From the Guidelines
The clinical significance of bipartite medial sesamoid is generally minimal, and it is often an incidental finding that does not require treatment, as supported by the American College of Radiology's appropriateness criteria for chronic foot pain 1. When an indeterminate linear lucency is visualized on radiographs, a negative bone scintigraphy suggests sesamoid bipartition, which can help differentiate it from other conditions such as sesamoiditis, inflammatory or deposition arthropathies, osteoarthritis, and osteonecrosis 1. Key points to consider in the clinical significance of bipartite medial sesamoid include:
- It is a congenital condition where the medial sesamoid bone fails to fuse during development, resulting in two separate bone fragments
- Most patients with bipartite sesamoids remain asymptomatic throughout life
- Clinical significance arises when trauma or repetitive stress causes inflammation or disruption at the synchondrosis, leading to pain in the ball of the foot
- Initial treatment for symptomatic cases includes rest, activity modification, padding, orthotic devices, and non-steroidal anti-inflammatory medications
- Distinguishing between a bipartite sesamoid and an acute fracture is crucial for proper management, with bipartite sesamoids typically having smooth, rounded edges compared to the sharp edges of acute fractures. Bone scintigraphy with single-photon emission computed tomography (SPECT)/CT can increase contrast resolution and anatomic localization of foci with increased osteoblastic activity, which can be helpful in assessing the hallucal sesamoids 1. In cases where the diagnosis is unclear, a bone scan can help identify increased uptake in pathologic conditions affecting the first metatarsal sesamoids, and a less dramatic uptake may be noted in stress fractures, which can help differentiate between them and acute fractures 1.
From the Research
Clinical Significance of Bipartite Medial Sesamoid
The clinical significance of bipartite medial sesamoid can be understood through various studies that have investigated its implications in different conditions. Some key points to consider include:
- Bipartite medial sesamoid can be a cause of severe pain, especially in cases of diastasis, as seen in a case report of a professional soccer player who suffered a turf toe injury 2.
- The condition can be associated with hallux abducto valgus, and the internal and external structural components of the bipartite metatarsal sesamoidal joint may contribute to symptomatology 3.
- Bipartite medial sesamoid can also be a site for sesamoiditis, which can be caused by various factors, including gout, as reported in a case of a 38-year-old male athlete 4.
- Sesamoiditis on a bipartite sesamoid bone can cause chronic great toe pain and may be overlooked due to lack of awareness, leading to misdiagnosis and delayed treatment 5.
- The normal interval for the bi-/multipartite sesamoid bone has been established to be up to 2 mm, and diastasis should be considered when the sesamoid interval is greater than 2 mm on a routine AP radiograph of the foot 6.
Diagnostic and Treatment Implications
The diagnosis and treatment of bipartite medial sesamoid-related conditions can be complex and may require a combination of imaging studies, including X-rays, computed tomography scans, and magnetic resonance imaging. Treatment options may include operative techniques, such as open reduction and screw fixation, as well as non-operative management, including immobilization and anti-inflammatory drugs. It is essential to consider the clinical significance of bipartite medial sesamoid in the diagnosis and treatment of various foot and ankle conditions, as seen in studies 2, 3, 4, 5, 6.