Bone Ingrowth into Harris-Galante Porous-coated Acetabular Cup Retrieved during Revision

Purpose: To investigate the extent of bone ingrowth into the porous-coated acetabular cups as well as the factors that correlated with bone ingrowth in total hip arthroplasty. Materials and Methods: Thirty six Harris-Galante porous-coated acetabular cups that were retrieved through revision surgery were examined in this study. Acetabular cups retrieved due to infection or severely destroyed cups (ed note: severe what?) were excluded. The extent of bone ingrowth into the acetabular cups was grossly measured, and its correlation with the variables including age, gender, weight, height, the duration of fixation, size, number of screws, inclination and anteversion was statistically analyzed. Results: The mean proportion of bone ingrowth was 52.9 21.9%(2~90%) and less than 30% in three cups(8.3%). The pattern and the location of bone ingrowth were not consistent. There was no correlation between the extent of bone ingrowth and age, gender, weight, height, the duration of fixation, cup size, number of screws, size, inclination and anteversion. Conclusion: Harris-Galante porous-coated acetabular cups showed satisfactory bone ingrowth regardless of the variables associated with the demographic or surgical conditions. Surface treatments with a fiber-metal porouscoating appears to be suitable for cementless acetabular cups in terms of the long term results.

The biomechanical study of the bone-prosthesis interface stability according to the difference of types of porous-coated acetabular implant / 대한정형외과학회잡지

PURPOSE: To analyze the effects of implant design on the primary stability and the contact between bone and prosthesis of three different porous coated acetabular implants. MATERIALS AND METHODS: The distal part of sixty bovine femurs were employed. 52 mm acetabular cups were inserted tightly after 2mm under-reaming. Trilogy acetabular cups were inserted in Group I, Mallory head finned RingLoc cups in Group II, Duraloc spiked cups in Group III. The gaps between the acetabular cups and the bones were measured on the radiography. The axial compression test and rotation test were performed using Instron. RESULTS: The gaps between the acetabular cup and bone of Gorup I and II was significantly smaller than Group III at its central adjacent and peripheral area (p0.05) . The mean torque of 1 degree rotation test was higher in the Group III than in the group I and II without statistical significance (p>0.05) . The mean torque of 2, 3 and 5 degree rotation test was highest in Group II among three, but there were no statistical differences among three groups (p>0.05) . CONCLUSION: Triology and Mallory-Head cup can be assumed to have better primary stability than Duraloc cup. And additional fin or spikes attached on the acetabular implant couldn't enhance the primary bone-prosthesis interface stability.

A Clinical Study of Microporous Coated Hemispherical Acetabular Cup / 대한정형외과학회잡지

In order to observe the differences in fixability and stability of the acetabular cup through the differences in cup size in relation to the size of acetabular reaming, we analyzed 75 cases of porous coated acetabular cup of Harris-Galante type which be followed up more that two years. All cases were divided into two group ; the first group (On line fit :45 cases) used with acetabular cup equal in size to the last reaming size and the second group (Press fit : 30 cases) used with acetabular cup 2mm larger than the last reaming size. For initial stability, all cases were fixed with acetabular screws. Both groups were analyzed for presence of gap, change of acetabular inclination, presence of radiolucent line, degree of displacement of vertical distance, stability and clinical results. The results were as follows; 1. The average Harris hip score was improved from 55.8 points preoperatively to 90.2 points postoperatively in the first group, from 56.9 points to 91.2 points in the second group, Clinical results are excellent in 39 cases, good in 4 cases, fair in 2 cases in the first group, and excellent in 29 cases and good in 1 case in the second group. 2. The gap between the acetabular cup and acetabulum was found initially at 17 zones in the first group but no gap at final follow up. In the second group, the gap was found at 23 zones and finally remained less that 1 mm gap was found at 3 cases in zone B1. 3. No radiologic instability of acetabular cup by Martell evaluation was noted in both 1st and 2nd group. Our data suggests that initial gap between acetabular cup and acetabulum in microporous coated acetabular cup were replaced with new bone and also, radiologic stability and good clinical results could be obtained in the second group used with acetabular cup 2 mm larger than the last reaming size.

Radiological Assessment of Porous-coated Acetabular Component with Screw Fixation in Primary Total Hip Arthroplasty / 대한정형외과학회잡지

This is a follow up study on 124 cases of primary total hip arthroplasty with Harris-Galante porous-coated acetabular component with the line-to-line technique, performed at the Department of Orthopaedic Surgery, Pusan National University Hospital from January 1986 to February 1992. The follow-up ranged from 24 months to 92 months, the average being 53 months. The results were as follows; 1. At the last follow-up, a radiolucent line was found in 20 cases(16.1%), but the width was less than one millimeter. Among the 20 cases, the continuous radiolucent line was found in two cases(1.6%), the progressive radiolucent line in five cases(4.0%). 2. Areas of non-contact(initial gap) between the porous mesh of the acetabular component and the bone were seen on the immediate postoperative radiographs of 35 cases(28.2%) among 124 cases. A radiolucent line developed around 13 cases(34.2%) of the 35 cases that were associated with an initial gap, but a radiolucent line developed around only seven cases(7.8%) of the 89 cases(71.8%) not associated with such a gap. 3. At the last follow-up, a vertical migration was found in five cases(4.0%), an angulation change of the acetabular cup in two cases(1.6%), but a horizontal migration of the acetabular cup was not found. 4. There was no evidence of the disruption of the titanium porous mesh of the acetabular component, and loosening, bending or breakage of the screw for fixation of the acetabular cup. And there was no revision for acetabular loosening. In conclusion, because overall loosening rate was less than 5%, the results were very satisfactory. Considering an initial gap is a important factor of acetabular loosening, we think that it is important to make less initial gap during operation.