The use of polymethyl methacrylate based cement for the fixation of joint replacements although commonly applied, is still limited by interfacial weakness. This study aims to document the effects of a variety of surface treatments on implant/cement bonding and link them to their surface properties.

Thirty seven femoral implant analogues of Ti6Al4V rods were given one of six different surface treatments: traditional grit blasting, wet and dry Vaquasheening, acid etching in concentrated sulphuric and hydrochloric acid, anodisation at 150V, and a combination of acid etching and anodisation, before being embedded into a commercially available poly(methyl methacrylate) bone cement. The interfacial strength, energy and stiffness were measured through pushout testing. Surface analysis included examination with scanning electron microscopy, wettability tests and roughness analysis. Results were analysed with a one-way ANOVA with post hoc tests.

Overall, the coarse blasted surface created the strongest interface, followed by both etched then anodised, acid etched only, wet Vaquasheened, anodised only and finally dry vaquasheened. While anodised samples showed a weaker bond than etched samples, the combination of etching and anodisation was not different to etching alone. In addition, six different types of interface failure modes were observed, and theories as to explain their mechanism, using experimental evidence were outlined.

Coarse blasted surfaces showed the strongest bonding, while other surface modifications may encourage tissue ingrowth and other biological responses, these surface treatments do not strengthen bonding for cemented fixation.

Purpose

Surgical training is based on an apprenticeship model. This training can be divided broadly into three main categories: practical skills, knowledge and decision making. The operating room is the nexus of a large part of surgical teaching. The supervising surgeon imparts both practical teaching as well as didactic information to the trainee during surgical procedures. A large amount of decision making skills are also acquired in the OR. Indeed, a large part of the surgical teams time is spent in the operating room which makes it an ideal educational environment.

Bench model training is one teaching modality whereby the novice surgeon is taught surgical skills on life-like models. This practice enhances and accelerates the ability of the trainee to acquire fundamental, technical and surgical skills in the operating room. Whether bench model training provides an advantage on the ability of the trainee to acquire knowledge and decision making skills is unknown. Based on the motor learning theories, it is hypothesized that bench-model training will allow junior residents to be more interactive than trainees lacking similar active hands-on training. In this study, we examined whether bench model training provides an advantage on the ability of the trainee to acquire knowledge and decision making skills.