Deep Gluteal Syndrome
Anatomy: Deep Gluteal Space
The deep gluteal space is bounded by the gluteus maximus muscle posteriorly and the posterior surface of the femoral neck anteriorly. Its upper limit is the inferior margin of the greater sciatic notch. Below, it continues into the posterior thigh. Within the space are to be found the lumbosacral plexus and the nerve trunks that derive therefrom and several muscles, notably the piriformis. Impingement of the sciatic nerve in the deep gluteal space has been visualized during surgical operations.
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The piriformis muscle originates on the anterior surface of the sacrum, close to or on the sacroiliac joint. Its tendon attaches to the medial aspect of the greater trochanter. Its principal action is to externally rotate the hip, additionally acting as a weak abductor and flexor. It is innervated by the spinal nerves L5 to S2.
The sciatic nerve has an intimate relationship to the piriformis muscle: it exits the pelvis usually inferior to the muscle at the greater sciatic notch.