Sesamoid Injuries

(Picture Credit: www.naturalfootgear.com)

Understanding Sesamoid Injuries

The sesamoid bones are two pea-shaped bones located in the ball of the foot, beneath the big toe joint. Like the kneecap, the sesamoids function as a pulley to provide leverage as the big toe pushes off. The sesamoids also serve as a weight-bearing surface for the first metatarsal bone that absorbs the impact forces placed on the ball of the foot when walking, running and jumping.

Due to their location and function, sesamoids are subjected to massive pressure, stress, and forces during every push off. Sesamoid injuries can involve the bones, tendons and the surrounding tissue in the joint. They are often associated with activities requiring increased pressure on the ball of the foot such as running, football, tennis, and ballet.

Types of Sesamoid Injuries in the foot

There are three types of sesamoid injuries in the foot:

Turf toe. Turf toe, also commonly known as a sprain of the big toe joint, is an injury of the soft tissue surrounding the big toe joint. Such injury usually occurs following excessive upward bending of the big toe joint beyond its normal range. Turf toe causes immediate, sharp pain, swelling and restricted motion on the big toe. Turf toe may result in an injury to the soft tissue attached to the sesamoid or a fracture of the sesamoid. Sometimes a “pop” is felt at the moment of injury.

Fracture. A fracture in a sesamoid bone can be either acute or chronic. An acute fracture is caused by a direct blow or impact to the bone which can produce immediate pain and swelling at the site of the break. A chronic fracture, on the other hand, is a stress fracture, a hairline break usually caused by repetitive stress or overuse. A chronic sesamoid fracture produces long-standing pain which tends to come and go, generally aggravated with activity and relieved with rest.

Sesamoiditis. This term is a general description for any irritation of the sesamoid bones. It is an overuse injury involving chronic inflammation of the sesamoid bones and the tendons involved with those bones.

In this post, we will focus more on learning about sesamoiditis.

How will a sesamoiditis feel like?

Similar to other sesamoid injuries in the foot, sesamoiditis is often associated with a dull, mild ache or intense throbbing long-standing pain beneath the big toe joint. The pain can be of gradual onset but generally aggravated by movement of the big toe joint, occurring with certain shoes or certain activities. There may be swelling, which can cause reduced movement of the big toe and difficulty walking.

What causes sesamoiditis?

Generally, sesamoiditis is found to be common amongst people participating in activities and sports that involve repetitive, excessive loading of the ball of the foot such as dancing. Any direct injury or trauma to the sesamoid bones, such as a fracture can also lead to sesamoiditis. Any increased activity such as speedwork, hill work or increased mileage can also lead to sudden increased activity and pressure on the sesamoid bones, hence increasing the risk of sesamoiditis.

It is also important to note that people with bony or high-arched feet, marked flat feet can all be predisposed to sesamoid injuries. If you have bony feet, you may not have enough fat pad underneath your foot to protect your sesamoid bones that are subjected to massive high pressure and stress occurred throughout every step you take. As for high arched feet, you will naturally tend to run or bear more pressure on the balls of your feet. Incorrectly fitting footwear or high-heeled shoes can also be a contributing factor, causing increased stress to the sesamoid area.

Will it get worse?

It is likely that sesamoiditis will get worse if the area is not protected and rested. It is not uncommon for people to ignore this problem initially only to find that it stops them walking normally, forcing them to seek treatment. Sesamoiditis, if not treated, over time can lead to fracture of the sesamoid bones and hence, further complications.

How is sesamoiditis treated? What can I do to reduce the pain?

Rest or activity modification
Anti-inflammatory medication as required
Wear well-fitted footwear suited to your activities
Avoid high heels
Wear a protective pad around the joint

What can a podiatrist do to assist with the management?

Advice appropriate footwear and relevant exercises
Strapping
Request appropriate investigations
Identify and address underlying causes to manage and prevent recurrence of the condition
Prescribe protective offloading padding
Orthotic therapy