The lesser trochanter is caudal to the GTsn. The lesser trochanter may obstruct the path of the caudal-to-cephalad approach of the needle or RF probe.GTsn: greater trochanteric sensory nerve; RF: radiofrequency; QF: quadratus femoris^: inferior gemellus (IG), GTsn; ←: lesser trochanter (lt), needle/probe