Interfacial strength of compression-molded specimens between PMMA powder and PMMA/MMA monomer solution-treated ultra-high molecular weight polyethylene (UHMWPE) powder

Abstract

The interface between bone cement and ultra-high molecular weight polyethylene (UHMWPE) has been considered a weak link of cemented UHMWPE acetabular cup in total hip replacement (THR). For the improvement of this weak interface, adhesion between the UHMWPE acetabular cup and bone cement made of polymethylmethacrylate (PMMA) has been investigated in our laboratory. Virgin UHMWPE powders were treated with methyl methacrylate (MMA) monomer and PMMA/MMA solution. The treated UHMWPE powders were then compression-molded with virgin UHMWPE powders or PMMA powders, creating two different interfaces, i. e., treated/virgin UHMWPE powder and treated UHMWPE/PMMA powder. For the present study, the interfacial strengths between PMMA powder and the treated UHMWPE power were investigated following the same protocol previously set. The maximum interfacial strength was 17.0 +/- 0.25MPa with the same molding condition of 166.5 degrees C, 38.7 MPa and l h. In addition to the molding condition, we tested the strengths for the treated UHMWPE powders, which have different ratios between PMMA/MMA solution and MMA-treated UHMWPE powders. Significant differences on the interfacial strengths resulted due to the ratio change; more PMMA in the PMMA/MMA solution-treated UHMWPE powder exhibited higher interfacial strength. Scanning electron microscopic (SEM) pictures showed that the interface is composed of three major portions: PMMA powder, UHMWPE, and coated PMMA, indicating strong mechanical interlocking of UHMWPE and PMMA powder matrix and chemical bonding between PMMA powder and the precoated PMMA onto the UHMWPE. In addition, another interfacial strength between PMMA powder, which is equivalent to the outermost part of the cup, and bone cement was investigated. The average strength reached up to 42.4 +/- 3.6 MPa, close to the tensile strength of bone cement itself.

Investigation of interfacial strength and its structure on the development of a new design of UHMWPE acetabular component

“…Effect of the coated PMMA concentration in the treated UHMWPE was also examined, with the above three variables kept constant. Details about preparations of the compression‐molded specimen and the interfacial tensile test can be seen in earlier publications 28, 29…”

“…Instead, the present method first conditions UHMWPE with methylmethacrylate‐ (MMA) monomer liquid, and then precoats them with the PMMA/MMA solution. The precoated UHMWPE powders are later compression molded with virgin UHMWPE or PMMA powder, which act as links for both PMMA and UHMWPE 28, 29…”

“…Interfacial tensile strengths of the two interfaces within the new acetabular cup design have been determined with the use of compression‐molded specimens 28, 29. With the high interfacial strength already confirmed, the rationale behind the interfacial strength buildup is regarded as another important aspect to be examined, and its strength is correlated with its structure.…”

Preoperative assessment and postoperative outcome of total hip replacement in adults with AVN

“…The principles and the basic concepts laid by Sir john Charnley remains the same. With advanced prosthesis and modern cementing techniques problems like femoral loosening have been reduced substantially [4] . Non cemented hip arthroplasty has taken over in the recent times and replaced conventional cemented total hip arthroplasty in young adults [5] , it has developed in response to evidence that cement debris play an important role in promoting bone lysis and loosening.…”

Surface and chemical properties of surface-modified UHMWPE powder and mechanical and thermal properties of its impregnated PMMA bone cement V. Effect of silane coupling agent on the surface modification of UHMWPE powder

“…[11][12][13][14][15][16][17][18][19] To improve these disadvantages, the several composite PMMA bone cements impregnated with organic or inorganic biomaterials have been prepared by using hydroxyapatite, 20 calcium phosphate, 21,22 carbon fibers, 23,24 graphite, 25 aramid, 26,27 bone particles, 28,29 titanium, 30 PMMA fibers, 31,32 and ultra high molecular weight polyethylene (UHMWPE) fiber. 33 In the present study, we proposed development on the composite PMMA bone cement impregnated with UHM-WPE powder for the improvement of the poor mechanical and thermal properties of conventional PMMA bone cement.…”