Clinical performance of the Femoral Neck System within 1 year in 125 patients with acute femoral neck fractures, a prospective observational case series

Comparable results for the Femoral Neck System and three-screw fixation in femoral neck fracture treatment

Objectives

To report outcomes of femoral neck fractures (FNFs) treated with Femoral Neck System (FNS) and to compare the risks of later conversion to arthroplasty for FNS and fixation with cannulated screws (CNSs).

Design

A retrospective study.

Setting

A single-center study (Turku University Hospital, Finland).

Patients

Data on 51 patients with FNFs treated with FNS between January 1, 2019, and May 31, 2021, were retrospectively reviewed. In addition, data on 301 patients treated with cannulated screws were collected and analyzed in a previous study.

Intervention

Patients with FNFs underwent osteosynthesis with FNS.

Main Outcome Measurements

Patients' preoperative and postoperative radiographs were analyzed and measured to determine preoperative displacement, preoperative posterior tilt, and quality of reduction. Later conversion to arthroplasty and other reoperations were recorded. The risk of later conversion to arthroplasty was compared between the FNS group and CNS group.

Results

The overall reoperation rate in the FNS group was 20%, and 16% of the patients treated with FNS underwent later conversion to arthroplasty. In the multivariate analysis, age, sex, and fracture displacement were not associated with increased risk of later conversion to arthroplasty. In comparison with fixation with cannulated screws, there was no statistically significant difference in the probability of later conversion to arthroplasty between the groups.

Conclusion

FNS seems to have a comparable reoperation rate and conversion-to-arthroplasty rate compared with the gold standard treatment.

Level of Evidence

III.

TiRobot-assisted versus freehand femoral neck system placement in the treatment of femoral neck fractures: a systematic review and meta-analysis

The purpose of this study is to assess the safety and effectiveness of TiRobot-assisted treatment for femoral neck fractures, in comparison to traditional freehand treatment methods. Throughout the research process, we conducted an extensive literature search across numerous databases, including PubMed, EMBASE, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), CQVIP, and Wanfang. Based on the literature screening criteria, we selected six studies, encompassing 358 cases of femoral neck fracture patients, for this meta-analysis. The study evaluated the effectiveness of TiRobot-assisted versus freehand placement of the Femoral Neck System (FNS). The results indicate that the TiRobot-assisted group demonstrated significant advantages in several surgical parameters. Specifically, the robot-assisted group showed superior outcomes regarding the frequency of guide pin insertion, frequency of X-ray fluoroscopy, operative time, invasive fixation time, intraoperative blood loss and incision length (MD < 0, p < 0.05). Furthermore, there was a significant difference in the Harris score, between the TiRobot-assisted group and the traditional freehand group (MD > 0, p < 0.05). However, the two groups had no significant differences concerning postoperative complications, fracture healing time, and fracture healing rate (p > 0.05). In conclusion, the comprehensive analysis suggests that the TiRobot-assisted technique has distinct advantages over the traditional freehand technique in treating femoral neck fractures. TiRobot-assisted technology, owing to its enhanced safety and efficacy, minimizes surgical trauma and expedites postoperative recovery.

Difference of Neck Shortening in Femoral Neck Fracture between Femoral Neck System and Multiple Cannulated Cancellous Screws: Single Center, Prospective Randomized Controlled Trial

Purpose

Fracture union after osteosynthesis of a fracture neck femur (FNF) occurs by compression of the fracture ends and potential neck shortening. Selection of an implant for fixation of a femoral fracture of the neck can be challenging when making management decisions. Femoral neck shortening after internal fixation of FNFs using a femoral neck system (FNS) or multiple cannulated cancellous screws (MCS) was compared.

Materials and Methods

This prospective interventional single-blinded randomized controlled trial was conducted at a university teaching hospital. Sixty patients undergoing internal fixation for management of sub-capital or trans-cervical FNFs were randomized and assigned, to one of the two groups-the test group (FNS group) and the control group (MCS group). Primary outcome was determined by measuring the difference in 1-year shortening of the femoral neck on radiographs between FNS and MCS. The secondary objective was to determine the correlation between neck shortening with patient reported outcome measures (PROMs) at the end of the final follow-up.

Results

At the final follow-up, shortening of the femoral neck was 3.77±1.87 mm in the FNS group, significantly lower compared with the MCS group, 6.53±1.59 mm.

Conclusion

Significantly less shortening of the femoral neck was observed in the FNS group compared with the MCS group. No statistically significant difference in PROMs was observed at 1-year follow-up. The findings of the study suggest that FNS can be regarded as a suitable alternative for internal fixation in young adults (<60 years) with trans-cervical and subcapital FNFs.

Outcomes of internal fixation with Femoral Neck System (FNS) for intracapsular femoral neck fractures

Background

Internal fixation of hip fractures is associated with high reoperation rates. This study investigated the reoperation rates after internal fixation with the femoral neck system (FNS).

Materials and Methods

A single-institution cohort study was conducted on patients aged 18 years or older who sustained intracapsular femoral neck fractures and underwent internal fixation with a fixed-angle implant. Surgeons, patients, and investigators were not blinded. The primary outcome was any hip reoperation at the final follow-up. Secondary outcomes were to characterize a cohort of patients regarding demographics, fracture classification, intraoperative findings, postoperative fracture complications and union rates, and postoperative pain.

Results

This study found that internal fixation with FNS for intracapsular femoral neck fractures was associated with a 23% rate of revision surgery. Of the initial 94 patients who received FNS internal fixation, 44 patients were included for analysis; of those, 10 patients underwent revision surgery. Patients had a 22% rate of in-hospital medical adverse events with a 30-day readmission rate of 9%. Increasing body mass index was associated with increased revision rates (P = 0.037). Patients who sustained displaced femoral neck fractures had a significant decrease in SF-12 Mental Health Composite, SF-12 Physical Health Composite, and quality-of-life subscale scores.

Conclusions

The FNS is a viable alternative for internal fixation of intracapsular femoral neck fractures. The observed rate of revision after internal fixation was comparable with previously published outcomes following fixation with cannulated screws and sliding hip screws.

Level of Evidence

Level IV, Therapeutic Study.

Fixation of adult femoral neck fractures: Retrospective comparison between cannulated screws and femoral neck system (FNS)

OBJECTIVE

The FNS System DePuy Synthes® (EEUU, 2018) represents a recent alternative treatment for the fixation of femoral neck fractures, providing biomechanical advantages with respect to cannulated screws (3 CS). The objective of this study is to compare the clinical results of both fixation methods.

METHOD

A retrospective collection of the 36 subcapital fractures treated with the FNS system was carried out compared with a retrospective search of the last 35 patients treated with 3 CS. Age, sex, fracture pattern, delay until the intervention, length of intervention, hospital length stay, and haemoglobin loss were analyzed. In addition, the rate of avascular necrosis, nonunion, symptomatic femoral neck shortening, and material protrusion with or without its removal were recorded during a minimum follow-up of 6 months.

RESULTS

No significant differences were found in age (p-value 0.32), fracture patterns (p-value 0.77), surgical delay (p-value 0.28), surgical time (p-value 0.226), length of hospital stay (p-value 0.921) and blood loss (p-value 0.086) between the two groups. A significantly higher overall complication rate was observed in the group treated with cannulated screws (p-value 0.004). Analysed separately, a higher rate of avascular necrosis, symptomatic shortening of the femoral neck, protrusion of the osteosynthesis material with or without removal was observed in the group treated with cannulated screws.

CONCLUSIONS

The FNS system represents a safe and reproductible alternative for the fixation of femoral neck fractures, showing non-inferior outcomes to treatment with cannulated screws.

Anti-Shortening Screw for the Prevention of Postoperative Shortening in Displaced Femoral Neck Fractures: A Retrospective Cohort Study

BACKGROUND

Early femoral neck shortening after femoral neck system (FNS) fixation for displaced femoral neck fractures can occur in 22.3%-39.1% of cases, leading to decreased hip joint function. This study aimed to investigate the effectiveness of using an anti-shortening screw (ASS) in FNS fixation to prevent postoperative femoral neck shortening in displaced femoral neck fractures.

METHODS

We retrospectively analyzed 106 cases of displaced femoral neck fractures treated with FNS at the Hospital from April 2020 to April 2023. Patients were divided into two groups based on the use of an ASS: the traditional group and the ASS group, each consisting of 53 cases. The ASS group was age-matched with the traditional group treated during the same period without an ASS. The study variables included age, sex, body mass index (BMI), smoking and drinking history, injury mechanism, side of injury, fracture type, surgical time, intraoperative blood loss, Harris Hip Score (HHS) at the final follow-up, radiographic assessment (femoral neck shortening), and complications (infection, femoral head necrosis, nonunion, and secondary surgery). Statistical analysis was performed using SPSS software, with continuous and categorical variables analyzed using appropriate parametric (t-test) and nonparametric (Mann-Whitney U test) tests, and chi-square or Fisher's exact tests, respectively. A p-value <0.05 was considered significant.

RESULTS

There were no significant differences in background characteristics between the traditional and ASS groups. The shortening distance at postoperative day 1 did not differ significantly between the two groups (0 vs. 0 mm, p = 0.120). However, at 1, 3 months, and 1 year postoperatively, the femoral neck shortening in the ASS group was significantly less than that in the traditional group (1 month: 2.3 vs. 3.1 mm, p = 0.007; 3 months: 2.6 vs. 3.5 mm, p = 0.005; 1 year: 2.6 vs. 3.5 mm, p = 0.002). The ASS group also had a significantly lower shortening distance during the fracture healing process (0.9 vs. 2.7 mm, p = 0.005). The incidence of moderate to severe shortening (≥5 mm) at 1 year postoperatively was lower in the ASS group compared with the traditional group (15.1% vs. 37.7%, p = 0.001). The ASS group had a longer surgical time (63.0 ± 13.4 vs. 73.0 ± 23.2 min, p = 0.008) and a higher HHS (90.7 vs. 94.8, p = 0.008). There was no significant difference in fracture healing time or postoperative complications between the two groups. The traditional group had 3.8% cutouts, 7.5% nonunions, 5.7% avascular necrosis, and 7.5% secondary hip replacements. The ASS group saw 0% cutouts, 1.9% nonunions, 3.8% avascular necrosis, and 3.8% hip replacements. No significant differences in complication rates (p > 0.05).

CONCLUSION

The use of an ASS in FNS fixation for displaced femoral neck fractures can reduce the degree of postoperative shortening and improve hip joint function.

Pre-sliding technique to improve femoral neck system against the shortening: a retrospective cohort study

OBJECTIVE

To investigate the efficacy of using pre-sliding technique to prevent postoperative shortening of displaced femoral neck fracture fixed with femoral neck system (FNS).

METHODS

Retrospective analysis of 110 cases of displaced femoral neck fracture treated with femoral neck system from September 2019 to November 2022 in our center, which were divided into 56 cases in the pre-sliding group and 54 cases in the traditional group. The baseline data such as gender, age, side, mechanism of injury, fracture type, operation time, intraoperative bleeding were recorded and compared between the two groups, and the quality of fracture reduction, shortening distance, Tip Apex Distance (TAD), union time, Harris score of the hip were also compared between the two groups.

RESULTS

The TAD value of the pre-sliding group was smaller than that of the traditional group, and the difference was statistically significant (P < 0.001). The shortening distance in both groups on postoperative day 1 was smaller in the pre-sliding group than in the traditional group, but the difference was not statistically significant (P = 0.07), and the shortening distance was smaller than in the traditional group at 1, 3, 6, and 12 months postoperatively, and the difference was statistically significant (all P < 0.001). Of the 110 cases, 34 (30.9%) had moderate or severe shortening, of which 24 (44.4%) were in the traditional group and 10 (17.9%) in the pre-sliding group, and the difference was statistically significant (P < 0.001), and the Harris score at 1 year, which was higher in the pre-sliding group than in the traditional group, and the difference between the two groups was statistically significant (P < 0.001). There was no statistically significant difference in the comparison of baseline data such as gender, age, side, mechanism of injury, fracture type, operation time, intraoperative bleeding, and quality of reduction between the two groups (all P > 0.05), and no statistically significant difference in fracture healing time between the two groups (P = 0.113).

CONCLUSION

The use of the pre-sliding technique of displaced femoral neck fracture fixed with FNS reduces the incidence of moderate and severe shortening, improves the postoperative TAD value, and improves the hip function scores, with a satisfactory midterm efficacy.

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.

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.

Characteristics and Treatment Strategies for Basicervical and Transcervical Shear Fractures of the Femoral Neck

This study aimed to define basicervical and transcervical shear fractures using area classification and to determine the optimal osteosynthesis implants for them. The clinical outcomes of 1042 proximal femur fractures were investigated. A model of the proximal femur of a healthy adult was created from computed tomography images, and basicervical and transcervical shear fractures were established in the model. Osteosynthesis models were created using a short femoral nail with a single lag screw or two lag screws and a long femoral nail with a single lag screw or two lag screws. The minimum principal strains of the fracture surfaces were compared when the maximum loads during walking were applied to these models using finite element analysis software. Basicervical fractures accounted for 0.96% of all proximal femur fractures, 67% of which were treated with osteosynthesis; the failure rate was 0%. Transcervical shear fractures accounted for 9.6% of all proximal femur fractures, 24% of which were treated with osteosynthesis; the failure rate was 13%. Finite element analysis showed that transcervical shear fracture has high instability. To perform osteosynthesis, multiple screw insertions into the femoral head and careful postoperative management are required; joint replacement should be considered to achieve early mobility.

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.