Rockwood Children CH8

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CHAPTER 8 • Fractures of the Distal Radius and Ulna

Reduction and Immobilization of Incomplete Fractures of the Distal Radius and Ulna

Closed Reduction and Cast Immobilization of Displaced Distal Radial Metaphyseal Fractures

Treatment of incomplete distal radial and ulna fractures is sim- ilarly dependent on patient age and remodeling potential, mag- nitude, and direction of fracture displacement and angulation, and the biases of the care provider and patient/family regard- ing fracture remodeling and deformity. In cases of incomplete or greenstick distal radius fractures—with or without ulnar involvement—with unacceptable deformity, closed reduction and cast immobilization are recommended. The method of reduction for greenstick fractures depends on the pattern of displacement. With apex volar angulated fractures of the radius, the rotatory deformity is supination. Pronating the radius and applying a dorsal-to-volar reduction force is utilized to restore bony alignment. Conversely, fractures with apex dorsal angulation result from pronation mechanisms of injury. Supinating the distal forearm and applying a volar- to-dorsal force should reduce the incomplete fracture of the radius. 137 Though these fractures are incomplete and patients often present with minimal pain, adequate analgesia will facil- itate bony reduction and quality of cast application. Typically, this is done with the assistance of conscious sedation. 64,79,114 Following reduction, portable fluoroscopy may be used to evaluate fracture alignment. Once acceptable alignment is achieved, a cast is applied with appropriate rotation and three- point molds, based on the initial pattern of injury. Long-arm casting is typically used for the first 4 weeks, and bony healing is achieved in 6 weeks in the majority of patients. A short-arm cast with acceptable cast indices is equally effective. As in the case of torus fractures, 197 there is a study indicating that soft bandages can be applied to treat incomplete greenstick forearm fractures 120 ; however, as the greenstick fracture is sub- stantially more unstable than the torus fracture, 168 the authors do not advocate soft bandage treatment of greenstick fractures.

Closed reduction and cast immobilization remains the stan- dard of care for children with displaced distal radial metaph- yseal fractures presenting with unacceptable alignment. Again, fracture reduction maneuvers are dependent on injury mecha- nism and fracture pattern. In patients with typical dorsal dis- placement of the distal epiphyseal fracture fragment with apex volar angulation, closed reduction is performed with appropri- ate analgesia, typically conscious sedation or general anesthe- sia. Finger traps applied to the ipsilateral digits may facilitate limb positioning and stabilization during fracture reduction but application of weights may hinder reduction by increasing dorsal periosteal tension. Recently, the lower extremity-aided fracture reduction maneuver (LEAFR) has been proposed as a simple, effective, reproducible, and mechanically advanta- geous technique of effectuating closed reductions in children with bayoneted distal radius fractures. 59 Given the stout, intact dorsal periosteum in these injuries, pure longitudinal traction is often insufficient to restore bony alignment, particularly in cases of bayonet apposition. Fracture reduction is performed first by hyperextension and exaggeration of the deformity, which relaxes the dorsal periosteal sleeve (Fig. 8-27). Longitu- dinal traction is then applied to restore adequate length. Finally, the distal fracture fragment is flexed to correct the translational and angular displacement, with rotational correction imparted as well. If available, fluoroscopy may be utilized to confirm ade- quacy of reduction, and a well-molded cast is applied. The optimal type of cast immobilization remains controver- sial. Both long- and short-arm casts have been proposed follow- ing distal radial fracture reduction. 31,88,93,207 Long-arm casts have the advantage of restricting forearm rotation and theoretically reducing the deforming forces imparted to the distal radius. However, above-elbow immobilization is more inconvenient

B

A

Figure 8-27.  A, B: Use of the thumb to push the distal fragment hyperdorsiflexed 90 degrees ( solid arrow ) until length is reestablished. Countertraction is applied in the opposite direction ( open arrows ).

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