[Translated article] Comparative clinical and biomechanical study of different types of osteosynthesis in the treatment of distal femur fractures.

INTRODUCTION AND OBJECTIVES: Distal femoral fractures represent a problem due to their high number of complications. The aim was to compare the results, complications and stability achieved with retrograde intramedullary nailing and the angular stable plate in the treatment of distal femoral diaphyseal fractures. MATERIAL AND METHOD: A clinical and experimental biomechanical study was carried out using finite elements. The results of the simulations allowed us to obtain the main results related to the stability of osteosynthesis. For clinical follow-up data, frequencies were used for qualitative variables, and Fisher's exact test and χ2 test were used to evaluate the significance of the different factors, with the condition of P<.05. RESULTS: In the biomechanical study, the retrograde intramedullar nails demonstrated superiority, obtaining lower values in terms of global displacement, maximum tension, torsion resistance, and bending resistance. In the clinical study, the rate of consolidation of the plates was lower than nails (77% vs. 96%, P=.02). The factor that most influenced the healing of fractures treated with plate were the central cortical thickness (P=.019). The factor that most influenced the healing of nail-treated fractures was the difference between the diameter of the medullary canal and the nail. CONCLUSIONS: Our biomechanical study shows that both osteosynthesis provide sufficient stability, but biomechanically behaves differently. Nails provide greater overall stability being preferable the use of long nails adjusted to the diameter of the canal. Plates form less rigid osteosynthesis, with little resistance to bending.

Comparative clinical and biomechanical study of different types of osteosynthesis in the treatment of distal femur fractures. / Estudio comparativo clínico y biomecánico de distintos tipos de osteosíntesis en el tratamiento de fracturas distales de fémur.

INTRODUCTION AND OBJECTIVES: Distal femoral fractures represent a problem due to their high number of complications. The aim was to compare the results, complications and stability achieved with retrograde intramedullary nailing and the angular stable plate in the treatment of distal femoral diaphyseal fractures. MATERIAL AND METHOD: A clinical and experimental biomechanical study was carried out using finite elements. The results of the simulations allowed us to obtain the main results related to the stability of osteosynthesis. For clinical follow-up data, frequencies were used for qualitative variables, and Fisher's exact test and χ2 test were used to evaluate the significance of the different factors, with the condition of P<.05. RESULTS: In the biomechanical study, the retrograde intramedullar nails demonstrated superiority, obtaining lower values in terms of global displacement, maximum tension, torsion resistance, and bending resistance. In the clinical study, the rate of consolidation of the plates was lower than nails (77% vs. 96%, P=.02). The factor that most influenced the healing of fractures treated with plate were the central cortical thickness (P=.019). The factor that most influenced the healing of nail-treated fractures was the difference between the diameter of the medullary canal and the nail. CONCLUSIONS: Our biomechanical study shows that both osteosynthesis provide sufficient stability, but biomechanically behaves differently. Nails provide greater overall stability being preferable the use of long nails adjusted to the diameter of the canal. Plates form less rigid osteosynthesis, with little resistance to bending.

Salvage of cephalomedullary nail cutout with the variable angle proximal femoral plate.

INTRODUCTION: Excellent results have been published in the treatment of the trochanteric fractures in the elderly with cephalomedullary nails or compression hip screws but not free of complications. The perforation of the lag screw through the superior cortex of femoral neck or head followed by rotation and varus collapse of the head-neck fragment, also known as cut-out, is one of them. Probably total hip arthroplasty is the most common solution, but there is no systematic technique for treatment. The objective of this study is to evaluate the results obtained in the treatment of this complication using a variable angle femoral plate. MATERIAL AND METHODS: This retrospective study concerns patients over 65 years with peritrochanteric fractures treated with cephalomedullary nail with cut-out failure solved by re-osteosyntesis with variable angle femoral plate between 1st January 2000 and 31 st December 2017. The series includes 29 patients, 26 women and 3 men with average age 87,3. Patients were followed up clinically and radiologically at regular intervals until fracture consolidation at least 9 months. RESULTS: No patients died at the first 9 months after surgery. Fracture mean consolidation has occurred in all patients in 14th weeks (6-20). Operative time was 93,2 minutes (62-129) including removal of nail. No intraoperative complications were observed. Five patients experienced medical complications and two had a superficial wound infection. The mean tip-apex distance (TAD) was 5mm (2-7mm). The neck-shaft angle was 127 degrees. The mean valgization achieved was 32 degrees (15-40). Only one patient needed a second revision surgery due to aseptic hip joint subluxation after 8 weeks of the surgery solved with total hip arthroplasty. CONCLUSIONS: The use of variable angle femoral plate in the cut-out treatment is an attractive option which allows the valgization of the fracture to virtually physiological limits and the placement of the cephalic screw in the most sutiable position with good outcomes and few complications.

Risk factors of periprosthetic femoral fracture after total knee arthroplasty. / Factores de riesgo en fractura periprotésica femoral tras artroplastia sustitutiva primaria de rodilla.

INTRODUCTION AND OBJECTIVES: Periprosthetic fractures after primary knee arthroplasty has great importance in our environment due to the increase in their incidence and to the challenge they pose to the surgeon. Multiple factors have been associated with its production. The objective of the study was to identify the risk factors that could influence the appearance of these fractures, which of them are all modifiable and generate a probability prediction model based on these factors. MATERIAL AND METHODS: Analytical, observational, retrospective, unpaired study of 38 cases of periprosthetic femoral knee fractures and 80 controls with knee prostheses. In total, 118 patients, 83 women and 35 men with a mean age of 72.49 years were included in the study. Sociodemographic data, medical history and drug consumption were collected, as well as those related to surgery. A univariate and bivariate analysis of the fracture determining factors was performed, using a logistic regression model to avoid confusion bias. RESULTS: Of all the factors studied according to the logistic regression model, it was obtained that female sex (OR = 7.6), dementia (OR = 5), motor/parkinson's alteration (OR = 19.3) and femoral overcut Previous (OR = 8.6) were factors associated with the increased risk of this type of fractures. CONCLUSIONS: This work allows us to conclude that there are risk factors such as female sex, dementia and parkinson's that increase the probability of periprosthetic fracture that are inherent to the patient and are not modifiable. However, there is any other totally modifiable that can be avoided by being demanding and thorough in the surgical technique, such as the anterior femoral overcut.