![]() Partial sesamoidectomy for sesamoid fractures is rarely advocated by surgeons due to the consistently poor outcomes of this procedure. Many surgeons prefer to excise the fibular sesamoid through a dorsal approach to enable immediate weight bearing on the foot post-op. The plantar incision affords a better approach to the fibular sesamoid but necessitates 3 weeks non-weight bearing following surgery to avoid direct pressure to the plantar incision. The fibular sesamoid is excised either through a dorsal (top of the foot) incision or a plantar (bottom) incision. The tibial (medial sesamoid) is excised through a 3-4 cm incision on the medial aspect of the great toe joint. Some sesamoid fractures will not heal and present with continued pain. In this case a surgical excision of the sesamoid called a sesamoidectomy is performed. If this is the case, patients will experience transient pain with increased activity. Often we'll see that this fibrous union is adequate for some activities but becomes painful with sports or increased duration of time on the feet. This fibrous union is not true bone but rather a tissue made of collagen that is strong enough to support the normal function of the sesamoid. ![]() The most common outcome of a sesamoid bone fracture is that the fracture heals with an asymptomatic fibrous union. A cam walker with a rocker sole can also be helpful in reducing load to the sesamoid while healing. The sesamoid can be off-loaded with the use of a dancer's pad or forefoot reliever off-loading shoe. Most patients who have a sesamoid fracture can remain ambulatory with just a few simple changes to weight bearing. Treatment during this conservative period includes decreased weight bearing and limitations on activities. The treatment of a sesamoid bone fracture begins with a 6-8 week period of conservative care. The differential diagnosis for a sesamoid bone fracture includes: Sesamoid bones are referred to by their location and are called the tibial sesamoid (medial) and the fibular sesamoid (lateral.) Tibial and fibular make reference to the bones of the lower leg: the tibia and fibula.Ĭontributing factors to sesamoid fractures include the use inappropriate shoes for work and sports. The net result is that the great toe plantarflexes using the sesamoid bones to glide around the plantar surface of the 1st MPJ. As the FHB fires, the load generated by the body of the muscle is transferred through the sesamoid to an extension of the FHB that attaches to the plantar aspect of the base of the great toe. The primary mechanical function of the FHB is to aid in balance and assist the calf with the toe off phase of gait. ![]() The flexor hallucis brevis muscle (FHB) originates on the plantar surface of the calcaneus (heel bone.) The mechanism of action of the FHB is to plantarflex the great toe. The sesamoid bones are an extension of the flexor hallucis brevis (FHB) muscle and give the FHB a greater range of motion and improved lever action at the level of the 1st MPJ. The two sesamoid bones are located on the bottom surface of the first metatarsal phalangeal joint (1st MPJ.) The sesamoids are a part of the 1st MPJ and articulate with the plantar surface of the first metatarsal. MRI represents the best diagnostic test in that MRI is able to differentiate between sesamoiditis, a fracture, and a bipartite sesamoid. Bipartite sesamoids usually have a rounded appearance at the separation of the two fragments, while fractures are typically sharp-edged, without rounded edges. Bipartite sesamoids are found in 7-30% of the general population.(1,2,3) Bipartite sesamoids are usually found bilaterally.(2) One way to differentiate a bipartite sesamoid from a fractured sesamoid is to take a comparison x-ray of the non-symptomatic foot. Sesamoid fractures need to be differentiated from bipartite, or two-part sesamoid bones. Although bone scans cannot specifically diagnose a sesamoid fracture, they can reveal areas of inflammation consistent with a fracture. The image at left shows a bone scan, suggesting a fracture of the right tibial sesamoid. Subtle sesamoid fractures can also be diagnosed with MRI or a bone scan. Less frequently, we'll see avulsion of the distal ligament of the sesamoid as seen in the x-ray image (right.)ĭiagnosis of a sesamoid bone fracture is often made with an x-ray. Sesamoid fractures occur most commonly through the midbody of the sesamoid. The function of the sesamoid bones is similar to that of the knee cap (patella.) Both the sesamoids and the patella facilitate the transfer of force generated by a muscle around a joint to create action distal to the joint. The sesamoids bones function to transfer the force of the flexor hallucis brevis (FHB) tendon as it rounds the undersurface of the great toe joint.
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