Returning patients: Please call the office to book an appointment.

X-Ray: What are those circles near the big toe?

Dr. Samuel Kellner often gets this question when reviewing X-rays with his patients. These circle shaped masses near the big

X-Ray: What are those circles near the big toe?


When reviewing X-rays with patients, I often get asked: what are those two circle shaped masses near my big toe? This question gets asked anxiously as if something may be wrong with their foot. However, it would be more concerning if these bones were not present as everyone is born with them.

These are called sesamoid and they perform a specific function: to act as a pulley system. This gives a mechanical advantage to stabilizing the big toe on the ground, and aids with propulsion of the foot when walking or running. 

Embedded within a flexor tendon that attaches under the big toe, the sesamoid bones have cartilage on their deep surface and serve as part of the big toe joint. It is quite a complex joint. 

Most people are much more familiar with the patella, or knee cap, which serves the quadricep tendon in the same way, to extend our knee joint more efficiently. It’s just that the sesamoid bones are not as noticeable.



All things that have a function can have dysfunction as well. “Sesamoiditis” is a common inflammatory condition of either or both of these bones. There is typically an underlying cause to why these might become inflamed. 

Overuse, impact injury, certain foot types, and poor movement patterns are most typical. Furthermore, repetitive stress injury to either of these bones can lead to arthritis or fracture of a sesamoid. 

If you are having pain in the ball of the foot near the big toe, sesamoiditis could be the culprit. A thorough history, examination and x-rays are necessary to provide the appropriate diagnosis and treatment plan. 

Call 508-757-4003 or text 508-625-7775 for an appointment in Worcester and Westborough. Same day visits might be available.


Dr. Samuel Kellner is a foot and ankle surgeon at Central Massachusetts Podiatry, in Worcester and Westborough. Dr. Kellner is dedicated to helping his patients heal from foot injuries that stop them from daily activities. He also plays basketball and likes to spend his free time with his wife, newborn son, and two cats. 

Dr. Sam Kellner

You Might Also Enjoy...

A Podiatrist’s view of the Good Feet Store

The Good Feet Store is now in Central Massachusetts. We thought it’s important that our other neighbors, friends and patients understand what they do and how a trip to a quality podiatrist is different in myriad ways. By Dr. Benjamim Saviet

How to easily put on and take off compression socks

The biggest challenge for people who wear compression socks is how to get them on and off. My gold tip if you are having a hard time with your compression socks is to consider a device called “Doff N’ Donner”. By Dr. Donald Pelto

This insole can help with big toe joint arthritis pain

This rigid carbon fiber shoe footplate prevents the painful movement of the arthritic big toe joint. The insert can replace, go under or over the sock lines based on whatever is most comfortable. Usually fits most sneakers. By Dr. Samuel Kellner

What should I do if I step on glass?

We want patients to come see us when there is still an "entry wound" for us to follow. If you wait 2-3 weeks, the track can be healed up and then the simple act of plucking out a sliver of glass becomes a fishing expedition. By Dr. Benjamin Saviet

Painful like walking on a tiny pebble: Porokeratoma

Have you ever felt pain on the bottom of the foot as if you were constantly walking on a small pebble, especially under a bony prominence? This could be a porokeratoma: a small hard round bump that develops due to a clogged sweat gland. By Dr. Donald Pelto

FAQ: What’s the best shoe to wear?

People come in all shapes and sizes and the same is true for feet! “What's the best shoe for me?” is a much better approach that takes into account this reality. By Dr. Benjamin Saviet