We report on a cadaveric study and early experience using patient specific drill guides to prevent cortex perforations and reduce the need for a trochanteric osteotomy in revision THA. Mimic software (Materialise) was used for 3D analysis of the cement mantle and cement plug. Based on the CT findings a Cannulated drill guide with the shape of the femoral stem was printed in medical graded nylon intraoperative findings and complications were recorded on videotape using a standard 5mm laparoscope for medullary inspection Surgical Technique was to attain a pre-operative CT scan with MARS protocol of the proximal femur to evaluate the femoral stem positioning, the 3D anatomy of the cement mantle, the length of the cement plug and the quality of the surrounding bone. Subsequent a 3D printing of patient specific cannulated drill guide with the shape of the removed femoral component but an eccentric cannulation was made. Endoscopic inspection was performed of the inside of the cement mantle, then insertion of the autoclaved cannulated drill guide in the existing cement mantle. After perforation of the distal plug through the PSI drill guide using either a long drill or an ultrasound plug perforation tool (Zimmer Biomet, Warsaw) the excessive cement was removed with standard available flexible femoral shaft reamers (Zimmer Biomet). Further laproscopic examination of the femoral canal performed to verify completeness of the cement removal CT scans with 3D reconstruction of the existing cement mantle is possible using Modern CT with MARS protocols. After the training on sawbones and cadaveric bones a predictable plug perforation was obtained in all clinical cases. There were no intraoperative cortex perforations and no intraoperative femoral fractures. CT scan analysis of femoral cement mantles together with patient specific drill guides are promising tools to reduce the risk of femoral perforation in revision total hip arthroplasty.Results
Conclusion
Cemented femoral stems have an excellent long-term outcome. Modern cement techniques should be used to optimize femoral stem fixation. Bleeding from the bone surface during cemented hip arthroplasty compromises the bone-cement interface. However, no studies have examined this bleeding in vivo nor the effect the different cleaning methods used. In the present study we evaluated bleeding patterns and efficacy of cleaning methods used in third generation cementing techniques. We prospectively performed a medulloscopy with a 10 mm laparoscope in 200 primary hip arthroplasties. Intramedullary bleeding was evaluated after femoral canal preparation and use of the different cleaning methods. The femoral canal was divided into three areas to facilitate comparison. The intramedullary bleeding was standardized on a four point scale. A non-parametric repeated measures ANOVA was used for statistical analysis.Background
Methods
