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CHAPTER 8 • Fractures of the Distal Radius and Ulna

A

B

Figure 8-29.  Radiographic evaluation of cast mold. A: Cast index (x/y) is the ratio of the inner cast diam- eter at the level of the fracture on the lateral projection (x) to the inner cast diameter at the level of the fracture as seen on the anteroposterior (AP) view (y). B: The three-point index is the sum of the three critical gaps divided by the contact area of the fracture fragments. The anteroposterior 3-point index is (a + b + c)/d. The lateral 3-point index is (e + f + g)/h. (Courtesy of Children’s Orthopaedic Surgery Foundation.)

techniques proposed for predicting the size of a wedge. Beb- bington et al. 14 suggested a technique that involves tracing the angle of displacement onto the cast itself thus representing the fracture fragments. Wedges are then inserted until the malalign- ment is reduced as the traced line becomes straight. Wells et al. recently described a technique in which the wedge position and opening angle are determined from the radiographic dis- placement and center of rotational alignment. Utilizing these methods on saw bones, they were able to reduce malalign- ment within 5 degrees with 90% success. 208 Regardless of the

method, if utilized appropriately, cast wedging reduces the risk of additional anesthesia and potential surgery.

Displaced Distal Radial Physeal Fractures Most displaced Salter–Harris I and II fractures are treated with closed reduction and cast stabilization. Closed manipulation of the displaced fracture is similarly performed with appropriate conscious sedation, analgesia, or, rarely, anesthesia to achieve pain relief and an atraumatic reduction. 64,79,114 Most of these