Shin Splints: They Could Be Stress Fractures

     This time of the year (September and October) is made for Shin Splints. Cross Country season is starting and all high school and some college coaches are drowning in Shin Pain. Most of the time the athlete's pain is related to the bone and muscles not being used to the activity and overuse occurs. A shin splint technically is when the muscle pulls so hard on the bone that the lining of the bone (called the periostium) is pulled away from the bone causing bleeding between the bone and bone covering. This normally is improved with time, icing, some stretching, and activity modifications.

      However, when the bone is weaker (poor base of running, low Vit D or Calcium, low estrogen, abnormal bone structure) than the muscle, the bone may actually be the weakest link in the chain and break. This break in the bone normally remains a stress hairline fracture not detectable by normal xrays. Only in rare cases does the bone break all the way through into a complete fracture. The complete fractures are easy to diagnosis, due to the intense pain. A hairline stress fracture, also called a fatigue fracture of the bone, can at times be run on for weeks and even months. Top athletes, with apparently high pain thresholds, have presented to our office with 3 to 5 stress fractures and still running with so-called "shin splint pain".

     So, when shin splints are not improving with the simple measures of relative rest, ice, shin sleeves, cross training, shoe changes, etc, I advocate the use of a bone scan. It is positive within several days of a stress fracture, and is less expensive than an MRI. In our hospital, for the same price you get both legs for comparison, where MRIs are now being charged for only one side at a time and small areas at a time. 

    Christina, a freshman X-Country runner in high school presented with significant pain right greater than the left tibias. Definitely she could not run through this pain. Bone Scans below documented a stress fracture only on the left side. The right tibia had generalized increase uptake of the dye which we call pre-tibial stress fracture or tibial stress reaction. Stress reaction can hurt just as much as a stress fracture, although heal quicker.

On this front view of the tibias, see the intense dye uptake in the middle of the left tibia. Since Christina is fourteen, she is still growing so her growth plates near the knees and ankles are still very active.

Here is a side view of both tibias with the left again showing the spot where the tibia broke.

     This is also a good example of why MRIs probably would have mislead us in Christina's case. Christina had more pain on her right side. Due to the expense of MRIs, and the fact that each side has a separate cost, I probably would have only done the right side. I would not have found the fracture, and probably allowed her to run sooner. We never will know. So consider getting a limited bone scan instead of an MRI when shin splints are not improving. Thank you Christina for being a good model, but sorry your shins hurt.