Mechanical analysis of modified femoral neck system in the treatment of osteoporotic femoral neck fractures.

BACKGROUND: Despite the explicit biomechanical advantages associated with FNS, it is currently inconclusive, based on the existing literature, whether Femoral Neck System (FNS) outperforms Cannulated cancellous screws (CSS) in all aspects. Due to variances in bone morphology and bone density between the elderly and young cohorts, additional research is warranted to ascertain whether the benefits of FNS remain applicable to elderly osteoporosis patients. This study aimed to investigate the biomechanical properties of FNS in osteoporotic femoral neck fractures and propose optimization strategies including additional anti-rotation screw. METHODS: The Pauwels type III femoral neck fracture models were reconstructed using finite element numerical techniques. The CSS, FNS, and modified FNS (M-FNS) models were created based on features and parameterization. The various internal fixations were individually assembled with the assigned normal and osteoporotic models. In the static analysis mode, uniform stress loads were imposed on all models. The deformation and stress variations of the femur and internal fixation models were recorded. Simultaneously, descriptions of shear stress and strain energy were also incorporated into the figures. RESULTS: Following bone mass reduction, deformations in CSS, FNS, and M-FNS increased by 47%, 52%, and 40%, respectively. The equivalent stress increments for CSS, FNS, and M-FNS were 3%, 43%, 17%, respectively. Meanwhile, variations in strain energy and shear stress were observed. The strain energy increments for CSS, FNS, and M-FNS were 4%, 76%, and 5%, respectively. The shear stress increments for CSS, FNS, and M-FNS were 4%, 65% and 44%, respectively. Within the osteoporotic model, M-FNS demonstrated the lowest total displacement, shear stress, and strain energy. CONCLUSION: Modified FNS showed better stability in the osteoporotic model (OM). Using FNS alone may not exhibit immediate shear resistance advantages in OM. Concurrently, the addition of one anti-rotation screw can be regarded as a potential optimization choice, ensuring a harmonious alignment with the structural characteristics of FNS.

Visual disturbance and Purtscher's retinopathy heralding an occult femoral fracture.

An 80-year-old fit and active gentleman presented with left hip pain and a new central scotoma in his right eye after falling from an electric bicycle. He was able to mobilise independently and presented to ophthalmic services where cotton wool spots were found in both eyes and a presumptive diagnosis of Purtscher's retinopathy (PuR) was made. The patient was referred to the emergency department for assessment of a potential fracture. The subcapital femoral neck fracture was subtle on X-ray and only detected the following day with radiological and orthopaedic review. Two screws were placed to stabilise the fracture with a good outcome for his hip and for his vision. PuR can be seen following trauma to the head, neck or chest, following long bone fracture and in renal failure or pancreatitis. Our case highlights how the non-specific finding of cotton wool spots becomes a highly specific diagnosis in the context of trauma and should lead to careful evaluation for fractures.

The Effects and Risk Factors of Femoral Neck Shortening after Internal Fixation of Femoral Neck Fractures.

Backgroud: Internal fixation has been established as a treatment of choice in relatively young patients with femoral neck fractures. Due to the characteristics of femoral neck anatomy and blood supply, complications such as malunion, nonunion, avascular necrosis, and femoral neck shortening can occur after internal fixation of femoral neck fractures. Unlike other complications such as avascular necrosis or nonunion, femoral neck shortening has not been relatively well studied. This study aimed to investigate the risk factors and clinical outcomes of femoral neck shortening after internal fixation of femoral neck fractures. Methods: From June 2012 to July 2022, among 102 patients who underwent internal fixation of femoral neck fractures, 94 patients who met inclusion and exclusion criteria were retrospectively analyzed. Internal fixation of the femoral neck was done with cannulated compression screws or a femoral neck system. Patients were divided into 2 groups; femoral neck shortening (≥ 5 mm) and no shortening (< 5 mm) according to measurement on follow-up hip anteroposterior (AP) simple radiographs compared with postoperative hip AP simple radiographs. Demographic and radiographic data were compared between the 2 groups. The modified Harris Hip Score (mHHS) and a visual analog scale (VAS) were used to evaluate the clinical outcomes. Results: Among 94 patients, femoral neck shortening was observed in 33 (35.1%). In chi-square test, Pauwels angle, Garden type III or IV (displacement), and cortical comminution were significantly correlated with neck shortening (p < 0.05). In the multifactorial logistic regression test, cortical comminution was significantly correlated with femoral neck shortening (p < 0.01). The shortening group showed significantly lower clinical scores in terms of mHHS and VAS (p < 0.01). Conclusions: The femoral neck shortening group showed significantly lower clinical scores of mHHS and VAS than the no-shortening group. The presence of cortical comminution in preoperative hip computed tomography is a risk factor of femoral neck shortening after internal fixation of femoral neck fractures.

Incidence of Ipsilateral Femoral Neck and Shaft Fractures in Pediatric and Adolescent Patients.

OBJECTIVES: To identify the incidence, patient characteristics, and effectiveness of radiographic screening methods for detecting ipsilateral femoral neck and shaft fractures in pediatric and adolescent trauma patients. DESIGN: Retrospective cohort study. SETTING: This study was conducted at a tertiary pediatric trauma hospital. PATIENT SELECTION CRITERIA: Patients younger than 18 years treated for a femoral shaft fracture between 2004 and 2018 were reviewed. Pathologic (metabolic bone disease or bone lesion), periprosthetic, and penetrating traumatic femoral shaft fractures were excluded. OUTCOME MEASUREMENTS AND COMPARISONS: Patient demographics, mechanisms of injury, treatment methods, and associated injuries were analyzed. Pretreatment x-rays and computed tomography (CT) scans were reviewed for the identification of ipsilateral femoral neck and shaft fractures. RESULTS: Among the 840 pediatric patients included in this study, 4 patients (0.5%) sustained ipsilateral femoral neck and shaft fractures. All the femoral neck fractures were observed in adolescents (aged 13-17 years) and involved in high-energy traumas. In adolescents involved in high-energy trauma, the incidence increased to 1.7%. Pretreatment sensitivity of both x-rays and CT scans was only 50% for the detection of femoral neck fractures. CONCLUSIONS: This study reveals that ipsilateral femoral neck and shaft fractures in pediatric patients are rare, occurring in adolescents involved in high-energy trauma. The findings suggest the need for a selective, rather than routine, use of CT scans based on the patient's age and the mechanism of injury. The use of alternative imaging methods such as magnetic resonance imaging should be considered to balance diagnostic accuracy while minimizing radiation exposure. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Periprosthetic bone mineral density, assessed using dual energy x-ray absorptiometry, following arthroplasty in patients with femoral neck fracture: 5-year outcomes of a randomized controlled trial.

OBJECTIVE: The relationship between the surgical approach used for hemiarthroplasty and periprosthetic bone mineral density (BMD) is not well understood. We have previously described a decrease in BMD 1 year postoperatively. Here, we assessed the medium-term changes in periprosthetic BMD. METHODS: We performed a follow-up study of patients with femoral neck fracture (FNF) who underwent uncemented hemiarthoplasty using a direct lateral or anterolateral approach. Dual-energy X-ray absorptiometry (DXA) was used to evaluate the changes in BMD in 23 patients over 5 years. RESULTS: A mean 6% loss of total BMD occurred over 1 year, but between 1 and 5 years, BMD was restored to the baseline value. The mean total BMD in the anterolateral group had decreased by 2% after 3 months and 3% after 12 months, and increased by 2% after 5 years, vs. decreases of 7%, 8%, and 3% for the direct lateral group. Between 1 and 5 years, BMD increased in Gruen zones 2, 3, 4, 5, and 6 in both groups. There was a significantly larger increase in zone 4 in the lateral group (4%) than the anterolateral group. CONCLUSION: The surgical approach affects periprosthetic BMD in patients with FNF. Furthermore, BMD is restored to the baseline value 5 years postoperatively.ClinicalTrials.gov registration number: NCT03753100.

Disappearance of femoral head shortly after femoral neck fracture: a case report and literature review.

This case report describes a woman in her 70s who presented with a 3-month history of hip pain and inability to walk. Upon admission, she was diagnosed with the extremely rare condition of complete femoral head disappearance. A comprehensive examination was conducted to determine the cause and devise an effective treatment strategy, taking the patient's medical history into account. Through interdisciplinary discussions, occult infection and other potential causes were ruled out. The femoral head disappearance was ultimately determined to be due to wear, ischemia, and absorption following a fracture. After informing the patient of the diagnosis and treatment plan, total hip arthroplasty was proposed. This case highlights the rarity and severity of femoral head disappearance in patients with femoral neck fractures, emphasizing the effectiveness of total hip arthroplasty and appropriate joint prostheses in managing such cases. This case has significant implications for clinical diagnosis, treatment, and complication prevention. The report also discusses the causes of acquired femoral head disappearance, relevant diagnostic assessments, and alternative treatment options.

Femoral Neck Shaft Angle Measurement for Differentiating Femoral Head Stress Fracture from Avascular Necrosis.

OBJECTIVE: The study aimed to evaluate whether the measurement of Femoral Neck Shaft Angle (FNSA) can be helpful in differentiating femoral head Stress Fracture (SF) from Avascular Necrosis (AVN). METHODS: From September 2019 to April 2022, sixty-four patients [median age 32.0 years, interquartile range (IQR) 23.0-39.0 years] who underwent both hip radiograph and Magnetic Resonance Imaging (MRI) and diagnosed as femoral head SF or AVN were included in our retrospective study. Patients were divided into as having either femoral head SF (n = 34) or AVN (n = 30). The FNSA was measured in anteroposterior hip radiography. Continuous values were compared using the Mann-Whitney U test. The assessment of the predictive value of FNSA for femoral head SF was performed by Receiver Operating Characteristic (ROC) analysis. RESULTS: The FNSA was significantly higher in patients with SF (median 133.5°, IQR 128.0-136.7°) than those with AVN (median 127.5°, IQR 124.0-132.0°) (p = 0.001). In addition, the FNSA was significantly higher in SF femurs (median 134.8°, IQR 129.2-137.4°) than in contralateral normal femurs (median 127.1°, IQR 124.3-132.5°) in patients with unilateral femoral head SF (n = 30) (p < 0.001). In ROC analysis, the sensitivity, specificity, and Area Under the Curve (AUC) for predicting the femoral head SF were 77.3%, 63.3%, and 0.785 (95% confidence interval: 0.666-0.905), respectively, at a cutoff of 130.2°. CONCLUSION: Increased FNSA was associated with femoral head SF; thus, measurement of FNSA could be helpful for differentiating femoral head SF from AVN.

Nonanatomical reduction of femoral neck fractures in young patients with different Pauwels classifications: a retrospective study and finite element analysis.

BACKGROUND: Previous studies have reported that positive buttress is as effective as anatomical reduction in treating young femoral neck fractures, but whether this effect is related to the Pauwels classification remains unclear. The purpose of this study was to retrospectively analyze the clinical prognosis of positive buttress in young femoral neck fractures with different Pauwels classifications, as well as to assess its biomechanical properties. METHODS: A total of 170 young patients with femoral neck fractures who were treated with three cannulated screws were included in this study. Patients were divided into three groups based on their preoperative Pauwels classification. Each group was divided into three subgroups based on the reduction quality: positive buttress, negative buttress and anatomical reduction. The femoral neck shortening, the incidence of necrosis of the femoral head (AVN) and the Harris hip scores at the last follow-up were compared across the three reduction quality within each Pauwels classification. Subsequently, a volunteer was recruited, CT data of the hip was obtained, and finite element models representing different reduction quality under varying Pauwels classifications were established. The biomechanical properties of each model were then evaluated following the application of strains. RESULTS: In Pauwels type I, there were no significant differences in postoperative femoral neck shortening, incidence of AVN, or Harris score among the three types of reduction quality (P > 0.05). However, positive buttress provided superior biomechanical stability compared to negative buttress and anatomical reduction. In Pauwels type II, the incidence of AVN was similar between the positive buttress and the anatomical reduction groups, and both were significantly lower than that in the negative buttress (P < 0.05). The Harris score of the positive buttress was higher than that of the negative buttress, and there was no significant difference in the occurrence of femoral neck shortening between the three groups (P > 0.05). Finite element analysis showed that the biomechanical stability of positive buttress was equivalent to anatomical reduction, and both were better than negative buttress. In Pauwels type III, the incidence of AVN in the anatomical reduction group was lower than that in both the positive buttress and negative buttress (P < 0.05). There was no significant difference in the occurrence of AVN or femoral neck shortening between positive buttress and negative buttress (P > 0.05). There was also no difference in postoperative Harris scores between the three reduction qualities (P > 0.05). Both positive buttress and negative buttress exhibited identical biomechanical qualities and were inferior to anatomical reduction. CONCLUSIONS: The biomechanical and clinical dominance of positive buttress correlates with Pauwels type. Specifically, Positive buttress is biomechanically stable in Pauwels types I and II. In Pauwels type III, positive buttress is not advantageous. As the Pauwels angle increases, the biomechanical benefit of the positive buttress is lost. Therefore, regardless of the Pauwels classification, negative buttress should be avoided after reduction of femoral neck fractures in young patients.

Evaluation of the clinical efficacy of using an inverted triangular cannulated compression screw in combination with positive or negative buttress reduction for the healing of femoral neck fractures.

OBJECTIVE: We aimed to compare the clinical efficacy of inverted triangular cannulated compression screws combined with Gotfried positive or negative buttress reduction in the healing of femoral neck fractures. METHODS: Between October 2017 and March 2021, 55 patients with femoral neck fractures underwent treatment using inverted triangular cannulated compression screws combined with Gotfried positive or negative buttress reduction. Among these patients, 29 received inverted triangular cannulated compression screws combined with Gotfried positive buttress reduction treatment. This group consisted of 16 males and 13 females, with an average age of 43.45 ± 8.23 years. Additionally, 26 patients received inverted triangular cannulated compression nails combined with Gotfried negative buttress reduction treatment. This group included 14 males and 12 females, with an average age of 41.96 ± 8.69 years. Postsurgery, various measurements were taken, including the degree of shortening of the femoral neck, degree of bone nonunion, degree of fixation failure, degree of ischemic necrosis of the femoral head, and Harris score of the hip joint. RESULTS: All patients were followed up for a minimum of 18 months. The group that underwent treatment with an inverted triangular cannulated compression screw combined with Gotfried positive buttress reduction did not experience any cases of bone nonunion, fixation failure, or ischemic necrosis of the femoral head. In the group that received treatment with inverted triangle cannulated compression screws combined with Gotfried negative buttress reduction, there was one case of bone nonunion, three cases of early fixation failure, and one case of ischemic necrosis. Ultimately, five patients (19.23% of the total) underwent joint replacement surgery. The average shortening lengths in the vertical plane were 4.07 ± 1.98 mm and 8.08 ± 3.54 mm, respectively. In the horizontal plane, the average shortening lengths were 3.90 ± 1.57 mm and 7.77 ± 3.31 mm, respectively. At the last follow-up, the group that received Gotfried positive buttress reduction had a greater Harris hip joint score. CONCLUSION: The success rate of combining inverted triangular cannulated compression screws with Gotfried positive buttress reduction surgery is relatively high. This surgical approach effectively prevents femoral neck shortening and improves hip joint function. Moreover, it is crucial to avoid negative buttress reduction when managing femoral neck fractures.

Precision reduction of femoral neck fractures: a novel strategy based on the femoral neck fracture morphology.

In femoral neck fractures the secondary damage caused by repeated multiple reductions needs to be prevented. Accordingly, the aim of this study was to achieve an anatomical reduction in the first manipulation of reduction in femoral neck fractures. We propose a new reduction strategy using the x-ray morphology of femoral neck fractures for preoperative planning. In the present study we compared this approach to conventional operation procedures for the treatment of femoral neck fractures. From 2020 to 2021, 35 patients with femoral neck fractures were operated with this reduction strategy. Those were compared with 34 patients treated without the proposed preoperative method. All patients were compared for consistency between the preoperative assessment and the intraoperative execution of the reduction approach, number of reductions, operative time, number of fluoroscopies, intraoperative bleeding, and reduction quality. The operative time of patients in the study group was significantly shorter (38.40 ± 10.26 min) than that of the control group (47.26 ± 9.09 min), and the number of reductions [1.0 (1.0, 1.0)] was significantly less than that of the control group [2.0 (1.75, 2.25)]. The number of fluoroscopies (10.27 ± 2.84) was also significantly less than that of the control group (13.53 ± 2.59) times. The KAPPA value = 0.886 shows the good agreement between the preoperative proposed protocol and the intraoperative protocol about the study group .The bleeding, quality of repositioning, Harris Hip score, MOS 12-item Short Form Survey (SF-12), and early complication rate were not statistically different between the groups (P > 0.05). The selection of the appropriate repositioning method based on the analysis of femoral neck fracture X-ray morphology can improve the efficiency and accuracy of preoperative planning. This reduces the secondary damage that may be caused by multiple reduction, shortens the operation time and reduces the exposure to radiation.

The clinical application value of 3.0T magnetic resonance T2 mapping imaging in evaluating the degree of acetabular cartilage degeneration in joint replacement surgery running title: MRI and acetabular cartilage degeneration.

BACKGROUND: To explore and compare the values of 3.0T magnetic resonance imaging (MRI) T2 mapping in evaluating the degree of acetabular cartilage degeneration in hip replacement surgery. METHODS: A total of 26 elderly patients with femoral neck fractures who were scanned in 3.0T MRI T2 mapping quantification technique were included. Basing on MRI images, the degree of acetabular cartilage degeneration was classified into Grade 0, 1, 2, 3 and 4, according to the International Cartilage Repair Society (ICRS) scores. In addition, 8 healthy volunteers were included for control group. RESULTS: By comparison with health population, T2 relaxation values in the anterior, superior, and posterior regions of acetabular cartilage in patients with femoral neck fracture were obviously increased (P < 0.001). Among the patients with femoral neck fractures, there were 16 hip joint with Grade 1-2 (mild degeneration subgroup) and 10 hip joints with Grade 3-4 (severe degeneration subgroup), accounting for 61.54% and 38.46%, respectively. Additionally, T2 relaxation values in the anterior and superior bands of articular cartilage were positively related to the MRI-based grading (P < 0.05); while there was no significant difference of T2 relaxation values in the posterior areas of articular cartilage between severe degeneration subgroup and mild degeneration subgroup (P > 0.05). Importantly, acetabular cartilage degeneration can be detected through signal changes of T2 mapping pseudo-color images. CONCLUSION: 3.0T MRI T2 mapping technology can be used to determine the degree of acetabular cartilage degeneration, which can effectively monitor the disease course.

Comparison of dynamic compression system versus multiple cancellous screws in the treatment of femoral neck fractures in young adults.

INTRODUCTION: Femoral neck fractures have posed a significant global healthcare challenge and had notable impacts on the quality of life. Current treatment strategies for femoral neck fractures in young individuals have varied, emphasizing the need for optimal fixation methods. This study compared the clinical and radiological outcomes of the dynamic compression system (DCS) and multiple cancellous screws (MCS) methods. METHODS: This retrospective study included a total of 275 young adults with fresh femoral neck fractures treated with DCS and MCS. A matching analysis with a 1:1 ratio based on age, gender, fracture classification, and reduction quality was conducted. Demographic data were recorded, and comparisons were made according to follow-up time (FUT), hospitalization period, operation duration, femoral neck shortening, caput-collum-diaphysis (CCD) angle, Harris Hip Score (HHS), and post-operative complications. RESULTS: A total of 42 fractures were matched with a median age of 42 years (range, 22-48). In the DCS group, vertical neck shortening (median 1.92) was significantly lower than that in the MCS group (median 4.53) (P < 0.05). In the DCS group, horizontal femoral neck shortening, resultant femoral neck shortening, the amount of change in CCD angle, and HHS were 0.57 mm (0.43, 4.74 mm), 1.82 mm (0.40, 3.53 mm), 0.13° (-0.78°, 1.80°), and 91 (85-93), respectively. They were all non-significant than 1.00 mm (0.56, 6.23 mm), 2.74 mm (1.59, 6.71 mm), -0.18° (-1.11°,1.85°), and 91 (75, 93) in the MCS group, respectively (P > 0.05). There was no statistical difference in FUT, hospitalization period, operation time, and post-operative complications at the latest follow-up (P > 0.05). There were no complications such as pulmonary embolism, deep vein thrombosis, and incision infection reported. CONCLUSION: DCS and MCS demonstrated effectiveness in treating femoral neck fractures in young adults. The DCS implant provides additional stability in the vertical axis. A prospective randomized controlled study with a large sample size was needed to validate these findings.

A simple CT scan protocol for planning of total hip arthroplasty in patients with femoral neck fractures.

We describe a method for planning total hip arthroplasty (THA) in patients with a displaced femoral neck fracture based on a simple CT scan protocol of the contralateral hip. This protocol was used on 22 consecutive patients during the inclusion period, followed by reconstruction and 2D templating to predict the implant size and positioning. The exact planned size was achieved in 21/22 (95%) cups, 14/22 (64%) femoral stems and 14/22 (64%) femoral heads. There were no intra- or postoperative fractures. After surgery in which this planning method had been applied, the differences in length and lateral offset were less than 5 mm on average relative to the opposite side (mean postoperative leg length difference of -2 mm (-8 to +3 mm) and lateralization of -4 mm (-14 to +3 mm)). While this technique exposes the patient to additional radiation, it does not require any specific devices or surgical approach and could be used in most hospitals. LEVEL OF EVIDENCE: IV.

CT scan-based 3D fracture mapping in civilian gunshot intracapsular fractures of the femur neck.

INTRODUCTION: Displaced intracapsular neck of femur (NOF) fractures secondary to civilian gunshots are rare injuries with universally poor outcomes following surgical fixation. No studies have been published on fracture mapping in NOF fractures secondary to civilian gunshots. OBJECTIVES: We performed CT scan-based fracture mapping to identify the most common fracture patterns in these injuries. METHODS: Design: Retrospective search of prospectively collected data. SETTING: Single Level 1 Trauma hospital. Patient selection criteria: All patients presenting with gunshot fractures to the femur neck between 01 January 2009 and 31 December 2022 were identified. Once identified from Picture Archiving and Communication System (PACS), computed tomography (CT) scans in Digital Imaging and Communication in Medicine (DICOM) format were imported into Mimics 16 software and fracture fragments were segmented and three-dimensional (3D) reconstruction was generated. The reduced fractures were exported to 3-Matic software to merge the fragments and adjust the orientation in three planes. An uninjured femur model was used as a template for reduction. Fracture lines and heat maps were then generated. Our outcome measures were successful mapping of the identified fracture lines. RESULTS: A total of 25 intracapsular femur neck fractures were identified and suitable for CT scan mapping. All patients were male with an average age of 22 (range 18-32). Once generated, fracture maps were used to show the location, distribution and frequency of the fracture lines. In all but two cases the fracture line propagation remained within the confines of the hip joint capsule. In three cases there was fracture extension into the superior aspect of the femur head, and in one case extension into the inferior aspect. CONCLUSION: This is the first study to perform 3D fracture mapping for intracapsular femur neck fractures secondary to civilian gunshot injuries. The exercise has helped us better understand the commonest fracture patterns and assisted us with surgical planning and execution.

Biomechanical comparison of the therapeutic effect of a novel proximal femoral bionic intramedullary nail and traditional inverted triangle hollow screw on femoral neck fracture.

OBJECTIVE: A novel Proximal Femoral Bionic Nail (PFBN) has been developed by a research team for the treatment of femoral neck fractures. This study aims to compare the biomechanical properties of the innovative PFBN with those of the conventional Inverted Triangular Cannulated Screw (ITCS) fixation method through biomechanical testing. METHODS: Sixteen male femoral specimens preserved in formalin were selected, with the donors' age at death averaging 56.1 ± 6.3 years (range 47-64 years), and a mean age of 51.4 years. The femurs showed no visible damage and were examined by X-rays to exclude diseases affecting bone quality such as tumors, severe osteoporosis, and deformities. The 16 femoral specimens were randomly divided into an experimental group (n = 8) and a control group (n = 8). All femurs were prepared with Pauwels type III femoral neck fractures, fixed with PFBN in the experimental group and ITCS in the control group. Displacement and stress limits of each specimen were measured through cyclic compression tests and failure experiments, and vertical displacement and strain values under a 600 N vertical load were measured in all specimens through vertical compression tests. RESULTS: In the vertical compression test, the average displacement at the anterior head region of the femur was 0.362 mm for the PFBN group, significantly less than the 0.480 mm for the ITCS group (p < 0.001). At the fracture line area, the average displacement for the PFBN group was also lower than that of the ITCS group (0.196 mm vs. 0.324 mm, p < 0.001). The difference in displacement in the shaft area was smaller, but the average displacement for the PFBN group (0.049 mm) was still significantly less than that for the ITCS group (0.062 mm, p = 0.016). The situation was similar on the posterior side of the femur. The average displacements in the head area, fracture line area, and shaft area for the PFBN group were 0.300 mm, 0.168 mm, and 0.081 mm, respectively, while those for the ITCS group were 0.558 mm, 0.274 mm, and 0.041 mm, with significant differences in all areas (p < 0.001). The average strain in the anterior head area for the PFBN group was 4947 µm/m, significantly less than the 1540 µm/m for the ITCS group (p < 0.001). Likewise, in the fracture line and shaft areas, the average strains for the PFBN group were significantly less than those for the ITCS group (p < 0.05). In the posterior head area, the average strain for the PFBN group was 4861 µm/m, significantly less than the 1442 µm/m for the ITCS group (p < 0.001). The strain conditions in the fracture line and shaft areas also showed the PFBN group was superior to the ITCS group (p < 0.001). In cyclic loading experiments, the PFBN fixation showed smaller maximum displacement (1.269 mm vs. 1.808 mm, p < 0.001), indicating better stability. In the failure experiments, the maximum failure load that the PFBN-fixated fracture block could withstand was significantly higher than that for the ITCS fixation (1817 N vs. 1116 N, p < 0.001). CONCLUSION: The PFBN can meet the biomechanical requirements for internal fixation of femoral neck fractures. PFBN is superior in biomechanical stability compared to ITCS, particularly showing less displacement and higher failure resistance in cyclic load and failure experiments. While there are differences in strain performance in different regions between the two fixation methods, overall, PFBN provides superior stability.

Femoral shaft displacement and Winquist classification provide predictive characteristics for combined femoral neck and femoral shaft fractures.

OBJECTIVES: The goal of this study is to establish radiographic features and characteristics of patient injury in cases of femoral shaft fractures that predict the presence of ipsilateral femoral neck fractures (IFNFs). METHODS: Patient data was retrospectively assessed from a single level I trauma center through the electronic health record using (Current Procedural Terminology) CPT codes for both isolated and combined ipsilateral femoral shaft and neck fractures. Demographic information, injury characteristics, and independently reviewed radiographic features were collected and compared against the same information from a group of isolated femoral shaft fractures. Multivariable logistic regression was performed to identify risk factors for concomitant IFNFs and their respective odds ratios. A probability algorithm for assessing ipsilateral femoral neck fractures based on independent multivariate predictors was constructed and used. RESULTS: A total of 113 patients with either isolated femoral shaft fractures or combined femoral shaft and IFNF (n = 33) met inclusion criteria and were identified for this study. Fracture displacement was most strongly associated with increased risk of combined injury with an aOR of 25.64 (95 %CI = 5.96-110.28) for every 100 % displacement. Motorcycle crash (MCC) was the mechanism associated with the highest risk of combined injury, with an aOR of 9.85 (95 % CI = 1.99-48.74). Combined injury was also correlated with lower Winquist score and presentation with a closed fracture, with aORs of 0.38 (95 %CI = 0.21 - 0.68) and 11.61 (95 %CI = 1.93-69.94), respectively. Presence of at least 3 of the statistically significant variables produced a positive predictive value (PPV) of ≥ 89 % for combined femoral shaft and IFNF. CONCLUSIONS: Identification of combined femoral shaft and IFNF is of critical importance when caring for orthopedic trauma patients. While diagnosis remains a challenging task, MCC mechanism, >100 % fracture displacement, and lower Winquist classification were found to be associated with combined injuries. The combination of these variables might assist in predicting the probability of combined injury and potentially guide decision making on the appropriateness of obtaining single sequence MRI or implementing prophylactic femoral neck fixation. LEVEL OF EVIDENCE: Level III.

[Examination of Optimal Frequency Processing in X-ray Images for Occult Femoral Neck Fractures].

PURPOSE: Osteosclerotic images are known as an image appearance of occult femoral neck fractures in X-ray images. The aim of this study is to investigate frequency enhancement processing that improves the visibility of the osteosclerotic image. METHODS: We acquired three sclerotic bone images with different thicknesses, and self-made bone equivalent phantoms were set up on a pelvic phantom. The frequency processing type and high-density enhancement coefficients were applied to the X-ray images taken at RF-A(1.0, 2.0), C(2.0, 4.0), D(1.0), and H(2.0, 4.0). For the physical index, we compared the difference in signal values between the sclerotic and background normal bone. We evaluated the preference using Scheffé's paired comparison methods for the visual index. RESULTS: For the physical index, RF-C(4.0) had the most significant signal value difference for all 3 bone stiffness images. For the visual index, RF-C(4.0) showed the highest preference. CONCLUSION: Using frequency-enhanced processing, RF-C(4.0) was suggested to improve the visibility of the osteosclerosis image.

Intracapsular neck of femur fractures secondary to civilian gunshot injuries: an inter- and intra-observer agreement study on classification and treatment using the AO/OTA classification.

PURPOSE: Numerous classification systems have been developed for neck of femur fractures, but none have been tested for reliability in gunshot injuries. Our primary objective was to assess the inter-observer and intra-observer reliability of the AO/OTA classification system when applied to intracapsular neck of femur fractures secondary to low-velocity civilian gunshots wounds (GSWs). Our secondary objective was to test the reliability of the AO/OTA classification system in guiding surgeon treatment choices for these fractures. PATIENTS AND METHODS: Eighteen reviewers (six orthopaedic traumatologists, six general orthopaedic surgeons and six junior orthopaedic fellows) were given a set of 25 plain radiographs and CT scans of femur neck fractures secondary to GSW. For each clinical case, all reviewers selected a classification as well as treatment option from a list of given options. Inter-observer reliability was measured at the initial classification. The exercise was repeated 10-12 weeks later by the same 18 reviewers to test intra-observer reliability. RESULTS: The Fleiss kappa values indicate only slight agreement amongst raters, across all experience levels, for both injury classification and treatment. Intra-observer agreement was fair across all experience levels for both injury classification and treatment. CONCLUSION: The AO/OTA classification showed only slight reliability in classification of gunshot fractures of the femur neck. With only fair reliability, it also failed to guide surgical treatment thus rendering its routine use in daily clinical practice of questionable value.

Preliminary clinical and radiological evaluation of osteosynthesis using the Femoral Neck System (FNS) for subcapital fractures of the femur.

Addressing subcapital fractures of the femur poses a substantial clinical challenge, complicated by the diverse range of available osteosynthesis materials. This study is dedicated to a comprehensive analysis of the clinical and radiological implications linked with the implementation of the Femoral Neck System (FNS) in osteosynthesis procedures. A descriptive study was conducted involving patients who underwent osteosynthesis for subcapital fractures of the femur utilizing the FNS during the period from 2019 to 2022. The investigation encompassed various facets, including the classification of fractures according to the Garden and Pauwells classifications, criteria for achieving precise reduction based on the Garden criteria and Tip Apex Distance (TAD). At the one-year follow-up, factors such as fracture consolidation, loss of reduction, fracture collapse, complications, and functional outcomes were evaluated utilizing the Harris Hip Score (HHS) scale. The study cohort included a total of 26 patients, among whom 22 exhibited non-displaced subcapital femur fractures categorized as Garden I and II. Successful reduction was accomplished in 23 cases, in which 24 cases (92.3%) displayed a TAD measurement below 25 mm. According to the HHS, patients achieved an average score of 90.9 (ranging from 63 to 100) following the surgical intervention, with predominantly "excellent" and "good" outcomes. The outcomes derived from our investigation corroborate the viability of the Femoral Neck System (FNS) as a reliable option for osteosynthesis in femoral neck fractures. The results obtained are comparable to those achieved with other available implants, as highlighted by previous studies.