Sesamoidits
Introduction
Sesamoidits is an inflammatory condition of the sesasmoid bones.
The medial and lateral sesamoids are two well defined bones located on the plantar surface of the first metatarsal head within Flexor Hallucis Brevis and Longus tendons which move the hallux.
Sesamoids are present in approximately 85% of the population. They appear in the third fetal month of development and remain cartilaginous until 8-10 years of age where they ossify.
The action of sesamoids is to:
Act as a fulcrum for the FHB tendon by increasing the mechanical force of the tendons
Serve to protect FHL tendon
Reduce friction
Absorb shock at forefoot during loading by redistributing ground reaction forces thus protecting the metatarsal head
Just over 1% of all running injuries involve the sesamoids, 40% of these are stress fractures and 30% are diagnosed as sesamoiditis.
Etiology
The many causes of sesamoids include:
Increase in activity
Aggravating sports: Jumping, Ballet, Irish Dancing
High heel shoes
Shoe with little cushioning
The location and force projected through these bones increases susceptibility to injury
Foot deformities: Pes Cavus, plantar flexed first rays, hyperextended hallux and pes planus or flat feet.
Relative lengths of the 1st and 2nd metatarsals
Examination
On examination there may be a history of gradual onset of pain localized to the plantar surface of the first metatarsal head or an initial trauma can offset symptoms. Pain on palpation on either of the sesamoid bones which can be distinguished by dorsiflexing and plantar flexing the hallux. Movement of the joint can increase pain. While swelling and erythema are often present thus limiting the first metatarsal/phalange joint range of motion. The favoring of one foot with a limp can be present.
How a Podiatrist can help?
Initial modification of patients exercise regime will be necessary to allow the sesamoids to recover. Conservative treatment includes: rest, ice, anti-inflammatory medication and flexibility exercises
We can assess the patient’s foot alignment, foot deformities and gait analysis. An Orthoses may be fitted to accommodate any foot deformities while offloading the sesamoids, redistributing the forces across the foot and preventing future difficulties. Thus reducing swelling and symptoms and allowing the sesamoids to heal.
Modifying footwear to provide support and cushioning
Limit the use of high heel shoes
