Sesamoid bones are small oval to round bones which are a few millimeters in size. They are located within the substance of tendons close to the joint surface.
Their main function is to
- increase the efficiency of muscles by increasing their leverage
- distribute the weight of the body
- protect the tendons from excessive pressure against bones
Two sesamoid bones are located within the substance of this tendon namely
The tibial sesamoid can be bipartite. This means that it consists of two bony parts joined by fibrous tissue. It is present in about 10% people.
The tibial sesamoid is more commonly injured because it is located directly below the first metatarsal bone in a central position.
Mechanism of injury is
- fall from height (direct axial load on the sesamoid)
- sports injuries (excessive extension of the great toe joint also known as turf toe)
- chronic stress injury (more common in a bipartite sesamoid)
Symptoms of the sesamoid fracture include
- history of injury
- pain around the metatarsophalangeal joint
- point tenderness over the sesamoid bone
- usually, no swelling is present
X-rays of the foot are done to confirm the diagnosis. Special views are required to see the sesamoid bones. A bone scan may be required if the diagnosis cannot be confirmed by x rays. It is useful to differentiate a fracture of the sesamoid from a bipartite sesamoid.
CT and MRI scans may be required. Treatment of sesamoid fracture can be operative or non-operative.
Non-operative treatment includes
- use of anti-inflammatory medication such aspirin, ibuprofen and diclofenac
- a non-weight bearing plaster cast for 6 weeks you have to use crutches to walk
- use of a metatarsal pad in the shoe to relieve pressure the sesamoid
- a foot splint along with the metatarsal pad
If there is no improvement after a reasonable trial (4 to 6 weeks) of non-operative treatment, then surgery is done.
In the surgery, the involved sesamoid bone is removed (partly or totally).
The above symptoms are also present in a condition called sesamoiditis. It includes the following conditions.
How long does it take for complete recovery after the operation?
It can take between 4 to 6 weeks for complete recovery after the operation.
What are the complications of sesamoid excision?
The following complications can occur
- injury to nerves
- the weakening of the flexor muscles of the great toe
- hammer toe deformity may develop
- surgical scar on the sole may become thick and painful