There are multiple definitions:

1. retrograde tibial nail(English)

   • a prototype intramedullary implant, offering double proximal and triple distal interlocking with an end cap leading to an angle-stable screw-nail construct of the most distal interlocking screw
   • ETN
   • Surgery, Orthopedics
   • https://doi.org…ury.2013.10.025

2. retrotrapezoid nucleus(English)

   • BB, BP, CBD, CPG, CVLM, HCSB, HF, HTN, OSA, PNS, RAAS, RVLM, SNS
   • Neurons, Brain (dys)function
   • https://doi.org….1002/ejhf.2819