Innervation of the Posterior Hip Capsule: A Cadaveric Study

Objective Recent studies of hip anatomy have turned to the posterior hip capsule to better understand the anatomic location of the posterior capsular sensory branches and identify nerves with potential for neural blockade. Current literature has shown the posterior hip capsule is primarily supplied by branches from the sciatic nerve, nerve to quadratus femoris, and superior gluteal nerve (1, 2). This cadaveric study investigated the gross anatomy of the posterior hip, while also identifying potential targets for hip analgesia, with emphasis on the superior gluteal nerve and nerve to quadratus femoris. Design Cadaveric study. Setting University of Texas Health San Antonio Anatomy Lab Methods 10 total cadavers (18 hips total), were posteriorly dissected identifying nerve to quadratus femoris, superior gluteal nerve, and sciatic nerve. Nerves were labeled with radio-opaque markers. Following the dissections, fluoroscopic images were obtained as sequential angles to identify neural anatomy and help expand anatomic knowledge for interventional pain procedures. Results The posterior hip capsule was supplied by the sciatic nerve in 1/16 hips, the nerve to quadratus femoris in 15/18 hips, and the superior gluteal nerve in 6/18 hips. Conclusions The nerve to quadratus femoris reliably innervates the posterior hip joint. Both the sciatic nerve and superior gluteal nerve may have small articular branches that may be involved in posterior hip innervation, but not this is not seen commonly. The results of this study may elucidate novel therapeutic targets for treatment of chronic refractory hip pain (i.e., the nerve to quadratus femoris).

Anatomical Course Demarcating the Safe Area for the Superior Gluteal Nerve

Iatrogenic injury to the superior gluteal nerve (SGN) persists despite a safe area being defined. Current descriptions of the course of the SGN are conflicting and do not provide agreeable distances to surface landmarks that are useful for most health care professionals. This study aimed to suggest a more conservative and gender-dependent estimate of the safe area between each buttock and genitals as defined by four bony surface landmarks. The posterior and lateral surfaces of each buttock in eight cadavers, four male and four female, were dissected. The surface anatomy of sixteen SGNs was defined in relation to the quadrate tubercle of the intertronchanteric crest of the femur (QTIF), the most cranial ridge of the iliac crest (IC), the anterior superior iliac spine (ASIS) and the posterior superior iliac spine (PSIS). Between the sexes, no significant difference existed concerning average SGN lengths across each buttock pair, (i.e. SGN length male/female difference df=3 (p=0.273); Pearson = - 0.76). There was no significant difference between both buttock sides concerning the SGN distances from each of the four bony surface landmarks across either sex (e.g. male QTIF df=3 (p=0.284); Pearson correlation = -0.31.) From our measurements we conclude that the standard safe area is too generous and should be half the size immediately adjacent to the tip of the greater trochanter.