DRUJ instability
A 34-year-old, right-hand-dominant male is brought to the emergency department by his friends with a chief complaint of right arm pain and deformity. Earlier in the day he was thrown from his dirt bike during an amateur race and attempted to break his fall with his arm. Your examination finds that he is nontender about his elbow but has significant pain and deformity about the forearm and wrist. His radiographs are shown in Figure 6–22A and B.
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Figure 6–22 A–B
Which of the following is not a radiographic indicator of possible distal radioulnar joint (DRUJ) instability?
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Shortening >5 mm of the radius
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Apex dorsal angulation of the radial shaft fracture
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Widening of the DRUJ on an AP radiograph
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DRUJ incongruity on a true lateral radiograph
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Fracture of the base of the ulnar styloid
Discussion
The correct answer is (B). Choices A, C, D, and E are all radiographic signs of possible DRUJ instability. The injury shown here is a radial shaft fracture with concomitant DRUJ injury, also known as a Galeazzi fracture. This fracture is treated surgically with ORIF of the radial shaft fracture followed by reassessment of the DRUJ with intraoperative fluoroscopy. If the DRUJ is found to be irreducible by closed means, it is possible that the ECU tendon is interposed between the radius and ulna. An unreducible DRUJ warrants open reduction and removal of any interposed
tissue.
Following anatomic reduction and rigid fixation of the radial shaft fracture, which of the following fracture patterns are most likely to be associated with a persistently unstable DRUJ?
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Radius fracture 4 cm proximal to the distal radius midarticular surface
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Radius fracture at the apex of the radial bow
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Radial shaft 9 cm proximal to the distal radius midarticular surface
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Fracture of the radius just distal to the radial tuberosity
Discussion
The correct answer is (A). Following ORIF of the radial shaft fracture, the DRUJ must be assessed for stability. Rettig and Raskin in their series of 40 Galeazzi fractures found that after fixation of the radius fracture, those fractures located less than 7.5 cm from the distal radius midarticular surface required fixation of a persistently unstable DRUJ 55% of the time, whereas fractures greater than 7.5 cm from the midarticular surface were persistently unstable at the DRUJ only 6% of the time.
After ORIF of the radius, the distal ulna is still able to be translated dorsally out of the sigmoid notch with the forearm held in supination.
What is the appropriate next step in management?
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Short arm thumb spica cast for 6 weeks to allow the TFCC to heal
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Long arm immobilization with the forearm in supination for 6 weeks
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Sugar tong splint with the forearm in neutral position for 4 to 6 weeks
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K-wire fixation of the DRUJ and long arm immobilization with the forearm in supination for 6 weeks
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K-wire fixation of the DRUJ and long arm immobilization with the forearm in pronation for 6 weeks
Discussion
The correct answer is (D). After fixation of the radius, the DRUJ is reassessed. At this point there are several possibilities: A stable DRUJ, a reducible but persistently unstable DRUJ, and a nonreducible DRUJ. If the DRUJ is stable, some suggest that no further immobilization is required and early motion should be initiated, whereas others suggest that the forearm should still be splinted in supination for 6 weeks. If the DRUJ remains unstable but is reducible, the ulna should be transfixed to the
Objectives: Did you learn...?
The radiographic signs suggesting DRUJ instability on injury radiographs?
The predictive value of fracture location as it relates to a persistently unstable DRUJ following radius fixation?
When the DRUJ warrants splinting versus pinning versus open surgical fixation?