The terrible triad of the elbow is defined as the combination of fractures of the radial head and ulnar coronoid process and dislocation of the elbow joint and is often associated with collateral ligament injuries. Skeletal components involved in the unhappy triad include the patella, femur, and tibia. No muscles are directly involved in this injury, only ligaments; However, strengthening the hip flexor and hip extensor muscles may help alleviate the injury.
Terrible triad is a fracture-dislocations of the elbow remain among the most difficult injuries to manage. Historically, the combination of an elbow dislocation, a radial head fracture, and a coronoid process fracture has had a consistently poor outcome; for this reason, it is called the terrible triad. Most terrible triad injuries are managed surgically, and good results are achievable using a standard treatment protocol that includes fixation of the coronoid fracture, fixation or replacement of the radial head, and repair of the lateral collateral ligament (LCL).
In 1936 Campbell asserted that “impairment of the anterior crucial and mesial ligaments is associated with injuries of the internal cartilage.” O’Donoghue in 1950 called attention to “that unhappy triad (1) rupture of the medial collateral ligament, (2) damage to the medial meniscus, and (3) rupture of the anterior.
Other Names
- Terrible Triad Injury of Elbow
- Elbow Fracture-dislocation
Pathophysiology
- General
- Terrible triad defined by Elbow Dislocation, Radial Head or Neck Fracture, and Coronoid Fracture
- Most commonly due to fall on an extended arm and outstretched hand from a standing position
- The elbow may spontaneously reduce before an initial evaluation
Mechanism
- Fall on an outstretched arm, slightly flexed with the forearm in supination
- Forces valgus stress, axial load, and posterolateral rotator forces
- Subsequent posterolateral dislocation
- Can be fall from standing or greater height[2]
Associated Injuries
- 39.9% of terrible triad injuries have additional fractures[1]
- Essex Lopresti Fracture
- Lateral Collateral Ligament Injury (Elbow)
- Ulnar Collateral Ligament Injury
Pathoanatomy
- Injury destabilizes the relationship between the Humerus and forearm bones
- Injured structures:
- Lateral Collateral Ligament
- Joint Capsule
- Proximal Radius, specifically Radial Head
- Proximal Ulna, specifically Coronoid Process
- Can also injure Ulnar Collateral Ligament
- Fractures
- Adult
- Radial Head Fracture
- Olecranon Fracture
- Capitellum Fracture
- Coronoid Fracture
- Terrible Triad of Elbow
- Pediatric
- Nursemaids Elbow
- Supracondylar Fracture
- Lateral Condyle Fracture (Peds)
- Medial Condyle Fracture (Peds)
- Olecranon Fracture (Peds)
- Radial Head Fracture (Peds)
- Medial Epicondyle Fracture (Peds)
- Salter-Harris Fracture
- Adult
- Dislocations & Instability
- Elbow Dislocation
- Proximal Radioulnar Joint Instability
- Tendinopathies
- Lateral Epicondylitis
- Medial Epicondylitis
- Distal Biceps Tendon Injury
- Triceps Tendon Injury
- Bursopathies
- Olecranon Bursitis
- Ligament Injuries
- Lateral Collateral Ligament Injury (Elbow)
- Ulnar Collateral Ligament Injury
- Neuropathies
- Cubital Tunnel Syndrome
- Radial Tunnel Syndrome
- Arthropathies
- Elbow Arthritis
- Other
- Valgus Extension Overload
- Posteromedial Rotatory Instability
- Posterolateral Rotatory Instability
- Osteochondral Defect
- Pediatric Considerations
- Little League Elbow
- Panners Disease (Avascular Necrosis of the Capitellum)
- Nursemaids Elbow (Radial Head Subluxation)
Diagnosis
- History
- Patients will endorse trauma
- Complain of pain, clicking, locking
- Physical: Physical Exam Forearm
- Tenderness, swelling, bruising
- If the elbow has not been reduced (spontaneously or manually), the deformity will be obvious
- Special Tests
- Elbow Valgus Stress Test: Evaluate the integrity of Ulnar Collateral Ligament
- Elbow Varus Stress Test: Evaluate the integrity of Lateral Collateral Ligament
Radiographs
- Standard Radiographs Elbow
- Strongly consider extending to the humerus, shoulder, forearm, and wrist
CT
- Helpful to better evaluate fracture pattern
- Useful for surgical planning
- N/A
Treatment
Acute Management
- Critical to identify on initial evaluation
- If missed and treated conservatively, patients develop recurrent dislocations and multiple future surgeries[3]
- Elbow Dislocation Reduction
- Typically performed under procedural sedation in the Emergency Department or Operating Room
- Immobilize with Posterior Long Arm Splint
Nonoperative
- Indications
- Almost universally a surgical injury pattern
- The decision should be made by an orthopedic surgeon for non-operative management
- Consider in patients who are poor surgical candidates
Operative
- Technique[4]
- Radial Head Arthroplasty
- LCL Reconstruction
- Coronoid ORIF
- UCL Reconstruction
