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DR.JAMAL AL-SAIDY
M.B.CH.B…F.I.C.M.S
MONTEGGIA FRACTURE DISLOCATION OF THE ULNA
The injury described by Monteggia in the early nineteenthth century (without benefit of
x-rays!) was a fracture of the shaft of the ulna associated with dislocation of the proximal
radio-ulnar joint; the radiocapitellar joint is inevitably dislocated or subluxated as well.
More recently the definition has been extended to embrace almost any fracture of the
ulna associated with dislocation of the radio-capitellar joint, including trans-olecranon
fractures in which the proximal radioulanr joint remains intact.
If the ulnar shaft fracture is angulated with the apex anterior (the commonest type) then
the radial head is displaced anteriorly;
If the fracture apex is posterior, the radial dislocation is posterior; and
If the fracture apex is lateral then the radial head will be laterally displaced.
In children, the ulnar injury may be an incomplete fracture (greenstick or plastic
deformation of the shaft).
Mechanism of injury
Usually the cause is a fall on the hand; if at the moment of impact the body is twisting, its
momentum may forcibly pronate the forearm.
The radial head usually dislocates forwards and the upper third of the ulna fractures and
bows forwards.
Sometimes the causal force is hyperextension.
Clinical features
The ulnar deformity is usually obvious but the dislocated head of radius is masked by
swelling.
A useful clue is pain and tenderness on the lateral side of the elbow.
The wrist and hand should be examined for signs of injury to the radial nerve.
X-ray With isolated fractures of the ulna, it is essential to obtain a true anteroposterior
and true lateral view of the elbow.
In the usual case, the head of the radius (which normally points directly to the capitulum)
is dislocated forwards, and there is a fracture of the upper third of the ulna with forward
bowing.
Backward or lateral bowing of the ulna (which is much less common) is likely to be
associated with, respectively, posterior or lateral displacement of the radial head.
Trans-olecranon fractures, also, are often associated with radial head dislocation.
Treatment
The key to successful treatment is to restore the length of the fractured ulna; only then
can the dislocated joint be fully reduced and remain stable. In adults, this means an
operation through a posterior approach.
The ulnar fracture must be accurately reduced, with the bone restored to full length, and
then fixed with a plate and screws; bone grafts may be added for safety.
The radial head usually reduces once the ulna has been fixed.
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DR.JAMAL AL-SAIDY
M.B.CH.B…F.I.C.M.S
Stability must be tested through a full range of flexion and extension. If the radial head
does not reduce, or is not stable, open reduction should be performed.
If the elbow is completely stable, then flexion–extension and rotation can be started after
very soon after surgery.
If there is doubt, then the arm should be immobilized in plaster with the elbow flexed for
6 weeks.
Complications
Nerve injury Nerve injuries can be caused by overenthusiastic manipulation of the radial
dislocation or during the surgical exposure.
Always check for nerve function after treatment.
The lesion is usually a neurapraxia, which will recover by itself.
Malunion Unless the ulna has been perfectly reduced, the radial head remains dislocated
and limits elbow flexion.
Non-union Non-union of the ulna should be treated by plating and bone grafting.
GALEAZZI FRACTURE-DISLOCATION OF THE RADIUS
Mechanism of injury
This injury was first described in 1934 by Galeazzi.
The usual cause is a fall on the hand; probably with a superimposed rotation force. The
radius fractures in its lower third and the inferior radio-ulnar joint subluxates or
dislocates.
Clinical features
The Galeazzi fracture is much more common than the Monteggia.
Prominence or tenderness over the lower end of the ulna is the striking feature.
It may be possible to demonstrate the instability of the radio-ulnar joint by ‘ballotting’
the distal end of the ulna (the ‘piano-key sign’) or by rotating the wrist.
It is important also to test for an ulnar nerve lesion, which may occur.
X-ray A transverse or short oblique fracture is seen in the lower third of the radius, with
angulation or overlap. The distal radio-ulnar joint is subluxated or dislocated.
Treatment
As with the Monteggia fracture, the important step is to restore the length of the fractured
bone.
In children, closed reduction is often successful; in adults, reduction is best achieved by
open operation and compression plating of the radius.
An x-ray is taken to ensure that the distal radio-ulnar joint is reduced.
There are three possibilities:
1. The distal radio-ulnar joint is reduced and stable No further action is
needed. The arm is rested for a few days, then gentle active movements
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DR.JAMAL AL-SAIDY
M.B.CH.B…F.I.C.M.S
are encouraged. The radio-ulnar joint should be checked, both clinically
and radiologically, during the next 6 weeks.
2. The distal radio-ulnar joint is reduced but unstable The forearm should be
immobilized in the position of stability (usually supination), supplemented
if required by a transverse K-wire. The forearm is splinted in an above
elbow cast for 6 weeks. If there is a large ulnar styloid fragment, it should
be reduced and fixed.
3. The distal radio-ulnar joint is irreducible This is unusual. Open reduction
is needed to remove the interposed soft tissues. The triangular
fibrocartilage complex (TFCC) and dorsal capsule are then carefully
repaired and the forearm immobilized in the position of stability (again,
usually supination, supported by a wire if needed) for 6 weeks.
THANK YOU
DR.JAMAL AL-SAIDY
M.B.CH.B..…… F.I.C.M.S