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AAOS Now

Published 12/1/2012
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Peter Pollack

Rotation Is Key to Treating Both-Bone Pediatric Forearm Fractures

Fracture treatments shift as technology and understanding improve

“Forearm fractures account for almost 4 percent of all pediatric fractures and almost a third of pediatric upper extremity fractures,” said Christine B. Caltoum, MD, speaking at the 2012 annual meeting of the Clinical Orthopaedic Society. “When you take into account wrist and diaphyseal fractures, they’re the third most common pediatric fracture.”

The most common mechanism of injury, she noted, is falling onto the outstretched arm, which leads to rotational displacement. If that rotational component is not restored, cautioned Dr. Caltoum, the patient will have reduced range of motion.

Dr. Caltoum explained that improved technology and a developing understanding of such fractures has resulted in a shift in treatment approach from what was common 10 or 15 years ago.

“Forearm development is an important consideration,” she said. “Most of the growth comes from the wrist. About 75 percent of the length of the radius comes from the distal radius physis and about 80 percent of the ulnar length comes from the distal ulnar physis. Overall, the distal physes of the forearm bones contribute about 40 percent of the length of the upper extremity.”

According to Dr. Caltoum, fractures that are closest to the distal radial physis are likely to remodel the best, especially among younger patients. In contrast, fractures in the proximal third of the forearm in an older child will not remodel significantly.

“Those fractures can be bad actors,” she said, “ones that can lead to problems later.”

Treatment goals
Dr. Caltoum outlined the following goals in treating such fractures:

  • restore alignment
  • restore the clinical appearance of the arm
  • achieve bony union
  • restore the forearm rotation

“Several cadaveric studies have demonstrated what happens when both-bone forearm fractures are malreduced,” she said. “A 40 percent malrotation of the forearm can lead to a 20° loss of pronation/supination, and 15° of angulation can lead to a 30° loss of rotation. According to a 1981 study based on eight different activities of daily living (ADL), at least 50° of pronation and 50° of supination is necessary. However, a 2011 study based on the same eight functions plus computer and cell phone use found that computer use required almost 65° of pronation, and cell phone used needed 145° of elbow flexion.”

In addition, Dr. Caltoum pointed out that pediatric patients, along with their parents, often have higher expectations for their recovery than adult patients might possess.

“All of the patients that come through my clinic think they’re going to grow up to be Olympic athletes,” she explained. “Is it really fair to say that our treatment goal is only to restore ADL? I think it’s important that we try to restore our patients to full range of motion.”

Gold standard
According to Dr. Caltoum, closed reduction and casting remain the gold standard for treatment of both-bone forearm fractures, although there is an increasing trend toward surgical fixation.

She iterated the importance of taking rotation into account when aligning the bones. “The bicipital tuberosity can be used as a guide to align the fractures,” she said. “The diameters of the radius and the ulna can be used to assess the fracture reduction. Several different methods can be used to ensure that the rotation is correct.

“Typically, I put my patients in a cast,” she continued. “I use a split cast that allows for swelling, and I follow the patients weekly for 2 to 3 weeks to check for alignment. If a loss of reduction occurs, the fracture can typically be remanipulated for up to 3 weeks.”

Surgical options
Dr. Caltoum recommended surgical treatment for open fractures and floating elbows. “Unstable fractures that cannot be reduced satisfactorily need to go to the operating room (OR) as well,” she said. “Refractures are often treated surgically, although some can be treated with closed reduction. An additional category of fractures that deserve surgical treatment includes those with less remodeling potential—such as occur in older patients with midshaft and proximal third both-bone forearm fractures. These patients should be treated surgically to ensure that the rotation is correct so they won’t have a deficit when the cast is removed.”

Regarding surgical options, she said that elastic intramedullary (IM) nailing is an effective stabilization method.

“It can restore the length, the rotation, and the angulation,” she said. “It’s minimally invasive, and typically requires less OR time. It also reduces blood loss and has a shorter return-to-sport time compared to open reduction internal fixation (ORIF) with screws.”

However, Dr. Caltoum pointed out that the procedure does have some drawbacks. A 2010 study based on 11-year follow-up found that patients treated with ORIF had an overall complication rate of 14 percent, a 6.7 percent rate of compartment syndrome, several cases of extensor pollicis longus rupture, and a greater likelihood of delayed union compared to patients treated with closed reduction and casting.

A separate study from 2004 looked at elastic IM nailing and found that longer operative times, longer tourniquet times, and multiple attempts to pass the wire were associated with the development of compartment syndrome.

Dr. Caltoum recommended making no more than three attempts to get the nail across the fracture. Otherwise, she said, “you might as well make the incision so that you’re not creating more soft tissue trauma on top of the trauma from the fracture.”

Dr. Caltoum stated that ORIF with plate and screws remains a good option, but carries with it some downsides, including a much larger scar and the need to remove the hardware later.

Finally, Dr. Caltoum cited a 2010 study that compared IM nailing to ORIF, and found that the ORIF group had a greater risk of major complications, including non- or delayed union, a fracture at the proximal aspect of the plate when the child fell after the fracture healed, and a hematoma that required evacuation after surgery.

Dr. Caltoum reports no conflicts.

Peter Pollack is a staff writer for AAOS Now. He can be reached at ppollack@aaos.org

Bottom Line

  • The rotational component should be taken into account when treating upper extremity fractures.
  • Pediatric patients and their parents have high expectations for good recovery.
  • Casting remains the gold standard for treatment of pediatric forearm fractures.
  • Surgical options are effective, but carry a greater risk of complications.

References

  1. Morrey BF, Askew LJ, Chao EY. A biomechanical study of normal functional elbow motion. J Bone Joint Surg Am. 1981 Jul;63(6):872-877 http://www.ncbi.nlm.nih.gov/pubmed/7240327
  2. Sardelli M, Tashjian RZ, MacWilliams BA. Functional elbow range of motion for contemporary tasks. J Bone Joint Surg Am. 2011 Mar 2;93(5):471-7. http://www.ncbi.nlm.nih.gov/pubmed/21368079
  3. Flynn JM, Jones KJ, Garner MR, Goebel J. Eleven years experience in the operative management of pediatric forearm fractures. J Pediatr Orthop. 2010 Jun;30(4):313-9.
  4. Yuan PS, Pring ME, Gaynor TP, Mubarak SJ, Newton PO. Compartment syndrome following intramedullary fixation of pediatric forearm fractures. J Pediatr Orthop. 2004 Jul-Aug;24(4):370-5.
  5. Shah AS, Lesniak BP, Wolter TD, Caird MS, Farley FA, Vander Have KL. Stabilization of adolescent both-bone forearm fractures: a comparison of intramedullary nailing versus open reduction and internal fixation. J Orthop Trauma. 2010 Jul;24(7):440-7.