Strength analyses of screws for femoral neck fractures

This article represents a multidisciplinary approach to biomechanics (engineering + medicine) in the field of "collum femoris" fractures. One possible treatment method for femoral neck fractures, especially for young people, is the application of cancellous (i.e. lag or femoral) screws (with full or cannulated cross-section) made of Ti6Al4V or stainless steel. This paper therefore aims to offer our own numerical model of cancellous screws together with an assessment of them. The new, simple numerical model presented here is derived together with inputs and boundary conditions and is characterized by rapid solution. The model is based on the theory of beams on an elastic foundation and on 2nd order theory (set of three differential 4th order equations, combination of pressure and bending stress-deformation states). It presents the process for calculating displacements, slopes, bending moments, stresses etc. Two examples (i.e. combinations of cancellous screws with full or cannulated cross-section made of stainless steel or Ti6Al4V material) are presented and evaluated (i.e. their displacement, slopes, bending moments, normal forces, shearing forces and stresses). Future developments and other applications are also proposed and mentioned.Web of Science38583481

Outcomes of total hip arthroplasty, as a salvage procedure, following failed internal fixation of intracapsular fractures of the femoral neck: a systematic review and meta-analysis.

AIMS: The optimal management of intracapsular fractures of the femoral neck in independently mobile patients remains open to debate. Successful fixation obviates the limitations of arthroplasty for this group of patients. However, with fixation failure rates as high as 30%, the outcome of revision surgery to salvage total hip arthroplasty (THA) must be considered. We carried out a systematic review to compare the outcomes of salvage THA and primary THA for intracapsular fractures of the femoral neck. PATIENTS AND METHODS: We performed a Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) compliant systematic review, using the PubMed, EMBASE and Cochrane libraries databases. A meta-analysis was performed where possible, and a narrative synthesis when a meta-analysis was not possible. RESULTS: Our analyses revealed a significantly increased risk of complications including deep infection, early dislocation and peri-prosthetic fracture with salvage THA when compared with primary THA for an intracapsular fracture of the femoral neck (overall risk ratio of 3.15). Functional outcomes assessment using EuroQoL (EQ)-5D were not significantly different (p = 0.3). CONCLUSION: Salvage THA carries a significantly higher risk of complications than primary THA for intracapsular fractured neck of femur. Current literature is still lacking well designed studies to provide a full answer to the question. TAKE HOME MESSAGE: Salvage THA is associated with more complications than primary THA for intracapsular neck of femur fractures

Intracapsular Femoral Neck Fractures—A Surgical Management Algorithm

Background and Objectives: Femoral neck fractures are common and constitute one of the largest healthcare burdens of the modern age. Fractures within the joint capsule (intracapsular) provide a specific surgical challenge due to the difficulty in predicting rates of bony union and whether the blood supply to the femoral head has been disrupted in a way that would lead to avascular necrosis. Most femoral neck fractures are treated surgically, aiming to maintain mobility, whilst reducing pain and complications associated with prolonged bedrest. Materials and Methods: We performed a narrative review of intracapsular hip fracture management, highlighting the latest advancements in fixation techniques, generating an evidence-based algorithm for their management. Results: Multiple different fracture configurations are encountered within the category of intracapsular hip fractures, with each pattern having different optimal surgical strategies. Additionally, these injuries typically occur in patients where further procedures due to operative complications are associated with a considerable increase in mortality, highlighting the need for choosing the correct index operation. Conclusions: Factors such as pathological causes for the fracture, pre-existing symptomatic osteoarthritis, patient’s physiological age and fracture displacement all need to be considered when choosing optimal management

Cannulated cancellous screws fixation in intracapsular fracture neck femur: a study with an emphasis on result of osteosynthesis

Background: Fracture neck of femur has always presented a great challenge to the orthopaedic surgeons. It is rightly called as “unsolved fracture” as far as treatment and results are concerned. Results generally depend upon time period elapsed from fracture to surgery, adequacy of reduction and fixation. Fixation with cannulated cancellous screw is usually adequate for femoral neck fractures. The aim of the study was to analyse the results of treatment of fracture neck of femur with cannulated cancellous screw fixation and to compare the results with others in the literature using the same modality.  Methods: 25 patients with intra capsular neck of femur fracture were followed for a period of two years post-surgery and their functional outcome was assessed based upon harris hip scoring system.Results: According to harris hip scoring system, we had excellent results in 72% cases, good in 16% cases, fair in 8% and poor in 4%. One patient went into non-union and two developed avascular necrosis of femoral head.Conclusions: Management of intracapsular fracture neck of femur with cannulated cancellous screw fixation is a very good method of treatment being a surgically easy procedure. Use of multiple cannulated cancellous screw have a compression effect at the fracture site. It also avoids re displacement and rotation

Meta-Analysis of a Complex Network of Non-Pharmacological Interventions: The Example of Femoral Neck Fracture

Background Surgical interventions raise specific methodological issues in network meta-analysis (NMA). They are usually multi-component interventions resulting in complex networks of randomized controlled trials (RCTs), with multiple groups and sparse connections. Purpose To illustrate the applicability of the NMA in a complex network of surgical interventions and to prioritize the available interventions according to a clinically relevant outcome. Methods We considered RCTs of treatments for femoral neck fracture in adults. We searched CENTRAL, MEDLINE, EMBASE and ClinicalTrials.gov up to November 2015. Two reviewers independently selected trials, extracted data and used the Cochrane Collaboration’s tool for assessing the risk of bias. A group of orthopedic surgeons grouped similar but not identical interventions under the same node. We synthesized the network using a Bayesian network meta-analysis model. We derived posterior odds ratios (ORs) and 95% credible intervals (95% CrIs) for all possible pairwise comparisons. The primary outcome was all-cause revision surgery. Results Data from 27 trials were combined, for 4,186 participants (72% women, mean age 80 years, 95% displaced fractures). The median follow-up was 2 years. With hemiarthroplasty (HA) and total hip arthroplasty (THA) as a comparison, risk of surgical revision was significantly higher with the treatments unthreaded cervical osteosynthesis (OR 8.0 [95% CrI 3.6–15.5] and 5.9 [2.4–12.0], respectively), screw (9.4 [6.0–16.5] and 6.7 [3.9–13.6]) and plate (12.5 [5.8–23.8] and 7.8 [3.8–19.4]). Conclusions In older women with displaced femoral neck fractures, arthroplasty (HA and THA) is the most effective treatment in terms of risk of revision surgery

A CLINICAL STUDY OF AO CANNULATED CANCELLOUS SCREWS FIXATION FOR GARDEN’S TYPE I AND TYPE II FRACTURE NECK OF FEMUR IN YOUNG ADULTS

Objectives: The objectives of this study were to study the functional outcome of surgically managed type I and II fracture neck of the femur by AO cannulated cancellous screws in young adults. Methods: A prospective study of 20 cases of type I and II Garden’s fracture neck of femur in young adults managed surgically by AO cannulated cancellous screws fixation in Chigateri Government Hospital and Bapuji Hospital, between September 2014 and September 2016 satisfying the inclusion and exclusion criteria which were studied. The functional outcome was evaluated using the Modified Harris hip scoring system. Results: In our study, we achieved 85% excellent results, 10% good, and 5% fair results. We had 95% satisfactory results in terms of the functional outcome. The results were comparable to other studies. Conclusion: Intracapsular fracture neck of femur in young adults treated surgically by closed reduction and 6.5 mm AO cannulated cancellous screw fixation gave excellent to good functional outcome in 95%. Hence, this would be the best procedure for intracapsular fracture neck of the femur, and this is going to stay for an extended period in orthopedic practice

Delayed hospitalization increases mortality in displaced femoral neck fracture patients

Background and purpose Reports regarding the relationship between delayed surgery and mortality in femoral neck fracture patients are contradictory. We could not find any study in the literature investigating delayed arrival to hospital and delayed surgery as separate factors affecting mortality in femoral neck fracture patients, which was the purpose of our study

Osteosynthesis of femoral neck fractures: two or three screws?

OBJECTIVES: To evaluate the efficacy of osteosynthesis on femoral neck fractures using two instead of three screws. METHODS: Thirtynine fractures were retrospectively evaluated, divided into groups in which two screws were used in parallel (n = 28) or three screws (n =11) in an inverted triangle configuration (in accordance with the AO technique). The patients were then followed up until reaching the outcome of either consolidation or failure. RESULTS: In the group in which two screws were used, consolidation was observed in 23 of the 28 fractures (82%). In the group in which three screws were used, consolidation was observed in 6 of the 11 fractures (55%). There was no statistically significant difference between these percentages. CONCLUSION: There was no difference in the prognosis for these fractures when treated using two screws in parallel or three screws in an inverted triangle in accordance with the AO technique. Further studies are needed in order to establish a definitive conclusion.OBJETIVOS: Avaliar a eficácia da osteossíntese de fraturas do colo femoral com dois em vez de três parafusos. MÉTODOS: Avaliadas, retrospectivamente, 39 fraturas, divididas em grupos nos quais foram utilizados dois (n = 28) parafusos paralelos e três parafusos (n = 11) na configuração de triângulo invertido segundo a técnica AO. Os pacientes foram acompanhados até o desfecho: consolidação ou falha. RESULTADOS: No grupo em que se utilizou dois parafusos, observamos consolidação em 23 das 28 fraturas (82%). No grupo de três parafusos observou-se consolidação em seis das 11 fraturas (55%). Não houve diferença estatística entre os valores obtidos. CONCLUSÃO: Não houve diferença no prognóstico dessas fraturas quando tratadas com dois parafusos paralelos ou três parafusos em triângulo invertido segundo a técnica AO-ASIF. Mais estudos são necessários para estabelecer conclusão definitiva.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Grupo de Patologias do Quadril AdultoUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Programa de Patologias do Quadril AdultoUNIFESP, EPM, Grupo de Patologias do Quadril AdultoUNIFESP, EPM, Programa de Patologias do Quadril AdultoSciEL