Treatment of Resorbed Mandibles with Titanium Plate and Immediate Implant-Supported Prosthesis - Case Series

Locking compression plate + T-type steel plate for postoperative weight bearing and functional recovery in complex tibial plateau fractures

BACKGROUND

Complex tibial plateau fractures can seriously affect quality of life and physical and mental health of patients. The anatomical relationship between the proximal tibial bone and soft tissue is complex, resulting in different types of tibial plateau fractures. Violent trauma can lead to displaced fracture, serious soft tissue injury, and potentially, dislocation of the knee joint. Therefore, tibial plateau fractures are extremely unstable.

AIM

To assess the use of locking compression plate (LCP) + T-type steel plate for postoperative weight bearing and functional recovery of complex tibial plateau fractures.

METHODS

Ninety-seven patients with complex tibial plateau fractures who underwent surgery at our hospital were selected for retrospective study. Forty-nine patients had been treated with LCP + T-type steel plate limited internal fixation (study group), and 48 patients with bilateral ordinary steel plate support (control group). The operation process index, postoperative rehabilitation related index, Rasmussen score of the knee joint, tibial plateau varus angle (TPA), tibial plateau retroversion angle (PA), and surgical complications of the two groups were compared.

RESULTS

The operation time and intraoperative bone graft volume in the study group were lower than those in the control group (P < 0.05). There were no significant differences in surgical bleeding, anterior external incision length, postoperative drainage, hospital stay duration, and fracture healing time between the groups (P > 0.05). There was no significant difference in the TPA and PA angle between the groups immediately and 18 mo after surgery (P > 0.05). At 12 mo after surgery, the Rasmussen scale score was higher in the study group than in the control group (P < 0.05). There was no significant difference in the Rasmussen scale score at 18 mo after surgery, and the radiology score at 12 and 18 mo after surgery, between the two groups (P > 0.05). The postoperative complication rate in the study group (3.77%) was lower than that in the control group (15.09%; P < 0.05).

CONCLUSION

LCP + T-type steel plate internal fixation has advantages in terms of minimizing trauma and enabling early postoperative functional exercise, promoting functional recovery and lower limb weight-bearing, and reducing postoperative complications.

Implant Volume Loss, Misfit, Screw Loosening, and Stress In Custom Titanium and Zirconia Abutments

Abstract The aim of this study was to verify the effect of the implant volume loss, vertical misfit between abutment and prosthetic platform, prosthetic screw loosening torque, and screw stress distribution in titanium and zirconia abutments. Ten CAD/CAM system custom abutments of each material were milled and attached to the titanium implants. The implant volume loss was evaluated by microtomography, the vertical misfit with optical microscopy, and digital torque wrench measured the prosthetic screw loosening. All experimental analyses were performed before and after mechanical cycle (1,000,000 cycles, 100 N/2 Hz). Virtual models of the structures were created for finite element analysis, and the stress on the screw obtained with von Mises procedure. Data were analyzed using an independent t-test, two-way ANOVA for repeated measures, and Tukey’s HSD test (a=0.05). There was no significant difference in the implant volume loss for the two abutment materials (p=0.662). Titanium abutments provided higher loosening torque values after mechanical cycling (p<0.001). Lesser marginal misfit was obtained with titanium abutments before and after mechanical cycling (p<0.001). The stress distribution on the screw was similar between abutment materials. In conclusion, CAD/CAM custom titanium abutment reduced the marginal misfit and increased the torque maintenance of prosthetic screws when compared to CAD/CAM custom zirconia abutment.