How is it possible to have a wrist fracture and not know it

Q: About a month ago, my left wrist started aching for no known reason. I finally had it X-rayed and sure enough, there was a fracture in the scaphoid bone. How is it possible to have a wrist fracture and not know it?

A: The scaphoid is the most common carpal bone to break. It is located on the thumbside of the wrist next to the radius (larger of the two forearm bones). And according to results of studies published in orthopedic journals, it's also not uncommon for patients to be unaware of a fracture or the cause. In other words, having no recollection of an injury resulting in a scaphoid fracture is not unusual.

The question then arises: why does this particular bone fail to heal? Is there something that creates a nonhealing response? Is it age or sex (male versus female)? Does the medical care patients receive fail to treat the problem correctly? Having a better idea of how and why scaphoid fractures result in a nonunion may help surgeons manage these cases more effectively in the future.

Some studies have reported a nonunion rate as high as 40 per cent. This high rate occurred when the patients were not diagnosed or treated right away. To give you an idea how that 40 per cent rate compares, there's a three per cent rate of nonunion when the problem is diagnosed and treated within 30 days of the injury. This finding supports the idea that timing of evaluation and treatment might be an important factor.

But it doesn't answer the question of why you had no symptoms at first. The answer to that isn't as clear. Some experts suggest the very fragile blood supply to the scaphoid area might be a factor. The location and severity of the fracture could also explain the lack of symptoms. A severe fracture of the scaphoid bone on the forearm side of the wrist is more prone to nonunion. Again, the reasons for this are not entirely clear.

The good news is that you have finally been diagnosed so that treatment can begin. Follow your physician's treatment plan carefully. Patient noncompliance (failure to cooperate with treatment) is one reason why nonunion fractures fail to respond.

Reference: King Wong, MB BCh, and Herbert P. von Schroeder, MD. Delays and Poor Management of Scaphoid Fractures: Factors Contributing to Nonunion. In The Journal of Hand Surgery. September 2011. Vol. 36A. No. 9. Pp. 1471-1474.