Patient Specific Instruments for Total Hip Replacement Surgery

Plastic laser sintered parts are nowadays used in many different applications ranging from basic prototypes to demanding end user products as airplane parts, automotive industry products etc. Since Additive Manufacturing methods fit very well into the markets demanding low volume or even bespoke production of parts medicine is one of the main potential users or consumers of individualized plastic products. The use of plastic jigs for endoprosthetic operations has been studied and clinically tested to prove the usefulness of individualized operating equipment. The aim of the modern endoprosthetic is the optimal imitation of the individual human biomechanics. This is achieved by determination of a real 3D-mechanical joint axis and joint kinematics. Preoperative 3D-CT scan of degenerated joint enables a creation of a virtual 3D-joint-model with the determination of optimal and exact joint resection levels. A standardized CT-protocol for joint images with minimum irradiation was created, supported by the specific computer program for trusty segmentation of the CT images, to create a 3D model of the affected joint. Upon this model the planed resection lines were incorporated into an individual joint model with belonging jigs. Personalized joint jigs for Hip endoprosthesis have been developed through the presented study. They enable for accurate bone cuts and preoperative determination of component placement, without modifying the common OPtechnique. The postoperative analysis of endoprosthesis positioning confirmed easier, quicker and more precise procedure.