Current Methods of Managing Tarsometatarsal Injuries in the Athlete
Certain types of athletes, football players for example, have a higher than usual risk of developing foot and ankle injuries. Tarsometatarsal injuries, those the area where the bones meet at the base or flat part of the foot, are usually caused by a high-energy trauma, but not when they happen to athletes. When an athlete sustains a tarsometatarsal injury, usually their symptoms are very subtle and the injury may be difficult to see by x-ray. For this reason, it's very important that doctors be aware of the possibility of this type of injury if an athlete complains of pain in the tarsometatarsal area.
The tarsometatarsal is really three joints together that are between the tarsals (small foot bones) and metatarsals (long foot bones). The combination of the bones and the joints is what helps form the arch of the foot and adds stability to the foot itself. This stability is made stronger by the ligaments, strong fibrous tissue, that holds them all the bones together. Although the bones are all very close together and work together, each has its own role to play in the foot and toe movements.
Because the joints are complex, the injuries that can happen are also complex. An high-impact cause, such as those by car accidents or crushing, cause different types of injuries than a low-impact injury, such as a twisted ankle or foot, which happens to an athlete out on the field. In fact, this type of injury is being seen more often now than before to athletes such as football players, because of the advancement in shoes that are meant to help the player.
Playing on artificial turf is very hard on the feet. It's like playing on concrete covered by an indoor/outdoor carpet. If an athlete falls while running on this foundation and a team mate or opponent falls on his or her foot, the force lands in such a way that it can cause damage to the tarsometatarsal joints. These injuries are divided into two categories: plantar flexion (flexing inward) or abduction, bending outwards.
When the force is pushed down onto the length of the foot as it's trapped usually causes a flexion injury. Another example would be when a player is running forward and has the base of his foot on the ground and the heel up as he is pushing off the ground. If he's tackled, while his foot is in that position, forcing the foot down, this results in the flexion injury. On the other hand, abduction can occur to athletes like equestrians. If their foot is in a stirrup and the front of the foot is forced down, this results in the abduction.
Aside from the flexion and abduction categories, there are others that describe if the bones are moved or not, if there are other fractures in the bones around the joint, and so on. An important point to remember is that it's not very often that an injury only happens to the joint itself. Often, the surrounding area has been injured as well.
Diagnosing a midfoot sprain can be challenging since the signs are often very subtle in athletes. A red flag would be if the athlete mentioned hearing a popping sound and complaints of pain when bearing weight on the foot. At this point, the signs may become more obvious. These include differences between the first and second toes, some swelling, and tenderness at a certain point over the midfoot area. If doctors are worried about the stability of the bones, by gently moving the foot up and down, they should be able to assess the amount of pain that is caused.
Some athletes will experience one or both provocative maneuvers, motions done deliberately by the doctor to see if they cause pain. These are done by pressing on the midfoot and squeezing on the sides of the foot in the middle. The second test seems to be a bit more reliable in assessing injury.
When x-rays are ordered, they should be done with the patient standing, bearing weight, on the injured foot. This will show if there are any bones that have moved and this may only be obvious when there is weight on the foot. If, however, the x-rays don't show an injury, the doctor can still evaluate how stable the foot is. This is done by repeating x-rays, but this time with the patient putting as much weight as possible on the injured foot. According to the author of this article, up to 20 percent of tarsometatarsal joint injuries are missed in the first round of x-rays.
If, because of tenderness over the joint, the doctors still suspect a mid-foot injury, despite negative x-rays, they can perform stress x-rays. For this, the patient must have anesthetic and the examination is done by fluoroscopy, sort of a "moving x-ray." This type of test allows the doctors to put more pressure on the foot and move it differently than if the patient is conscious, revealing injuries that might not otherwise be detected.
In some cases, computed tomography imaging (CT scans) can be useful in detecting injuries. This type of scanning provides a more detailed look of the bones and tissue around them. However, doctors must be cautious as the authors note that sometimes the CT scan finds "injuries" that aren't really there. Also, because of how the CT scans are done, they can't be done with the patients putting any weight on their foot, so finding if bones have been displaced is more difficult. Magnetic resonance imaging (MRI) is another sensitive test where the images are made with magnets rather than radiation. This type of test is usually done as a back up to confirm injuries rather than detect them. Finally, some doctors prefer to use a test called bone scintigraphy. This test uses a dye injected into the patients' vein to see various aspects of the bone and soft tissues.
Treatment for tarsometatarsal injuries usually are surgical if the injury is unstable, even if minimally. If they aren't treated, the patient may eventually develop arthritis in the injured area. However, surgery isn't always needed if the injury is stable. In a study performed by Curtis and colleagues, they found that of 17 athletes with tarsometatarsal injures, seven of nine patients who didn't have surgery reported good results, two of three who had surgery did well, but the seventeenth athlete, who was treated with a cast, wasn't able to return to his or her previous level of sports.
The authors of this article wrote that stable injuries, on weight bearing, may be treated by immobilizing the foot in a boot, with follow-up x-rays within two weeks and with weight-bearing as the patient can tolerate. They also recommend using a store-bought padded orthotic arch support inside the boot while the injury is healing or until there is no pain in the midfoot area. If treatment is done this way, it's important that the athlete be careful when returning to his or her previous level of activity. This means although training and exercising will be permitted, activity that could result in the foot being twisted or injured shouldn't be permitted and that a solid-soled shoe should be worn for at least six months while healing continues.
If surgery is chosen, there are several procedures available to the surgeon. The timing of the surgery is important: the sooner the better because this allows the athlete to begin rehabilitation more quickly. Delayed surgery due to delayed diagnosis or other circumstances could result in a less than ideal outcome and longer rehabilitation.
The hardware that's inserted to stabilize the joints usually stays in for a minimum of four months to allow for proper stabilization and healing. However, sometimes the hardware is left in permanently if it doesn't cause the patient any problems.
Mark S. Myerson, MD, and Rebecca A. Cerrato, MD. Current Management of Tarsometatarsal Injuries in the Athlete. In The Journal of Bone & Joint Surgery. November 2008. Volume 90. No. 11. Pp. 2522-2533.