The sesamoid bones are two very small bones that are in the weightbearing area under the big toe joint. The function of those two small bones is to act much like the patella (knee cap) does and help act a fulcrum for the lever of the tendons to work better on the joint. Because of the position of the bones under the big toe joint, they are well positioned to be subjected to a lot of trauma and overuse. If that overuse and trauma becomes two much a sesamoiditis may result. “Sesamoiditis” is probably not an appropriate name for this condition (but is very widely used to describe it). The condition is more of a peri-sesamoiditis as the condition also involves an inflammation of the structures surrounding the sesamoid bones.
Symptoms of Sesamoiditis:
There is pain under the big toe joint on weightbearing and tenderness to palpation of the sesamoid bones. There may be thickening or inflammation of a bursa on the plantar surface. X-rays are generally normal. There may be symptoms elsewhere (eg peroneal tendons) from the changes in gait from the pain.
Causes of Sesamoiditis:
The primary cause of sesamoiditis is overuse. Too much weight or load for too long is placed on the area. This is more likely to occur in sports like basketball or tennis in which the big toe joint is used a lot to pivot on and push off from. Foot biomechanics play a role, in that conditions like a plantarflexed first ray that are less mobile can create a greater load on the sesamoid bones. A lack of fatty padding under the foot can also contribute to this higher load as the sesamoid bones have lost some of their natural protection.
Treatment of Sesamoiditis:
The approach to the treating sesamoiditis is usually to get the diagnosis right first and then: pain relief, activity modification, offloading, and then a return to activity levels:
- Pain relief is the first thing to consider. Typically that just might mean applying ice after activity. On a few occasions NSAID’s might be used for the pain and inflammation to help settle is down. The really painful and chronic cases may get a cortisone injection.
- Activities need to be reduced and modified. Weight bearing activities need to be reduced to a frequency and intensity that can be tolerated and do not make the pain worse. Non-weight bearing activities such as swimming may be used to help maintain aerobic fitness levels.
- Offloading is crucial in sesamoiditis. The best short term approach is to use self-adhesive podiatry felt on the foot shaped to get weight off the sesamoids. It needs to be thick enough and placed in the right position to really reduce the load on the sesamoid bones (often this is placed wrong and is not thick enough). On some occasions a walking boot may also be used in the short term to reduce load and restrict activity. In the medium term, felt or another material may be used on the shoe insole to get load off the area. In the long term, custom made foot orthotics to more evenly and accurately redistribute the loads under the forefoot could be used, especially with a shock absorbing top cover material. Loads can also be reduced by wearing lower heel shoes and staying away from higher heel shoes. Mobilization of the first ray to increase the range of motion may also help reduce the force on the sesamoid bones from a plantarflexed first ray.
- The final step in the process is to plan for a return to activity. This has to be slow and steady. The intensity and frequency of sports activity needs to be slowly increased over a period of time.
If that treatment of sesamoiditis is not working, then there are surgical options such as a removal of the sesamoid bone(s) or a dorsiflexory osteotomy of the first metatarsal..
Forums Questions and Discussion:
Personal Opinion on Sesamoiditis:
If the treatment of sesamoiditis is not working, most of the time it is because the offloading was not adequate soon enough. The offloading needs to be substantial (ie thick enough) and in the right place and used early. If that is done, then the outcome is usually much more successful.
University lecturer, runner, cynic, researcher, skeptic, forum admin, woo basher, clinician, rabble-rouser, blogger, dad.