*Review* **Biological Approach in the Treatment of External Popliteal Sciatic Nerve (Epsn) Neurological Injury: Review**

**Alejandro León-Andrino 1, David C. Noriega 1,2,\*, Juan P. Lapuente 3, Daniel Pérez-Valdecantos 4, Alberto Caballero-García 5, Azael J. Herrero <sup>6</sup> and Alfredo Córdova <sup>4</sup>**


**Abstract:** The external popliteal sciatic nerve (EPSN) is the nerve of the lower extremity most frequently affected by compressive etiology. Its superficial and sinuous anatomical course is closely related to other rigid anatomical structures and has an important dynamic neural component. Therefore, this circumstance means that this nerve is exposed to multiple causes of compressive etiology. Despite this fact, there are few publications with extensive case studies dealing with treatment. In this review, we propose to carry out a narrative review of the neuropathy of the EPSN, including an anatomical reminder, its clinical presentation and diagnosis, as well as its surgical and biological approach. The most novel aspect we propose is the review of the possible role of biological factors in the reversal of this situation.

**Keywords:** external popliteal sciatic nerve (EPSN); common peroneal nerve; compression; neurolysis; foot drop; growth factors
