1. Introduction

    The replacement of joint surfaces is required primarily for inflammatory or degenerative conditions within the joint, such as those accompanying rheumatoid arthritis or osteoarthritis from degeneration of the synovium or cartilage. As normal joint tissues deteriorate or degenerate, the bone ends are exposed, causing pain and limitation of joint movements. Joint stiffness and muscle atrophy follow, further increasing pain and limiting movement and mobility. Exposed bone surfaces lead to bone growth that may eventually adhere to the opposing bone ends, causing bony ankylosis and loss of joint movement. Therefore, replacement of the deteriorated or degenerated tissues and bones restores movement and relieves pain.

    The hip joint is one of the most frequently replaced joints. Typically, the patient is placed in the lateral decubitus position, which offers greater range of motion and visibility throughout the surgical procedure. This procedure requires a large incision, extending from near the iliac crest across the joint to the midthigh level. Several large muscle groups must be incised and dissected through to gain access to the joint, after which the joint is disarticulated. The femoral head and neck are excised, leaving the femoral canal open. The femur is filled with rich marrow because it is one of the erythrocyte production areas for the body; therefore, it is also richly vascular. The acetabulum is a part of the pelvic girdle, also one of the erythrocyte production areas, and is richly vascular as well. After the femoral head and neck are removed, the femoral canal is reamed to the appropriate diameter to accommodate the prosthetic head and neck. The acetabulum is then reamed in a similar manner to accommodate its own prosthesis. During the reaming for both prosthetic components, bone is shaved from the canal and acetabulum to produce a smoother bony surface to achieve better adherence of the prosthetic device and cement. Also during the reaming process, venous sinuses within these bony structures are opened and often destroyed, and this can result in significant blood loss.

    After the femoral canal has been satisfactorily prepared, the canal is cleaned out using pulse irrigation, which forces irrigation solution deep within the femoral canal under pressure in a high-frequency, pulsatile manner. The canal is further cleaned with a sponge, after which methylmethacrylate (MMA) cement may be instilled into the femoral canal. For some procedures, usually in younger or very physically active patients, MMA is not used to secure the femoral prosthesis, and the prosthesis is referred to as being “press-fit.” After instillation of the MMA cement, the femoral prosthesis is inserted into the canal and is forcibly seated with a mallet. The acetabular component is secured in place with screws and bone grafting. The dislocated joint is reduced, and the soft tissues are returned to normal anatomic position during wound closure.

2. Preoperative assessment and patient preparation