Amphiphilic bonder improves adhesion at the acrylic bone cement-bone interface of cemented acetabular components in total hip arthroplasty: in vivo tests in an ovine model.
BACKGROUND
Even following the introduction of the "third generation" cementing technique, an improvement of the fixation of the acetabular component similar to that of the femoral has not been shown in clinical studies. The goal of the present study was to achieve a better stability with the use of an amphiphilic bonder while preserving the mechanically important subchondral sclerosis.


METHODS
In a total of 20 sheep, a cemented total hip replacement was implanted. In the treatment group (n = 10), the implantation was carried out following surface conditioning of the acetabular bed with an amphiphilic bonder. All the sheep were followed for 9 months. To assess the biocompatibility, the osseous ingrowth at the cement-bone interface was depicted with the help of an in vivo fluorescent marking of the osteoblasts. Additionally, conventional radiographs were obtained over the course of treatment. Finally, the ovine pelvic regions were split following a standardized technique allowing for histological evaluation of the cement-bone interfaces.


RESULTS
The acetabular components of the treatment group revealed a stable cement-bone compound. In the control group, the implants were easily dislodged from their beds. This finding was consistent with the radiological and histological results, which had revealed increased, progressive lytic radiolucent lines and the interposition of fibrous tissue at the cement-bone interface in the control group compared to the treatment group. The bonder was biocompatible.


CONCLUSIONS
Following the application of the bonder, the cemented acetabular components revealed an improved stability without signs of inflammation or neoplasia in a viable acetabular osseous bed. With the help of this technique, the in vivo longevities of cemented acetabular components can be increased in the clinical setting without sacrificing the biomechanical relevant subchondral sclerosis.
Müller-Rath
Ralf
R
Department of Orthopedic Surgery, University Hospital of the RWTH Aachen, Pauwelsstr. 30, Aachen, Germany. rmueller-rath@ukaachen.de
Wirtz
Dieter C
DC
Siebert
Christian H
CH
Andereya
Stefan
S
Gravius
Sascha
S
Hermanns-Sachweh
Benita
B
Marx
Rudolf
R
Mumme
Torsten
T
D000077:Acetabulum / Q000473:pathology / Q000601:surgery*; D000704:Analysis of Variance; D000818:Animals; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects / Q000379:methods*; D002484:Cementation / Q000379:methods; D004195:Disease Models, Animal; D005260:Female; D006622:Hip Prosthesis; D007150:Immunohistochemistry; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000517:prevention & control*; D010012:Osteogenesis; D019904:Polymethyl Methacrylate / Q000737:chemistry / Q000494:pharmacology*; D011336:Probability; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D011859:Radiography; D011897:Random Allocation; D012016:Reference Values; D012307:Risk Factors; D012680:Sensitivity and Specificity; D034561:Sheep, Domestic
D019904:Polymethyl Methacrylate