[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.

Influence of plate size and screw distribution on the biomechanical behaviour of osteosynthesis by means of lateral plates in femoral fractures.

Distal femoral fractures are fractures associated with high rates of morbidity and mortality, affecting to three different groups of individuals: younger people suffering high-energy trauma, elderly people with fragile bones and people with periprosthetic fractures around previous total knee arthroplasty. They have been classically treated with conventional plates and intramedullary nails and more recently with locked plates that have increased their indications to more types of fractures. The main objective of the present work is the biomechanical study, by means of finite element simulation, of the stability achieved in the osteosynthesis of femoral fractures in zones 4 and 5 of Wiss, by using locked plates with different plate lengths and different screw configurations, and analysing the effect of screw proximity to the fracture site. A three dimensional (3D) finite element model of the femur from 55-year-old male donor was developed, and then a stability analysis was performed for the fixation provided by Osteosynthesis System LOQTEC® Lateral Distal Femur Plate in two different fracture zones corresponding to the zones 4 and 5 according to the Wiss fracture classification. The study was focused on the immediately post-operative stage, without any biological healing process. The obtained results show that more stable osteosyntheses were obtained by using shorter plates. In the cases of longer plates, it results more convenient disposing screws in a way that the upper ones are closer to fracture site. The obtained results can support surgeons to understand the biomechanics of fracture stability, and then to guide them towards the more appropriate osteosynthesis depending on the fracture type and location.

Hip fracture in centenarians, what can we expect? / Fractura de cadera en pacientes centenarios, ¿qué podemos esperar?

INTRODUCTION: Hip fractures in centenarians are rising due to the increase in life expectancy. The objective of this study is to compare the characteristics of centenarians' hip fracture with a younger control group, and to analyze whether there are differences in terms of in-hospital mortality, complications, and short-medium-term survival between them. MATERIAL AND METHODS: Retrospective case-control study, with a series of 24 centenarians and 48 octogenarians with a hip fracture. Comorbidities and Charlson index, surgical delay, complications and mortality during admission, and hospital stay were analyzed. At discharge, early mortality, survival after one year, and return to previous functionality were assessed. RESULTS: No significant differences were found in baseline parameters or comorbidities (P>.05), and the type of was a woman with an extracapsular fracture. Hospital stay was longer in the control group (P=.038), and the most frequent complication was anemia requiring transfusion (23/24 in centenarians, P<.0001). In-hospital mortality and accumulated at one year in the centenarians was 33 and 67%, respectively, compared to 10 and 25% in the octogenarians (P=.017, OR=4.3 [1,224-15,101] and P=.110). Only 2 centenarian patients were able to walk again after the intervention, while in the control group 53.84% returned to the previous functional situation (P=.003). CONCLUSIONS: Compared to a control group of younger patients, in-hospital mortality and in the first year after a hip fracture is significantly higher in centenarians, and very few recover activity prior to the fracture.

Primary total hip arthroplasty for acetabular fractures in elderly patients. / Artroplastia total de cadera primaria en fractura de acetábulo en el paciente anciano.

INTRODUCTION: Life expectancy has risen, leading to an increase in acetabular fractures in fragile patients. Total hip arthroplasty with a reinforcement cage is a technically complex option, but allows fracture control and early mobilization. Our aim is to assess whether the use of Burch-Schneider cage in fragile patients with acetabular fractures allows immediate load stabilization without threatening the early survival of the arthroplasty. MATERIAL AND METHODS: Descriptive study of a series of 14 patients with acetabular fractures treated by a reinforcement cage associated with autologous bonegraft plus a cemented acetabular cup, and mobilization and bearing. Judet Letournel fracture types, surgical delay, and complications during admission were analyzed. Following hospital discharge we recorded the incorporation of grafts according to Gie's classification, presence of calcifications according to Brooker, consolidation of the fracture, loosening of implants and functional aspects according to the HHS and Merlé D'Aubigné Postel score. RESULTS: The most common fracture was both columns (6/14), with a surgical delay being of 11 days mean and 21,5 days of length of stay. One patient died after surgery. The mean follow-up was 34.4 months. All fractures healed and the bonegraft was incorporated in all cases. The mean HHS was 82 points and the Merle Score was 15/18. There were no complications related to arthroplasty. CONCLUSIONS: Total hip arthroplasty with Burch-Schneider cage on bonegraft and no added osteosynthesis is a good option of treatment of all types of displaced acetabular fractures in a fragile patient.