Imaging Assessment in Posterior Hip Pathology

Abstract

Posterior hip pain is among the most common diagnostic and therapeutic challenges for orthopedists and radiologists. In this chapter we describe the useful imaging techniques for the assessment of posterior hip mainly focusing on the MRI, the diagnostic procedure that may substantially influence the management of these patients. We also describe the radiological anatomy of the posterior hip and, subsequently, two poorly known causes of posterior hip pain, deep gluteal syndrome and ischiofemoral impingement. Both remain poorly recognized conditions because symptoms are often nonspecific. The etiology, pathophysiology, diagnosis, and classification of these entities are discussed from the point of view of the image with emphasis on MR imaging with endoscopic correlation. A broad spectrum of pathologies may nonspecifically trigger DGS, which can be classified as traumatic, iatrogenic, inflammatory/infectious, vascular, gynecologic and tumors/pseudotumors. Specific entrapments include fibrous bands, piriformis syndrome, obturator internus/gemellus syndrome, quadratus femoris and ischiofemoral pathology, hamstring conditions, gluteal disorders, or orthopedic causes. On the other hand, potential sources of ischiofemoral impingement include anatomical variants of the proximal femur or pelvis, functional disorders as hip instability, pelvic/spinal instability or abductor/adductor imbalance, ischial tuberosity enthesopathies, trauma/overuse or extreme hip motion, iatrogenic conditions, tumors, and other pathologies. Finally, we briefly evaluate the role of image in the assessment of other well-known but equally important conditions of the posterior hip including fractures, other neural pathologies, bursae diseases, posterior femoroacetabular impingement, hamstring conditions, or pathology of the sacroiliac joints.