Background: The sciatic nerve is the largest branch of the sacral plexus. Variations of its origin, exit from the pelvis, emergence and branching in the posterior region of the thigh, especially in regards to the piriformis muscle, are an object of interest due to the possibility to be involved in the pathogenensis of clinically significant non-discogenic sciatica or piriformis syndrome. Case report: We present a case of variant anatomy of the sciatic nerve, discovered during routine dissection of the left gluteal region of an adult female cadaver. We observed a non-formation of the main trunk of the nerve; rather, the tibial nerve passed inferiorly to the piriformis muscle, while the common peroneal nerve went through the body of the bifid piriformis muscle, immediately next to its tendon. The two branches continued their course in the thigh without joining and forming a proper sciatic nerve. The medical records of the body donor did not reveal any neurological impairment which could be linked to this anatomical peculiarity. Conclusion: The anatomy of the sciatic nerve could be considered to be a factor of clinical significance. The high prevalence of similar anatomical variations should be kept in mind during the diagnostic process of clinical entities involving the sciatic nerve.

Background: Norsodyne is a new material for conservation and durable preservation of biological objects. The form we use is H 13212 TAE (Polynt Composites USA, Inc., Bergamo, Italy). This is an unsaturated polyester resin in styrene that is of low styrene emission. Features: resin has a specific weight 1.10 g/cm2 at 20°C. Using test method MT-CUT23V the manufacturer has established that Brookfield viscosity at 23°C is 450-650 mPa.s. The jelly starts in 14-18 minutes and reaches its peak in 27-37 minutes at 23°C too. Acording to the test results of ISO 527 (2012) tensile strength of Norsodyne is 57 MPa and flexural strength is 98 MPa (ISO 178 (2011). Conclusion: This characteristic of Norsodyne indicates that the material can be used for the preservation and long-term storage of anatomical preparations for the needs of anatomy training. However, the Norsodyne needs special storage conditions. The material should be stored in a dark place. According to the manufacturer shelf life at 23°C in the dark is six months then spontaneous rubbing begins. The manufacturer's recommendations are: Store in the shade, out of direct sunlight. Keep storage temperature below 25°C. Unseal container just before use. Shelflife will be reduced reaching higher temperature.