Sesamoiditis is

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

of the

sesamoid bone In anatomy, a sesamoid bone () is a bone embedded within a tendon or a muscle. Its name is derived from the Greek word for 'sesame seed', indicating the small size of most sesamoids. Often, these bones form in response to strain, or can be presen ...

Humans

Sesamoiditis occurs on the bottom of the foot, just behind the

big toe Toes are the Digit (anatomy), digits of the foot of a tetrapod. Animal species such as cats that walk on their toes are described as being ''digitigrade''. Humans, and other animals that walk on the soles of their feet, are described as being ' ...

. There are normally two sesamoid bones on each foot; sometimes sesamoids can be bipartite, which means they each comprise two separate pieces. The sesamoids are roughly the size of jelly beans. The sesamoid bones act as a fulcrum for the

flexor In anatomy, flexor is a muscle that contracts to perform flexion (from the Latin verb ''flectere'', to bend), a movement that decreases the angle between the bones converging at a joint. For example, one's elbow joint flexes when one brin ...

tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...

s, the tendons which bend the big toe downward. Symptoms include inflammation and pain. Sometimes a sesamoid bone is fractured. This can be difficult to pick up on

X-ray An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

, so a

bone scan A bone scan or bone scintigraphy is a nuclear medicine imaging technique used to help diagnose and assess different bone diseases. These include cancer of the bone or metastasis, location of bone inflammation and fractures (that may not be vis ...

MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and rad ...

is a better alternative. Among those who are susceptible to the malady are dancers, catchers and pitchers in baseball, soccer players, and American football players.

Horses

In the horse it occurs at the horse's

fetlock Fetlock is the common name in horses, large animals, and sometimes dogs for the metacarpophalangeal and metatarsophalangeal joints (MCPJ and MTPJ). Although it somewhat resembles the human ankle in appearance, the joint is homologous to the ...

. The sesamoid bones lie behind the bones of the fetlock, at the back of the joint, and help to keep the tendons and

ligament A ligament is a type of fibrous connective tissue in the body that connects bones to other bones. It also connects flight feathers to bones, in dinosaurs and birds. All 30,000 species of amniotes (land animals with internal bones) have liga ...

s that run between them correctly functioning. Usually periostitis (new bone growth) occurs along with sesamoiditis, and the suspensory ligament may also be affected. Sesamoiditis results in inflammation, pain, and eventually bone growth.

Causes

In humans, excessive forces caused by sudden bending upwards of the big toe,

high heels High-heeled shoes, also known as high heels (colloquially shortened to heels), are a type of shoe with an upward-angled sole. The heel in such shoes is raised above the ball of the foot. High heels cause the legs to appear longer, make the we ...

, or a stumble can contribute to sesamoiditis. Once the sesamoid bone is injured it can be very difficult to cure, because additional pressure is put on the sesamoid bone during walking.

Treatment

Treatment in humans consists of anti-inflammatory medication,

cortisone Cortisone is a pregnene (21-carbon) steroid hormone. It is a naturally-occurring corticosteroid metabolite that is also used as a pharmaceutical prodrug. Cortisol is converted by the action of the enzyme corticosteroid 11-beta-dehydrogenase ...

injections, strapping to immobilize the big toe, and

orthotics Orthotics () is a medical specialty that focuses on the design and application of orthoses, sometimes known as braces, calipers, or splints. An is "an externally applied device used to influence the structural and functional characteristics of ...

with special accommodations to keep pressure off the affected bone. In horses, sesamoiditis is generally caused by excess stress on the fetlock joint. Conformation that promotes sesamoiditis include long

pastern The pastern is a part of the leg of a horse between the fetlock and the top of the hoof. It incorporates the Equine_forelimb_anatomy#Metacarpal_bones, long pastern bone (proximal phalanx) and the Equine_forelimb_anatomy#Middle_phalanx, short past ...

s, or horses with long toes and low heels.

Notable cases

Josh Zeid Joshua Alexander Zeid ( ; ; born March 24, 1987) is an American-Israeli former professional baseball pitcher and current coach. He plays for Israel national baseball team, Team Israel. He played in Major League Baseball (MLB) for the Houston Ast ...

, major league baseball pitcher * Melvin Upton, major league baseball player * JJ O'Donnell, football player for Gateshead FC

References

External links

{{Osteochondropathy Equine injury and lameness Disorders of fascia Inflammations Overuse injuries Pain