Achieving a stable bone-implant interface is an important factor in the long-term outcome of joint arthroplasty. In this study, we employed an ovine bicortical model to compare the bone-healing response to five different surfaces on titanium alloy implants: grit blasted (GB), grit blasted plus hydroxyapatite (50 microm thick) coating (GBHA), Porocoat(R) (PC), Porocoat(R) with HA (PCHA) and smooth (S). Push-out testing, histology, and backscatter scanning electron microscope (SEM) imaging were employed to assess the healing response at 4, 8, and 12 weeks. Push-out testing revealed PC and PCHA surfaces resulted in significantly greater mechanical fixation over all other implant types at all time points (p <.05). HA coating on the grit-blasted surface significantly improved fixation at 8 and 12 weeks (p <.05). The addition of HA onto the porous coating did not significantly improve fixation in this model. Quantification of ingrowth/ongrowth from SEM images revealed that HA coating of the grit-blasted surfaces resulted in significantly more ongrowth at 4 weeks (p <.05).

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BackgroundThe ankle fracture is one of the most common fractures, increasing in an ageing population, but not generally seen as an osteoporotic fracture. The aim of this study was to examine the relationship between different AO/OTA classes of ankle fractures, age, sex and type of trauma.MethodsAnkle fractures, treated at any of the hospitals in Norrbotten County in Sweden between 2009 and 2013, were retrospectively identified and classified according to the AO/OTA-classification system. Information about the trauma mechanism was also obtained.ResultsIn Norrbotten County, 1756 ankle fractures in 1735 patients aged 20 years or older were identified. This gave an incidence in the county of 179 per 100,000 person-years. Of these patients, 34.6% were 65 years or older, 58.4% were women and 68.2% of the trauma leading to a fracture was defined as low-energy. In 1.5% of the cases the fractures were open. Incidences of type B fractures increased substantially with age, from 62 (95% CI 50–77) at 30–39 years of age to 158 (95% CI 131–190) in patients older than 80 years of age per 100,000 person-years. Type B fractures showed a slightly higher proportion of low-energy trauma while type C showed a lower mean age and proportion of women.ConclusionsThis study shows an incidence of 179 adult ankle fractures annually per 100,000 persons. More than two thirds of the fractures were caused by a low-energy trauma and ankle fractures are more frequent among females. Females generally have an increased incidence during their life, mainly between the ages of 30 and 60. This is in contrast to men who have more of an even distribution throughout their life. Classification according to AO/OTA reveals some heterogeneity among the classes of ankle fractures in age and gender as well as the energy involved in the trauma.