Rockwood Children CH8

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CHAPTER 8 • Fractures of the Distal Radius and Ulna

Potential Pitfalls and Preventative Measures

casting include poor casting, bayonet apposition, age greater than 10 years, translation of more than 50% the diameter of the radius, apex volar angulation of more than 30 degrees, isolated radial fractures, and radial and ulnar metaphyseal fractures at the same level. More specifically, Mani et al. 132 concluded that initial displacement of the radial shaft of over 50% was the single most reliable predictor of failure of reduction. Proctor et al. 165 found that complete initial displacement resulted in a 52% incidence of redisplacement of distal radial fractures in children and described remanipulation rates of 23%. Pretell et al. 164 found that postreduction translation of the radius greater than 10% in the sagittal plane resulted in 2.7 times more likely loss of reduction. Alemdarog˘lu et al. 6,7 suggest that radial frac- tures with greater than 30 degrees of obliquity have 11.7 times more likelihood to redisplace than a straight transverse fracture. In addition to the initial and postreduction angulation, a poor casting technique is often implicated as a cause of loss of reduc- tion. It has become evident that casting alone is likely not suffi- cient to prevent loss of reduction for high-risk fractures. Miller et al. 138 reported that despite these optimal conditions, 30% of high-risk patients treated with cast immobilization alone sus- tained a loss of reduction that required remanipulation. These findings have generated enthusiasm for percutaneous pinning and casting as a preferable method to avoid loss of reduction. 78,219 Although the authors of these studies, and others, 219 conclude that pinning is a safe, effective means of treating distal radial metaphyseal fractures (see Controversies), the results of casting and pinning were equivalent after 2 years postfracture. 38,135 In general, loss of reduction has been tolerated because of the remodeling potential of the distal radius. 70,155,223 However, given that remodeling can be incomplete leading to malunion (see Malunion section) with functional deficits, high rates of loss of reduction have led to considerable controversies regarding acceptable displacement, casting techniques, remanipulation, and need for initial percutaneous pinning. We prefer to reduce forearm fractures as near to perfect alignment as possible. No element of malrotation is accepted in the reduction. As indicated in the treatment sections, fractures at high risk of loss of reduc- tion and malunion are treated with anatomic reduction and pin or, rarely, plate fixation. Fractures treated in a cast are followed closely and rereduced for any loss of alignment of more than 10 degrees. Although loss of forearm rotation can occur with ana- tomic healing, 146,191 it is less likely than with a malunion. MALUNION While complications from metaphyseal and physeal fractures of the radius are relatively rare, malunions do occur. 11,31,37–39,44,50,200 De Courtivron 45 reported that of 602 distal radial fractures, 14% had an initial malunion of more than 5 degrees. In addition, as noted above, the rate of loss of reduction for distal radius frac- tures ranges from 20% to 30%, and although many of these fractures will be rereduced, inevitably surgeons will encoun- ter malunion of the distal radius, most often due to decisions to avoid injury to the physis from remanipulation beyond 7 days of injury or a patient may miss follow-up appointments before healing occurs. Fortunately, with significant growth remaining, many angular malunions of the distal radius will

Distal Radius Fractures: POTENTIAL PITFALLS AND PREVENTIONS Pitfall Preventions • Loss of reduction

• Correct diagnosis of bicortical disruption • Optimal fracture reduction • Well-molded cast application • Serial radiographic evaluation • Avoidance of repeated forceful reduction maneuvers acutely • Avoidance of late manipulation for loss of reduction in children with considerable remaining growth • Thorough neurovascular evaluation at time of initial presentation • Avoidance of excessive forceful manipulation during reduction maneuvers • Immediate pin fixation in patients with excessive soft tissue swelling or neurovascular compromise • Bivalve circumferential casts to avoid excessive external compression • Timely surgical stabilization with fasciotomies or carpal tunnel release in patients with impending compartment syndrome • Use of small incisions for nerve identification and retraction during pinning procedures • Pin placement using oscillating technique

• Posttraumatic growth arrest

• Compartment syndrome

• Radial sensory nerve injury

MANAGEMENT OF EXPECTED ADVERSE OUTCOMES AND UNEXPECTED COMPLICATIONS IN FRACTURES OF THE DISTAL RADIUS AND ULNA

Distal Radial and Ulna Fractures: COMMON ADVERSE OUTCOMES AND COMPLICATIONS • Loss of reduction

• Malunion • Nonunion • Growth disturbance (radius or ulna) • Ulnocarpal impaction

• TFCC tears • Synostosis • Neuropathy • Infection

LOSS OF REDUCTION Loss of reduction is a common occurrence after closed reduc- tion and cast immobilization of displaced distal radius fractures (Fig. 8-52). Multiple studies demonstrate an incidence of loss of reduction of 20% to 30%. 6,7,10,48,57,90,103,133,136,141,165,166,200,207,218,221 From these studies, factors that have been identified as increas- ing the risk of loss of reduction with closed manipulation and