Bone and Soft Tissue Infection

Infection of the hips and pelvis has become a common clinical problem due to many invasive treatments in the area and the increasing number of patients who are immunosuppressed. Thus, haematogenous inoculation, spread from a contiguous source of infection or direct inoculation from injury or a medical procedure, may be involved. Early diagnosis is related to successful treatment. Imaging is important in diagnosing bone and joint infections, determining the severity and extent of the disease, planning an image-guided biopsy, and monitoring the response to treatment. However, imaging diagnosis is often challenging because of several overlaps with non-infectious disorders. In this chapter, we present septic arthritis of the hip joint, pubic symphysis and sacroiliac joints, osteomyelitis of the pelvic bones and proximal femoral bone, and soft tissue infection in late adolescence and adulthood, by utilizing the most appropriate imaging methods. The indications and limitations of different modalities will be discussed and the value of MR imaging will be stressed. Various non-infections disorders may mimic chronic osteomyelitis and septic arthritis in the pelvis and hip area. The mimickers presented in this chapter include SAPHO syndrome, calcium pyrophosphate deposition disease, rapidly destructive osteoarthritis of the hip, pubic osteitis, and reactive arthritis.