Shin Splints: part II
As mentioned in my previous post on shin splints, “shin splints” is a very general term which generally refers to symptoms rather than a proper diagnosis. It can be considered an umbrella term, which encompasses a variety of lower extremity disorders related to the tibia. When athletes or coaches find themselves facing “shin splints”, a true diagnosis must be made in order to ensure the correct course of action for recovery. Generally, there are 3 distinctive conditions which underlies “shin splints”:
1) Medial/Lateral Tibial Stress Syndrome: This was discussed in extensively in my previous post on shin splints. It is the most common form of “shin splints” and generally the least severe. It generally takes 2-3 weeks to heal and chances of recurrence are slim if proper precautions are taken.
2) Tibial Stress Fractures: Often occurs if medial/lateral stress syndrome is not treated soon enough. Chronic impact to the tibia can cause micro-fractures in the bone itself. The diagnosis of tibial stress fractures is often confused with medial/lateral tibial stress syndrome and there are various methods to differentiate the two:
In most cases, the pain associated with medial/lateral tibial stress syndrome will reside with gradual activity. In the case of stress fractures, the pain will gradually get worse with activity. However, this is not absolute. In some rare instances of medial/lateral tibial stress syndrome, the damage may have progressed far enough to mimic the pain of stress fractures.
Pain due to stress is supposedly more localized (i.e. you can pinpoint an exact point on the bone that hurts). From my experience this is not always true especially if the fracture is deep in the posterior tibia, the pain can feel quite widespread.
Physicians can perform a quick test with a tuning fork. A vibrating tuning fork is put against the tibia and if there is a stress fracture, the high frequency vibrations will send a sharp pain through the periosteal nerves. This test may not work if the stress fracture is deep in the tibia (ie under the gastrocnemius and soleus muscles).
X-ray imaging can sometimes show stress fractures. But often the resolution is not high enough. Some signs such as periosteal thickening can point to healing stress fractures.
The best test to determine if a stress fracture is present is a bone scan. A radionuclide is injected into the patient’s bloodstream. The radionuclide will be localized in areas of high bone turnover (which is indicative of a stress fracture). This is then detected my special cameras that sense the radiation emitted by the radionuclide. The presence of a “hot spot” will pretty much confirm a stress fracture. So why not skip all the above and just jump right to the bone scan? Well it has to do with demand and a lack of resources. Waiting lists for a non-emergency bone scan can be up to a month (especially with the health care here in Canada). Also in places with no universal healthcare and/or individuals with no health insurance, a bone scan can typically cost $500-$700.
3) Chronic Exertional Compartment Syndrome (CECS): This is probably the worst of all three conditions because there is currently no non- surgical cure. When the muscles of the lower leg are exerted, they expand against the inflexible fascia of the shank which divides the lower leg into compartments. In some individuals, there isn’t enough space between the fascia and muscle to accommodate the expansion. The result is an increase in compartmental pressure which can pinch nerves and cause a numb sensation in the leg. Along with the pain and numbness, CECS can cause a decrease in ankle range of motion (especially dorsiflexion). Once the activity has ceased, the pain will subside when the compartmental pressure drops. This can take anywhere from 10-30 minutes.