Injection at the mid-trochanteric process

A local anesthetic block placed below the gluteus medius tendon at the periosteum of the trochanteric process can confirm the presence of trochanteric bursitis. The patient is placed in the lateral decubitus position with the affected side up and the knees flexed to 90 degrees. The superior, posterior, and anterior edges of the trochanteric process are palpated and marked. The point of entry is directly over the center point of the trochanter, approximately 4 cm (1.5 in) below the superior trochanter. Alternatively, the point of entry is at the crown of the trochanter viewed tangentially. Topical anesthetic (eg, ethyl chloride) is applied to the skin. Local anesthetic is injected at the gluteus medius tissue plane (1 mL) and at the periosteum of the femur (0.5 to 1 mL). A 4 cm (1.5 in), 22-gauge or 22-gauge spinal needle is inserted perpendicular to the skin; the depth is 4 to 7.5 cm (1.5 to 3 in) to the femur. The needle is held lightly and advanced through the low resistance of the subcutaneous fat to the firm, rubbery resistance of the gluteus medius tissue plane. Following anesthesia at this level, the needle is advanced with firm pressure approximately 1.3 cm (0.5 in) farther to the periosteum of the femur. The patient will usually experience sharp pain as the needle touches the periosteum. Injection at this deeper level requires firm pressure. The needle should be rotated 180 degrees or withdrawn slightly if excessive pressure is encountered. If the trochanter tenderness is significantly relieved with anesthetic injection, 1 mL of triamcinolone acetonide 40 mg/mL can be injected through the same needle.