Abstract
Introduction
Long term results of Total Hip Arthroplasty (THA) are affected by wear of articulation. Ceramic on ceramic articulation have been used especially for young patients because of its low wear and bio-inert property. However, because of its hardness, it is concerned that ceramic fracture, chipping, or squeaking might happen with ceramic on ceramic articulation.
Objective
The purpose of this study was to investigate over 10-years clinical and radiographic results of ceramic bearing cementless THA.
Methods
Evaluation was performed in 60 patients (68 joints) who underwent primary cementless THA from May 2003 to April 2007. Mean age at surgery was 59 years. Mean follow up period was 11.2 years. Forty-nine patients were female. Mean BMI at surgery was 24.0 kg/m2. Fifty-one patients had osteoarthrosis, 6 patients had osteonecrosis, 2 patients had rheumatoid arthraitis, and 1 patient had PSS. A 28mm-size femoral head was used in all patients. Clinical evaluation was performed with Japanese Orthopaedic Association Hip Score (JOA score). Radiographic results were evaluated with standard bilateral hip radiograph in supine position.
Results
Mean clinical score at surgery was 45 (pain: 13/40, ROM: 12/20, gait: 9/20, ADL: 12/20). Mean clinical score at final follow up was 92 (pain: 39/40, ROM: 17/20, gait: 17/20, ADL: 18/20). Pain score was dramatically improved from 13 to 39 (maximum pain score: 40). One stem was revised because of recurrent dislocation. Two other patients experienced one time dislocation during follow up. One stem showed 5mm of subsidence. ALL cups and stems showed bone ingrowth at final follow up. Cortical hypertrophy was seen in 17 joints. However, there was no patient complained thigh pain. Stress shielding was seen in 55 joints (81%). First, second and third degree of stress shielding were seen in 12, 40, and 3 joints, respectively. Most of the female patients who had surgery at the age over 60 years showed second and third degree of stress shielding. There was no measurable wear. No osteolysis was found around the implants. There were no ceramic fracture, chipping, and squeaking.
Conclusion
This study demonstrated excellent clinical and radiographic results of ceramic bearing cementless THA. Excellent long term results will be expected with this system.
