Fig 1.
Schematic showing an infected hip implant under NCIH treatment, where heat transfer to the bone is shielded by a layer of PMMA or HA.
Fig 2.
A diagram outlining the general study design.
Fig 3.
3D-printed cement templates of thickness 1, 3 and 5 mm, and Ti6Al4V coupons used to create Ti6Al4V-PMMA constructs with controlled PMMA layer thickness.
Fig 4.
Ti6Al44-PMMA constructs with a PMMA layer of 1, 3 and 5 mm thickness.
Fig 5.
Ti6Al4V coupon coated with HA.
Fig 6.
SEM images of the HA coated coupon made at 100x magnification: A) SEM close-up of the HA coating surface, and B SEM image of the border of the HA coating, with non-coated Ti6Al4V at the top and the HA coating at the bottom.
Fig 7.
Ti6Al44-PMMA constructs with a PMMA layer of 1, 3 and 5 mm thickness after spray-painting with black paint.
Fig 8.
Addition of the PAA gel to the constructs using a 3D-printed PLA template: A) PLA template filled with PAA gel; B) final construct after removing the template.
Fig 9.
Diagram of the placement of thermocouples on the different construct modalities: A) negative control/uncemented implants, B) HA-coated implants, and C) cemented implants. For each configuration, Ttop represents the implant-tissue interface.
Fig 10.
Thermal measurements on the negative control sample heated to 70°C: A) Temperature curve, B) temperature cross-section and C) thermograph.
The black line in the thermograph indicates the position of the temperature cross-section. Tmetal and Ttop refer to the location of the thermocouple on the construct, see Fig 9. 1 and 2 refer to duplicate measurements.
Fig 11.
Thermal measurements on the HA coated sample heated to 70°C: A) Temperature curve, B) temperature cross-section and C) thermograph.
The black line in the thermograph indicates the position of the temperature cross-section. Tmetal and Ttop refer to the location of the thermocouple on the construct, see Fig 9. 1 and 2 refer to duplicate measurements.
Fig 12.
Thermal measurements on the sample with 5 mm of PMMA bone cement heated to 70°C: A) Temperature curve, B) temperature cross-section and C) thermograph.
The black line in the thermograph indicates the position of the temperature cross-section. Tbottom and Ttop refer to the location of the thermocouple on the construct, see Fig 9. 1 and 2 refer to duplicate measurements.
Fig 13.
Thermal measurements on the negative control sample with a PAA gel layer heated to 70°C: A) Temperature curve, B) temperature cross-section and C) thermograph.
The black line in the thermograph indicates the position of the temperature cross-section. Tmetal and Ttop refer to the location of the thermocouple on the construct, see Fig 9. 1 and 2 refer to duplicate measurements.
Fig 14.
Thermal measurements on the HA coated sample with a PAA gel layer heated to 70°C: A) Temperature curve, B) temperature cross-section and C) thermograph.
The black line in the thermograph indicates the position of the temperature cross-section. Tmetal and Ttop refer to the location of the thermocouple on the construct, see Fig 9. 1 and 2 refer to duplicate measurements.
Fig 15.
Thermal measurements on the sample with 5 mm of PMMA bone cement and a PAA gel layer heated to 70°C: A) Temperature curve, B) temperature cross-section and C) thermograph.
The black line in the thermograph indicates the position of the temperature cross-section. Tbottom and Ttop refer to the location of the thermocouple on the construct, see Fig 9. 1 and 2 refer to duplicate measurements.
Table 1.
Tmax and CEM43 values for different samples. All outcomes represent the average of 2 experiments (the full data for all replicates can be found in S3 Table). Values highlighted in green represent thermal doses below 16 CEM34, considered safe for bone tissue. Ttop refers to the location of the thermocouple on the construct, see Fig 9.
Fig 16.
Thermal doses measured Ttop.