FCPS IMM Master: Distal Humerus Fractures & Orthobullets Pearls

FCPS IMM / OBQ Master Orthobullets High-Yield Notes

Distal Humerus Fractures

MCQ Progress: 0/10 Completed

Orthobullets & FCPS IMM High-Yield Module

Distal Humerus Fractures: Advanced Clinical Pearls

OBQ-referenced high-yield core concepts for FCPS, IMM, and Orthopaedic Board exams.

1. Total Elbow Arthroplasty (TEA) vs ORIF in Elderly

OBQ19.134, OBQ15.6

Must-Know

TEA Preferred Indications

Low-demand elderly patients (Age > 65).
Severe osteoporotic bone.
Comminuted bicollumnar intra-articular fractures not amenable to stable fixation.

TEA Advantages & Evidence

Better functional outcomes and greater ROM early post-op.
Fewer complications and lower reoperation rate (12% vs 27% for ORIF).
ORIF vs TEA: Similar DASH scores by 2 years, but TEA has significantly superior early outcomes.

2. Plating Configuration & O'Driscoll Fixation Principles

OBQ18.200, SAE11UE.49

High Yield

Parallel Plating vs Orthogonal Plating

Parallel plating > Orthogonal plating biomechanically (demonstrates greater torsional rigidity and bending rigidity). However, both have similar clinical outcomes.

O'Driscoll Fixation Principles (ABSOLUTE MUST KNOW)

1 Every screw must pass through a plate.

2 Each screw should be as long as possible.

3 Screws engage maximum articular fragments.

4 Screws from each plate should interdigitate.

5 Achieve compression in both columns.

! NO interfragmentary screws alone (must pass through a plate).

3. Ulnar Nerve Management

OBQ18.200

In situ cubital tunnel release is preferred over transposition in distal humerus ORIF.
Transposition indications: ONLY if the nerve contacts hardware or experiences excessive intraoperative traction.
Meta-Analysis Neuropathy Rates:
• Overall: 19.3%
• In situ release: 15.3%
• Transposition: 23.5%

4. Olecranon Osteotomy

OBQ15.259, OBQ14.259

Best Exposure: Exposes 57% of articular surface (vs 46% TRAP, 35% triceps-splitting).
Chevron Osteotomy: Apex distal, 2 cm from palpable tip.
Screw Angle: Angle medially (proximal ulna has varus angulation).
Bare Area Location: 0.53 cm wide, 2.1 cm from olecranon tip.
Complications: Nonunion <10%, symptomatic hardware 8–33% (most common).

5. Capitellar & Trochlear Shear Fractures

Bryan & Morrey / McKee Classification

Type I (Hahn-Steinthal): Large coronal shear fragment containing full capitellum + part of trochlea.
Type II (Kocher-Lorenz): Thin articular cartilage sleeve shell with minimal subchondral bone.
Type III (Broberg-Morrey): Comminuted / crushed capitellar fracture.
Type IV (McKee Variant): Extends medially to involve most of trochlea ("Coronal Shear"). Fixation requires headless screws (Herbert) anteroposterior or posteroanterior.

6. Stiffness & Contracture Release

Post-traumatic Elbow Contracture

Functional Arc: 30° to 130° flexion, 50° pronation to 50° supination (Morrey).
Flexion Loss Release: Excision of posterior capsule + posterior bundle of MCL + posterior osteophytes.
Critical Preservation: Do NOT release the anterior bundle of MCL, as it provides primary resistance to valgus stress!
Expected Outcome: 20–25% permanent loss of elbow flexion strength vs normal side.

FCPS OBQ-Style MCQs 10 High-Yield Questions

Official OBQ-referenced scenarios with complete rationale for exam preparation

Score 0 / 10

Summary Table & Exam Tricks

Quick memory recall triggers for exam day

Concept	Key Point	Exam Trick / Pitfall
TEA Indications	Elderly > 65, osteoporotic, low demand, comminuted intra-articular	Contraindicated in young patients
Parallel Plating	Greatest construct rigidity (torsional & bending)	Orthogonal has similar clinical outcomes
Olecranon Osteotomy	Apex distal, 2 cm, screw angled medially	Bare area = 2.1 cm from tip
Ulnar Nerve Management	In situ release preferred (15.3% neuropathy)	Transposition ONLY if nerve contacts hardware
AIN Injury	K-wire through anterior ulnar cortex	Inability to flex thumb IP joint (FPL)
Flexion Contracture Loss	Release posterior bundle of MCL + posterior capsule	DO NOT release anterior bundle (causes valgus instability)
Capitellum Type IV	McKee variant extends into trochlea	Requires headless screws (Herbert) AP or PA
Expected Outcome	25% loss of elbow flexion strength	Full ROM is rare

Quick Revision Red Flags

Chronic ulnar neuropathy + distal humerus fracture

In situ cubital tunnel release (not transposition unless touching hardware).

Flexion < 90° post-trauma

Release posterior MCL bundle + posterior capsule.

K-wire perforation anterior ulna

Suspect AIN injury (loss of thumb IP flexion).

Elderly + osteoporotic + comminuted

Total Elbow Arthroplasty (TEA) over ORIF.

Olecranon osteotomy screw direction

Angled medially due to proximal ulna varus angulation.

Extra-articular distal humeral shaft

Functional bracing acceptable (motion loss same as surgery).

Mnemonics & Decision Flowchart

Essential rules, acronyms, and interactive revision flashcards

O'DRISCOLL Fixation Rules

5 GOLD RULES

P - Plate: Every screw MUST pass through a plate.

L - Length: Make each screw as long as possible.

A - Articular: Screws engage maximal articular fragments.

I - Interdigitate: Screws from opposing plates mesh together.

C - Compression: Achieve intercondylar & columnar compression.

OLECRANON OSTEOTOMY "2.1 - 2.0"

BARE AREA

• 2.0 cm: Chevron osteotomy apex distal from palpable tip.

• 2.1 cm: Distance from olecranon tip to bare area of trochlear notch.

• 0.53 cm: Transverse width of bare area free of cartilage.

• Medial Angle: Screw must angle medially (proximal ulna varus).

Distal Humerus Fracture Management Algorithm

EXTRA-ARTICULAR / DISPLACED SHAFT

Functional Bracing vs ORIF

Closed reduction + functional brace if acceptable alignment. If open or neurovascular compromise -> ORIF with posterolateral plate.

INTRA-ARTICULAR (< 65 YEARS)

Olecranon Osteotomy + Bicolumnar ORIF

Parallel or orthogonal plating following O'Driscoll principles. In situ ulnar nerve release. Re-fix olecranon with tension band or plate.

ELDERLY (> 65 YRS + COMMINUTED)

Total Elbow Arthroplasty (TEA)

Triceps-sparing or triceps-reflecting approach. Linked semi-constrained prosthesis. Immediate motion; lower complication rate in osteoporotic bone.

Interactive Flashcards Deck

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QUESTION (CLICK TO FLIP)

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HIGH-YIELD ANSWER

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FCPS / OBQ Pearl

Distal Humerus Fractures OBQs