The sesamoid bones are small, rounded bones typically found embedded within certain tendons and joint capsules. Unlike most other bones in the human body that connect via joints, sesamoid bones are located within soft tissue and offer protection and leverage to the surrounding soft tissue without directly attaching to other bones.
The largest and most well-known sesamoid bone is likely the patella or kneecap; however, there are two small sesamoid bones beneath the big toe. These foot sesamoids at the metatarsophalangeal joint are often known as the tibial and fibular sesamoids.
Problems with Sesamoid Bones
Issues that may develop regarding the tibial and fibular sesamoid bones in the foot include the following -
- Sesamoiditis – this issue refers to an inflammation of the tissues around the sesamoid bones, which is symptomized by pain and swelling. This podiatric issue tends to develop due to overuse, repetitive stress, ill-fitting shoes, or a traumatic incident where it becomes challenging to walk or bear weight on the impacted foot/toe.
- Sesamoid Fractures – these fractures often result from some sort of trauma or excessive, chronic stress on the affected bones. Fractures may be acute or stress-related, causing pain and limiting movement.
- Sesamoid Dislocations – an injury or repetitive overuse that can cause a sesamoid bone to move or shift from its normal or correct position.
Ossicle Problems
Ossicles (OS), which refer to relatively small and distinct bones (extra nodules), can develop near joints or within tendons. In the foot, an accessory ossicle refers to a small bony structure that is not present in everyone (thus, considered a variation of normal anatomy). Ossicles are relatively common and may include the following –
- OS Peroneum - This ossicle exists within the peroneus longus tendon, located on the lateral/outer side of the midfoot. It is one of the tendons that help control the foot's movement. OS perineum issues result in discomfort, inflammation, and more.
- OS Trigonum – This accessory bone is located in the back of the foot near the ankle. Individuals who experience symptoms from this sesamoid bone will be challenged by pain and potentially a reduced range of motion when flexing their foot.
- OS Intermetatarseum – This accessory bone or sesamoid bone tends to be less common - is located with the tendons between the base of the first and second metatarsal bones.
Common Symptoms of Sesamoid Bone Problems
Sesamoid bones tend to be prone to injuries and inflammation because of their placement within the tendons in the foot. However, sesamoid issues typically develop gradually over time. This is especially true when the cause is chronic stress or persistent overuse.
Among the most common symptoms of sesamoid bone issues is persistent or chronic pain at the ball of the foot – particularly below the joint of your big toe, which worsens when bearing weight and can be dull or sharp.
Swelling/Tenderness/Bruising
Inflammation can cause swelling, and pressing on or touching the affected area or sesamoid bone may cause pain. When there is a sesamoid fracture or serious inflammation, bruising may appear.
Reduce Range of Motion
A person may have less flexibility and range of motion in their big toe.
Difficult to Bear Weight
Issues with sesamoid bones can create pain, and other symptoms may make it difficult to bear weight when walking, running, and more.
Podiatric Treatment Options
Rest, Ice, Compression, and Elevation (RICE guidance) are the most conservative options to follow. In addition, other treatment options that can help manage sesamoid or OS problems include –
- Custom orthotics.
- Appropriate footwear.
- Medication – either over-the-counter NSAIDS or prescription meds to help with inflammation and pain. Additionally, corticosteroid injections can be used to help reduce inflamed areas.
- Physical therapy can help with flexibility and strengthen supporting muscles and tendons.
Surgical intervention may be considered in severe instances, persistent fractures, and more.
If you experience foot discomfort or pain, seeking medical guidance to determine specific underlying causes and an appropriate treatment plan is essential.