Long Arm Vs Short Arm Fiberglass Cast for Treatment of Displaced Distal Radius Fractures

Overview

The aim of the study is to determine by multicenter randomized controlled trial whether short arm fiberglass casts are as effective as long arm casts for immobilizing displaced pediatric distal third forearm fractures that have undergone closed reduction. The primary outcome is loss of reduction requiring cast wedging, recasting, repeat reduction, or surgical intervention. Secondary outcomes will include Patient Reported Outcome Measures for physical function, such as Pedi-FABS, PROMIS (Patient Reported Outcomes Measurement Information System) Upper Extremities , and UCLA (University of California Los Angelos) Activity Scale, and pain/comfort levels,such as PROMIS Pediatric Pain Interference, PROMIS Pediatric Pain Intensity, and VAS ( Visual Analogue Scale) comfort in cast. In addition, secondary outcomes include complications (skin irritation, compartment syndrome, elbow stiffness, cast saw burns etc). The investigators will assess potential risk factors for loss of reduction including initial displacement, level of fracture (physeal, metaphyseal, meta-diaphyseal), initial translation, initial angulation, age, sex, cast index, padding index, adequacy of initial reduction, and provider level of training.

The most common type of fracture in pediatric patients is the distal third forearm fracture, with over 600,000 cases in the in the United States each year. Traditionally long arm casts have been used for displaced distal forearm fractures, but it may be the case that short arm casts are sufficient. Three RCTs (Randomized Control Trials) have been performed comparing the efficacy of plaster short and long arm casts for displaced distal forearm fractures; these studies have shown no significant difference in angulation or displacement. If short and long arm casts offer comparable stability, the short arm version would likely be desirable as patient satisfaction and cost effectiveness are improved with short arm casts. Despite the results of three well-executed RCTs, it is still common practice for long arm casts to be applied for distal forearm fractures. Many surgeons continue to recommend that their residents apply long arm casts for all displaced forearm fractures, including distal third fractures. At NYP (New York Presbyterian) Cornell and NYP Queens, residents routinely apply long arm casts for all forearm fractures. Long arm casts are more likely to result in elbow stiffness, although this is often a temporary complication. Long arm casts also require more material and take longer to apply or remove, potentially leading to higher treatment costs. Additionally, when a longer cast is worn there is a larger distance where a cast burn could occur. Skin irritation, particularly at the cubital fossa, is likely more common with a long arm cast, and they are overall less comfortable, due to elbow restriction and a heavier weight. Short arm casts that are well molded to the arm's contours have been shown to control forearm supination and pronation. A low cast index has been shown to significantly increase the rate of fracture redisplacement. The cast index determines the quality of cast molding, and is measured by dividing the sagittal width of the cast by the coronal width. Substantial changes in cast angulation have been attributed to poor cast-molding and a low cast index. The results suggested that short arm casts when appropriately molded can be effective in treating fractures of the distal third of the forearm. If short arm casts are equivalent in providing stability for distal third forearm fractures, providers should be using them preferentially to avoid the potential complications of elbow stiffness, cast burn, skin irritation, and patient dissatisfaction. However, surgeons persist with using long arm casts. Rationale for the persistent use of long arm cast is believed to include anecdotal concerns of residents placing inadequate short arm casts, leading to an increased risk for translation or angulation requiring recasting. Previous RCTs, however, do not provide clear recommendations, merely demonstrating that treatment using short and long arm casts lead to similar outcomes. Additionally, these past RCTs have limitations. Previous studies were conducted with plaster casts and could not extend their findings to other casting material. Valving techniques were also not noted in these studies; it is unclear whether or not casts were bivalved, which is currently the standard of care in the United States. These previous studies also randomized patients to short or long arm cast prior to cast application. As a result, it is possible that when long arm casts were applied the portion of cast overlying the fracture site was not molded as carefully as for short arm casts. Previous studies commented on cast index, but it was not clear whether residents were trained in ideal cast application and molding prior to study initiation. Finally, the outcome measures used in previous studies were an arbitrary loss in angulation or translation, instead of a focus on whether the fracture slipped sufficiently to change the treatment required (need for cast wedging, repeat reduction and casting, or surgical intervention). The aim of the study is to determine by multicenter randomized controlled trial whether short arm fiberglass casts are as effective as long arm casts for immobilizing displaced pediatric distal third forearm fractures that have undergone closed reduction.