Knee osteoarthritis is a major painful and debilitating orthopaedic disease affecting a large number of adult individuals on a global scale. Over the years, this severe condition has been widely studied and while many alternatives have been utilized, platelet-rich plasma (PRP) remains one of the most popular solutions among researchers and clinicians alike. While there are different formulations and techniques involved in the preparation of PRP, produced either manually or via the use of commercial kits, the presence of leukocytes in a PRP mixture is a factor that raises concern due to their well-known proinflammatory activity. Although it is reasonable to worry about this, it should be taken into consideration that in order for the healing process to occur, the inflammatory phase is necessary. Leukocytes present in the inflammatory phase release both pro and anti-inflammatory molecules and, when combined with activated platelets, their potential increases. Additionally, due to the macrophage's plasticity to switch from the subtype 1 to subtype 2, it is suggested that the inclusion of the components from the buffy coat layer in a PRP mixture, classifying it as leukocyte-rich platelet-rich plasma or L-PRP, may provide benefits instead of detriments, from a standpoint of the regenerative potential of PRP.

This literature review explores recent and past investigations carried out by researchers in various settings pertaining to the orthopaedic field of medicine, in attempts to show a possible connection between the deficit in sex hormone levels and the potential consequences it brings about on orthopaedic health, namely, osteoarthritis. There is some evidence in the literature suggesting that suboptimal concentrations of steroid hormones can negatively impact bone health, making it more susceptible to physical injury, especially when the hormone in question is estrogen. Several studies have shown that this biomolecule is quite essential to human health due to its effects on not only sexual development and function but also on bone metabolism, in both men and women. Investigations revolving around estrogenic compounds reveal their significance in physical capacitation of adult individuals, since it has already been found that estrogens play a pivotal role on bone maintenance by directly interacting with osteocytes, osteoblasts, osteoclasts and even T-cells, to name a few examples. Large scale studies also bring up plausible evidence by evaluating the links between measured sex steroid concentrations and incidence of osteoarthritic joint replacement in adults. Taking that into consideration, there is sufficient motivation to look into hormonal fluctuation in adult individuals, calling for suitable medical intervention in order to keep a patient’s health under control, avoiding and even treating the detrimental effects caused by the deficiency of certain steroid hormones.