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The research aims to analyze the tibial component rotation using the finite element method by resecting the tibia in a transverse plane at an angle between 1.5° (external rotation) and -1.5° (internal rotation). We used a three-dimensional scanner to obtain the tibia's geometrical model of a cadaveric specimen. We then exported the surfaces of the tibial geometrical model through the Computer- Aided Three-dimensional Interactive Application (CATIA), which is a Computer-Aided Design (CAD) program. The CAD program three-dimensionally shaped the tibial component, polyethylene, and cement. Our analysis determined that the maximum equivalent stress is obtained in the case of proximal tibial resection at -1.5° angle in a transverse plane (internal rotation) with a value of 12.75 MPa, which is also obtained for the polyethylene (7.693 MPa) and cement (6.6 MPa). The results have shown that detrimental effects begin to occur at -1.5°. We propose the use of this finite element method to simulate the positioning of the tibial component at different tibial resection angles to appreciate the optimal rotation. [ABSTRACT FROM AUTHOR]

Background. This study aims to analyse the tibial component using the finite element method by cutting the tibial in frontal and sagittal planes at an angle between 1.5° (valgus and anterior tilt) and -1.5° (varus and posterior tilt). Methods. This experimental study used the finite element method as an useful tool for simulating the positioning of the tibial component in order to create a personal pre-operative planning. For the finite element method analysis, a geometrical model of a tibia from a cadaver was three – dimensionally scanned and the tibial component, polyethylene and cement, were three-dimensionally shaped in Computer-Aided Design program using material data such as Young modulus (gigapascal – GPa) and the Poisson coefficient. The analysis determined the equivalent von Mises stress, the maximum displacement of the components and the equivalent von Mises deformation. The results showed that equivalent tension and deformation have higher values in the tibia and the polyethylene, which deform faster than cement and the tibial component. In our study, we chose to simulate the tibial resection at a cutting angle ± 1.5° from neutral positioning (which is represented in frontal plane by the perpendicular on the mechanical axis and in sagittal plane by the posterior slope of 7 degree) in frontal and sagittal plane in order to find the minimum threshold from which the tibial component malalignment may begin to determine unfavourable effects. Results. Our results have shown detrimental effects begin to appear for the polyethene component at -1.5° in frontal plane, and the rest of the components at 1.5° in sagittal plane. Conclusion. This finding leads us to propose preoperative planning based on personal calculus of predefined angles, which may show the surgeon the optimal implantation position of the tibial component. [ABSTRACT FROM AUTHOR]

Isolated lesser tuberosity fracture avulsion without an associated posterior shoulder dislocation or in the context of a three- or four-part proximal humerus fracture are extremely rare, with an estimated incidence rate of only 0.46 persons per 100,000. Diagnosis remains challenging, often leading to delayed treatment. In contrast with fractures of the greater tuberosity, there are no displacement guidelines to assist the surgeon in treatment decision-making for lesser tuberosity fractures. The aim of this study was to highlight diagnostic features as well as surgical treatment. We present a case of a 54-year-old male with an isolated lesser tuberosity fracture avulsion. We performed open reduction and osteosynthesis of the lesser tuberosity fragment with suture anchors and transosseous sutures. At 11-month follow-up the patient was able to normally perform his daily living and professional activities, had full, painless range of motion of the affected shoulder and regained almost full strength. [ABSTRACT FROM AUTHOR]

OBJECTIVES: THE MASQUELET TECHNIQUE (INDUCTION OF BIOMEMBRANE) IS AN EFFECTIVE METHOD OF BONE RECONSTRUCTION IN LARGE SEGMENTAL DEFECTS. METHODS: WE PRESENT A DIFFICULT CASE OF A 20 YEAR-OLD PATIENT, WITH RIGHT FEMUR OPEN COMMINUTED DIAPHYSEAL FRACTURE, INFECTED WHICH REQUIRED REPEATED INTERVENTIONS: TEMPORARY CEMENT SPACER FOLLOWED BY STAGED BONE GRAFTING- (AUTOGRAFT AND ALLOGRAFT) AND FINALLY FIXED WITH AN LCP PLATE. INITIALLY THE PATIENT WAS OPERATED IN ANOTHER ORTHOPAEDIC HOSPITAL FOR BILATERAL DIAPHYSEAL FEMUR FRACTURE. ON THE LEFT SIDE A STATIC LOCKING OF INTRAMEDULLARY NAILING WAS CHOSEN WITH FAVORABLE EVOLUTION. ON THE OTHER SIDE, AT FIRST A THOROUGH WOUND DEBRIDEMENT WAS MADE, THEN AN EXTERNAL FIXATOR WAS INSTALLED FOLLOWED BY LOCKED INTRAMEDULLARY NAILING. IN EVOLUTION THE WOUND BECAME INFECTED WITH STAPHYLOCOCCUS, ENTEROBACTER,AND KLEBSIELLA. THE INFECTION WAS TREATED BY NAIL EXTRACTION, SUSTAINED ANTIBIOTIC THERAPY AND EXTERNAL FIXATION. AT THAT MOMENT THE PATIENT WAS REFERRED TO OUR CENTRE. RESULTS WE ARE IN FRONT OF AN INFECTED MAJOR SEGMENTAL BONE DEFECT (12 CM) OF THE RIGHT FEMUR AND THE FIRST APPROACH WAS TO INSERT AN ANTIBIOTIC CEMENT SPACER (VANCOMYCIN) ACCORDING TO MASQUELET METHOD AND TO USE AN SINGLE PLANE EXTERNAL FIXATOR. SIX MONTHS LATER, AFTER THE BIOMEMBRANE WAS INDUCED, WE WERE ABLE TO PERFORM THE OSTEOPLASTY WITH AUTOGRAFT AND ALLOGRAFT. THE EXTERNAL FIXATOR WAS EXTRACTED THREE MONTHS LATER FOLLOWED BY LCP PLATE OSTEOSYNTHESIS A GOOD FUNCTIONAL OUTCOME (EVALUATED BY SF 36) WAS OBTAINED SEVEN MONTHS AFTER THE LAST INTERVENTION. CONCLUSION:THE USE OF THE MASQUELET TECHNIQUE ENSURED AN ANATOMICAL RECONSTRUCTION AND A SATISFYING FINAL FUNCTIONAL OUTCOME. [ABSTRACT FROM AUTHOR]