By Dr. Eric W. Edmonds
In the treatment of childhood sporting injuries, some wrist pains can be a bit difficult to diagnosis, especially the area on the side of the wrist opposite the thumb. Injuries to this area may include fractures, sprains, tendon pathology, nerve irritation and cyst formation to name a few. One unique structure that is also at risk for injury at this anatomic location is the triangular fibrocartilage complex (TFCC).
The TFCC is a combination structure that is made up of ligaments and tissue similar to the meniscus in the knee. It forms a sling between the ends of the two forearm bones and creates a triangular shape. The best way to envision the TFCC is to picture a tiny hammock made of memory foam; the hammock holds two opposite structures together while at the same time functioning to cushion motion on that side of the wrist.
The design of the TFCC, and the adjacent wrist bones, makes it possible for the wrist to move in six different directions – bending up and down, rolling over and under, and tilting side-to-side. Because of all the motion seen at this location, the TFCC is at risk for injury. Most injuries are in the form of a tear, either a hole in the foam, or a rip from one of the trees in the hammock analogy. A traumatic injury or a fall onto an outstretched hand is the most common cause of injury, but athletes such as tennis players or gymnasts are also at risk for TFCC injuries due to the repetitive forces placed on the wrist.
The symptoms of a TFCC tear may include pain along the little finger side of the wrist and perhaps clicking or popping with motion. The location of the pain can help direct a medical work-up, but since this area is full of many potential pain generators, further diagnostic studies should be performed to differentiate the etiology.
X-rays should be done to assess that the bones have not been fractured, and the work-up may require specialized X-rays because of the complex three-dimensional nature of the wrist. An MRI of the wrist, most often with dye placed into the joint can be quite beneficial in determining the presence of a TFCC tear, but the accuracy is not great.
Once a TFCC tear is identified it is important to realize that there are a percentage of adults that have these tears without pain, and many do not recall any childhood injury to the wrist. But, for painful TFCC tears, there are a few different treatment possibilities in a young athlete. The first option is nonsurgical and involves cessation of the offending activities and using a splint, or cast, to immobilize the wrist. After four to six weeks, physical therapy can be started for an additional six weeks when return to activity can be progressed.
If conservative management fails to restore function and decrease pain, then surgery may be considered. Surgery is usually done to either repair or remove the torn tissue depending on the location and the quality of the TFCC tear. Unfortunately, although most athletes report improvement in their symptoms, many will continue to have some residual pain in their wrist during sports.
These injuries may be preventable with strength training and teaching appropriate mechanics.
Dr. Eric W. Edmonds is a pediatric and adolescent orthopedic sports medicine specialist at Rady Children’s Hospital-San Diego and an assistant professor of orthopedics at UC San Diego. He can be reached at firstname.lastname@example.org.