The Common Vein Copyright 2011
Definition
Fractures of the ulna are usually caused by by direct trauma The olecranon fractures occur by either direct trauma or by a strong sudden contraction of the triceps during a fall onto an outstretched upper extremity.
Olecranon fractures can be classified by either the Mayo Classification or the Schatzker Classification. The Mayo Classification has three types; Type I, II, and III. Type I fractures are non-displaced or minimally displaced. Type IA denotes noncomminuted, while Type IB denotes a comminuted fracture. Type II has displacement of the proximal fragment without instability. Type IIA is noncomminuted, while IIB is comminuted.
The Schatzker classification of olecranon fractures is based on the fracture pattern. The types are transverse, transverse-impacted, oblique, comminuted with associated injuries, oblique-distal, and fracture-dislocation.
The ulna shaft can break either in isolation or in combination with the radial shaft. The fractures of both bones are classified as closed vs open, by location, by the number of fragments, displacement, angulation, and rotational alignment. Fractures can be comminuted, segmental or multifragmental. Isolated ulnar shaft fractures are nightstick, Monteggia, or stress fractures. Nightstick fractures are from direct trauma to the ulna. Monteggia fractures are fractures of the proximal ulnar with a radial head dislocation.
A reverse Galeazzi fracture is a fracture of the distal ulna with injury to the distal radioulnar joint.
The ulnar styloid can be fractured from trauma. These fractures usually occur along with a distal radius fracture.
The fracture may be complicated in the acute phase by neurovascular injury, or in the subacute or chronic phases by nonunion, malunion, infection, osteonecrosis, or osteoarthritis. Specific to the ulna are complications that include ulnar neuritis, heterotopic ossification, and stiffness.
The diagnosis of this injury is usually made by a combination of physical examination and x-ray imaging.
Imaging includes the use of plain x-rays, and if indicated CT-scan, or MRI.
Olecranon fractures can be treated according to the Mayo Classification. Type I fractures are nonoperative. Type IIA fractures are treated with tension band wire fixation. Type IIB fractures are treated with plate and screw fixation. Type III fractures require ORIF.
Most fractures of both the radial and ulnar shaft in adults are treated with open reduction and internal fixation.
Nightstick fractures are treated with plaster immobilization in a sugar tong splint initially then with functional bracing for non-displaced fractures. Displaced fractures of greater than 10 degrees of angulation or 50% displacement of the shaft are treated with ORIF using a dynamic compression plate.
Monteggia fractures require surgery in the adult population. The radial head may need to be reduced and the annular ligament repaired.
Ulnar styloid fractures do not routinely undergo fixation and usually are given a chance to try to heal with only a reduction maneuver and splinting/casting. They can be surgically repaired with ORIF or with excision of the fragment.
Bowing Deformity (a) and Transverse Fractures (b) of the Radius and Ulna |
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This set of X-rays in the antero-posterior (A-P) projection shows the difference of the effect of a lateral force on the mid shafts of a pliable pediatric radius and ulna (a) and on the more brittle mature bones of a 19 year patient (b). In the pediatric bones they respond to the force by a bowing deformity without obvious macrofracture. This is a type of greenstick fracture. In the adult the bone shows transverse fracture of the radius and ulna. Courtesy Ashley Davidoff Copyright 2011 101293.8bc01 |
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9 year old radius ulna epiphysis greenstick fracture of the shaft og the ulna trauma plain film X-ray Courtesy Ashley Davidoff MD 73593c01 |
Impacted Fracture of the Ulna |
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Three views of the distal radius and ulna in the anteroposterior (a), oblique (b), and lateral (c), projection show an acute simple transverse and impacted (arrow) fracture of the shaft of the distal ulna with near anatomic alignment. Courtesy Ashley Davidoff MD 76722c.81L |
References
Davis MF, Davis PF, Ross DS. Expert Guide to Sports Medicine. ACP Series, 2005.
Elstrom J, Virkus W, Pankovich (eds), Handbook of Fractures (3rd edition), McGraw Hill, New York, NY, 2006.
Koval K, Zuckerman J (eds), Handbook of Fractures (3rd edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Lieberman J (ed), AAOS Comprehensive Orthopaedic Review, American Academy of Orthopaedic Surgeons, 2008.
Moore K, Dalley A (eds), Clinically Oriented Anatomy (5th edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Wheeless’s Textbook of Orthopaedics: Ulna/Ulnar Shaft Fracture (http://www.wheelessonline.com/ortho/ulna_ulnar_shaft_fracture)