CASE 10.1 PIRIFORMIS SYNDROME
A 32-year-old female complains of a nagging tenderness in the center of her right buttock and episodes of numbness and tingling in the posterior thigh and calf regions on this same side. Relevant Clinical Findings History
The patient relates that she stays physically fit by running and playing hockey on a local semiprofessional women's team. Until recently, she participated in most local charity runs. The presenting complaint has greatly reduced her training and participation. She believes that the muscles of her right lower limb are weaker than those of the left. Physical Examination
The following findings were noted on physical examination:
Imaging Studies Clinical Problems to Consider
Dysesthesia elicited in right gluteal region with deep pressure or medial rotation and adduction of hip.
Dysesthesia not present with pressure to ischial tuberosity or posterior thigh.
Deep gluteal pressure caused paresthesia in right posterior thigh.
Crossed straight-leg raise (SLR) test was negative.
Side-to-side strength comparison of gluteal and posterior thigh muscles was inconclusive.
Describe the structure and relationships of the gluteal region and posterior thigh.
Describe the greater sciatic foramen and list structures that pass through it.
Explain the anatomical basis for the signs and symptoms associated with this case.
The tissue plane on the deep side of gluteus maximus contains nerves and vessels that distribute to the lower limb and perineum. Most of these structures enter the gluteal region from the true pelvis by passing through the greater sciatic foramen (Fig. 10.1.1). The boundaries of this foramen are rigid and include:
Posterior view of the gluteal region (gluteal muscles removed) showing structures passing through the greater sciatic foramen.
In addition to nerves and blood vessels, this foramen also transmits the belly of the piriformis muscle as it passes from the pelvic surface of the sacrum to the greater trochanter of the femur. The position of piriformis in the deep gluteal region serves as a landmark for identifying other structures that accompany it through the foramen.
Inferior gluteal nerve (L5-S2) and vessels
Sciatic nerve (L4-S3)
Posterior cutaneous nerve of the thigh (S1-S3)
Pudendal nerve (S2-S4) and internal pudendal vessels
The gluteal nerves and vessels distribute to the gluteal muscles. The sciatic nerve and posterior cutaneous nerve of the thigh descend through the gluteal region and enter the posterior thigh at the lower border of the ...