The sensory innervation of the hip joint--an anatomical study.

Typically obturator nerve blockade is used to relieve hip pain. It sometimes only has a minor effect in resolving symptoms. This clinical observation led us to examine comprehensively the sensory nerve innervation of formalin-fixed hip joint capsules. Following macroscopic preparation, the area of the hip joint capsule was inspected with the aid of an operating microscope. We discovered a separation between the anterior and posterior sensory innervation of the hip joint capsule. The anteromedial innervation was determined by the articular branches of the obturator n. Additionally, the anterior hip joint capsule was innervated by sensory articular branches from the femoral n. In the posterior part we found articular branches from the sciatic n., which in addition to the articular branches from the nerves to the quadratus femoris m., innervate the postero-medial section of the hip joint capsule. Moreover, articular branches of the superior gluteal n. were found, which innervate the posterolateral section of the hip joint capsule. This anatomical study demonstrates that the obturator n. block is insufficient for the treatment of hip pain. Further investigations will determine if these nn. can be reached percutaneously. Effective neural blockade of the hip joint must include the femoral n., the sciatic n. and the superior gluteal n.