Terrible Triad Injury of Elbow

Topic updated on 07/26/15 10:43am
  • A traumatic injury pattern of the elbow characterized by
    • elbow dislocation (often associated with posterolateral dislocation or LCL injury)
    • radial head fracture
    • coronoid fracture
  • Pathophysiology
    • mechanism
      • fall on extended arm that results in a combination of 
        • valgus, axial, and posterolateral rotatory forces  
          • produces posterolateral dislocation
      • structures of elbow fail from lateral to medial
        • anterior bundle of MCL last to fail
        • LCL disrupted in most cases
  • Radial head
    • forearm in neutral rotation, lateral portion of articular margin devoid of cartilage
      • roughly between radial styloid and listers tubercle
    • provides anterior and valgus buttress 
  • Coronoid process
    • provides an anterior and varus buttress
  • Medial collateral ligament  
    • anterior bundle, posterior bundle, and transverse ligament components
    • anterior bundle most important to stability, restraint to valgus and posteromedial rotatory instability
      • inserts on sublime tubercle (anteromedial facet of coronoid) 
      • specifically inserts 18.4mm dorsal to tip of coronoid process
  • Lateral collateral ligament  
    • inserts on supinator crest distal to lesser sigmoid notch
    • restraint to varus and posterolateral rotatory instability
    • two components
      • lateral ulnar collateral ligament (most important for stability)
      • lateral radial collateral ligament
        • attaches to annular ligament
  • Symptoms
    • patients complain of pain, clicking and locking with elbow in extension
  • Physical exam
    • varus instability
    • may show valgus instability if injury to MCL
  • Radiographs   
    • evaluate for concentricity of ulnohumeral and radiocapitellar joints
    • line drawn through center of radial neck should intersect the center of the capitellum regardless of radiographic projection
    • evaluate lateral radiograph for coronoid fracture
  • CT
    • better evaluation of coronoid fracture
    • 3D imaging for determining fracture line propagation
  • Nonoperative
    • immobilize in 90 deg of flexion for 7-10 days
      • indications (rare)
        • ulnohumeral and radiocapitellar joints must be concentrically reduced
        • elbow should extend to at least 30 degrees before becoming unstable
        • CT must show insignificant radial head/neck fx, no block to motion
        • coronoid fx limited to tip
      • technique
        • active motion initiated with resting splint at 90 degrees, avoiding terminal extension
        • static progressive extension splinting at night after 4-6 weeks
        • strengthening protocol after 6 weeks
  • Operative
    • acute radial head stabilization, coronoid ORIF, and LCL reconstruction, MCL reconstruction if needed
      • indications
        • terrible triad elbow injury that includes a unstable radial head fracture, a type III coronoid fracture, and an associated elbow dislocation 
  • Acute radial head stabilization, coronoid ORIF, and LCL reconstruction, MCL reconstruction if needed
    • approach
      • posterior skin incision advantageous
        • allows access to both medial and lateral aspect of elbow
        • lower risk of injury to cutaneous nerves
        • more cosmetic
    • technique
      • radial head ORIF vs. arthroplasty
        • radial head arthroplasty indicated for comminuted radial head fracture 
          • use of modular prosthesis preferable
          • sizing based on fragments removed from elbow
          • implant should articulate 2mm distal to the tip of the coronoid process
          • radial head resection without replacement is NOT indicated in presence of Essex-Lopresti lesion or in young active patient
        • it <25% head damaged or fragments not reconstructable and nonarticulating, can excise fractured portion if elbow stable (rarely indicated)
        • radial head ORIF indicated if non comminuted with good bone stock and fracture involves < 40% articular surface 
          • 1.5, 2.0, or 2.4mm countersunk screws
          • plating if necessary; 2.0 plates cause minimal loss of motion even when placed on radial neck
      • coronoid ORIF
        • can be fixed through radial head defect laterally
        • fix with suture passed through 2 drill holes, or posterior to anterior lag screws if fragment large
        • basal coronoid fxs (rare) fixed with anteromedial or medial plate on proximal ulna
      • LCL repair 
        • usually avulsed from origin on lateral epicondyle
        • reattach with suture anchors or transosseous sutures 
          • must be reattached at center of capitellar curvature on lateral epicondyle
        • if MCL is intact, LCL is repaired with forearm in pronation
        • if MCL injured, LCL is repaired with forearm in supination to avoid medial gapping due to overtightening
        • repairs are performed with elbow at 90 degrees of flexion
      • MCL repair
        • indicated if instability on exam after LCL and fracture fixation, especially with extension beyond 30 degrees
      • instability after complete bone and soft tissue repair indicates need for hinged or static elbow fixator application
      • postoperative
        • immobilize elbow in flexion with forearm pronation to provide stability against posterior subluxation q
        • if both MCL and LCL were repaired, splint in flexion and neutral rotation.
  • Instability
    • more common following type I or II coronoid fractures
  • Failure of internal fixation
    • most common following repair of radial neck fractures
      • poor vascularity leading to osteonecrosis and nonunion
  • Posttraumatic stiffness 
    • very common
    • initiate early ROM to prevent
  • Heterotopic ossification
    • consider prophylaxis in pts with head injury or in setting of revision surgery
  • Posttraumatic arthritis
    • due to chondral damage at time of injury and/or residual instability


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Qbank (9 Questions)

(OBQ12.250) A 26-year-old male sustains a fall from a ladder onto his outstretched right hand. He is evaluated in the emergency room and is found to have a closed injury to his elbow without evidence of neurovascular compromise. Plain radiographs are obtained and are shown in Figures A and B. During surgery a sequential approach is used to treat each element of this injury. Which part of the procedure is felt to add the most to rotatory stability? Topic Review Topic
FIGURES: A   B        

1. Radial head replacement
2. Radial head ORIF
3. Capsular plication
4. Lateral collateral ligament complex repair or reconstruction
5. Medial collateral ligament complex reconstruction

(OBQ09.168) At the elbow, the anterior bundle of the medial collateral ligament inserts at which site? Topic Review Topic

1. Radial tuberosity
2. 3mm distal to the tip of the coronoid
3. Anteromedial process of the coronoid
4. Medial border of the olecranon fossa
5. Radial side of ulna at origin of annular ligament

(OBQ06.81) A 35-year-old woman presents with an elbow injury which includes a coronoid fracture involving more than 50%, a comminuted radial head fracture, and an elbow dislocation. What is the most appropriate treatment? Topic Review Topic

1. closed reduction and early range of motion
2. radial head resection and lateral collateral ligament reconstruction
3. radial head resection and coronoid open reduction internal fixation
4. radial head arthroplasty and coronoid open reduction internal fixation
5. radial head arthroplasty, coronoid open reduction internal fixation, and lateral collateral ligament repair

(OBQ05.52) You are planning operative treatment of the injury shown in figure A. If the MCL is intact, in what position should the elbow and forearm be splinted at the end of the case? Topic Review Topic
FIGURES: A          

1. extension and pronation
2. extension and supination
3. extension and neutral rotation
4. flexion and pronation
5. flexion and supination

(OBQ05.127) A 62-year-old man slips on ice and sustains an elbow dislocation. Post-reduction imaging reveals a highly comminuted radial head fracture and coronoid fracture through its base. What is the most appropriate treatment? Topic Review Topic

1. Early passive range-of-motion in a hinged elbow brace
2. Application of a static spanning external fixator for 6 weeks
3. Radial head excision, coronoid excision, and repair of the lateral ulnar collateral ligament and medial collateral as needed
4. Radial head excision, open reduction internal fixation of the coronoid, and repair of the lateral ulnar collateral ligament and medial collateral as needed
5. Radial head replacement, open reduction internal fixation of the coronoid, and repair of the lateral ulnar collateral ligament and medial collateral as needed

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