The historical use of various clinical applications of amniotic membranes began relatively early in the 20th century. The first applications were in wound healing, followed by a large variety of other applications, including use in musculoskeletal conditions. More recently, applications have been described for using umbilical cord and various other combinations of birth tissue. The use of amniotic fluid as a treatment for orthopedic conditions was recorded as early as 1938.
Amniotic fluid has a variety of homologous uses as in utero it naturally functions to protect and cushion, reduce inflammation and enhance mobility.2,6 It is a dynamically changing biological fluid that changes in both volume and composition throughout the course of gestation and the fluid normally ranges from 25 mL at 10 weeks to about 400 mL at the time of delivery.
Composition of amniotic fluid. Key elements of amniotic fluid include growth factors, carbohydrates, proteins, lipids, electrolytes, and other nutrients, as well as hyaluronic acid (HA), a principle component of viscosity and lubrication in synovial fluid.
Functions of the amniotic fluid in utero include:
•An extension of the fetal extracellular compartment.
•A connection between the intracoelemic and extracoelemic components of the developinginfant.
•A physiologic buffer for various extra-fetal compounds.
•Modulation of fluid and electrolyte transport between the mother and fetus across fetal andplacental membranes.
•Nutritional support of the fetus.
•Provision of a supportive fluid cushion to the developing fetus, allowing fetal movement andgrowth.
•Protective functions provided by the inclusion of multiple growth factors and biologicalmolecules.
•Provide antimicrobial effectors that protect the fetus