The Impact of Hormone Replacement Therapy on the Clavicle

One of the many medical procedures of gender transition that are available for transgender individuals involve the use of cross-sex hormones to align one’s physical characteristics with one’s gender identity. During this process, transgender male-to-female patients may see the feminization of their bodies, while transgender female-to-male patients may see the masculinization of their bodies. Currently, little research has been done to show the full range of the effects that hormone replacement therapy induces, specifically regarding its impact on skeletal morphology. This lack of analysis is not only to the detriment of transgender patients themselves but also to the field of forensic anthropology. Methods of sex estimation on deceased individuals do not presently take gender identity or medical transition into consideration, potentially leading to misidentifications and unsolved cases. This literature review explores the potential influence of hormone replacement therapy in the development of the clavicle in transgender individuals under the age of 30, the average age at which the clavicle halts medial epiphyseal fusion and overall growth. The clavicle was chosen to study due to its ability to continue growing in length even after puberty has been surpassed, emphasizing that the introduction of cross-sex hormones at any point before medial epiphyseal fusion could influence its growth in length. This literature review also serves as a foundation for a future quantitative research study that measures the clavicle lengths of 17 transgender and non-transgender descendants to determine if there is a correlation between hormone replacement therapy and the clavicle’s length at death