Performance of bioactive PMMA-based bone cement under load-bearing conditions: an in vivo evaluation and FE simulation

Abstract

In the past, bioactive bone cement was investigated in order to improve the durability of cemented arthroplasties by strengthening the bone-cement interface. As direct bone-cement bonding may theoretically lead to higher stresses within the cement, the question arises, whether polymethylmethacrylate features suitable mechanical properties to withstand altered stress conditions? To answer this question, in vivo experiments and finite element simulations were conducted. Twelve rabbits were divided into two groups examining either bioactive polymethylmethacrylate-based cement with unchanged mechanical properties or commercially available polymethylmethacrylate cement. The cements were tested under load-bearing conditions over a period of 7 months, using a spacer prosthesis cemented into the femur. For the finite element analyses, boundary conditions of the rabbit femur were simulated and analyses were performed with respect to different loading scenarios. Calculations of equivalent stress distributions within the cements were applied, with a completely bonded cement surface for the bioactive cement and with a continuously interfering fibrous tissue layer for the reference cement. The bioactive cement revealed good in vivo bioactivity. In the bioactive cement group two failures (33 %), with complete break-out of the prosthesis occurred, while none in the reference group. Finite element analyses of simulated bioactive cement fixation showed an increase in maximal equivalent stress by 49.2 to 109.4 % compared to the simulation of reference cement. The two failures as well as an increase in calculated equivalent stress highlight the importance of fatigue properties of polymethylmethacrylate in general and especially when developing bioactive cements designated for load-bearing conditions.

Enhanced osteointegration of poly(methylmethacrylate) bone cements by incorporating strontium-containing borate bioactive glass

“…Among them, incorporation of bioactive inorganic fillers such as bioactive glasses (BGs) [8,9] and glass -ceramics [10] or hydroxyapatite [11] into the PMMA matrix has been found to be an effective approach. Although these bioactive fillers can improve the bioactivity of PMMA cement, they are far from optimal, because large percentage of bioactive fillers may impair the mechanical strength and handling properties of PMMA [12], not to mention that apatite -wollastonite (A -W) glass -ceramic and hydroxyapatite lack sufficient biodegradability and osteostimulative activity [4].…”

Acrylate–gelatin–carbonated hydroxyapatite (cHAP) composites for dental bone-tissue applications

“…[8][9][10][11][12] Scaffolds made of synthetic polymers have been studied for bone-tissue engineering applications as they are able to produce materials that exhibit both toughness and plasticity, the most commonly used synthetic polymers are polylactic acid (PLA), polyglycolic acid (PGA), copolymers of PLA and PGA, polycaprolactone, and polymethylmethacrylate (PMMA). [13][14][15][16][17][18][19][20] Due to their different mechanical properties and degradation rates, as well as the absence of osteoconductivity (supporting bone growth and encouraging the ingrowth of surrounding bone), the synergistic combination of calcium phosphate (CaP) as an osteoconductive bioabsorbable ceramic in a polymeric matrix has been explored. [21][22][23] These inorganic-organic hybrids possess an advantage over single components as their interactions at a molecular level can provide interdependent properties while acting as a single-phase material.…”

Poly (methyl methacrylate)/biphasic calcium phosphate/nano graphene bone cement for orthopedic application

“…[4] One of the common bone cements is poly (methyl methacrylate) (PMMA)[5] which is used due to its favorable properties such as nontoxicity and ease of functionalization. [6] One of the most important problems of the implants is loosening in the long-term using in the physiological environment of the human body,[27] which can be due to fatigue[8] and nonbioactivity of PMMA. PMMA as an artificial material leads to form a fibrouse layer is formed on PMMA as an bio-inert material.…”