Summary and unique distinctions of more specific amnion terminology used throughout the selected articles. Additional summary of spine surgery uses among the selected articles.
| Term | Distinctions | Potential Uses in Spine Surgery |
| HAF | Amniotic fluid surrounds the embryo contained in the amniotic sac and is highly proliferative. This fluid can be obtained through amniocentesis with little risk to the fetus and the mother. | Bolat et al33 used to examine the effects of HAF on spinal epidural fibrosis. Kara et al38 used to examine prevention of postlaminectomy spinal epidural fibrosis. Luo et al39 used to examine impact on intervertebral disc height and morphology after disc degeneration. Oner et al40 used to determine effect on vertebral fusion. Walker et al43 used to determine prevention of spinal retethering after detethering. |
| HAM | The amniotic membrane is the inner lining of the placenta. This membrane can be harvested after cesarean section. | Kara et al38 used to examine prevention of postlaminectomy spinal epidural fibrosis. Luo et al39 used to examine impact on intervertebral disc height and morphology after disc degeneration |
| Freeze-dried HAM | Freeze drying is more abrasive than drying alone, as the process requires drying and freezing, both of which impose stress on biomaterials. | Choi et al34 used this to evaluate the effects on epidural adhesions after laminectomy. Tao and Fan42 used to reduce epidural scar adhesion after laminectomy. |
| Cryopreserved HAM | Cryopreservation includes storing the specimen in liquid nitrogen. | Kamson and Smith37 used this to study PROM after endoscopic-assisted lumbar decompression. Anderson et al32 studied the use of this to compare functional outcomes and recurrent herniation after lumbar microdiscectomy. |
| Dehydrated HAM | Amniotic membranes undergo a process that desiccates and removes all water from the tissue. Dried samples can be stored at room temperature and typically have a much longer shelf life. | Subach and Copay41 used this to evaluate epidural scar formation after transforaminal lumbar interbody fusion. |
| Cross-linked amniotic membrane | Amniotic membrane can be cross-linked through exposure to chemicals and radiation to increase stability of the biomolecules within the membrane. | Tao and Fan42 used to reduce epidural scar adhesion after laminectomy. |
| Amnion-derived epithelial cells | These are cells that can be derived from the inner lining of the placenta after birth. As such, there are fewer ethical concerns. | Goldschlager et al36 used to observe effect on promoting osteogenesis. |
| Dual-layered, chorion-free, amnion patch | This is derived from HAM and consists of 2 layers of amniotic membrane stacked on top of each other. | Cunningham et al35 used to follow effect following lumbar laminectomy. |
Abbreviations: HAF, human amniotic fluid; HAM, human amniotic membrane; PROM, patient-reported outcome measures.