Identify the boundaries of the ischioanal fossa. The medial wall is formed by the pelvic diaphragm, and the lateral wall is formed by the obturator internus muscle, which is covered by the obturator internus fascia.
Finally, confirm that the posterolateral border of the fossa is partially formed by the gluteus maximus muscle and the underlying sacrotuberous ligament . Cut the gluteus maximus muscle and reflect it posteriorly to reveal the course of the sacrotuberous ligament.
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