No statistically significant pattern of metatarsophalangeal sesamoid distribution has been reported in the literature in relation to genetic pool or group, unilaterality or bilaterality, or sesamoid division. A study was undertaken to evaluate the presence and distribution of the metatarsophalangeal sesamoid bones of the foot in Turkish subjects. A total of 602 foot radiographs from 371 patients without forefoot complaints other than those of the hallux were included in the study. Absence or hypoplasia of the first-ray sesamoids was seen on 0.7% of the radiographs, and second-, third-, fourth-, and fifth-ray sesamoids were present on 2.8%, 0.5%, 1.0%, and 15.1% of the radiographs, respectively. Fifth-ray sesamoids were more prevalent in men (odds ratio, 2.71; 95% confidence interval, 1.52–4.84). The frequency of a normal foot profile (two sesamoids in the first ray) was 83.2%. Divisions of the sesamoids were seen on 4.0% of the radiographs at the first ray and on 20.9% at the fifth ray. Distribution and division of sesamoids were predominantly bilateral (κ = 0.91, 0.91, and 0.95 for the first, second, and fifth digits, respectively; P < .001). (J Am Podiatr Med Assoc 96(5): 437–441, 2006)
Posterior tibial tendinopathy (PTT) is the most common cause of acquired (progressive) flatfoot deformity in adults. To date, PTT research has mainly focused on management rather than on causal mechanisms. The etiology of PTT is likely to be multifactorial because both intrinsic and extrinsic risk factors have been reported. We sought to critically evaluate reported etiologic factors for PTT and consider the concept of genetic risk factors.
A detailed review of the literature published after 1936 was undertaken using English-language medical databases.
No clear consensus exists as to the relative importance of the risk factors reported, and neither has any consideration been given to a possible genetic basis for PTT.
To date, studies have examined various intrinsic and extrinsic risk factors implicated in the etiology of PTT. The interaction of these factors with an individual's genetic background may provide valuable data and help offer a more complete risk profile for PTT. A properly constructed genetic association study to determine the genetic basis of PTT would provide a novel and alternative approach to understanding this condition.