Osteosynthesis of non-displaced femoral neck fractures in the elderly population using the femoral neck system (FNS): short-term clinical and radiological outcomes

Two-year outcomes of internal fixation with femoral neck system in patients with femoral neck fracture in an Asian population

Background

Femoral neck fractures (FNF) are one of the most common fractures, with a projected increase in incidence with population growth and ageing. The Femoral Neck System (FNS) launched in 2019 was developed specifically for fixation of FNF with the purported advantages of providing both angular and rotational stability. We report our experience with the FNS and evaluate its effectiveness and associated complications.

Methods

A retrospective case series of 50 patients who underwent surgical fixation for FNF from August 2020 to October 2021 using the FNS in two Singapore tertiary institutions with at least 2 years follow-up were included. Clinical data (patients' demographics, fracture classification, intra-operative and post-operative complications) were reviewed. Radiological analysis assessed the pre- and immediate post-operative garden alignment index (GAI) and presence of femoral neck shortening at 3 months.

Results

The mean age was 63.5 years (SD 16.9, range 26-92). Five (10 %), 34 (68 %) and 11 (22 %) were ASA 1, 2 and 3 respectively. Twenty-four (48 %), 16 (32 %), 4 (8 %), and 6 (12 %) patients sustained Garden's 1, 2, 3 and 4 FNF respectively. The mean operative duration was 66.2 min (SD 20.5) and length of stay was 6.9 days (SD 4.6).The post-operative improvement in garden alignment index (GAI) was a mean of 9.1° (p < 0.001) on lateral view. The mean femoral neck shortening was 1.97 mm (SD 5.3) at 3 months. There were no intra-operative complications. Post-operatively, 1 (2 %) patient required blood transfusion, 1 (2 %) patient had implant cut-out and non-union managed non-operatively, 2 (4 %) patients developed avascular necrosis and required revision to total hip replacements. There were two (4 %) cases of 1-year mortality.

Conclusion

The FNS achieved good outcomes with low rates of complications. The promising results justify its continued use and further evaluation in comparison to other devices.

Comparison of femoral neck system versus cannulated cancellous screws for the fixation of femoral neck fracture: a single-center retrospective cohort study

INTRODUCTION

The dynamic hip screw (DHS) and cannulated compression screws (CCS) have been the two implants most frequently employed for the fixation of femoral neck fractures. The objective of this study is to compare clinical and radiographic outcomes between patients treated with the FNS and those treated with CCS.

MATERIAL AND METHODS

We conducted a retrospective analysis of a consecutive series of femoral neck fractures treated with FNS or CCS between May 2019 and June 2022. The study included 144 patients who met the inclusion criteria. Collected data encompassed age, sex, Garden fracture classification, Pauwels classification, duration of surgery, length of hospital stays, Harris Hip Score (HHS), complications, and injured side.

RESULTS

The FNS group comprised 70 patients, while the CCS group consisted of 74 patients. The operation time was 43.6 ± 12.09 min for the FNS group and 56.47 ± 22.42 min for the CCS group. At the end of the follow-up, the mean HHS was 87.07 ± 11.77 for the FNS group and 76.20 ± 13.64 for the CCS group. The mean reduction in hemoglobin levels from pre- to post-surgery was 1.05 mg/dl in the FNS group and 0.87 mg/dl in the CCS group. The reintervention rate was 8.1% for the CCS group and 2.85% for the FNS group.

CONCLUSION

The FNS does not demonstrate superiority over CCS regarding femoral neck shortening, complication rate, and reduction in hemoglobin levels. However, FNS does appear superior to CCS in terms HHS, operation time, and reoperation rate.

Low reoperation rate after fixation of displaced femoral neck fractures with the femoral neck system (FNS)

PURPOSE

Operative fixation of femoral neck fractures (FNFs) remains challenging. Complications are not infrequent, especially in displaced patterns. Numerous fixation techniques have been previously described in the literature; however, there remains a paucity of data regarding outcomes of these injuries treated with the femoral neck system (FNS).

METHODS

Patients with a displaced FNF (OTA/AO 31B) treated with the FNS at a single level 1 academic trauma center between 1/1/2019 and 1/1/2023 were identified. Radiographs were reviewed to assess fracture displacement, location, and characteristics. Patient records were further reviewed to assess for complications, reoperations, and osseous union.

RESULTS

Forty-three patients (65% male) with 44 FNFs were identified with a mean age of 35.0 years (range, 13-61 years). Two patients developed a deep infection requiring surgical debridement, four patients underwent a total hip arthroplasty, and one patient underwent a valgus intertrochanteric osteotomy for nonunion. There were three cases of femoral head AVN. Mean follow-up was 482.5 days among all patients, and 36 fractures had at least 6 months of follow-up or reached bony union.

CONCLUSIONS

Here, we present a series of patients treated with the FNS for internal fixation and report a 18% reoperation rate. This is lower than the average rate that has been previously reported in similar patient populations in the literature treated with alternative methods of internal fixation. Thus, the FNS appears to be a safe and effective option for treatment of these injuries.

Comparison of femoral neck shortening after femoral neck system and cannulated cancellous screw fixation for displaced femoral neck fractures in young adults

BACKGROUND

The purpose of this study was to compare the outcomes of femoral neck shortening between the femoral neck system (FNS) and the cannulated cancellous screws (CCS) for displaced femoral neck fractures in young adults PATIENTS AND METHODS: In this retrospective analysis, 225 patients aged 18-65 years with displaced femoral neck fracture were divided into two groups according to internal fixation: 135 patients in the FNS group and 90 patients in the CCS group. The length of hospital stay, duration of surgery, intraoperative blood loss, quality of reduction, extent of femoral neck shortening, incidence of femoral neck shortening, femoral neck shortening at each follow-up visit, Harris hip score (HHS), reoperation, and complications were compared between the two groups.

RESULTS

The median follow-up time was 28.2 (26.0, 31.2) months in the FNS group and 30.2 (26.3, 34.7) months in the CCS group. The follow-up time, age, sex distribution, body mass index (BMI), mechanism of injury, injured side, length of hospital stay, time from injury to surgery, and fracture classification were similar between the groups. Duration of surgery was longer in the FNS group (65.0 (55.0, 87.0) min versus 55.0 (50.0, 65.0) min, P<0.001); intraoperative blood loss was greater in the FNS group (50.0 (20.0, 60.0) ml versus 20.0 (10.0, 35.0) ml, P<0.001). Femoral neck shortening was 2.4 (1.0, 4.5) mm in the FNS group versus 0.6 (0.0, 2.6) mm in the CCS group at 1 month postoperatively (P<0.001); 3.7 (1.8, 6.4) mm in the FNS group versus 1.2 (0.6, 3.8) mm in the CCS group at 3 months (P<0.001); 4.1(2.4, 7.7) mm in the FNS group versus 2.3 (1.1, 4.4) mm in the CCS group at 6 months (P<0.001); 4.2 (2.6, 7.7) mm in the FNS group versus 2.6 (1.3, 4.6) mm in the CCS group at 12 months (P<0.001); and 4.5 (2.8, 8.0) mm in the FNS group versus 2.8 (1.5, 4.8) mm in the CCS group at 18 months (P<0.001). The two groups showed no significant differences in HHS, reoperation, and reduction quality.

CONCLUSION

Compared to CCS, FNS is deficient in preventing femoral neck shortening. Future research should focus on improving FNS in terms of preventing femoral neck shortening.

Pre-sliding of the femoral neck system to prevent postoperative shortening of femoral neck fractures

Objective

The purpose of this study is to evaluate the effect of pre-sliding of the femoral neck system (FNS) in the prevention of postoperative femoral neck shortening in femoral neck fractures.

Method

This study was designed to retrospectively analyze data from 109 patients with femoral neck fractures who were admitted to a Level I trauma center between April 2020 and June 2022. Of these patients, 90 were followed up for more than 12 months. The study included 52 males and 38 females, with 35 cases of Garden I and II fractures and 55 cases of Garden III and IV fractures. The Harris Hip Score at 12 months postoperatively were recorded. The patients were divided into two groups based on their surgical records and postoperative radiography: the Pre-sliding group and the No-pre-sliding group. The purpose of this study is to analyze the role of pre-sliding in preventing femoral neck shortening, fracture healing time, degree of postoperative shortening, complications, and Harris Hip Score, and to make a comparison between the two groups.

Results

All 90 patients were followed up for over one year after surgery. A statistically significant difference was observed in the preoperative Garden classification (P < 0.05). At 1 year after the operation, the shortening distance was 6.5 ± 6.4 mm in the No-pre-sliding group and 3.9 ± 3.4 mm in the Pre-sliding group. The Harris Hip Score were 88.7 (79.8, 93.5) in the No-pre-sliding group and 94.8 (87.7, 96.9) in the Pre-sliding group, with a statistically significant difference between the two groups (P < 0.05). Shortening was concentrated at 3 months postoperatively and reached a stable state within 6 months, with less persistent shortening occurring after 6 months. There was no statistically significant difference in the preoperative baseline data.

Conclusion

Pre-sliding of the FNS prevents postoperative shortening of the femoral neck and improves hip function as measured by the Harris Hip Score.

Comparative Short-Term Outcomes of Femoral Neck System (FNS) and Cannulated Screw Fixation in Patients with Femoral Neck Fractures: A Multicenter Study

Background

Femoral neck fractures need to be treated in their early stages with accurate reduction and stable fixation to reduce complications. The authors compared the early radiologic outcomes of femoral neck fractures treated with the recently introduced Femoral Neck System (FNS, Depuy-Synthes) with conventional cannulated screws (CS) in a multicenter design. Furthermore, the factors associated with early failure after FNS were analyzed.

Methods

The FNS group included 40 patients treated between June 2019 and January 2020, and the CS group included 65 patients treated between January 2015 and May 2019. The operation was performed in 3 university hospitals. Patient demographics, fracture classification, postoperative reduction quality, sliding distance of FNS or CS, union and time to union, and complication rates were examined. Logistic regression analysis was performed on candidate factors for early failure of the FNS group.

Results

The FNS group had a 90% union rate and a mean time to union of 4.4 months, while the CS group had similar results with an 83.1% union rate and a mean time to union of 5.1 months. In the subgroup analysis of Pauwels type III fractures, the union rates were 75.0% and 58.8% in the FNS and CS groups, respectively, and the time to union was significantly shorter in the FNS group with 4.8 months compared to 6.8 months in the CS group. Early failure rate within 6 months of FNS fixation was observed to be 10%, which included 3 reduction failures and 1 excessive sliding with a broken implant. Risk factors for early failure after FNS were identified as displaced fractures (Garden classification type III or IV), poor reduction quality, longer tip-apex distance, greater sliding distance, and 1-hole implants, of which sliding distance was the only significant risk factor in multivariate analysis.

Conclusions

In femoral neck fractures, FNS and CS did not show significant differences for short-term radiologic results. FNS resulted in shorter operative time than cannulated screw fixation and favorable outcomes in Pauwels type III femoral neck fractures. The FNS could be considered a reliable and safe alternative to CS when treating femoral neck fractures.

Comparison of young femoral neck fractures treated by femoral neck system, multiple cancellous screws and dynamic hip screws: a retrospectively comparison study

BACKGROUND

Implant choice for the fixation of femoral neck fracture is one of the most important management controversies. This study aims to evaluate and compare the short-term outcomes associated with the use of the Femoral Neck System (FNS), Multiple Cancellous Screws (MCS), and Dynamic Hip Screws (DHS) in treating femoral neck fractures in a young patient population.

METHODS

From June 2018 to June 2021, a total of 120 surgeries for a primary femoral neck fracture were retrospectively analyzed. This review encompassed demographic details of the patients and the mechanisms behind the injuries. Key surgical parameters such as operation duration, intraoperative blood loss, fluoroscopy duration, and hospital stay were meticulously documented. The employed surgical technique was described. All patients were followed up at 6 weeks, 3 months, 6 months, and 12 months postoperatively. Avascular necrosis of the femoral head (AVN), nonunion, malreduction, implant failure or other complications were noted. The functional status at the last follow-up was assessed using the Harris functional scoring criteria.

RESULTS

There were 90 males and 30 females, with a mean age of 40.4 years. As to patient characteristics, there were no significant differences between the three groups. DHS group showed longer operation time(52.15 ± 4.80 min), more blood loss(59.05 ± 5.87 ml) and longer time of hospitalization(7.6 ± 0.90 d) than FNS group (39.65 ± 2.84 min, 45.33 ± 9.63 ml and 4.87 ± 0.48 d) and MCS group (39.45 ± 3.10 min, 48.15 ± 7.88 ml and 5.04 ± 0.49 d) (p < 0.05). In addition, the time of fluoroscopy in FNS group (15.45 ± 3.67) was less than that in MCS group (26.3 ± 4.76) and DHS group (27.1 ± 5.67) (p < 0.05). The cost of FNS group(44.51 ± 2.99 thousand RMB) was significantly higher than the MCS and DHS groups. The FNS, MCS and DHS groups showed a similar mean length of femoral neck shortening (LFNS) and Harris score. The FNS, MCS and DHS groups showed a similar mean rate of AVN and internal fixation failure.

CONCLUSIONS

Following successful fracture reduction, FNS, MCS, and DHS are effective for in the young femoral neck fractures. No difference was found in complications between the three groups. However, the reduced fluoroscopy time associated with FNS contributes to shorter operation durations. The adoption of minimally invasive techniques correlates with decreased blood loss and shorter hospital stays. Nevertheless, these advantages may be offset by the potential economic burden they impose.

Femoral neck system versus multiple cannulated screws for the fixation of Pauwels classification type II femoral neck fractures in older female patients with low bone mass

BACKGROUND

Femoral neck fractures in older adult patients are a major concern and often necessitate surgical intervention. This study compared the clinical outcomes of 2 surgical techniques: the femoral neck system (FNS) and cannulated compression screws (CCSs).

METHODS

A total of 40 female patients (mean age 73.50 ± 11.55 years) with femoral neck fractures of Pauwels classification type II and receiving surgical fixation between 2020 and 2022 were enrolled. The patients were categorized into an FNS group (n = 12) or a CCS group (n = 28), and surgical duration, intraoperative blood loss, length of hospital stay, and incidence of postoperative adverse events were analyzed.

RESULTS

No significant intergroup differences in demographic characteristics were discovered. The mean surgical duration for all patients was 52.88 ± 22.19 min, with no significant difference between the groups. However, the FNS group experienced significantly higher intraoperative blood loss (P = 0.002) and longer hospital stay (P = 0.023) than did the CCS group. The incidence of osteonecrosis was higher in the CCS group, whereas the incidence of nonunion or malunion was higher in the FNS group. The surgical method did not appear to be a significant risk factor. The main risk factor for revision surgery was longer duration until the first adverse event (P = 0.015).

CONCLUSION

The FNS does not appear to provide superior surgical outcomes compared with CCSs in older adult women with Pauwels classification type II femoral neck fractures. A longer duration between surgical fixation and the first adverse event before stabilization of the fracture site may be a risk factor for revision surgery.

Application of robot navigation system for insertion of femoral neck system in the treatment of femoral neck fracture

PURPOSE

To evaluate the short-term clinical efficacy and advantages of surgery robot positioning system for insertion of Femoral Neck System (FNS) in the treatment of femoral neck fractures.

METHODS

The clinical data of 52 patients with Femoral neck fracture (FNF) who had been treated with FNS between June 2020 and September 2021 were retrospectively analyzed. Among them, 26 patients were treated with traditional FNS (control group), while 26 additional patients were treated with FNS assisted by an orthopaedic robot positioning system (study group). The operation duration, frequency of key-guide needle placement, intraoperative blood loss, incision length, fracture healing rate, fracture healing time, and the Harris scores at the last follow-up were calculated and compared between the 2 groups.

RESULTS

The study group had shorter operation duration, fewer numbers of placing the key-guide needle, less intraoperative blood loss, and smaller surgical incisions than the control group (all, P < 0.05). There was no significant difference in the rate of fracture healing rate between the 2 groups (P = 0.47), while the fracture healing duration of the study group was shorter than that of the control group (P = 0.03). At the last follow-up, compared with the control group, the Harris score and the number of excellent and good ratings were significantly higher in the study group (all, P < 0.05).

CONCLUSIONS

Using orthopaedic surgery robot positioning system-assisted FNS in the treatment of FNFs can effectively improve the efficiency of surgery, shorten operation time, and reduce the number of placing the key-guide needle, intraoperative blood loss, and operative trauma. Simultaneously, it shortens the duration of fracture healing and improves the recovery of hip function.

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 .

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.

Choose the appropriate implantation position of the Femoral Neck System in the femoral neck: a finite-element analysis

PURPOSE

There is no specific literature on the best implantation position of the Femoral Neck System (FNS) for treating Pauwels type III femoral neck fracture in young adults.

METHODS

Use finite-element analysis to compare the mechanical properties of implantation positions: FNS in the central position, FNS in the low position, and FNS in the low position combined with cannulated screw (CS). The CT data of the femur were imported into the mimics20.0 to obtain the three-dimensional model of the femur; imported into geomagic2017 and SolidWorks 2017 for optimizations; models of FNS and CS are built on the basis of the device manuals. Grouping is as follows: FNS group, FNS-LOW group, and FNS-CS group. Assemble and import them into abaques6.14 for load application. The displacement distribution and von Mises Stress value of them were compared.

RESULTS

On femoral stability and stress distribution, the FNS-CS group performs best, followed by the FNS-LOW group, and finally FNS group. The FNS-LOW group has an improvement over the FNS group but not by much.

CONCLUSION

In operations, when the implantation position of the central guide wire is not at the center of the femoral neck but slightly lower, it is recommended not to adjust the wire repeatedly in pursuit of the center position; for femoral neck fractures that are extremely unstable at the fracture end or require revision, the insertion strategy of FNS in the low position combined with CS can be adopted to obtain better fixation effects.

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.

Predictors of Mortality in Head-Preserving Treatment for Dislocated Proximal Humerus Fractures: A Retrospective Analysis of 522 Cases with a Minimum Follow-Up of 5 Years

PURPOSE

Proximal humerus fractures (PHFs) are among the most common fractures in elderly patients, but there is still inadequate knowledge about mortality risk factors after such injuries. In order to provide the best possible therapy, individual risk factors have to be considered and evaluated thoroughly. There is still controversy regarding treatment decisions for proximal humerus fractures, particularly for the elderly.

METHODS

In this study, patient data from 522 patients with proximal humerus fractures were obtained from 2004 to 2014 at a Level 1 trauma centre. After a minimum follow-up of 5 years, the mortality rate was assessed, and independent risk factors were evaluated.

RESULTS

A total of 383 patients (out of 522) were included in this study. For our patient collective, the mean follow-up was at 10.5 ± 3.2 years. The overall mortality rate was 43.8% in our respondent group and was not significantly impacted by concomitant injuries. The binary logistic regression model showed an increased risk for mortality by 10% per life year, a 3.9 times higher mortality risk for men and a 3.4 times higher risk for conservative treatment. The most powerful predictor was a Charlson Comorbidity Index of more than 2, with a 20 times higher mortality risk.

CONCLUSIONS

Outstanding independent predictors of death in our patient collective were serious comorbidities, male patients, and conservative treatment. This patient-related information should influence the process of decision making for the individual treatment of patients with PHFs.

Comparison of femoral neck system versus cannulated screws for treatment of femoral neck fractures: a systematic review and meta-analysis

BACKGROUND

Recently, some studies on the efficacy of the femoral neck system (FNS) in treating femoral neck fractures (FNFs) have been published. Therefore, a systematic review was performed to clarify the efficacy and safety of FNS versus cannulated screws (CS) for the treatment of FNFs.

METHOD

The PubMed, EMBASE, and Cochrane databases were systematically searched for studies comparing FNS and CS fixations in FNFs. Intraoperative indicators, postoperative clinical indicators, postoperative complications, and postoperative scores were compared between the implants.

RESULTS

A total of eight studies were included in the study, involving 448 FNFs patients. The results showed that patients in FNS group were significantly lower than the CS group in the number of X-ray exposures (WMD = -10.16; 95% CI, -11.44 to -8.88; P < 0.001; I² = 0%), fracture healing time (WMD = -1.54; 95% CI, -2.38 to -0.70; P < 0.001; I² = 92%), length of femoral neck shortening (WMD = -2.01; 95% CI, -3.11 to -0.91; P < 0.001; I² = 0%), femoral head necrosis (OR = 0.27; 95% CI, 0.08 to 0.83; P = 0.02; I² = 0%), implant failure/cutout (OR = 0.28; 95% CI, 0.10 to 0.82; P = 0.02; I² = 0%), and Visual Analog Scale Score (WMD = -1.27; 95% CI, -2.51 to -0.04; P = 0.04; I² = 91%). And the Harris Score was significantly higher in the FNS group than in the CS group (WMD = 4.15; 95% CI, 1.00 to 7.30; P = 0.01; I² = 89%).

CONCLUSIONS

Based on this meta-analysis, FNS shows better clinical efficacy and safety in treating FNFs compared to CS. However, due to the limited quality and number of included studies and the high heterogeneity of the meta-analysis; large samples and multicenter RCTs are needed to confirm this conclusion in the future.

LEVEL OF EVIDENCE

II, Systematic review and Meta-analysis.

TRIAL REGISTRATION

PROSPERO CRD42021283646.

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.

Mechanical effects of sagittal variations on Pauwels type III femoral neck fractures treated with Femoral Neck System(FNS)

BACKGROUND

The spatial position of internal fixation play a role in determining the stability of internal fixations, both in clinical practice and research. Researchers have examined the stability of FNS (Femoral neck system) in the presence of coronal plane changes. In our knowledge, due to the biomechanical limitations of the specimens, there are no mechanical studies on the sagittal variation of FNS. This study aimed to investigate the biomechanical behavior of sagittal variations on Pauwels type III femoral neck fractures treated with FNS through finite element analysis.

METHODS

Finite element models including Pauwels type III femoral neck fracture and FNS were reconstructed. Five fracture models(superior, central, inferior, anterior, posterior) were created in accordance with the bolt location in the sagittal plane within the femoral head. Equivalent stress, shear stress, and total deformation of each model under the same physiological load were recorded.

RESULTS

According to the results, the central model exhibited the slightest stress and displacement, with the exception of the superior model. The internal fixation stress of the superior model was smaller than that of the central model. However, the maximum interfragmentary stress, total deformation and shear resistance area of the superior model was larger than that of the central model.

CONCLUSIONS

Central position of FNS in the sagittal plane allowed axial compression while reducing shear stress of internal fixation and interfragmentary equivalent stress. Off-axis fixation of the femoral neck increased the strain area and total displacement of the bone, raising the risk of fixation failure. Therefore, the central placement of FNS may be a better surgical target in the treatment of femoral neck fractures.

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.

Biomechanical and clinical evaluation of interlocking hip screw in Pauwels Ⅲ femoral neck fractures: A comparison with inverted triangle cannulated screws

Purpose: To compare biomechanical and clinical properties of the novel internal fixation Interlocking Hip Screw (IHS) and conventional inverted triangle cannulated screws (ITCS) for treatment of Pauwels Ⅲ femoral neck fractures. Methods: Twenty synthetic femurs were osteotomized to simulate 70° Pauwels Ⅲ femoral neck fractures and randomly divided into two groups: Group IHS and Group ITCS. Specimens were loaded in quasi-static ramped and cyclical compression testing in 25° adduction to analyze for axial stiffness, failure load, and interfragmentary displacement. 21 matched patients with Pauwels Ⅲ femoral neck fracture who received closed reduction and internal fixation from January 2020 to January 2021 in both Group IHS and Group ITCS. Demographic data, time to surgery, operating duration, intraoperative blood loss, number of fluoroscopies, length of hospital stay, fracture healing time, Harris Hip Score (HHS), the score of Visual Analogue Scale (VAS) and complications such as nonunion, avascular necrosis, and femoral neck shortening were compared. Results: All specimens in the two groups survived in the axial and cyclical compression test. The axial stiffness was significantly higher for Group IHS (277.80 ± 26.58 N/mm) versus Group ITCS (205.33 ± 10.46 N/mm), p < 0.05. The maximum failure loading in Group IHS performed significantly higher than in Group ITCS (1,400.48 ± 71.60 N versus 996.76 ± 49.73 N, p < 0.05). The interfragmentary displacement of the cyclic loading test for Groups IHS and Group ITCS was 1.15 ± 0.11 mm and 1.89 ± 0.14 mm, respectively, p < 0.05. No significant difference was found in terms of demographic data, time to surgery, intraoperative blood loss, length of hospital stay and the occurrence of nonunion and avascular necrosis between groups. Shorter operating duration and fewer intraoperative fluoroscopic views were noticed using IHS compare to ITCS, p < 0.05. The HHS was 72.14 ± 5.76 and 86.62 ± 5.01 in Group IHS, and was 67.29 ± 5.27 and 81.76 ± 5.13 in Group ITCS at 3-month and 6-month follow-up, respectively, p < 0.05. The magnitude of femoral neck shortening was significantly lower in Group IHS compared to Group ITCS (4.80 ± 1.03 mm versus 5.56 ± 1.21 mm, p < 0.05). Conclusion: Our study demonstrated that IHS provided better biomechanical and clinical performance due to its unique biological and biomechanical mechanisms, compared with ITCS. Thus, IHS is a feasible alternative to ITCS for the fixation of Pauwels Ⅲ femoral neck fractures.

Comparison Between Femoral Neck Systems and Cannulated Cancellous Screws in Treating Femoral Neck Fractures: A Meta-Analysis

Background

We performed a meta-analysis to compare the efficacy and safety of the femoral neck system (FNS) with cannulated cancellous screws (CCSs) in treating femoral neck fractures (FNFs) in controlled clinical trials.

Methods

Eligible scientific articles published prior to September 2021 were retrieved from the PubMed, Web of Science, Springer, ScienceDirect and Cochrane Library databases. The statistical analysis was performed with RevMan 5.1.

Results

Seven retrospective studies met the inclusion criteria. Meta-analysis showed that there were significant differences in perioperative blood loss, the postoperative Harris score, healing time, fluoroscopy frequency, total complications, femoral head necrosis, femoral neck shortening and screw cutout. No significant differences were found regarding operation time, length of hospital stay or nonunion between the two groups.

Conclusion

Compared with CCSs, the FNS showed better clinical efficacy and fewer complications in treating FNFs. Due to the limited quality and data of the currently available evidence, more high-quality randomized controlled trials are needed.

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.