In the foot, sesamoiditis usually refers to an inflammation of the sesamoid bones under the 1st metatarsal head, on the ball of the foot just behind the big toe.
The usual symptom is pain in the ball-of-the-foot, especially on the medial or inner side near the great toe. The term is a description for any irritation of the sesamoid bones. They are small bones within the tendons that run to the big toe. The sesamoids increase the leverage of the tendons that control the toe. When you push off against the toe the sesamoids are involved, and eventually they can become inflamed, and they can even fracture if there is enough stress against them. The sesamoid bones at the base of the great toe, beneath the metatarsal head actually lie in the flexor tendons. Sesamoiditis in the flexor tendons can also be described as tendonitis.
Most bones in our body are connected to each other at joints. However, there are a few bones that are not connected to other bones. Instead, they are connected only to tendons or are embedded in muscle. These bones are called sesamoids. We are essentially discussing the two sesamoids beneath the first metatarsal head. These are constant sesamoids and generally are found in all persons. They are considered to be anatomical. There are other sesamoids that may be seen on the foot that we are generally not aware of, other than an incidental finding on an x-ray examination that was taken for another reason. They do not generally cause any problems or serve any purpose. They are atavistic and are congenital.
In the foot, the medial (tibial) and lateral (fibular) sesamoids are found on the underside of the 1st metatarsal head, within the 1st metatarso-phalangeal joint. This joint is located at the base of the big toe.
Occasionally a sesamoid may be referred to as bi-partite, this means that the sesamoid is in two pieces. This can occur in either or both anatomical sesamoids. It may be difficult to determine if a sesamoid is bi-partite or fractured. On an x-ray exam this may appear very similar. This is very suspect if the sesamoid happens to be symptomatic.
Primary Function of the Sesamoids:
Because the sesamoids protrude down, underneath the head of the 1st metatarsal, they act as a fulcrum for the big toe flexors, giving these muscles extra leverage and power. This power allows the big toe to “”push”” us forward with extra force each time we take a step forward. Without the medial and lateral sesamoids, the big toe loses some of its power and force.
Sesamoiditis can usually be distinguished from other painful forefoot conditions by its gradual onset of symptoms under the 1st metatarsal head, just behind the big toe. The most common symptoms of sesamoiditis include:
- Early Stage:
- Sesamoids are tender when direct pressure is applied to them.
- Mild pain occurs when walking barefoot or in thin-soled shoes. Pain is worse
when running and jumping.
- Pain subsides quickly with rest.
- Mild swelling under the sesamoids that usually subsides with rest and elevation of
- Later Stage:
- Constant pain may be present under the sesamoids. This pain becomes worse when:
- Walking, running, and especially jumping, even in well-padded shoes.
- Applying direct pressure to the sesamoids.
- Bending the toe up.
- Swelling is increased, and may not subside with rest and elevation of the foot.
- Eventually, the entire 1st metatarso-phalangeal joint may become swollen. This
may cause stiffness in the big toe.
- Constant pain may be present under the sesamoids. This pain becomes worse when:
If the above symptoms occur abruptly, or after an injury to the forefoot, one or both sesamoids may be fractured. Fractured sesamoids should be cared for by your physician or by a foot and ankle specialist.
The most common causes of Sesamoiditis include:
- Injury to the sesamoids may occur in one of two ways:
- Direct injury to the sesamoids (such as stepping on a rock while walking or running barefoot).
- Micro-trauma is an overuse injury due to excessive or repetitive stress on the sesamoids. This type of injury occurs over a period of time. Examples include:
- Dancing barefoot or in shoes with thin soles.
- Squatting for long periods of time (such activities may be performed by a baseball catcher, plumber, or carpet installer).
- Running and jumping on the balls of the feet.
- Wearing high heel shoes while standing or walking for long periods of time.
- Age-related changes. As we age, we all develop osteoarthritis and osteoporosis to one extent or another. Both of these conditions can cause sesamoiditis:
- Osteoarthritis may cause small bone spurs to form on the sesamoids. These spurs may irritate the flexor tendon that the sesamoids lie in. When this occurs, the results are inflammation, swelling, and pain in the sesamoid and tendon.
- Osteoporosis occurs when bones lose calcium and become weaker and thinner. If the sesamoids become weak, they may not be able to withstand the force applied to them with each step we take. If this should occur, small stress fractures may form within the sesamoid (small, shallow cracks in the bone). Stress fractures produce pain, swelling and inflammation of the sesamoid.
- Hereditary Defects are those defects that we are born with, which predisposes us to sesamoiditis:
- Feet with high arches are usually more rigid than normal and will not allow the high arch to come into contact with the ground when we step down. Therefore, as we step forward, all of our weight is thrown on to the balls of the feet, rather than some of the weight being carried by the arch. This will force the bones in the balls of the feet to bear excessive weight, especially the big toe and first metatarsal head. The result of this repetitive and excessive weight on the big toe and sesamoid bones under the first metatarsal head is compression, deterioration, inflammation, and pain in the sesamoids.
- A plantar flexed first metatarsal is one of the most common predisposing hereditary factors of sesamoidtis. This condition occurs when the first metatarsal head is tilted down in the forefoot, rather than lying straight. Because the first metatarsal head and sesamoids are lower than the other forefoot bones, each time we take a step forward, the sesamoids are forced to bear more of the body’s weight than is normal. Over time, this results in the sesamoids becoming over-stressed, which may lead to inflammation, erosion of the sesamoids, and pain.
- Pronation occurs when the foot rolls outward at the ankle, forcing us to walk more on the inner border of the foot than is normal. Therefore, as we walk, pronation causes us to place excessive weight and pressure on the big toe, the first metatarsal head, and the sesamoids. This extra weight and pressure will eventually over-stress the sesamoids causing them to become compressed, inflamed, and painful.
- Enlarged sesamoids. When we are born with larger than normal sesamoids, they are forced to bear abnormal amounts of the body’s weight each time we take a step forward. Eventually, due to this excessive weight and pressure forced on these bones, they begin to deteriorate and become inflamed and painful.
Long Term Treatment must be directed towards:
- Stabilizing the foot. When the foot is maintained in its normal, or neutral position, it cannot pronate and roll out. When pronation is controlled, the big toe, the first metatarsal head, and the sesamoids no longer bear excessive weight. This reduces forceful and destructive compression of the sesamoids. Thus, the sesamoids remain healthy and pain free.
- Supporting high arches in order to relieve excess pressure on the balls of the feet, especially the first metatarsal head and the sesamoids. When these structures no longer must bear excessive amounts of weight as they help “”push”” us forward, the sesamoids are protected from excessive weight and force. This will result in healthy sesamoids, free of deterioration and pain.
- Elevating the plantar flexed first metatarsal head and sesamoids will prevent them from bearing abnormal and excessive amounts of weight. When this is achieved, the sesamoids under the first metatarsal head will no longer be subjected to excessive weight and pressure. This will prevent the sesamoids from being over-stressed and eroding. The results are healthy and pain free sesamoids.
- Providing shock absorption for the foot. The arches of our feet are the body’s main shock absorbers. As we take each step, the arch of the foot helps to absorb and disperse the tremendous force that occurs when our foot strikes the ground. This force can equal 3 to 7 times our body weight, depending on whether we are walking or running. When the arch is higher than normal, shock absorption by the arch is reduced. When this occurs, the big toe, sesamoids, forefoot, and heel of the foot, must absorb this shock. The effect on the sesamoids is to forcefully jam them into the under surface of the first metatarsal head, which may cause them to eventually fracture.
Custom-Made Orthotics are considered to be the treatment of choice, especially in the prevention and early stages of Sesamoiditis. Our custom-made orthotics for this condition are constructed of thin, comfortable, shock absorbent materials, which gently and effectively:
- Stabilize the foot by using uniquely placed medial wedges, deep heel cups, and “posts” (stabilizers). When the foot is stabilized, it is brought back to a neutral or normal alignment. When the foot is in its normal alignment, pronation is reduced or completely corrected, and, the big toe is no longer forced to bear excessive body weight. This prevents abnormal wear and tear on the big toe cartilage, and helps to stop or prevent Hallux Limitus/Rigidus from occurring.
- Provide the specific amount of arch support that your foot requires. Our custom-made orthotics support not only the arch as a whole, but each individual bone and joint that forms the arch. When the arch is properly supported, it is allowed to function in providing optimal shock absorption for the foot, especially to the big toe joint. This will reduce the wear and tear on the joint cartilage.
- Reduces or eliminates the weight that the sesamoids are forced to bear during the gait cycle. This is accomplished through the use of a uniquely shaped and placed cut-out pad called a Dancer’s Pad. It is embedded in our custom-made orthotics, and placed under the forefoot in such a way that the weight the sesamoids would normally carry is transferred to the rest of the forefoot and arch. This dramatically reduces or eliminates the excessive and damaging weight that the sesamoids usually bear. This will help the sesamoids to heal and eliminate pain.
Custom-made orthotics for Sesamoiditis are constructed of durable, comfortable, shock absorbent materials. From the impressions of your feet that you make with our Foam Impression Kit, and the information you provide us with, we design and construct a pair of orthotics that will help to:
- Stabilize your feet
- Gently reduce or eliminate the weight that the sesamoids must carry each time we take a step and provide support and comfort for the entire foot.
All conservative treatments begin with the shoes that you wear. While shoes may help to reduce the pain of Sesamoiditis, they do not prevent this disease from becoming worse. This is due to the fact that shoes wear down quickly, and whatever soothing effects they may have when they are new, are quickly lost as they wear down. This is one reason why custom-made orthotics are more cost effective than orthopedic shoes…custom-made orthotics last for years without breaking down, while shoes do not.
Make sure that your shoes are:
- Wide enough across the ball of the foot and toe area, so that there is no pressure on the big toe joint and sesamoids.
- The shoes must be the correct length for your foot.
- The heel of the shoe should be no higher than 1″”.
- The innersole of the shoe should be well padded in order to cushion and protect the sesamoids.
Immediate Treatment must be directed towards reducing the inflammation, swelling, and pain in the sesamoids. In the very early stages of sesamoiditis, the following self-help treatments may be effective:
- Rest the foot by keeping weight off of it. Each time you take a step, the sesamoids are aggravated and abused. They cannot calm down if you do not keep weight off of the foot.
- Shoes can help to protect the sesamoids if they have the following features:
- A well padded innersole. This will help to cushion the sesamoids with each step that is taken.
- A wide and deep toe box prevents side-to-side squeezing of the sesamoids.
- A flat shoe reduces the pressure and weight that the sesamoids must bear when walking. As the heel is raised, the sesamoids are forced to carry more of the body’s weight.
- Proper length shoes will also go a long way in reducing sesamoid pain.
- Reduce pressure on the sesamoids with a Dr. Jill’s gel pad. This soft gel pad cushions the ball of the foot and reduces pressure on the sesamoids. Self-stick, re-usable pad makes for easy application.
- Gentle massage with a topical pain reliever can help to provide comfort. By combining the pain relieving properties of Corganics Relief Topical Analgesic Cream with gentle massage, pain, swelling, and inflammation can be reduced or eliminated.
If the pain becomes worse, the foot more swollen or inflamed, or if you think that you have a serious problem, see a doctor immediately.
Surgical intervention for sesamoiditis is generally reserved for the most persistent cases that have not responded to the usual conservative methods for alleviating pain. The surgical procedure relieves symptoms rapidly with quick recovery and postoperative time. There can be problems related to surgery and the most common is progression of a Hallux Valgus deformity (Bunion) if the medial or tibial sesamoid is removed. Frequently during certain types of Bunion operations the lateral sesamoid is removed as part of the corrective procedure and this generally does not cause any additional problems.
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