FRACTURE OF SHAFT
OF RADIUS
Isolated fractures of the radial shaft are
often accompanied by a disruption of the distal radioulnar joint, usually at
the junction of the middle and distal thirds. The eponyms Galeazzi fracture and
Piedmont fracture are frequently used to describe this type of injury. The
injury is called the fracture of (surgical) necessity because of the
difficulties and historically poor results associated with closed treatment
methods.
Initially, Galeazzi postulated that
a direct blow to the dorsolateral wrist caused this fracture dislocation. More
recent studies suggest that the usual mechanism of injury is a fall on the
outstretched hand with the forearm in extreme pronation. The force across the radiocarpal
joint causes fracture and shortening of the radial shaft. As further
displacement occurs, the distal radioulnar joint dislocates, tearing the
triangular fibrocartilage within it.
Hughston, in his classic report of
35 of 38 unsatisfactory results after closed treatment, delineated four
deforming forces that lead to treatment failure: (1) the weight of the hand and
the force of gravity cause sub-luxation of the DRUJ and dorsal angulation of
the fracture; (2) the pronator quadratus muscle rotates the distal radius
fragment in a volar, ulnar, and proximal direction; (3) the brachioradialis
muscle rotates the distal fragment and produces shortening at the site of the
radius fracture; and (4) the thumb abductors and extensors cause further
shortening and displacement of the radius.
A volar surgical approach is used
for ORIF of the radial shaft fracture. Retracting the flexor carpi radialis
muscle ulnarly and the radial artery and brachioradialis muscle radially
exposes the fracture site, which can be fixated with a compression plate.
Reduction and secure fixation of the radius fracture usually reduce the distal
radioulnar dislocation as well.
After fixation of a radius
fracture, the surgeon must look for any residual dislocation or subluxation of
the DRUJ. Full passive supination of the forearm usually restores joint
congruity. If the DRUJ cannot be satisfactorily aligned with closed means
(e.g., supination), the joint must be surgically reduced and either pinned with
Kirschner wires or with operative reattachment of the TFCC. A long-arm cast is
applied, with the elbow flexed 90 degrees and the forearm in full supination.
The limb is immobilized for 6 weeks to maintain the reduction.
If a transfixation pin has been used to stabilize the DRUJ, it is left in place
for 6 to 8 weeks.
If this fracture-dislocation is not
diagnosed and appropriately treated soon after injury, later reconstructive
surgery is often needed to correct the deformity of the radius and restore the
function of the DRUJ. If the distal ulna cannot be adequately reduced,
reconstruction or salvage excision must be undertaken.
