Cementless Total Hip Arthroplasty Using Ceramic Femoral Head on Cross-Linked Ultra-High-Molecular Weight Polyethylene Liner in Patients Older than 65 Years: Minimum Five-Year Follow-Up Results / 대한정형외과학회잡지

PURPOSE: To evaluate the utility of ceramic-on-polyethylene articular bearing surface when cementless total hip arthroplasty is performed in patients older than 65 years through an analysis of the minimum five-year follow-up results using the ceramic femoral head and cross-linked polyethylene liner. MATERIALS AND METHODS: From March 2010 to September 2012, 51 patients (56 hips) who were older than 65 years were enrolled in this retrospective study. The mean age at surgery was 70.9±5.1 years old. A clinical assessment was analyzed using the Harris hip score. For the radiographic assessment, the cup inclination and anteversion, stem alignment, and wear amount were measured. The postoperative complications were also determined. RESULTS: The mean Harris hip score was improved from preoperative 48 points to postoperative 87 points (p < 0.05). The mean cup inclination was 40.9°±6.4° and the mean cup anteversion was 20.3°±8.1°. The mean cup anteversion of the elevated liner-used group (16 cases) was 14.3°±7.9° and the mean cup anteversion of the neutral liner used group (40 cases) was 22.4°±9.1° (p < 0.05). The mean stem alignment angle was 0° (range, varus 4°–valgus 4°). The mean linear wear amount was 0.458±0.041 mm and the average annual linear wear rate was 0.079±0.032 mm/yr. Six cases (10.7%) of intraoperative periprosthetic femoral fractures were encountered. CONCLUSION: Based on these results, the use of a ceramic-on-polyethylene articular bearing surface in elderly patients with cementless total hip arthroplasty is beneficial. On the other hand, careful effort is needed to prevent intraoperative periprosthetic femoral fractures.

A Comparative Study of the in vivo Wear of Zirconia and Metal Heads Articulating with Polyethylene Liners in Total Hip Arthroplasty / 대한정형외과학회잡지

PURPOSE: The purposes of this paper was to determine the wear rates and volumetric wears of ceramic (Zirconia) and metal (Cobalt-chrome) femoral heads, and to differentiate creep from true wear. Another purpose was to determine the extent of wear and volumetric wear per annum. MATERIALS AND METHODS: We examined 86 patients (111 hips) who were continuously followed up from 180 patients (225 hips) who received THRA with AVN of stage III or above at our hospital. Patients were followed until December 1999 for more than a minimum of 3 years from June for 1996. The hip joint AP radiographs that had been taken immediately after the operations, six weeks postoperatively and annually thereafter were compared. We used the computer assisted vector wear analysis program of Martell to measure the wear rate, volumetric wear and vector wear. RESULTS: The wear rate and the volumetric wear in the zirconia ceramic head group (1.443 mm/year, 665.433 mm3/year) and metal head group (2.161 mm/year, 1271.831 mm3/year) were high immediately after operation and six weeks postoperatively, and this was significantly more than during all for other periods, giving a wear rate and volumetric wear in the ceramic head group of 0.180 mm/year and 81.101 mm3/year, and in the metal head group of 0.219 mm/year and 124.149 mm3/year. Moreover, the average wear rates and volumetric wear rates of these two groups were significantly different, and annual wear and volumetric wears showed a trend to decrease with time. CONCLUSION: Wear rate and volumetric wear six weeks after operation were remarkably high compared with the other periods. This is interpreted as the result of a creep phenomenon, which occurred mainly during the six weeks following the operation. The Zirconia ceramic head group showed little wear, which confirms the theoretical advantage of the zirconia ceramic head in vivo.

A Case of Failure of a Ceramic Head in Total Hip Arthroplasty: A Case Report / 대한정형외과학회잡지

In 1970, Boutine introduced a alumina ceramic for cemented total hip replacement . A ceramic articulation thought to be superior to metal on polyethylene due to its extremely low coefficient of friction and its potential for resistance to wear. Mechanical failure of ceramic femoral head is rare. We report a case of fracture of ceramic femoral head, which occured after implantation of uncemented total hip replacement.