Get the Answers to Treat Your Foot Injury Right in Our Podiatry FAQ
Our Issaquah podiatrists have heard a lot of questions over the years, and we’ve compiled the most popular on one page to help future patients. Visit our FAQ for quick answers on bunions, neuromas, corns, ingrown toenails, and more.
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All About Cortisone Injections for Plantar Fasciitis
Below are frequently asked questions about cortisone injections.
The purpose of cortisone injections:
The goal is to decrease the inflammation directly at the site of the problem. When an oral anti-inflammatory medication is taken, it has to go throughout the whole body. Often, the dosage in your foot is the same as your legs and in your hands with an oral medication. But if you have a painful heel, you are not getting the ideal therapeutic dosage. So, when a cortisone injection is done we are able to put a therapeutically effective dosage of the medication right where it is needed.
Often times we are able to use ultrasound guidance to make certain that the cortisone is placed in the exact location necessary. This has several benefits; we can use a lower dosage by having it exactly where it is needed. Also we can avoid injecting into areas where it's not as effective or specificallycould cause potential problems. For example, an injection for plantar fasciitis in the heel is most effective at the layer between the plantar fascia and the fat pad. If we inject into the fascia directly there is a higher risk of the fascia will weaken and even have a partial tear. If the injection was done into the plantar fat pad and this could thin the fat pad out (especially with repeated injections). But if it is injected between the 2 layers, then the potential for these problems is minimized.
How quickly will be injection-medication work?
Sometimes it takes 2 or 3 days before the injection really is effective. This is partly because the longer acting component of the cortisone is in a crystalline form and requires time after the injection to become usable by the body (the crystals need to "dissolve"). During this time frame it can actually hurt worse than before the injection. But once the cortisone has passed this initial threshold time frame, there is usually dramatic reduction in pain and inflammation.
How long will the cortisone injection work?
It should last for least 3 weeks but sometimes can last 2 or 3 months, or longer. Many problems with the foot are mechanical in nature. Therefore, there is often both an inflammatory component of the problem and a mechanical component to the problem. So, if we are able to address the mechanical dysfunction, for example with prescription orthotics, then the cortisone injection can effectively address the inflammatory component. Oftentimes there is more of a long-term resolution with this approach.
Can I go exercise right away?
It is recommended that you take it easy for least 2 or 3 days after a cortisone injection. It is recommended that you discuss (with your Doctor) any special plans for high-impact exercise such as running.
Are there any risks with an injection?
There is a very small risk of infection related to the injection. Therefore the injection site is prepped with alcohol to help minimize this risk. There is also the risk that some the underlying structures are weak prior to the injection and will become further weakened with cortisone. As mentioned, a cortisone injection directly into the plantar fascia is commonly done. But this increases the risk of partial tearing of the fascia. Therefore at our clinic, we like to inject at the interface between the fascia and the fat pad to help minimize this risk.
Some patients might be leery of an injection in their foot, but our office has a solution to this fear. We used what is called a Transcutaneous Electrical Nerve Stimulation (TENS) unit. The TENS unit works by sending stimulating pulses across the surface of the foot and along the nerve strands. The stimulating pulses help prevent pain signals from reaching the brain so a patient doesn't even feel the injection as it's happening.
Why use a night splint for plantar fasciitis?
Plantar fasciitis can be a chronic problem that may require long-term solutions. Ideal long-term solutions include special prescription orthotics, ideal shoes, avoiding going barefoot at home, and a night splint. Studies show that the use of a night splint for plantar fasciitis is an effective treatment. Usually a night splint will offer immediate reduction in that severe pain first thing in the morning.
Plantar fasciitis, when it occurs at the heel, typically causes pronounced pain in the morning. This is called post-static dyskinesia. There are several reasons why this occurs. One reason is that without the weightbearing pressure of being on your feet during the day, the plantar fascia becomes more inflamed and more fluid accumulates in this area-swelling or edema (overnight). Fluid will also accumulate because the foot is in a relaxed position (plantar flexion or flexion of the ankle) and there is minimal tension on the fascia allowing for more "engorgement". So upon arising, you get up and walk on this inflamed fluid-filled plantar fascia at the heel level. Until some extra fluid is literally "worked out", there is severe pain and often limping.
By holding the foot and calf muscle under tension (extension or more accurately - dorsi flexion of the ankle) it is not possible for fluid to accumulate as much. As a result, this pain upon arising in the morning does not occur. Another reason why this occurs is because the calf muscle is held in a more stretched position and is not allowed to tighten up overnight. The more you can stretch out the calf muscle the less tension in the whole system that includes the calf muscle, Achilles tendon, heel bone and plantar fascia. See also our blog on stretching for plantar fasciitis. (Part One, Part Two)
Night splints range from a classic posterior night splint to the front of the foot and shin style night splint. They are very padded and should be fairly comfortable. But nonetheless they are fairly bulky. The anterior (front of the foot and shin style) is much less bulky and can be more comfortable. The disadvantage to the anterior style of night splint is that does not hold the foot up as
effectively as a posterior night splint. But again the posterior night splint is fairly bulky. For severe cases plantar fasciitis a posterior night splint is the best option.
Another option is not to have the foot held in a dorsiflexed position overnight at all. But instead, to allow for some compression on the plantar fascia so that this area is not allowed to become swollen. This does not address the tight calf but it does address the fluid accumulates overnight. Therefore this can be effective at reducing the pain first thing in the morning. The most effective but light weight splint in this case is the Bledsoe brace.
One of the last options is to use a Strasburg sock. A Strasburg sock is fairly inexpensive and spans from the calf to the foot and out to the toes, then attached back to the front of the shin. These are available on line and at some athletic shoe stores.
For people who sleep on their backs or the sides night splints are fairly easy to use. However if you sleep on your stomach, this alone can be a big factor in why plantar fasciitis just won't go away. The foot is forced into a plantar-flexed or relaxed position and the calf muscle always tightens up overnight and the plantar fascia is allowed to become more swollen overnight. One way to address this is to have your feet hanging out over the end of the foot of the bed so that they are not forced into this position. Another option is to have a fairly thick pillow that suspends the tip of their foot off the bed when you sleep on your stomach.
One problem with a posterior night splint is that the heel tends to lift up and the foot is not held in ideal position. However, just by having the foot at 90° there is some benefit. Ideally speaking it should be and 5-10° of dorsiflexion. But again another problem is individuals with a high arch foot are prone to nerve irritation overnight and your feet may seem to go numb. Potentially this could be a problem and usually causes enough irritation that goes individuals with high arch feet or nerve irritation will have to discontinue the use of the night splints. There are many different types of night splints because patient's have different preferences and foot types. One reason why there are so many types of night splints, is that they are an effective adjunct to long-term treatment for plantar fasciitis.
What causes heel pain in the morning?
Do you have heel pain when you initially get out of bed in the morning? Pain experienced with the first few steps in the morning is often a symptom of plantar fasciitis. The term used to describe this symptom is post static dyskenisia. This is very common for people suffering from plantar fascitiis and can easily be alleviated.
Plantar fasciitis is not the only cause of morning stiffness or heel pain but it is one of the most common. There are many reasons for morning heel pain and morning stiffness, however one of the most common is attributed to microscopic tearing of the plantar fascia which occurs when one initially takes their first steps after a night of rest.
While sleeping, the mechanical tension is reduced on the plantar fascia and Achilles tendon and the fascia has a chance to begin the reparative process. When one steps out of bed, the inflammatory cycle is often initiated and pain is experienced. Normally, the pain begins to subside with more walking, however, it usually returns again towards the end of the day and always returns again overnight. Stretching of the Achilles complex and plantar fascia can often greatly reduce this pain.
If you are experiencing pain when you initially get out of bed in the morning, please contact us for an appointment.