This study will evaluate a midterm clinical and radiologic outcome patients who undergo new alumina-zirconia composite ceramic bearing THA.

Total hip arthroplasty (THA) using a metal-on-polyethylene articulation has become one of the most effective procedures for the surgical treatment for end-stage hip disease.

However, polyethylene wear debris-induced osteolysis has been postulated to cause/contribute to the aseptic loosening of a THA, and hence, is regarded to be an important factor in its in vivo longevity.

In the third generation of ceramic manufacturing, many improvements, such as hot isostatic pressing, laser marking, and non destructive proof-testing for all ceramic components, have been introduced. This third generation ceramic component has high purity, high density, and small grain size, and, therefore, has a very high potential for resisting crack propagation, which may culminate in its fracture. In spite of this, a number of substantial concerns, such as ceramic fracture, impingement-associated fatigue failure, wear, and osteolysis after long-term follow-up, persist with the use of ceramics in THA.

In addition, the third generation ceramic articulation is associated with an increased incidence of dislocation because ceramic liners with elevated rim and extended-long-neck ceramic heads are not available.

However, new alumina-zirconia composites bearing implants (4th generation ceramic bearing) affords various options such as large head and thin liner, which may decrease the ceramic fracture rate and dislocation rate and improve the longevity of THA. In addition, large head can improve the range of motion and possible traditional cross-legged sitting position of Koreans without impingement between the neck and liner rim.

So far, the patients who are underwent THA using 28 mm femoral head diameter complains limitation of range of motion and feeling impingement sensation at sitting on the floor with their legs crossed. There have been increasing complaints especially from Korean patients regarding the difficulties associated with carrying out their daily activities, whose life style involves sitting on the floor with their legs crossed. Therefore, large head of new alumina-zirconia composites bearing implants(4th generation ceramic bearing) expects increasing satisfaction of Korean patients.

This is the first study, to our knowledge, of an evaluation of clinical outcome of THA with use of the new alumina-zirconia(4th generation ceramic bearing) composite ceramic bearing and the functional outcome.

Inclusion Criteria:

• Subjects who have femoral head osteonecrosis
• Subjects who have primary or secondary osteoarthritis
• Subjects who have femoral neck fracture
• Subjects who have infection sequels
• Subjects who have rheumatoid arthritis or ankylosing spondylitis
• Subjects who have developmental dysplasia of the hip or acetabular dysplasia

Exclusion Criteria:

• Subjects who have active infection
• Subjects who have unstable medical illness
• Subjects who have rapidly progressive neurological disease
• Subjects who have revision surgery or bipolar endoprosthesis