Endogenous Causes of Obturator Nerve Entrapment: Literature Review and Proposal of a Treatment Algorithm

Background: Obturator nerve entrapment can result from endogenous and exogenous causes. Due to its long course, which includes both endopelvic and exopelvic segments, the nerve is susceptible to irritation from multiple etiologies. However, as obturator nerve entrapment is relatively uncommon, a thorough understanding of endogenous factors contributing to nerve entrapment is lacking. Nevertheless, understanding the endogenous factors contributing to obturator nerve entrapment is crucial for an effective treatment approach. Material and Methods: We performed a systematic literature search on studies investigating the diagnostic and (surgical) therapeutic approaches to obturator neuropathy due to endogenous causes. Studies were grouped according to the etiology responsible for nerve irritation. Lastly, data were synthesized to create a clinical work-up flowchart for obturator nerve entrapment syndromes due to endogenous causes. Results: Data from 45 studies comprising 175 patients met our inclusion criteria. We were able to summarize these data into six broad etiologies (tumor, obturator hernia, endometriosis, cystic lesions, vascular, and idiopathic causes) responsible for nerve irritation and saw that the most important factors for therapy are the onset of the symptoms and the anatomical localization. MRI emerged as the most valuable diagnostic tool for chronic conditions, especially in identifying the precise etiology and location of nerve compression. Conclusions: This review offers a structured framework for diagnosing and managing obturator nerve entrapment due to endogenous causes. We propose a diagnostic and therapeutic algorithm based on the identified etiologies to facilitate clinical decision-making.