Review of Hallucal Sesamoid Problems
There are two tiny sesame-shaped bones under the base of the big toe. These are called the hallucal sesamoids. They are prone to injury. Anatomy, types of injuries and other conditions affecting the hallucal sesamoids, and treatment are discussed in this review article on the topic.
Inflammation, uneven wear and tear, fracture and loss of blood supply called osteonecrosis are the most common problems encountered. The sesamoids bear 50 per cent of a person's body weight. During push-off of the big toe in the walking cycle, this load can increase to 300 per cent or more of the body weight.
The ligaments and tendons attached to these bones make them susceptible to inflammation from stress and overuse. Fracture is most often the result of trauma when the toe gets bent back too far. Running injuries also contribute to sesamoid fractures. Ballet dancers who put repeated stress on the big toe are at increased risk of sesamoid fractures.
Other problems include osteoarthritis, infection, and dislocation of the sesamoid bones in patients with bunions. In the case of dislocation, the deformity causing the bunion also pushes the sesamoid bones out of place. Less often, the sesamoid bones pinch a nerve in the toe causing pain.
Treatment for most sesamoid problems is with rest, ice, and antiinflammatory drugs. Special shoe inserts called orthotics are very helpful. A gel insert may be put directly under the bones. Custom-made inserts may be used for some problems. Casting is needed for most fractures.
If the fracture doesn't heal or a fractured sesamoid bone is displaced, then surgery is done to remove the bone fragments. Because of problems that occur without these tiny bones, surgeons try to repair and save them if at all possible. The authors review and discuss specific surgical techniques involving the sesamoids.
Doctors can expect to see more cases of sesamoid problems in the future. Increased sports activities, high-impact aerobics, and more common use of artificial playing surfaces will likely contribute to these problems.
Barnaby T. Dedmond, MD et al. The Hallucal Sesamoid Complex. In Journal of the American Academy of Orthopaedic Surgeons. December 2006. Vol. 14. No. 13. Pp. 745-753.