Comparative analysis of osseointegration in various types of acetabular implant materials

Background: There is a lack of comparative data on osseointegration (BIC) of acetabular cup surfaces in hip arthroplasty in both normal bone mineral density and in conditions of osteoporosis. Aim: To compare osseointegration of acetabular implants with various types of surfaces in an animal model with normal and osteoporotic bone tissue. Material and Methods: The study was performed on 60 rats. To simulate osteoporosis ovariectomy was performed in 30 animals. Thirty healthy rats served as controls. In standardised defects of the distal metadiaphysis of the femur we implanted: porous tantalum Trabecular Metal (A), Trabecular Titanium (B), Titanium with Gription coating (C), Stiktite (D), and Tritanum (E). Bone apposition (osseointegration) was defined as all areas of direct bone-to-implant contact (BIC). Results: No qualitative morphological differences in the evaluation of BIC around different implant types was seen in normal rats and rats with osteoporosis. Connective tissue areas around implants were larger in rats with osteoporosis. Morphometric studies showed that the highest BIC were seen in implants A and B, both in healthy animals ([72.00 +/- 3.48]% and [67.46 +/- 1.69]%) and ones with osteoporosis ([59.19 +/- 2.10]% and [53.36 +/- 2.57]%). BIC was (60.10 +/- 2.05)%, (60.26 +/- 2.36)%, and (61.78 +/- 2.27)% around implants C, D and E in healthy rats, respectively. BIC in osteoporosis was (45.39 +/- 2.37)%, (47.81 +/- 2.41)% and (42.10 +/- I .44)%, respectively. Conclusion: Our study showed that the evaluated implants have good BIC features. Furthermore, based on histomorthometry and histology, Porous tantalum Trabecular Metal (A) and Trabecular Titanium (B) implants exhibit higher BIC with bone tissue.