From the RSNA Refresher Courses. Radiological Society of North America. Adult chronic hip pain: radiographic...

Adult chronic hip pain can be difficult to attribute to a specific cause, both clinically and radiographically. Yet, there are often subtle radiographic signs that point to traumatic, infectious, arthritic, neoplastic, congenital, or other causes. Stress fractures appear as a lucent line surrounded by sclerosis or as subtle lucency or sclerosis. Subtle femoral neck angulation, trabecular angulation, or a subcapital impaction line indicates an insufficiency fracture. Apophyseal avulsion fractures appear as a thin, crescentic, ossific opacity when viewed in tangent and as a subtle, disk-shaped opacity when viewed en face. Effusion, cartilage loss, and cortical bone destruction are diagnostic of a septic hip. Transient osteoporosis manifests as osteoporosis and effusion. The earliest finding of avascular necrosis is relative sclerosis in the femoral head. Subtle osteophytes or erosive change is indicative of arthropathy. Osteoarthritis can manifest as early cyst formation, small osteophytes, or buttressing of the femoral neck or calcar. Rheumatoid arthritis may manifest as classic osteopenia, uniform cartilage loss, and erosive change. A disturbance of the trabecular pattern might suggest an early permeative pattern due to a tumor. Knowledge of common causes of chronic hip pain will allow the radiologist to seek out these radiographic findings.