Comparison of the clinical efficacy of a femoral neck system versus cannulated screws in the treatment of femoral neck fracture in young adults

A finite element analysis of a low-profile femoral neck system of screws in sleeves in a vertical femoral neck fracture model

BACKGROUND

Femoral neck system (FNS) has exhibited some drawbacks, such as non-fit of the plate with the lateral femoral cortex, postoperative pain, and the potential risk of subtrochanteric fractures. We have developed a low-profile FNS system that addresses some compatibility issues in FNS. In this study, we conducted finite element analysis on the 1-hole FNS (1 H-FNS), 2-holes FNS (2 H-FNS), and low-profile FNS (LP-FNS) and compared their biomechanical performance.

METHODS

After the mesh convergence analysis, we established three groups of 1 H-FNS, 2 H-FNS, and LP-FNS. The interfragmentary gap, sliding distance, shear stress, and compressive stress and the bone-implant interface compression stress, stiffness, and displacement were determined under the neutral, flexion, or extension conditions of the hip joint, respectively. The stress and displacement of the femur after the implant removal were also investigated.

RESULTS

(1) There were no obvious differences among the three FNS groups in terms of the IFM distance. However, the LP-FNS group showed less rotational angle compared with conventional FNS (neutral: 1 H-FNS, -61.64%; 2 H-FNS, -45.40%). Also, the maximum bone-implant interface compression stress was obviously decreased under the neutral, flexion, or extension conditions of the hip joint (1 H-FNS: -6.47%, -20.59%, or -4.49%; 2 H-FNS: -3.11%, 16.70%, or -7.03%; respectively). (2) After the implant removal, there was no notable difference in the maximum displacement between the three groups, but the maximum von Mises stress displayed a notable difference between LP-FNS and 1 H-FNS groups (-15.27%) except for the difference between LP-FNS and 2 H-FNS groups (-4.57%).

CONCLUSIONS

The LP-FNS may not only provide the same biomechanical stabilities as the 1 H-FNS and 2 H-FNS, but also have more advantages in rotational resistance especially under the neutral condition of the hip joint, in the bone-implant interface compression stress, and after the implant removal. In addition, the 1 H-FNS and 2 H-FNS have similar biomechanical stabilities except for the maximum von Mises stress after the implant removal. The femur after the LP-FNS removal not only is subjected to relatively little stress but also minimizes stress concentration areas.

Fixation of femoral neck fracture with femoral neck system: a retrospective cohort study of 43 patients

BACKGROUNDS

This study aimed to analyze the clinical outcomes of femoral neck fractures (FNF) in patients treated with a femoral neck system (FNS, DePuy Synthes), which is a recently introduced device.

METHODS

This retrospective cohort study of 43 patients who underwent osteosynthesis using FNS for FNF between July 2019 and June 2021 with a minimum follow-up of 6 months. The researchers examined the patients' demographic factors and radiologically evaluated the fracture type and fixation status, bone union, and postoperative complications.

RESULTS

Of 43 patients, 25 were female, and the patients' mean age and body mass index were 62.1 years and 22.5 kg/m2, respectively. According to the Association of Osteosynthesis/Orthopaedic Trauma Association (AO/OTA) classification, the most common fracture types were 31B1.1 and B1.2 (13 cases each), followed by B2.3, B2.1, and B2.2 (seven, five, and four cases, respectively). Radiological bone union was confirmed in 39 patients (90.7%), and the mean time to union was 3.6 months. Two cases of nonunion, one case of lag screw cut-out, and one case of osteonecrosis were confirmed; all four cases later underwent arthroplasty. The mean time to reoperation was 4.5 months. Meanwhile, five patients underwent implant removal after the bone union, and distal locking screw stripping was noted in three patients. All three patients required metal plate cutting to remove the implants.

CONCLUSIONS

Osteosynthesis of FNF using the newly introduced FNS showed favorable clinical outcomes and no specific hardware-related complications were reported during the follow-up. However, attention must be paid to the issue regarding distal locking screw failure during hardware removal.

Factors associated with early failure of the femoral neck system (FNS) in patients with femoral neck fractures

BACKGROUND

Femoral neck system (FNS) is a new type of internal fixation system which has been widely used for treating femoral neck fractures (FNFs).Compared with other internal fixation methods, FNS is minimally invasive and stable, and often achieves satisfactory short-term efficacy.Early failure of FNS (EFFNS) is not uncommon, however, there are few literatures and reports on factors associated with EFFNS.This study aimed to survey the prevalence and risk factors of EFFNS.

METHODS

We retrospectively analysed 62 patients with FNFs and underwent FNS fixation between 2019 and 2021. Demographic data, clinical characteristics, radiographic features and treatment process were described. Multifactor logistic regression analysis was used to analyse the different influencing factors.

RESULTS

Out of the 62 FNFs patients, 10 patients (16.1%) developed EFFNS, including 6 cases of severe femoral neck shortening, 2 cases of screw-out, 1 case of avascular necrosis of the femoral head and 1 case of nonunion. In the failure group, all patients were younger than 65 years old, which was significantly higher than 59.6% in the healing group (P = 0.012). There were no significant differences in sex(P = 0.490), BMI (P = 0.709), injured side (P = 0.312), injury mechanism (P = 0.617), reduction method(P = 0.570),femoral neck-shaft angle(P = 0.545), Pauwels classification (P = 0.564) and Garden classification (P = 0.195). Moreover, we not found that Garden classification (P = 0.464) and age (P = 0.128) were statistically significant risk factors for EFFNS at multivariate analysis.

CONCLUSION

In this study, sex, BMI, injury side, injury mechanism, reduction method, Pauwels angle, femoral neck-shift angle, Pauwels classification and Garden classification were excluded as EFFNS risk factors. Moreover, our study demonstrated that age and Garden classification were not significant risk factors at multivariate analysis.

TRIAL REGISTRATION

ChiCTR, ChiCTR2100051360. Registered on 21 September, 2021. https://www.chictr.org.cn/index.aspx .

Open reduction and internal fixation of irreducible displaced femoral neck fracture with femoral Neck System: a preliminary study

BACKGROUND

Most displaced femoral neck fractures can achieve satisfactory anatomical reduction by closed reduction, but there are still some that cannot reset satisfactorily after closed reduction, and open reduction are required. Such fractures that cannot be repositioned successfully by closed reduction are called irreducible displaced femoral neck fractures in this study. The objective of our study was to evaluate the efficacy of direct anterior incision with the Femoral Neck System in the treatment of irreducible displaced femoral fractures.

METHODS

A total of 16 young and middle-aged patients with irreducible displaced femoral neck fractures involving Garden type III and IV were treated using Femoral Neck System fixation by open reduction through Direct Anterior Approach between January 2020 to September 2021. Functional outcomes and postoperative complications were assessed during follow-up. Clinical outcomes were evaluated by the Hip Harris score. The postoperative reduction was evaluated by the Garden Index. Observe postoperative complications.

RESULTS

All patients were followed up with a mean follow-up time of 21.1(12-30) months, and according to radiological results, all patients achieved fracture healing, with a mean healing time of 4.25 months. All 16 patients received grade Garden I and II reductions, and there was no significant difference in the anteroposterior Garden reduction index between the first day after surgery (166.13 ± 5.61) and the 12th month after surgery(164.94 ± 4.49) (P>0.05) and no significant difference in lateral Garden index between the first day after surgery(171.06 ± 4.46) and the 12th month after surgery(169.38 ± 3.98) (P<0.05). According to the Hip Harris score scale, 13 patients received excellent and 3 patients received good. The postoperative Hip Harris Score(17.19 ± 4.8) was significantly higher than the preoperative score(92.19 ± 3.4), and the difference was statistically significant (P < 0.05). No or mild femoral neck shortness occurred in 12 (75%) patients, moderate shortening occurred in 3 (18.75%) patients, and severe shortening occurred in 1 (6.25%) patient. None of the patients experienced femoral head necrosis, fracture nonunion, or incision infection. One patient developed deep venous thrombosis of the lower extremity.

CONCLUSIONS

The Direct Anterior Approach combined with Femoral Neck System is an excellent treatment for irreducible displaced femoral neck fracture and achieved good functional outcomes and anatomical reduction with low complications.

Superior short-term outcomes of FNS in combination with a cannulated screw in treating femoral neck fractures

BACKGROUND

This study aimed to evaluate the clinical efficacy of the femoral neck system alone or in combination with a cannulated screw compared with other internal fixation methods for treating femoral neck fractures. We further investigated the predictive effects of tip-apex distance (TAD) on clinical efficacy.

METHODS

Data from 129 young adults with femoral neck fractures followed up at The Second Affiliated Hospital of Fujian Medical University between January 2016 and June 2022 were retrospectively collected. The patients were categorized into four groups based on the different internal fixation methods. Analysis and comparisons of the four group were performed according to age, ASA score, operation time, blood loss, fracture classification, fracture healing time, Harris score, TAD value, presence of complications (osteonecrosis of the femoral head, screw failure, and femoral neck shortening), and changes in the neck-shaft angle.

RESULTS

All 129 patients were followed up for at least one year. The group who received treatment with the femoral neck system combined with a cannulated screw exhibited the shortest fracture healing time. Differences were observed in the change of neck-shaft angle among the four groups (P < 0.001), with the smallest change observed in the aforementioned group (0.76 ± 0.54°). The femoral neck shortening was also lower in groups with the femoral neck system or combined with a cannulated screw. At the last follow-up surgery, the combined treatment group achieved the highest HHS score. Subgroup analysis revealed that when the TAD was less than 25 and 49 mm for the femoral neck system and combined groups, respectively, there was less femoral neck shortening, less change in the neck-shaft angle, and a higher HHS score.

CONCLUSIONS

The femoral neck system alone or combined with a cannulated screw demonstrated better short-term efficacy in the treatment of femoral neck fractures. Furthermore, TAD may serve as a predictive indicator of the potential success of femoral neck fracture treatment.

Restoration of Hip Geometry after Femoral Neck Fracture: A Comparison of the Femoral Neck System (FNS) and the Dynamic Hip Screw (DHS)

BACKGROUND

The femoral neck system (FNS) was introduced as a minimally invasive fixation device for managing femoral neck fractures.

OBJECTIVE

To compare radiographic, clinical, and patient-reported outcome measures (PROMs) of femoral neck fracture patients following FNS compared to dynamic hip screw (DHS) implantation combined with an anti-rotational screw.

METHODS

Patients who underwent closed reduction and internal fixation of a femoral neck fracture between 2020 and 2022 were retrospectively included. We measured leg length, femoral offset, and centrum-collum-diaphyseal (CCD) angle in plain radiographs. Scar length, Harris Hip Score, short-form health survey 36-item score (SF-36), and Numeric Rating Scale (NRS) were assessed during follow-up visits.

RESULTS

We included 43 patients (22 females) with a median age of 66 (IQR 57, 75). In both groups, leg length differences between the injured and the contralateral side increased, and femoral offset and CCD angle differences were maintained over time. FNS patients had shorter scars and reported fewer emotional problems and more energy. There were no differences between groups regarding the remaining SF-36 sub-scores, Harris Hip Score, and NRS.

CONCLUSIONS

The FNS allows for a comparable leg length, femoral offset, and CCD angle reconstruction while achieving similarly high functional and global health scores to the DHS.

Subtrochanteric fracture after femoral neck system of femoral neck fractures: a report of four cases

BACKGROUND

The femoral neck system (FNS) is commonly used for internal fixation of femoral neck fractures and has shown promising results. However, we have observed cases of peri-implant subtrochanteric femur fractures associated with the use of FNS at our institution. This case series aims to investigate four cases of peri-implant subtrochanteric fractures in patients treated with the FNS implant for femoral neck fractures.

CASE PRESENTATION

We reviewed 35 patients who underwent treatment with FNS for femoral neck fractures between January 2017 and December 2021 at our level 1 trauma institution. Among these patients, four cases of peri-implant subtrochanteric femur fractures were identified. In contrast, no such fractures occurred in patients treated with cannulated screws or dynamic hip screws (DHS). Interestingly, all four cases of peri-implant fractures were seen in patients with incomplete nondisplaced femoral neck fractures. Only one case involved an identifiable technical error.

CONCLUSIONS

This case series sheds light on peri-implant subtrochanteric femur fractures as a previously unreported complication associated with the use of FNS for femoral neck fractures. These fractures were observed exclusively in patients with incomplete nondisplaced fractures who received FNS fixation. No similar complications were observed in patients treated with other types of fixation. This finding suggests the need for caution and further investigation when considering FNS as a treatment option for this specific fracture pattern. The identification of peri-implant subtrochanteric femur fractures as a potential complication of FNS usage in incomplete nondisplaced femoral neck fractures raises important considerations for clinical decision-making and patient management in orthopedic trauma.

Safe range of femoral neck system insertion and the risk of perforation

BACKGROUND

Internal fixation of the femoral neck carries a risk of perforation due to the presence of the isthmus of the femoral neck. At present, there are few studies on the safe and risk zones of the femoral neck system (FNS) implantation. This study aimed to recommend the safe range of injection of FNS in the lateral wall of the proximal femur, parallel to the axis of the femoral neck, during FNS treatment of femoral neck fracture (FNF).

METHODS

Femoral computed tomography (CT) data of 80 patients (male: 40; female: 40) who met the inclusion criteria were collected. Mimics 21.0 software was used to complete the modeling. 3-Matic 13.0 software was used to establish the axis of the femoral neck and its vertical plane, perform the cutting of the femoral neck, and project it on the vertical plane of the femoral neck axis. After matching a rectangle for each projection map, all sample sizes (80 cases) were standardized and superimposed to obtain gradient maps of the safe zone (SZ) and dangerous zone (RZ), thereby securing edge key points and safe FNS insertion range.

RESULTS

In the 80 samples, the mean diameter of the smallest femoral neck section was 33.87 ± 2.32 mm for men and 29.36 ± 1.92 mm for women. All 80 femoral necks had safe and risky areas. The SZ/S × 100% was 77.59 (± 2.22%), and the RS/S × 100% was 22.39% (± 2.22%). The risk area was composed of four parts: (1), (2), (3), and (4), respectively, corresponding to 3.45 ± 1.74%, 5.51 ± 2.63%, 6.22 ± 1.41%, and 7.22 ± 1.39%. Four marginal key points, perforation risk, and safe ranges (SR) of FNS were analyzed on the lateral wall of the femoral neck.

CONCLUSIONS

The SR of FNS placement was recommended by digital simulation. In addition, Regions (3) and (4) posed a higher risk of penetrating the cortex. Using the gradient map of RZ for preoperative evaluation is recommended to avoid iatrogenic perforation.

Femoral neck system vs. cannulated screws on treating femoral neck fracture: a meta-analysis and system review

Objective

This meta-analysis aimed to compare the relative safety and efficacy of cannulated compression screw (CCS) and femoral neck system (FNS) in treating patients with femoral neck fractures and to provide evidence-based medical evidence for FNS in treating femoral neck fractures.

Methods

PubMed, Embase, Cochrane, and China National Knowledge Infrastructure databases were searched to collect outcomes related to femoral neck fractures treated with FNS and CCS, including time to fracture healing, incidence of non-union, incidence of osteonecrosis of the femoral head, incidence of failure of internal fixation, rate of femoral neck shortening, Harris hip score, Barthel index, operative time, intraoperative blood loss, fluoroscopy frequency, and complications. A meta-analysis was performed using RevManv5.4 (The Cochrane Collaboration) and Stata v14.0 software.

Results

This analysis included 21 studies involving 1,347 patients. The results showed that FNS was superior to CCS in terms of fracture healing time [mean difference (MD) = -0.75, 95% CI = (-1.04, -0.46), P < 0.05], incidence of bone non-union [odds ratio (OR) = 0.53, 95% CI = (0.29, 0.98), P = 0.04], incidence of osteonecrosis of the femoral head [OR = 0.49, 95% CI = (0.28, 0.86), P = 0.01], incidence of internal fixation failure [OR = 0.30, 95% CI = (0.18, 0.52), P < 0.05], rate of femoral neck shortening [OR = 0.38, 95% CI = (0.27, 0.54), P > 0.05], Harris hip score [MD = 3.31, 95% CI = (1.99, 4.63), P < 0.001], Barthel index [MD =  4.31, 95% CI = (3.02, 5.61), P < 0.05], intraoperative bleeding [MD = 14.72, 95% CI = (8.52, 20.92), P < 0.05], fluoroscopy frequency [OR = 0.53, 95% CI = (0.29, 0.98), P = 0.04], and complications [OR = 0.31, 95% CI = (0.22, 0.45), P < 0.05]. The difference between FNS and CCS in operative time was not statistically significant [MD = -2.41, 95% CI = (-6.88, 2.05), P = 0.29].

Conclusion

FNS treatment of femoral neck fracture can shorten the fracture healing time; reduce the incidence and translucent rate of bone non-union, osteonecrosis of the femoral head, and internal fixation failure; reduce intraoperative blood loss and postoperative complications; and improve hip joint function and activity. We are confident in the findings that FNS, an effective and safe procedure for internal fixation of femoral neck fractures, is superior to CCS.

Trajectory of bolt and length of plate in femoral neck system determine the stability of femur neck fracture and risk of subsequent subtrochanteric fracture : a finite element analysis

BACKGROUND

This study aimed to analyze the differences in the stability of fractures, stress distribution around the distal-most screw according to the length of the plate and the trajectory of the bolt in Pauwels type III femoral neck fracture using the femoral neck system (FNS).

METHODS

Finite element models of Pauwels type III femoral neck fractures were established with surgical variations in the trajectory of the bolt (central, inferior, valgus, and varus) and length of the lateral plate (1- and 2-hole plate). The models were subsequently subjected to normal walking and stair-climbing loads.

RESULTS

The screw-holding cortical bone in subtrochanter in the model with a 2-hole plate and the bolt in the inferior trajectory and the models with 1-hole or 2-hole plate and the bolt in valgus trajectory had shown greater maximum principal strain than the models with central or varus trajectories. The gap and sliding distance on the fracture surface were larger with inferior or varus trajectories of the bolt and smaller with the valgus trajectory of the bolt under both loads, compared to those of the central trajectory.

CONCLUSION

For the fixation of Pauwels type III femoral neck fracture, the trajectory of the FNS bolt and the length of the plate affect the mechanical stability of the fracture and the strain of cortical bone around the distal-most screw. The surgical target should stay on the central trajectory of the bolt and the 2-hole plate's mechanical benefits did not exceed the risk.

What makes vertical femoral neck fracture with posterior inferior comminution different? An analysis of biomechanical features and optimal internal fixation strategy

BACKGROUND AND PURPOSE

Fracture comminution occurs in 83.9%-94% of vertical femoral neck fractures (VFNFs), the majority of which were located in posterior-inferior region, and poses a clinical challenge in fixation stability. We conducted a subject-specific finite element analysis to determine the biomechanical features and optimal fixation selection for treating VFNF with posterior-inferior comminution.

PATIENTS AND METHODS

Eighteen models with three fracture types (VFNF without comminution [NCOM], with comminution [COM], with comminution + osteoporosis [COMOP]) and six internal fixation types (alpha [G-ALP], buttress [G-BUT], rhomboid [G-RHO], dynamic hip screw [G-DHS], invert triangle [G-ITR], femoral neck system (G-FNS)) were created based on the computed tomography data. By using the subject-specific finite element analysis method, stiffness, implant stress, yielding rate (YR) were compared. Additionally, in order to elucidate distinct biomechanical characters of different fracture types and fixation strategies, we calculated interfragmentary movement (IFM), detached interfragmentary movement (DIM), shear interfragmentary movement (SIM) of all fracture surface nodes.

RESULTS

Generally, in comparison with NCOM, COM showed a 30.6% reduction of stiffness and 1.46-times higher mean interfragmentary movement. Besides, COM had a 4.66-times (p = 0.002) higher DIM at the superior-middle position, but similar SIM across fracture line, which presented as varus deformation. In COM and COMOP, among all six fixation strategies, G-ALP had significantly the lowest IFM (p<0.001) and SIM (p<0.001). Although G-FNS had significantly highest IFM and SIM (p<0.001), it had the highest stiffness and lowest DIM (p<0.001). In COMOP, YR was the lowest in G-FNS (2.67%).

CONCLUSIONS

Posterior-inferior comminution primarily increases superior-middle detached interfragmentary movement in VFNF, which results in varus deformation. For comminuted VFNF with or without osteoporosis, alpha fixation has the best interfragmentary stability and anti-shear property among six current mainstream fixation strategies, but a relatively weaker stiffness and anti-varus property compared to fixed-angle devices. FNS is advantageous owing to stiffness, anti-varus property and bone yielding rate in osteoporosis cases, but is insufficient in anti-shear property.

Nonanatomical reduction of femoral neck fractures in young patients treated with femoral neck system: a retrospective cohort study

PURPOSE

Negative buttress reduction should be avoided in the treatment of femoral neck fractures (FNFs) using conventional fixation. As the femoral neck system (FNS) has been recently developed and utilized widely to treat FNFs, the association of reduction quality with postoperative complications and clinical function has not been clarified. The purpose of this study was to evaluate the clinical effect of nonanatomical reduction in young patients with FNFs treated with FNS.

METHODS

This multicenter, retrospective cohort study included 58 patients with FNFs treated with FNS between September 2019 and December 2021. According to the reduction quality immediately following surgery, patients were classified into positive, anatomical, and negative buttress reduction groups. Postoperative complications were assessed with 12 months of follow-up. The logistic regression model was used to identify risk factors for postoperative complications. The postoperative hip function was assessed using the Harris hip scores (HHS) system.

RESULTS

At a follow-up of 12 months, a total of eight patients (8/58, 13.8%) had postoperative complications in three groups. Compared with the anatomical reduction group, negative buttress reduction was significantly associated with a higher complication rate (OR = 2.99, 95%CI 1.10-8.10, P = 0.03). No significant associations were found between positive buttress reduction and the incidence of postoperative complications (OR = 1.21, 95%CI 0.35-4.14, P = 0.76). The difference was not statistically significant in Harris hip scores.

CONCLUSION

Negative buttress reduction should be avoided in young patients with FNFs treated with FNS.

Femoral neck fractures in non-geriatric patients: femoral neck system versus cannulated cancellous screw

BACKGROUND

The fractures of femoral neck account for 50% among hip fractures with around 3%-10% occurring in younger population of below 65 years. The newly introduced FNS as management approach appears to be a potential alternative to the traditional CCS. The aim of this study was to compare the clinical efficacy and outcome of the femoral neck system (FNS) and the cannulated cancellous screw (CCS) in the treatment of femoral neck fractures in adult below 65 years of age.

METHODS

Data of 114 patients between 18-65 years, admitted in our department for femoral neck fracture from January 2019 to March 2021 were retrospectively studied and ranged into two groups based on the surgical methods: FNS group (56 patients) and CCS group (58 patients). The variables of interest including demographic and clinical variables (age, gender, fracture mechanism, injury side and classification), perioperative parameters(operation time, intraoperative bleeding, incision length and hospitalization time), postoperative outcomes and complications (fracture healing time, nonunion rate, femoral neck avascular necrosis, aseptic screw loosening and the Harris Hip Score), were analyzed and compared between the two groups.

RESULTS

All 114 patients presented satisfactory reduction and were followed-up for a period of 12 to 36 months (mean 27 ± 2.07 months); there were no significant differences between both groups in terms of age, gender, fracture classification, side of injury, mechanism of injury, the operative time, intraoperative blood loss and the hospital length of stay. However, the fracture healing time between FNS group and CCS group was statistically significant (p < 0.05), respectively 2.86 ± 0.77 and 5.10 ± 0.81 months. The significant differences were also found in terms of numbers of fluoroscopies 8.34 ± 1.38 Vs 17.72 ± 2.19, the HHS 87.80 ± 1.92 Vs 84.28 ± 2.24, postoperative complications 8 (14.28%) Vs 26 (44.82) respectively in FNS and CCS group.

CONCLUSION

FNS presented satisfactory outcomes had significantly lower complications rate, therefore, can be one of the alternatives for internal implantation devices in treatment of femoral neck fracture in non-geriatric population.

Survivability of the Femoral Neck System for the treatment of femoral neck fractures in adults

INTRODUCTION

Hip fractures are common injuries in the elderly, with an incidence that continues to rise. The femoral neck system (FNS) recently emerged as a novel treatment option for femoral neck fractures, but long-term survivability of the implant remains uncertain. The purpose of this study is to evaluate survivability of the FNS and assess risk factors for implant failure.

METHODS

One hundred five adult patients who received the FNS (DePuy Synthes, Raynham, MA) for femoral neck fractures (AO/OTA 31B) were included. Surgeries were performed within a regional hospital system comprising 18 facilities. All patients had a minimum follow-up of 1 year. The primary outcome measures were cumulative incidence of implant failure and 1-year mortality, including risk factor analysis.

RESULTS

Twelve implants failed at a follow-up ranging from 17 days to 8 months, and 7 failed within 90 days. Cumulative incidence of implant failure was 2% at 30 days, 7% at 90 days, 12% at 6 months, and 13% at 1 year. Causes of implant failure included cut-out (n = 5), non-union (n = 4), peri-implant fracture (n = 2), and avascular necrosis (n = 1). Univariate Cox regression identified Pauwels type III fractures and an increasing AP Parker ratio as significant risk factors for failure. Pauwels type III fractures showed a 5.48 times higher risk compared to Pauwels types I & II. Every 10% increase in AP Parker ratio increased risk of failure by 2.39 times. The 1-year mortality rate was 21%, and univariate logistic regression identified age as the only risk factor (odds ratio = 3.71).

CONCLUSIONS

The incidence of implant failure and 1-year mortality rate in this study suggests that the FNS can provide reliable fixation compared to rates in the literature, but complications are not uncommon. Avoiding Pauwels type III fractures and optimizing implant placement appear crucial to preventing implant failure.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Efficacy of the femoral neck system in femoral neck fracture treatment in adults: A systematic review and meta-analysis

BACKGROUND

Controversy remains around the available choices for the internal fixation of a femoral neck fracture. The femoral neck system (FNS) was developed in 2018 and has been widely applied since then as it can provide rigid fixation stability with less damage to the bone mass around the fracture. However, no systematic reviews and meta-analyses have investigated the efficacy of the FNS in comparison with that of traditional internal fixation in the treatment of femoral fractures.

AIM

To assess the efficacy of the FNS in comparison with that of cannulated compression screws (CCS) in the treatment of femoral fractures through systematic review and meta-analysis.

METHODS

Five electronic databases (PubMed, Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, and Wanfang) were searched from the earliest publication date to December 31, 2021. Reference Citation Analysis (https://www.referencecitationanalysis.com/) was used to check the results and further analyze the related articles. Controlled trials were included if the FNS was applied for the femoral neck fracture in adults and if it was compared with CCS for the achievement of internal fixation. The measurement outcomes included the required operation time, observed patient’s blood loss, extent of fracture healing, patient’s Harris Hip score (HHS) at the last follow-up, and records of any complications (such as failure of internal fixation, femoral neck shortness, avascular necrosis of the femoral head, and delayed union or nonunion).

RESULTS

Ten retrospective controlled studies (involving 711 participants) were included in this meta-analysis. The meta-analysis showed that compared with CCS, use of the FNS could not decrease the operation time [standardized mean difference (SMD): -0.38, 95% confidence interval (CI): -0.98 to 0.22, P = 0.21, I² = 93%), but it could increase the intraoperative blood loss (SMD: 0.59, 95%CI: 0.15 to 1.03, P = 0.009, I² = 81%). The pooled results also showed that compared with CCS, the FNS could better promote fracture healing (SMD: -0.97, 95%CI: -1.65 to -0.30, P = 0.005, I² = 91%), improve the HHS at the last follow-up (SMD: 0.76, 95%CI: 0.31 to 1.21, P = 0.0009, I² = 84%), and reduce the chances of developing femoral neck shortness (OR: 0.29, 95%CI: 0.14 to 0.61, P = 0.001, I² = 0%) and delayed union or nonunion (OR: 0.47, 95%CI: 0.30 to 0.73, P = 0.001; I² = 0%) in adult patients with femoral neck fractures. However, there was no statistically significant difference between the FNS and CCS in terms of failure of internal fixation (OR: 0.49, 95%CI: 0.23 to 1.06, P = 0.07, I² = 0%) and avascular necrosis of the femoral head (OR: 0.46, 95%CI: 0.20 to 1.10, P = 0.08, I² = 0%).

CONCLUSION

Compared with CCS, the FNS could decrease the chances of developing femoral neck shortness and delayed union or nonunion in adults with femoral neck fractures. Simultaneously, it could accelerate fracture healing and improve the HHS in these patients.

Comparison of daytime and after-hours surgical treatment of femoral neck fractures

Background

The timing of surgery for femoral neck fractures in young adults remains controversial. Nonetheless, the debate continues about whether orthopedic trauma cases should be operated daytime or after hours.

Aim

This study compared the clinical and radiological outcomes of surgery on femoral neck fractures during daytime versus after-hours.

Patients and Methods

A total of 124 patients aged 18-60 years who were operated for femoral neck fractures between 2015 and 2020 were included in the study. The patients were separated into two groups. Seventy-two patients operated between 08:00 and 17:00 hours were defined as the daytime group and 52 patients operated between 17:01 and 07:59 hours were defined as the after-hours group. Demographic data, reduction quality, duration of operation, intraoperative estimated blood loss (EBL), postoperative complications, revision rates, and postoperative Harris hip score results of the two groups were recorded for analysis.

Results

There was no significant difference between the groups in terms of age, gender, body mass index, smoking, fracture type and follow-up time, reduction quality, postoperative complication rates, revision rates, and Harris hip score results. Waiting times until surgery, operation duration, and intraoperative EBL amounts were, in the daytime group, significantly higher than in the after-hours group.

Conclusion

In this study comparing femoral neck fractures operated on daytime and after-hours in adults, the waiting time until surgery was found to be higher in the daytime group. Operation duration and EBL were higher in the after-hours group.

Comparison of Femoral Neck System Versus Cannulated Cancellous Screws for the Fixation of Femoral Neck Fracture in Young Adults: A Systematic Review and Meta-Analysis

A femoral neck fracture is a very common injury in the elderly. However, its incidence is low among young adults, usually presenting as an emergency. In young adults, implant choice is one of the important factors. This systematic review aims to analyze the femoral neck system (FNS) versus cannulated cancellous (CC) screw for the fixation of femoral neck fractures in young adults through well-defined objectives. A comprehensive search from the electronic database (PubMed, Google Scholar, Web of Science, Cochrane Library) was conducted from the beginning till February 18, 2022. The data regarding study type, authors, year of publication, country, union time, Harris hip score, intraoperative blood loss, operating time, neck shortening, and hospital stay were extracted from the selected articles and analyzed using RevMan 5.4.1 software. For continuous data, e.g., healing time, intraoperative blood loss, operation time, Harris hip score, neck shortening, and hospital stay, the mean difference (MD), either weighted mean difference (WMD) or standardized mean difference (SMD), with a 95% confidence interval (CI) was recorded. A p-value less than 0.05 was taken as statistically significant. The Newcastle Ottawa scale was used for the risk of bias assessment. Six retrospective cohort studies including 427 patients were selected for the meta-analysis. There was significantly less healing time (WMD= -1.10, 95% CI: -1.73 to -0.47), shorter operation duration (WMD=7.70, 95% CI: -0.06 to 15.46), and better Harris hip score (WMD=4.79, 95% CI: 2.12-7.46) in the FNS than CC screw fixation method. However, intraoperative blood loss was significantly less in the CC screw system (WMD=21.27, 95% CI: 8.20-34.35). There was no significant difference between the two approaches in-hospital stay duration and femoral neck shortening. This can be concluded that FNS is better than CC screw fixation for treating neck of femur fractures in adults on the outcome basis of union time, less operation time, and better Harris hip score (HHS) with significant heterogeneity.

The use of the femoral neck system (FNS) leads to better outcomes in the surgical management of femoral neck fractures in adults compared to fixation with cannulated screws: A systematic review and meta-analysis

BACKGROUND

Intracapsular femoral neck fractures are challenging to treat, with outcomes depending on the quality of reduction, and the stability of fixation. Cannulated cancellous screws (CCS) are the most commonly used implants to fix these fractures, but failure rates are significant. The recently introduced femoral neck system (FNS) may be a better option than CCS fixation and this review attempts to compare the results.

METHODS

Four electronic databases were searched for eligible articles that had comparative data on the outcomes of fixation of adult femoral neck fractures with FNS and CCS. Data on various outcome parameters were collected. Meta-analysis was conducted using a random-effects model with 95% confidence intervals.

RESULTS

Eight studies with 509 cases having a mean age of 50.8 years were included for final analysis. FNS was found to be associated with significantly reduced complication rates (p < 0.001), decreased incidence of postoperative femoral neck shortening (p < 0.001), quicker time to fracture union (p = 0.002), and better functional outcome scores (p < 0.001) compared to cannulated screws. FNS was also associated with a shorter operating time (mean difference 6.65 min) although not statistically significant (p = 0.24). CCS group had significantly reduced mean blood loss (p < 0.001).

CONCLUSION

The available literature supports FNS as a better option for adult femoral neck fractures, with a lower complication rate, quicker union, and better clinical outcomes.

LEVEL OF EVIDENCE

Level 3.

Femoral neck system versus cannulated screws for fixation of femoral neck fracture in young adults: a systematic review and meta-analysis

PURPOSE

Femoral neck fracture treatment in young adults remains controversial. Cannulated screws (CS) and femoral neck system (FNS) are well-accepted methods for femoral neck fracture treatment; however, these methods are associated with complications. This meta-analysis aimed to evaluate the relative safety and effectiveness of CS and FNS for treating young patients with femoral neck fractures.

METHODS

We searched the following sources for studies that compared CS and FNS fixation: Cochrane library, Embase, PubMed, Web of Science, Wanfang data, China National Knowledge Infrastructure, China Biology Medicine disc, and Chinese Science and Technology Journals. The outcomes were surgical and prognostic results and complications.

RESULTS

This meta-analysis included eight studies. The pooled results revealed that the two fixation methods were similar in terms of the operation time, length of hospital stay, healing time, intraoperative blood loss, non-union, femoral head necrosis, and internal fixation cut-out. Compared with CS fixation, FNS fixation required fewer intraoperative fluoroscopies and had better Harris Hip Score, earlier weight-bearing, lower number of total complications, lesser femoral neck shortening, and lesser extent of nail retreat.

CONCLUSION

FNS fixation outperforms CS fixation in terms of intraoperative fluoroscopies, Harris Hip Score, and morbidity in young patients with femoral neck fractures. Clinicians should consider FNS as a first choice in treating femoral neck fracture in young adults, except where this approach is contraindicated.

Is Femoral Neck System a Valid Alternative for the Treatment of Displaced Femoral Neck Fractures in Adolescents? A Comparative Study of Femoral Neck System versus Cannulated Compression Screw

Background and Objectives: The femoral neck system (FNS) is a new minimally invasive internal fixation system for femoral neck fractures (FNFs), but its use has not been reported in adolescents. The aim of this study was to compare the clinical and radiographic outcomes of displaced FNF in adolescents treated with FNS or a cannulated compression screw (CCS). Materials and Methods: A retrospective study of 58 consecutive patients with displaced FNF treated surgically was performed; overall, 28 patients underwent FNS and 30 CCS fixation. Sex, age at injury, type of fracture, associated lesions, duration of surgery, radiation exposure, and blood loss were collected from the hospital database. The clinical and radiographic results, as well as complications, were recorded and compared. Results: The patients were followed up for 16.4 ± 3.1 months on average after index surgery (range, 12 to 24). Consolidation time among patients treated with FNS was significantly lower than those managed by CCS (p = 0.000). The functional scores of patients treated with FNS were significantly higher than those managed by CCS (p = 0.030). Unplanned hardware removal in patients treated with FNS was significantly lower than in those managed by CCS (p = 0.024). Conclusions: FNS has a lower complication rate and better functional outcome than CCS. It may be a good alternative to treat femoral neck fractures in adolescents.

Femoral neck system reduces surgical time and complications in adults with femoral neck fractures: A systematic review and meta-analysis

PURPOSE

Femoral neck fractures (FNF) in adults are conventionally managed with surgical options. This paper is aimed to assess the safety, and functional outcomes of the novel Femoral neck system (FNS) for FNF treatment in adult population.

METHODS

An organized quest of four literature databases (PubMed, Scopus, Web of Science, and Cochrane Library) was performed on March 1, 2022 using the term "femoral neck system". Fixed or random-effect meta-analysis was used to analyse the outcome measures after selecting relevant studies and assessing their quality. Heterogeneity was considered when calculating pooled effect sizes and 95% confidence ranges.

RESULTS

On comparing FNS with cannulated cancellous screws (CCS) or other methods, in a total of 762 patients (351 FNS and 411 CCS) in the 11 comparative studies considered for meta-analysis, blood loss was pointedly higher overall in the FNS group, mean difference 115.77 ml; 95% CI 3.11 ml, 28.42 ml; test of overall effect: z = 1.68, p = 0.09); with considerable heterogeneity. However, in the FNS group the operative time was substantially lower (Mean difference -7.91 min; 95% CI -15.01, -0.80; test of overall effect: z = 2.18, p = 0.03, with marked heterogeneity). Moreover, complications such as infections, non-union, osteonecrosis, implant cut-out were significantly lower in the FNS group with a Mantel Haenszel Odds ratio of 0.20 (95% CI 0.12, 0.34: Z = 6.01, p < 0.0001).

CONCLUSION

Keeping in mind the heterogenicity of the studies, -management of adult patients with FNF with FNS can provide results comparable to traditional fixation methods with significantly lower rate of complications.

Neck of femur fractures treated with the femoral neck system: outcomes of one hundred and two patients and literature review

Introduction

The recently developed femoral neck system (FNS) for treatment of femoral neck fractures (FNF), comprises theoretical biomechanical advantages compared to other implants. The aim of this study was to validate the safety and to report outcomes of patients treated with the FNS.

Method

A retrospective multicentric analysis of patients treated by FNS with a minimum of three months of follow-up. Details analysed from three medical centres were operative duration, estimated blood loss, initial hospitalisation duration, fixation quality as well as complications and reoperation rate. Patients who had revision surgery were compared to all other patients to identify risk factors for failure. In addition, a literature review was performed to analyse data on FNS clinical implementation and patient’s outcomes. The two data sets were combined and analysed.

Results

One-hundred and two patients were included in this study cohort with an average follow-up of seven months (range 3–27). Ten papers were included in the literature review, reporting data on 278 patients. Overall, 380 patients were analysed. Average age was 62.6 years, 52% of the fractures were classified as Gardens 1–2. Overall, the revision rate was 9.2% (14 patients diagnosed with cut-out of implant, 10 with AVN, 8 with non-union and 8 with hardware removal). For the 102 patients in the cohort risk factors for reoperation included patients age, surgeon seniority and inadequate placement of the implant.

Conclusion

This study shows that FNS is a safe treatment option for FNF. Intra-operative parameters and failure rates are comparable to previously reported rates for this implant and other frequently used implants.

Comparing Perioperative Outcome Measures of the Dynamic Hip Screw and the Femoral Neck System

Background and Objective: Various fixation devices and surgical techniques are available for the management of proximal femur fractures. Recently, the femoral neck system (FNS) was introduced, and was promoted on the basis of less invasiveness, shorter operating time, and less fluoroscopy time compared to previous systems. The aim of this study was to compare two systems for the internal fixation of femoral neck fractures (FNF), namely the dynamic hip screw (DHS) with an anti-rotation screw (ARS) and an FNS. The outcome measures included operating room time (ORT), dose−area product (DAP), length of stay (LOS), perioperative changes in haemoglobin concentrations, and transfusion rate. Materials and Methods: A retrospective single-centre study was conducted. Patients treated for FNF between 1 January 2020 and 30 September 2021 were included, provided that they had undergone closed reduction and internal fixation. We measured the centrum-collum-diaphyseal (CCD) and the Pauwels angle preoperatively and one week postoperatively. Results: In total, 31 patients (16 females), with a mean age of 62.81 ± 15.05 years, were included. Fracture complexity assessed by the Pauwels and Garden classification did not differ between groups preoperatively. Nonetheless, the ORT (54 ± 26.1 min vs. 91.68 ± 23.96 min, p < 0.01) and DAP (721 ± 270.6 cGycm² vs. 1604 ± 1178 cGycm², p = 0.03) were significantly lower in the FNS group. The pre- and postoperative CCD and Pauwels angles did not differ statistically between groups. Perioperative haemoglobin concentration changes (−1.77 ± 1.19 g/dl vs. −1.74 ± 1.37 g/dl) and LOS (8 ± 5.27 days vs. 7.35 ± 3.43 days) were not statistically different. Conclusions: In this cohort, the ORT and DAP were almost halved in the patient group treated with FNS. This may confer a reduction in secondary risks related to surgery.

Association between General Anesthesia and the Occurrence of Cerebrovascular Accidents in Hip Fracture Patients

Background

General anesthesia is an important factor leading to postoperative complications, and cerebrovascular accidents take the first place in the causes of postoperative death. Therefore, it is extremely important to explore the correlation between general anesthesia and the occurrence of cerebrovascular accidents in hip fracture patients.

Objective

To explore the association between general anesthesia and the occurrence of cerebrovascular accidents in hip fracture patients.

Methods

The data of 240 hip fracture patients treated in our hospital from February 2017 to February 2021 were retrospectively analyzed, and the patients were divided into the general anesthesia group (n = 120) and nongeneral anesthesia group (n = 120) according to whether or not they received general anesthesia, so as to compare their incidence rate of cerebrovascular accidents between the two groups, record their hemodynamic changes, and analyze the association between various risk factors under general anesthesia and the occurrence of cerebrovascular accidents.

Results

No statistical differences in patients' general information such as age and gender between the two groups were observed (P > 0.05); compared with the nongeneral anesthesia group, the incidence rate of cerebrovascular accidents was significantly higher in the general anesthesia group (P < 0.001); between the two groups, the heart rates and mean arterial pressure (MAP) at 15 min after anesthesia, at the time of skin incision, and 15 min before the end of surgery were significantly different (P < 0.05); according to the multiple logistic regression analysis, general anesthesia was a risk factor affecting the occurrence of cerebrovascular accidents in hip fracture patients, and under general anesthesia, age ≥80 years, BMI ≥23 kg/m², types of anesthetic drugs ≥4, intraoperative blood pressure ≥140 mmHg, and intraoperative heart rate ≥80 bpm were also regarded as the risk factors.

Conclusion

General anesthesia is a risk factor affecting the occurrence of cerebrovascular accidents in hip fracture patients, and under general anesthesia, age ≥80 years, BMI ≥23 kg/m², types of anesthetic drugs ≥4, intraoperative blood pressure ≥140 mmHg, and intraoperative heart rate ≥80 bpm will further increase the possibility of cerebrovascular accidents.