Surface replacements have shorter femoral component stems allowing less bone to be resected and are, therefore, important options for younger patients. A fixation screw maintains stability so that bone ingrowth can occur.
The acetabular metal backing has an irregular surface adjacent to the bone for bone ingrowth. The nonopaque acetabular liner is marked by a thin circular wire about its rim (arrow). Uncomplicated bone ingrowth total hip arthroplasty. Some areas of investigation, include optimizing implant positioning, decreasing wear, preserving bone and minimally invasive surgery. Recent investigations seek to further improve these prostheses and techniques to allow use of prostheses in younger individuals who may have greater physical demands and the desire for early return to work. In patients aged 55 to 65, a longer course of conservative treatment is usually warranted before joint replacement is considered. Patients 65 years of age or older suffering pain that interferes with sleep or activities and is unresponsive to 3 to 6 months of conservative treatment (such as anti-inflammatory medication) may be candidates for joint replacement. Candidates for total hip replacement usually have arthritis with disabling hip pain and functional limitation in spite of adequate medical therapy ( Table 30-1 ).
Joint replacement is generally considered for patients 65 years of age or older. A total of 202,500 primary total hip arthroplasties were performed in the United States in 2003, and it is estimated that by 2030, the demand for these operations will grow by 174% to 572,000. Currently, over 600,000 hip replacements are performed in Europe each year. The foundation for this success was the introduction by Sir John Charnley of the cemented metal to polyethylene prosthesis in the early 1960s. Modern prostheses are expected to last more than 15 years. Results of total hip replacement are excellent, producing marked improvement in physical function, social interaction, and overall health. Joint replacement surgery is one of the great success stories of modern medicine.