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CHAPTER 8 • Fractures of the Distal Radius and Ulna

IMMOBILIZATION The position and type of immobilization after reduction also have been controversial. Recommendations for the position of postreduction immobilization include supination, neutral, and pronation. The rationale for immobilization in pronation is that reduction of the more common apex volar fractures requires correction of the supination deformity. 63 Following this ratio- nale, apex dorsal fractures should be reduced and immobilized in supination. Pollen 162 believed that the brachioradialis was a deforming force in pronation and was relaxed in supination (Fig. 8-61) and advocated immobilization in supination for all displaced distal radial fractures. Kasser 113 recommended immo- bilization in slight supination to allow better molding of the volar distal radius. Some researchers advocate immobilization in a neutral position, believing this is best at maintaining the interosseous space and has the least risk of disabling loss of fore- arm rotation in the long term. Davis and Green 44 and Ogden 148 advocated that each fracture seek its own preferred position of stability. Gupta and Danielsson 88 randomized immobilization of distal radial metaphyseal greenstick fractures in neutral, supina- tion, or pronation to try to determine the best position of immo- bilization. Their study showed a statistical improvement in final healing with immobilization in supination. More recently, Boyer et al. 24 prospectively randomized 109 distal third forearm frac- tures into long-arm casts with the forearm in neutral rotation, supination, or pronation following closed reduction. No signifi- cant differences in final radiographic position were noted among the differing positions of forearm rotation. Another area of controversy is whether or not long- or short- arm cast immobilization is better. Historically, most publications on pediatric distal radial fracture treatment advocated long-arm cast treatment for the first 3 to 4 weeks of healing. 20,93,148,162 The rationale is that elbow flexion reduces the muscle forces acting to displace the fracture. In addition, a long-arm cast may fur- ther restrict the child’s activity and therefore decrease the risk of

displacement. However, Chess et al. 31 reported redisplacement and reduction rates with well-molded short-arm casts similar to those with long-arm casts. They used a cast index (sagittal diameter divided by coronal diameter at the fracture site) of 0.7 or less to indicate a well-molded cast. In addition, two prospec- tive studies have recapitulated these findings. The short-arm cast offers the advantage of elbow mobility and better patient accep- tance of casting. Two recent randomized prospective clinical trials and a meta-analysis review compared the efficacy of short- and long-arm cast immobilization following closed reduction for pediatric distal radial fractures. 20,93 Bohm et al. 20 randomized 102 patients over the age of 4 years to either short- or long- arm casts following closed reduction of displaced distal radial metaphyseal fractures. No statistically significant difference was seen in loss of reduction rate between the two treatment groups. Webb et al. 207 similarly randomized 103 patients to short- or long-arm casts after reduction of distal radial fractures. No sig- nificant difference in rate of lost reduction was seen between the two cohorts. Patients in short-arm casts, however, missed fewer days of school and required less assistance with activities of daily living than those with long-arm casts. In both of these studies, quality of fracture reduction and cast mold were influential fac- tors in loss of reduction rates. These studies have challenged the traditional teaching regarding the need for elbow immobiliza- tion to control distal radial fracture alignment. IMMEDIATE PINNING OF DISPLACED DISTAL RADIUS FRACTURES In the past decade or two, closed reduction and percutane- ous pinning have become more common as the primary treat- ment of distal radial metaphyseal fractures in children and adolescents. 78,95,129,185,194,219 Despite this practice change, a meta- analysis review of the data comparing cast immobilization versus immediate pinning reveals equivalent long-termoutcomes, despite more loss of reduction in the cast groups and more pin compli- cations in the pin groups. 11 The indications cited include fracture instability and high risk of loss of reduction increasing the like- lihood of the need for remanipulation, 7,48,57,90,103,132,135,140,164,165,221 excessive local swelling that increases the risk of neurovascular compromise, 15,44,204 and ipsilateral fractures of the distal radius and elbow region (floating elbow) that increase the risk of com- partment syndrome. 19,172,183 In addition, surgeon’s preference for pinning in a busy office practice has been considered an accept- able indication because of similar complication rates and long- term outcomes with pinning and casting 134,137 and the avoidance of remanipulation because alignment is secure. OPEN FRACTURES There have been multiple studies 51,104 demonstrating that the infection rate (2.5% to 4%) following nonoperative treatment of Gustilo grade 1 open fractures results in infection rates com- parable to reported rates for operative 84 treatment (2.5%). How- ever, these were retrospective studies and likely will not change the standard of care of these fractures until an appropriate pro- spective randomized study has been conducted. Even with pro- spective studies, it is unclear if the studies will be large enough to include the rare gas gangrene infection.

Pronation

Supination

Figure 8-61.  The brachioradialis is relaxed in supination but may become a deforming force in pronation. (Reprinted with permission from Pollen AG. Fractures and Dislocations in Children. 1st ed. Churchill Livingstone, MD: Williams & Wilkins; 1973.)