Mechanism of injury:
Is by a force directed towards an elbow which is flexed > 90° which causes the ulna to drive against the trochlea
Riseborough and Radin Classification
• Type I: Nondisplaced
• Type II: Slight displacement with no rotation between the condylar fragment.
• Type III: Displacement with rotation
• Type IV: Severe comminution of the articular surface.
Classification of Mehne and Matta:
1. High T.
2. Low T
3. Y-type
4. H-type.
5. Medial.
6. Lateral
The Mehne and Matta classification describes the most often encountered fracture patterns intraoperatively.
Clinical Features:
1. The elbow maybe held in 90° flexion and forearm is kept pronated
2. Crepitus may be elicited
3. Independent mobility of the medial and lateral condyle can be elicited
4. The normal 3 point bony relationship between the olecranon, medial epicondyle and lateral epicondyle is lost
X-Rays:
Standard AP and lateral views are obtained
CT scan is helpful to further delineate the fracture pattern
Nonoperative Treatment
• Elderly patients with severe osteopenia and comminution or Patients with significant comorbid conditions precluding operative management.
Operative Treatment
Open reduction and internal fixation:
• Restores articular congruity
• Interfragmentary screws and dual-plate fixation: One plate is placed medially and another plate posterolaterally. Reconstruction plate and one-third plate are used commonly.
• Total elbow arthroplasty (semi constrained): May be considered in markedly comminuted fractures and in fractures with osteoporotic bone.
Pearls of Internal fixation for distal humerus fractures (O’Driscoll et al..)
1. olecranon osteotomy provides the best exposure of the articular surface of the distal humerus (1), but problems due to non union and symptomatic implants maybe seen
2. Alternative approaches include the triceps reflecting, anconeus pedicle, or TRAP exposure described by O'Driscoll or elevating the triceps from the posterior humerus, but leaving it attached to the olecranon(Allonso Llamas) approach(2)
3. Identify the ulnar nerve and protect it throughout the procedure.
4. Transpose the ulnar nerve if hardware is placed medially to prevent irritation from the hardware
5. Perform the olecranon osteotomy in the area of the olecranon that is normally devoid of articular cartilage.
6. Drill and tap olecranon prior to performing the osteotomy.
7. When performing the olecranon osteotomy, remember that the semilunar notch is “V-shaped” with the central area being the thickest (the site for the osteotomy—about 2 cm distal to the olecranon tip)
8. Create a chevron osteotomy with the apex pointing distally.
9. Anatomic reduction and preliminary fixation with Kirschner wires or interfragmentary lag screw fixation of the articular condyles
10. Fixation of the lateral column with a well-molded posterior plate
11. Fixation of the medial column with a medial plate extending down to, and on occasion wrapping around, the medial epicondyle
12. Multiple interfragmentary screws, usually through the plates or independent of the plates, to secure the fracture construct together
13. If one large fragment of the joint surface can be reduced to either medial or lateral column, it can be used to surgeon’s advantage. Once this stable construct has been established other fragments can be added
14. Try to place every screw in a fragment through the plate
15. If the fracture extends distally, the plates should be contoured over the respective epicondyles and placed adjacent to the articular margin
16. Distal plate placement may result in impingement during terminal elbow extension
therefore, before definitive plate fixation the elbow should be examined to ensure an acceptable ROM with absent bony or soft tissue impingement
17. Some surgeons prefer cannulated screws because these can be placed over the preliminary K- wires
18. Avoid injury to the radial nerve by identifying the nerve if proximal exposure is necessary.
19. Avoid narrowing the trochlea with lag fixation in cases with articular comminution.
Ref:
1. Wilkinson JM, Stanley D. Posterior surgical approaches to the elbow: a comparative anatomic study. J Should Elbow Surg 2001;10:380-382.
2. Alonso-Llames M. Bilaterotricipital approach to the elbow. Acta Orthop Scand 1972;43:479-490.
3. Muller ME, Allgower M, Schneider R, et al. Manual of internal fixation. Techniques recommended by the AO-ASIF Group. 3rd ed. Berlin: Springer-Verlag; 1991.
4. O’Driscoll SW, Jupiter JB, Cohen MS, Ring D, McKee MD: Difficult elbow
fractures: Pearls and pitfalls. Instr Course Lect 2003;52:113-134.
