Young children in good health are known to heal quickly. This is generally true for many conditions from bug bites to bone fractures. Some bone fractures can be complicated by infection or joint dislocation. Forearm fractures affecting both bones in the forearm (the radius and the ulna) can present some unique problems. A delay in union is one of those complications presented in this article.
Orthopedic surgeons from the University of Zaragoza in Spain reviewed over 400 cases of both-bone forearm fractures treated in their hospital. About three per cent (14 cases) were associated with delayed bone union. The question is why? Why are there some children who experience a very slow recovery and healing time?
Surgeons explore questions like this in hopes of finding ways to predict (and prevent) such problems. Most children show X-ray evidence of a healing bone formation called a callus at the fracture site four weeks after the injury. Complete healing is often present by the end of eight weeks. Failure to callus formation or healing at the fracture site by 11 weeks is a signal that there is a delay in bone union.
What are the contributing factors to this problem? In particular, why does delay in healing occur when there aren't other risk factors (e.g., infection, surgery, dislocation, multiple bone fragments) for delayed healing? The authors suspected there were other predictive risk factors but didn't know for sure what those factors were.
By comparing the children with delayed union to children with the same type of forearm fractures, they were able to isolate some additional contributing risk factors. For example, older children (10 years old or older) were more likely to need more time for healing.
Surgery to correct the problem was also a significant risk factor. In fact, open reduction was the strongest predictor of delays in healing forearm fractures. Open reduction means that an incision is made and the bones are realigned. Then the bones are held in place with hardware such as a metal plate, screws, and/or pins.
Further observation of the nonunion group of children showed that all but one did eventually heal fully. That one case involved a second surgery with eventual healing as well. All children in the delayed union group had unstable fractures requiring open surgery. Children with stable fractures who were treated conservatively with a forearm cast were much less likely to develop delayed bone union.
The question was also raised as to whether or not keeping the hardware in a long time is also a risk factor for delayed union. There is no set time for hardware removal in these cases. Sometimes the plates, screws, or pens are removed within seven weeks of the injury. In other cases, it's a full year before the hardware is taken out.
After analyzing all the data carefully, the authors concluded that the single biggest predictive factor of delayed fracture healing when both bones in the forearm are involved is open reduction surgery. For this reason, they recommend closed reduction for both-bone forearm fractures in children whenever possible. There is less risk of damage to the periosteum (outer covering of bone) and/or blood vessels in the area. Disruption of either of these anatomic features could contribute to the delayed healing observed with open reduction.
Reference: Antonio Lobo-Escolar, PhD, et al. Delayed Union in Pediatric Forearm Fractures. In Journal of Pediatric Orthopaedics. January/February 2012. Vol. 32. No. 1. Pp. 54-57.