RESUMO
Peri-implant fractures have gained increasing importance in orthopedics as the number of surgical procedures involving orthopedic implants rises globally. These fractures pose a significant challenge in terms of diagnosis, treatment, and postoperative management. They manifest as stress fractures distal to the implant site. Developing an effective treatment strategy involves evaluating multiple influencing factors. This article presents a rare case of a peri-implant distal radius fracture in a 63-year-old man, with no comorbidities, resulting from a car accident, classified as C1U in the Michele D'Arienzo system. The surgical intervention included plate fixation for the radius and wire fixation for the ulna. The wire was used for ulna instead of a plate, due to skin injuries, with good results. As life expectancy rises and individuals remain active in their elder years, the incidence of peri-implant fractures is expected to increase. Factors such as the implant type, surgeon's approach, and patient-specific elements may influence peri-implant fracture occurrence. The widespread use of plate fixation for distal radius fractures may also contribute to a parallel increase in such fractures. Providing detailed context and specific case presentation allows better understanding and implications for clinical practice.
RESUMO
Biomechanical testing is a necessity given the development of novel implants used in the osteosynthesis of hip fractures. The purpose of biomechanical testing is to recreate realistic conditions similar to the in vivo conditions. Although biomechanical testing of hip arthroplasty has been standardized since the 1970s, there is no consensus at present on testing methodology for osteosynthesis of hip fractures. Most biomechanical studies examining the fractures of the proximal femur in order to optimize implants opt for loading the bone-implant ensemble directly on the femoral head or using a metallic loading part. This loading technique fails to perform a mechanical stress distribution similar to in vivo conditions, which could alter the outcome. The present study aimed to design loading/unloading cups with mechanical properties that resemble those of the cartilage at the hip level. Through the impression and scanning of the cast models obtained, a digital 3D model was created in STL format and this was processed in order to obtain the computer numerical control (CNC) trajectories of the printing head. For prototyping using additive manufacturing technology, a thermoplastic polymer with biochemical properties, such as tensile strength, that resemble those of the adult hip and a Stratasys FORTUS 250 mc CNC machine were used. Loading/unloading cups with similar anatomy and biomechanical forces compared with those of the adult hip were created, which allowed the experimental simulation of the conditions during walking.