A patient with piriformis syndrome describes buttock pain with radiation to the ipsilateral posterior thigh and lateral lower leg. Which of the following nerves is most likely involved?
Piriformis syndrome often results in pain in the buttock radiating down the ipsilateral leg or hip. The path of buttock pain follows the course of the piriformis originating from the anterior surface of the S2-S4 vertebrae, capsule of the sacroiliac joint and gluteal surface of the ilium inserting on the medial greater trochanter. Additionally, patients may have low back pain.
Radiation of pain down the ipsilateral posterior thigh and lateral lower leg is an indication of sciatic nerve irritation. Typically, the sciatic nerve, posterior femoral cutaneous nerve, gluteal nerves and gluteal vessels course longitudinally deep to the piriformis muscle.
The sciatic nerve and piriformis muscle have a variable anatomic relationship. In 84 percent to 98 percent of individuals, the sciatic nerve courses...