **90-90 Configuration (Traditional)** - Medial plate on medial column - Lateral plate on posterolateral column - Plates perpendicular to each other - Creates box-like construct **Parallel Plating (Modern)** - Both plates on posterior surface - One medial, one lateral - Plates parallel to each other - May be more biomechanically stable **Evidence Summary:** - O'Driscoll et al: Parallel plating biomechanically superior - Sanchez-Sotelo et al: No significant clinical difference - Both achieve union rates greater than 95% - Choice depends on fracture pattern and surgeon preference **When to Choose:** - 90-90: Better for comminuted medial column, allows more distal fixation medially - Parallel: Better mechanical properties, useful for osteoporotic bone - Key: Adequate plate length, at least 2 screws in distal fragment, long interdigitating screws **Exam Tip:** Know both techniques and be able to justify your choice based on fracture pattern and bone quality. ## Ulnar Nerve Decision Algorithm **Identification** - ALWAYS identify ulnar nerve early in approach - Located posterior to medial epicondyle - Mobilize from arcade of Struthers to first motor branch in FCU **Options:** 1. **In-situ protection**: Safe if hardware won't overlie nerve 2. **Subcutaneous transposition**: Most common, anterior to medial epicondyle 3. **Submuscular transposition**: For revision or severe scarring 4. **Intramuscular transposition**: Rarely used **Indications for Transposition:** - Pre-operative ulnar nerve symptoms - Plate will overlie cubital tunnel - Significant medial column comminution - Revision surgery - Concern for post-operative compression **Technique for Subcutaneous Transposition:** 1. Mobilize nerve with surrounding tissue (internal neurolysis unnecessary) 2. Release intermuscular septum to prevent kinking 3. Transpose anterior to medial epicondyle 4. Secure with fascial sling to prevent subluxation **Outcomes:** - Transposition associated with 15-20% transient symptoms - Most resolve by 6 months - Permanent deficit rare if meticulous technique ## Olecranon Osteotomy Technique **Indications:** - AO Type C fractures (complete articular) - Need for visualization of trochlea - Complex B2/B3 patterns **Location:** - At "bare area" of sigmoid notch (apex of trochlear notch) - Approximately 2cm distal to tip - No articular cartilage at this level **Types:** - **Chevron (Inverted V)**: Most common, provides rotational stability - **Transverse**: Simpler but less inherently stable - **Step-cut**: Alternative for osteoporotic bone **Technique:** 1. Pre-drill for later fixation (6.5mm cannulated screw or plate holes) 2. Mark osteotomy with electrocautery 3. Score cortices with oscillating saw (avoid articular surface) 4. Complete with thin osteotome - preserves cartilage 5. Reflect olecranon with triceps proximally **Fixation:** - Tension band wire (traditional): Converts extension to compression - Plate fixation: Better for comminuted or revision - 6.5mm cannulated screw with washer: Good for simple osteotomy **Complications:** - Non-union: 2-5% - Hardware prominence: 40-50% (often requires removal) - Infection at osteotomy site: Less than 1% ## Post-operative Rehabilitation Protocol **Immediate (Days 1-7):** - Splint in 45-90° flexion (comfortable position) - Remove splint day 1-3 for gentle ROM - Active-assisted flexion/extension - No passive stretch (risk of HO) - Overhead elevation to reduce swelling **Early (Weeks 1-6):** - Discard splint by week 2 if stable - Hinged elbow brace if needed for protection - Active ROM exercises 5-6 times daily - Target: 30-130° by 6 weeks - Forearm rotation exercises - No lifting more than 1kg **Intermediate (Weeks 6-12):** - Progressive strengthening - Full ROM goal achieved - Lifting restrictions gradually increased - Dynamic splinting if stiffness developing **Late (Months 3-6):** - Return to sport/work - Full activity 4-6 months - Hardware removal if symptomatic (40-50%) **HO Prophylaxis:** - Indomethacin 75mg daily for 6 weeks (per eTG), OR - Single-dose radiation 700cGy if NSAIDs contraindicated - Indicated for: severe soft tissue injury, associated brain injury, previous HO **Patient Position**: Lateral decubitus with arm over padded bolster (allows elbow extension), OR prone position on chest rolls. Arm draped free to allow full ROM assessment. **Surgical Approach**: Posterior midline approach with olecranon osteotomy provides best visualization of articular surface. **Tourniquet**: Sterile tourniquet on upper arm (avoid brachial plexus compression from non-sterile tourniquet). **Equipment**: Pre-contoured anatomical distal humerus plates (medial and lateral), 2.7mm and 3.5mm screws, tension band wire set, fluoroscopy. ### Step 1: Positioning and Incision Position in lateral decubitus with arm over bolster allowing full elbow extension, or prone. Make posterior midline incision 15-20cm centered on olecranon tip, curving laterally around the olecranon to avoid direct pressure on skin over bony prominence. Identify and protect medial cutaneous nerve of forearm in subcutaneous tissue. **Technical Tip**: EXAM KEY: Posterior midline incision curved laterally around olecranon tip avoids pressure over bony prominence. Skin flaps raised full-thickness. ULNAR NERVE identification is FIRST PRIORITY - find it proximally in the posterior compartment before any deep dissection. - Ulnar nerve injury if not identified early - Skin necrosis over olecranon if incision directly over tip - Medial cutaneous nerve of forearm injury (causes numbness medial forearm) ### Step 2: Ulnar Nerve Identification and Management Identify ulnar nerve behind medial epicondyle in cubital tunnel, proximal to its entry between the two heads of FCU. Trace from arcade of Struthers proximally to first motor branch distally. Protect with vessel loop. Decide: in-situ protection if hardware won't overlie nerve, or anterior subcutaneous transposition if plates will compress or if pre-operative symptoms present. **Technical Tip**: EXAM KEY: Ulnar nerve is at risk throughout procedure. Identify it FIRST in every case. Release arcade of Struthers, intermuscular septum, and FCU fascia if transposing. For transposition, mobilize 10cm of nerve with surrounding vascular tissue (don't strip adventitia). NEVER leave nerve under hardware. - Ulnar nerve injury from traction - Devascularization during aggressive mobilization - Failing to release intermuscular septum (causes kinking if transposed) - Leaving nerve under plates ### Step 3: Olecranon Osteotomy Perform chevron (inverted V) osteotomy at bare area of sigmoid notch. Pre-drill olecranon for later screw or tension band fixation. Mark osteotomy line with electrocautery. Score cortices with oscillating saw to depth of 2-3mm, avoiding articular cartilage. Complete osteotomy with thin osteotome, applying controlled force. Reflect olecranon fragment with attached triceps proximally to expose distal humerus articular surface. **Technical Tip**: EXAM KEY: Chevron osteotomy at bare area (apex of trochlear notch) provides best visualization and rotational stability for fixation. Pre-drilling is ESSENTIAL - cannot drill accurately after osteotomy. Score with saw, complete with osteotome to protect articular cartilage at osteotomy edges. The exposed view of trochlea is unparalleled by any other approach. - Articular cartilage damage if osteotomy too distal - Triceps avulsion if too much traction on reflected fragment - Inadequate exposure if osteotomy too proximal - Inability to fix osteotomy if pre-drill holes lost ### Step 4: Fracture Assessment and Articular Reduction Assess fracture pattern with direct visualization. Irrigate and remove small loose fragments. Identify all articular fragments and their orientation. REDUCE ARTICULAR SURFACE FIRST - this is the key principle. Reconstruct trochlea by reducing condyles to each other. Use provisional K-wire fixation. Articular reduction must be anatomic, aiming for less than 2mm step-off. Consider bone graft or substitute for central comminution. **Technical Tip**: EXAM KEY: "ARTICULAR FIRST" - reconstruct the trochlea anatomically before addressing the columns. The articular block must be anatomically reconstructed, then attached as a unit to the metaphysis and diaphysis. Step-off more than 2mm leads to post-traumatic arthritis. Provisional K-wires hold reduction while assessing fit. - Articular malreduction leading to post-traumatic OA - Trochlear fragmentation from aggressive manipulation - Missing posterior fragments (common and easily overlooked) - Creating additional comminution during reduction attempts ### Step 5: Column Reconstruction and Plate Application Attach reconstructed articular segment to metaphysis and diaphysis. Apply pre-contoured anatomical plates - medial plate on medial column ridge, lateral plate on posterolateral column. Use either 90-90 configuration or parallel plating based on fracture pattern and bone quality. Plates should be long enough to span metaphysis to diaphysis with at least 2-3 screws in each major fragment. **Technical Tip**: EXAM KEY: Two-plate principle is mandatory for bicolumnar fractures. Parallel plating may be biomechanically superior but 90-90 works well. Key is adequate plate length extending onto diaphysis. Use long screws that interdigitate through the articular segment - provides compression and stability across the distal construct. Anatomical pre-contoured plates reduce need for bending and improve fit. - Inadequate fixation with short plates or insufficient screws - Hardware prominence (especially medially over thin soft tissue) - Intra-articular screw penetration - Ulnar nerve impingement from medial plate ### Step 6: Screw Placement and Interdigitation Place screws through plates ensuring cortical purchase. Use long screws through distal holes to interdigitate through the articular block - one from medial plate into lateral condyle, one from lateral plate into medial condyle. This creates a stable construct. Check under fluoroscopy that no screws penetrate articular surface or olecranon fossa (blocks extension). Ensure screws avoid ulnar nerve course. **Technical Tip**: EXAM KEY: Long interdigitating screws are critical for construct stability - medial plate screws into lateral condyle and vice versa. Check olecranon fossa clearance - posterior screws can block extension. Fluoroscopy in full extension confirms no fossa impingement. At least 5-6 screws per plate, minimum 2 in each major fragment. Pre-contoured plates reduce need for contouring. - Intra-articular screw penetration (check all screws on fluoro) - Olecranon fossa screw impingement blocking extension - Inadequate screw length (must be bicortical where possible) - Screw interference with ulnar nerve path ### Step 7: Olecranon Osteotomy Fixation Reduce olecranon osteotomy anatomically. Fix using tension band wire technique (converts extension force to compression), or plate fixation, or 6.5mm cannulated screw with washer. For tension band: two parallel K-wires from olecranon tip into anterior ulnar cortex, figure-of-8 wire through triceps insertion and around K-wires. Alternative: pre-contoured olecranon plate if comminuted or osteoporotic. **Technical Tip**: EXAM KEY: Tension band principle - figure-of-8 wire anterior to the axis of rotation converts triceps extension force into compression at the osteotomy site. K-wires must penetrate anterior cortex. Bury K-wire tips to reduce hardware prominence. Alternative: 6.5mm cannulated screw for simple chevron osteotomy (less prominent, good compression). Plate for comminuted osteotomy or poor bone. - Olecranon non-union (2-5% with any technique) - Hardware prominence requiring later removal (40-50%) - Articular step at osteotomy site - K-wire migration ### Step 8: Range of Motion Assessment Take elbow through full ROM on table. Check: full extension (should reach 0° unless pre-existing contracture), flexion to 140°, full pronation and supination. Confirm no impingement from screws or plates. Assess stability of fixation through arc. Check ulnar nerve position - should not be compressed at any position. Ensure olecranon osteotomy stable through motion. **Technical Tip**: EXAM KEY: Intraoperative ROM assessment is essential - any block to motion must be identified and addressed before closure. Extension block suggests olecranon fossa impingement or anterior hardware. Flexion block suggests posterior hardware or swelling. Confirm ulnar nerve not stretched or compressed in flexion. Stable construct allows early motion. - Unrecognized impingement leading to permanent stiffness - Accepting restricted motion that could be corrected - Missing unstable fixation requiring additional screws - Ulnar nerve compression in flexion ### Step 9: Final Imaging and Wound Closure Obtain final fluoroscopy: AP, lateral, and oblique views. Confirm anatomical articular reduction, adequate plate position and length, no intra-articular or olecranon fossa hardware. Irrigate copiously (minimum 3L). Release tourniquet and achieve meticulous hemostasis. Place drain deep to triceps. If ulnar nerve transposed, confirm it is in subcutaneous position without tension. Close triceps fascia, subcutaneous tissue, and skin. Apply well-padded splint in 45-90° flexion. **Technical Tip**: EXAM KEY: Final fluoroscopy must confirm articular congruity, adequate fixation, and no intra-articular hardware. Lateral view key for olecranon fossa clearance. Close triceps fascia over drain to reduce dead space. Splint in 45-90° flexion for comfort, but early motion (day 1-3) is critical for outcome. HO prophylaxis if indicated (brain injury, high-energy trauma). - Unrecognized malreduction on imaging - Hematoma from inadequate hemostasis - Wound breakdown over olecranon - Ulnar nerve compression from closure tension ### Step 10: Post-operative Protocol Splint for comfort days 1-3, then remove for active-assisted ROM exercises. Early motion is CRITICAL - stiffness is the most common complication. Active elbow flexion/extension and forearm rotation. No passive stretching initially (increases HO risk). Hinged brace for protection if needed. No lifting more than 1kg for 6-8 weeks. Outpatient physiotherapy supervision. Serial radiographs at 2, 6, and 12 weeks. **Technical Tip**: EXAM KEY: Early motion (day 1-3) is the single most important factor in preventing stiffness. Active-assisted ROM, not passive stretching. Overhead elevation reduces swelling. HO prophylaxis with indomethacin 75mg daily for 6 weeks (per eTG) or single-dose radiation if NSAIDs contraindicated. Hardware removal for prominence often required (40-50%) once healed at 12-18 months. - Stiffness from prolonged immobilization (most common complication) - Heterotopic ossification (especially with brain injury) - Wound dehiscence with early motion - Hardware failure if weight-bearing too early **Immediate (Days 1-3):** - Posterior splint in 45-90° flexion for comfort - Elevation above heart level to reduce swelling - Ice therapy - Remove splint day 1-3 for gentle active-assisted ROM - Wound check at 2 weeks, suture removal **Early (Weeks 1-6):** - Active-assisted ROM exercises 5-6 times daily - NO passive stretching (increases HO risk) - Hinged elbow brace for protection if needed - Target: 30-130° ROM by 6 weeks - No lifting more than 1kg - Outpatient physiotherapy supervision **Intermediate (Weeks 6-12):** - Progressive strengthening - Full ROM goal - Increase lifting restrictions gradually - Dynamic splinting if stiffness developing (less than 100° flexion) - Radiographs at 6 and 12 weeks **Late (Months 3-6):** - Return to normal activities - Full activity 4-6 months - MUA consideration if less than 90° flexion at 3 months - Hardware removal if symptomatic once healed (12-18 months) **HO Prophylaxis (if indicated):** - Indomethacin 75mg daily for 6 weeks (per eTG) - OR single-dose radiation 700cGy within 72 hours - Indications: brain injury, high-energy trauma, previous HO, burns ## References 1. Ring D, Jupiter JB. Fractures of the distal humerus. Orthop Clin North Am 2000;31(1):103-113. 2. O'Driscoll SW. Optimizing stability in distal humeral fracture fixation. J Shoulder Elbow Surg 2005;14(1 Suppl S):186S-194S. 3. Sanchez-Sotelo J, Torchia ME, O'Driscoll SW. Complex distal humeral fractures: internal fixation with a principle-based parallel-plate technique. J Bone Joint Surg Am 2007;89(5):961-969. 4. McKee MD, Wilson TL, Winston L, et al. Functional outcome following surgical treatment of intra-articular distal humeral fractures through a posterior approach. J Bone Joint Surg Am 2000;82(12):1701-1707. 5. Coles CP, Barei DP, Nork SE, et al. The olecranon osteotomy: a six-year experience in the treatment of intraarticular fractures of the distal humerus. J Orthop Trauma 2006;20(3):164-171. 6. Morrey BF, Askew LJ, Chao EY. A biomechanical study of normal functional elbow motion. J Bone Joint Surg Am 1981;63(6):872-877. 7. Athwal GS, Hoxie SC, Rispoli DM, Steinmann SP. Precontoured parallel plate fixation of AO/OTA type C distal humerus fractures. J Orthop Trauma 2009;23(8):535-540. 8. Chen RC, Harris DJ, Leduc S, et al. Is ulnar nerve transposition beneficial during open reduction internal fixation of distal humerus fractures? J Orthop Trauma 2010;24(7):391-394. 9. Australian Therapeutic Guidelines (eTG). Heterotopic ossification prophylaxis. 2024. 10. Watts AC, Morris A, Robinson CM. Fractures of the distal humeral articular surface. J Bone Joint Surg Br 2007;89(4):510-515.

ORIF Distal Humerus Fracture - Olecranon Osteotomy Approach

ORIF Distal Humerus Fracture - Olecranon Osteotomy Approach