Femoral Neck Fractures in Adults Treated With Internal Fixation: A Prospective Multicenter Chinese Cohort

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.

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.

Biomechanical investigation of positive reduction in the femoral neck fracture: a finite element analysis

Background

Gotfried positive reduction offers an alternative strategy for femoral neck fracture (FNF) when achieving anatomical reduction is challenging. However, the biomechanical consequences of positive reduction remain unclear. The purpose of this study was to investigate the biomechanical behavior of positive reduction across different Pauwels classification, providing a reference for quantifying positive reduction in clinical practice.

Methods

Three-dimensional (3D) models of FNF were established and categorized according to the Pauwels classifications (Pauwels I, II, and III), each of them contained seven models with different reduction qualities, including an anatomical reduction model, two negative reduction models, and four positive reduction models, all of which were stabilized with dynamic hip screws (DHS) and cannulated screws (CS). We investigated the maximal von-Mises stress of internal fixation and proximal femoral, femoral fragment displacement, and maximal von-Mises strain at the proximal fragment fracture site when a 2100 N load was applied to the femoral head.

Results

The maximum von-Mises stress on the internal fixators in each Pauwels group was lowest in the anatomical reduction model. In the Pauwels I group, positive reduction exceeding 3 mm resulted in the maximum von-Mises stress on the internal fixators surpassing that of the negative reduction model. For the Pauwels II group, positive reduction beyond 2 mm led to the maximum von-Mises stress on the internal fixators exceeding that of the negative reduction model. In the Pauwels III group, positive reduction beyond 1 mm caused the maximum von-Mises stress on the internal fixators to be higher than that of the negative reduction model. The maximum von-Mises strain at the fracture site of proximal femur fragment increased with positive reduction. Varus displacement increased in positive reduction models as the Pauwels angle rose, potentially exacerbating rotation deformity in Pauwels III group.

Conclusion

Excessive positive reduction may increase the risk of FNF failure after internal fixation. From a biomechanical stability perspective, positive reduction should be limited to 3 mm or below in the Pauwels I group, restricted to not exceed 2 mm in the Pauwels II group, and should not exceed 1 mm in the Pauwels III group. Negative reduction should be avoided in all Pauwels groups.

Association between surgical delays for femoral neck fractures and early postoperative complications in young and middle-aged adults: A study based on the national inpatient sample database

BACKGROUND

Femoral neck fractures (FNF) in young and middle-aged adults are primarily caused by high-energy injuries in traffic accidents. Surgical delays often occur due to transportation issues, preoperative evaluations, and economic burdens.

METHODS

A retrospective analysis was conducted on young and middle-aged FNF patients undergoing reduction and internal fixation surgeries from 2010 to 2019 with the use of the National Inpatient Sample database. Logistic regression analysis was used to assess the relationship between surgical delays and complications, and the independent risk factors contributing to delays. Categorical variables were investigated via a chi-square test, while continuous variables including Elixhauser Comorbidity Index (ECI) scores, length of hospital stay (LOS), and total medical costs were analyzed via t-test or rank-sum test.

RESULTS

9,204 patients undergoing reduction and internal fixation surgeries were included. In the delayed group, patients had higher ECI scores, longer hospital stays, higher expenses, and increased inpatient mortality (1.61% vs. 0.28 %, P < 0.0001). Longer surgical delays were associated with higher risks of complications, including femoral head osteonecrosis, internal fixation loosening and breakage, and respiratory complications. Fluid and electrolyte disorders, metastatic cancer, pulmonary circulation disorders, and renal failure were identified as independent risk factors for surgical delays. Except for anemia (OR=2.37, P < 0.0001), no significant differences in early postoperative complications were found between open-reduction and closed-reduction internal fixation (ORIF/CRIF) surgeries.

CONCLUSION

Early surgical intervention, within a 2-days period after injury, seems to be crucial for young adults with FNF. If CRIF is challenging in some cases, ORIF can be another choice.

Biomechanical Study of Three Cannulated Screws Configurations for Femur Neck Fracture: A Finite Element Analysis

Background

To improve the performance of cannulated screws (CSs) in the treatment of femoral neck fractures (FNF), a number of new screw configurations have been proposed. However, most of the studies have only analyzed the biomechanical performance of different screw configurations under static conditions. This study aimed to investigate the biomechanical performance of three cannulated screws configurations under different loadings through finite element analysis.

Methods

In this FEA study, nine numerical models of proximal femur were employed to analyze the mechanical response of various fracture types and different fixation strategies (three inverted triangular parallel cannulated screws (TCS), four non-parallel cannulated screws (FCS) and biplane double-supported screw fixation (BDSF) respectively). The maximum principal strain (MPS) on the proximal femur and the von Mises stress on the screws were compared for different models.

Results

In Pauwels I and II fractures, FCS had the lowest peak MPS on the proximal femur and the BDSF had highest peak MPS value. In Pauwels III fractures, BDSF performance in MPS is improved and better than FCS under partial loading conditions. FCS exhibits the lowest von Mises stress in all load conditions for all fracture types, demonstrating minimal risk of screws breakage.

Conclusions

FCS is an ideal screw configuration for the treatment of FNF. And BDSF has shown potential in the treatment of Pauwels type III FNF.

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

BACKGROUND

Previous studies have reported that positive buttress is as effective as anatomical reduction in treating young femoral neck fractures, but whether this effect is related to the Pauwels classification remains unclear. The purpose of this study was to retrospectively analyze the clinical prognosis of positive buttress in young femoral neck fractures with different Pauwels classifications, as well as to assess its biomechanical properties.

METHODS

A total of 170 young patients with femoral neck fractures who were treated with three cannulated screws were included in this study. Patients were divided into three groups based on their preoperative Pauwels classification. Each group was divided into three subgroups based on the reduction quality: positive buttress, negative buttress and anatomical reduction. The femoral neck shortening, the incidence of necrosis of the femoral head (AVN) and the Harris hip scores at the last follow-up were compared across the three reduction quality within each Pauwels classification. Subsequently, a volunteer was recruited, CT data of the hip was obtained, and finite element models representing different reduction quality under varying Pauwels classifications were established. The biomechanical properties of each model were then evaluated following the application of strains.

RESULTS

In Pauwels type I, there were no significant differences in postoperative femoral neck shortening, incidence of AVN, or Harris score among the three types of reduction quality (P > 0.05). However, positive buttress provided superior biomechanical stability compared to negative buttress and anatomical reduction. In Pauwels type II, the incidence of AVN was similar between the positive buttress and the anatomical reduction groups, and both were significantly lower than that in the negative buttress (P < 0.05). The Harris score of the positive buttress was higher than that of the negative buttress, and there was no significant difference in the occurrence of femoral neck shortening between the three groups (P > 0.05). Finite element analysis showed that the biomechanical stability of positive buttress was equivalent to anatomical reduction, and both were better than negative buttress. In Pauwels type III, the incidence of AVN in the anatomical reduction group was lower than that in both the positive buttress and negative buttress (P < 0.05). There was no significant difference in the occurrence of AVN or femoral neck shortening between positive buttress and negative buttress (P > 0.05). There was also no difference in postoperative Harris scores between the three reduction qualities (P > 0.05). Both positive buttress and negative buttress exhibited identical biomechanical qualities and were inferior to anatomical reduction.

CONCLUSIONS

The biomechanical and clinical dominance of positive buttress correlates with Pauwels type. Specifically, Positive buttress is biomechanically stable in Pauwels types I and II. In Pauwels type III, positive buttress is not advantageous. As the Pauwels angle increases, the biomechanical benefit of the positive buttress is lost. Therefore, regardless of the Pauwels classification, negative buttress should be avoided after reduction of femoral neck fractures in young patients.

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

INTRODUCTION

Femoral neck fractures have posed a significant global healthcare challenge and had notable impacts on the quality of life. Current treatment strategies for femoral neck fractures in young individuals have varied, emphasizing the need for optimal fixation methods. This study compared the clinical and radiological outcomes of the dynamic compression system (DCS) and multiple cancellous screws (MCS) methods.

METHODS

This retrospective study included a total of 275 young adults with fresh femoral neck fractures treated with DCS and MCS. A matching analysis with a 1:1 ratio based on age, gender, fracture classification, and reduction quality was conducted. Demographic data were recorded, and comparisons were made according to follow-up time (FUT), hospitalization period, operation duration, femoral neck shortening, caput-collum-diaphysis (CCD) angle, Harris Hip Score (HHS), and post-operative complications.

RESULTS

A total of 42 fractures were matched with a median age of 42 years (range, 22-48). In the DCS group, vertical neck shortening (median 1.92) was significantly lower than that in the MCS group (median 4.53) (P < 0.05). In the DCS group, horizontal femoral neck shortening, resultant femoral neck shortening, the amount of change in CCD angle, and HHS were 0.57 mm (0.43, 4.74 mm), 1.82 mm (0.40, 3.53 mm), 0.13° (-0.78°, 1.80°), and 91 (85-93), respectively. They were all non-significant than 1.00 mm (0.56, 6.23 mm), 2.74 mm (1.59, 6.71 mm), -0.18° (-1.11°,1.85°), and 91 (75, 93) in the MCS group, respectively (P > 0.05). There was no statistical difference in FUT, hospitalization period, operation time, and post-operative complications at the latest follow-up (P > 0.05). There were no complications such as pulmonary embolism, deep vein thrombosis, and incision infection reported.

CONCLUSION

DCS and MCS demonstrated effectiveness in treating femoral neck fractures in young adults. The DCS implant provides additional stability in the vertical axis. A prospective randomized controlled study with a large sample size was needed to validate these findings.

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.

Clinical observation of Gofried positive buttress reduction in the treatment of young femoral neck fracture: A systematic review and meta-analysis

BACKGROUND

Femoral neck fractures in young adults(<65 years), have always been a difficult problem, characterized by high rates of nonunion and avascular necrosis (AVN). The clinical efficacy of anatomical reduction and non-anatomical reduction methods needs to be supported by clinical data. Therefore, we conduct a meta-analysis on the clinical efficacy of different reduction methods to better guide clinical practice.

METHODS

Relevant studies published using internal fixation to treat femoral neck fracture in several databases were searched. The outcomes sought included Harris score and the rate of AVN, nonunion and femoral neck shortening (<5 mm). Included studies were assessed for methodological bias and estimates of effect were calculated. Potential reasons for heterogeneity were explored.

RESULTS

The clinical results showed that compared with the anatomical reduction and positive buttress, there is no significant difference in the rate of AVN (OR = 0.87, 95%CI: 0.55-1.37, P = .55), nonunion (OR = 0.54, 95%CI: 0.21-1.41, P = .21), femoral neck shortening (<5 mm) (OR = 1.03,95%CI: 0.57-1.86, P = .92), the Harris score (MD = -0.28, 95%CI: -1.36-0.80, P = .61) and the excellent and good rate of Harris score (OR = 1.73, 95%CI: 0.84-3.56, P = .61). However, compared with negative buttress, the rate of AVN (OR = 0.62, 95%CI: 0.38-1.01, P = .05), nonunion (OR = 0.34, 95%CI: 0.12-1.00, P = .05) and femoral neck shortening (<5 mm) (OR = 0.27, 95%CI: 0.16-0.45, P < .00001) were significantly lower, and the Harris score (MD = 6.53, 95%CI: 2.55 ~ 10.51, P = .001) was significantly better in positive buttress.

CONCLUSIONS

In the case of difficult to achieve anatomical reduction, for young patients (< 65 years) with femoral neck fracture, reduction with positive buttress can be an excellent alternative and negative buttress should be avoided as much as possible.

Femoral Neck System vs. four cannulated screws in the treatment of Pauwels III femoral neck fracture

OBJECTIVE

To compare the clinical efficacy of the Femoral Neck System (FNS) vs. four cannulated screws in Pauwels III femoral neck fractures.

METHODS

This retrospective study included patients with newly occurred type Pauwels III femoral neck fracture treated at author' Hospital of between January 2017 and February 2021. The patients received FNS (n = 27) or four cannulated screws (control group, n = 31). The operation time, blood loss, fracture healing time, incidence of complications (such as short femoral neck, necrosis of femoral head, nonunion of fracture, and failure of internal fixation withdrawal), and hip Harris score at the last follow-up were analyzed.

RESULTS

The operation time, blood loss, and fracture healing time were not significantly different between the two groups (all P > 0.05). In the FNS group, three and one patients were with femoral neck shortening and femoral head necrosis, respectively, while no fracture nonunion or failure of internal fixation withdrawal occurred. In the control group, seven, two, one, and two patients were with femoral neck shortening, femoral head necrosis, nonunion, and internal fixation failure, respectively. The cumulative complication incidence was 14.8% and 38.7% in the FNS and control groups (P = 0.042). The excellent and good rates of the hip Harris score at the last follow-up were 92.6% and 71.0% in the FNS and control groups, respectively (P = 0.036).

CONCLUSION

The study suggested that the clinical efficacy of FNS was better than internal fixation using four cannulated screws in treating Pauwels III type femoral neck fracture.

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.

Fibula allograft with cannulated screw fixation versus ordinary cannulated screw fixation for femoral neck fractures: a 10-year retrospective comparative study

BACKGROUND

For femoral neck fractures in young and middle-aged patients, both fibula allograft with cannulated screw fixation and ordinary cannulated screw fixation are clinically effective treatments. However, for unstable femoral neck fractures, ordinary cannulated screw fixation is characterized by a high risk of postoperative complications and a high rate of mechanical failure after internal fixation. For this study, we systematically compared the long-term efficacy and postoperative complications of these two procedures.

METHODS

A total of 156 subjects diagnosed as femoral neck fractures participated in our study. Subjects in the combination group underwent fibula allograft with cannulated screw fixation (n = 76), and those in the control group were treated with ordinary cannulated screw fixation (n = 80). Baseline characteristics, perioperative outcomes, Harris hip score (HHS) and EuroQoL five-dimension questionnaire (EQ-5D); and the incidence of postoperative and bone healing complications in the two groups were recorded and compared.

RESULTS

The average follow-up time was more than 10 years. Intra-operative blood loss significantly increased in the combination group compared with the control group (P < 0.05). There were significantly improved performances in healing time, the time course of recovery of full-weight-bearing stepping, HHS and EQ-5D scores in the combination group compared with the control group (P < 0.05). Besides, the incidence rates of femoral head necrosis, nonunion, femoral neck shortening and total hip replacement were significantly lower in the combination group than those in the control group (P < 0.05).

CONCLUSION

Fibula allograft with cannulated screw fixation shows a better long-term therapeutic effect than ordinary cannulated screw fixation for femoral neck fractures in young and middle-aged patients. Patients receiving the combination strategy have faster and high-quality functional recovery after femoral neck fractures and a lower incidence rate of postoperative complications.

Mechanical analysis of the femoral neck dynamic intersection system with different nail angles and clinical applications

BACKGROUND

The femoral neck dynamic intersection system (FNS) is mechanically more stable than other internal fixation techniques. Current studies have confirmed that the structural design of FNS has good biomechanical properties in European and American populations. However, whether the suitability of the FNS's 130° main nail angle design for Asian populations has been thoroughly investigated remains unclear.

AIM

To compare the biomechanical stability differences among different main nail angles of the FNS in the treatment of femoral neck fractures in Asian populations.

METHODS

Computed tomography data of the femur of healthy adult male volunteers were imported into Mimics software to create a three-dimensional model of the femur. The model was adapted to the curve using Geomagic software and imported into Solidworks software to construct the Pauwels I femoral neck fracture model and design the FNS internal fixation model using different main nail angles. Afterward, the models were assembled with the FNS fracture model and meshed using the preprocessing Hypermesh software. Subsequently, they were imported into Abaqus software to analyze and evaluate the biomechanical effects of different angles of the FNS main nail on the treatment of femoral neck fractures.

RESULTS

The peak displacement of the proximal femur under different angles of FNS fixation under stress was 7.446 millimeters in the 120° group and 7.416 millimeters in the 125° group; in the 130°, 135°, and 140° FNS fixation groups, the peak displacement was 7.324 millimeters, 8.138 millimeters, and 8.246 millimeters, respectively. In the 120° and 125° FNS fixation groups, the maximum stresses were concentrated at the main nail and the anti-rotation screw, which intersected the fracture line of the femur neck, resulting in peak stresses of 200.7 MPa and 138.8 MPa, respectively. Peak stresses of 208.8 MPa, 219.8 MPa, and 239.3 MPa were observed on the angular locking plate distal to the locking screw in the 130°, 135°, and 140° fixation groups.

CONCLUSION

FNS has significant stress distribution properties, a minimal proximal femoral displacement, and an optimal stability for treating femoral neck fractures in Asian populations when performed with a 130° main nail angle.

Mechanical analysis of the femoral neck dynamic intersection system with different nail angles and clinical applications

BACKGROUND

The femoral neck dynamic intersection system (FNS) is mechanically more stable than other internal fixation techniques. Current studies have confirmed that the structural design of FNS has good biomechanical properties in European and American populations. However, whether the suitability of the FNS's 130° main nail angle design for Asian populations has been thoroughly investigated remains unclear.

AIM

To compare the biomechanical stability differences among different main nail angles of the FNS in the treatment of femoral neck fractures in Asian populations.

METHODS

Computed tomography data of the femur of healthy adult male volunteers were imported into Mimics software to create a three-dimensional model of the femur. The model was adapted to the curve using Geomagic software and imported into Solidworks software to construct the Pauwels I femoral neck fracture model and design the FNS internal fixation model using different main nail angles. Afterward, the models were assembled with the FNS fracture model and meshed using the preprocessing Hypermesh software. Subsequently, they were imported into Abaqus software to analyze and evaluate the biomechanical effects of different angles of the FNS main nail on the treatment of femoral neck fractures.

RESULTS

The peak displacement of the proximal femur under different angles of FNS fixation under stress was 7.446 millimeters in the 120° group and 7.416 millimeters in the 125° group; in the 130°, 135°, and 140° FNS fixation groups, the peak displacement was 7.324 millimeters, 8.138 millimeters, and 8.246 millimeters, respectively. In the 120° and 125° FNS fixation groups, the maximum stresses were concentrated at the main nail and the anti-rotation screw, which intersected the fracture line of the femur neck, resulting in peak stresses of 200.7 MPa and 138.8 MPa, respectively. Peak stresses of 208.8 MPa, 219.8 MPa, and 239.3 MPa were observed on the angular locking plate distal to the locking screw in the 130°, 135°, and 140° fixation groups.

CONCLUSION

FNS has significant stress distribution properties, a minimal proximal femoral displacement, and an optimal stability for treating femoral neck fractures in Asian populations when performed with a 130° main nail angle.

Postoperative clinical outcome and complications of combined cannulated cancellous screw with Kirschner wire in adolescent femoral neck fractures

Purpose

Fractures of the femoral neck account for less than 1% of pediatric and adolescent fractures. Due to the high incidence of complications, and the age of the patients, the choice of fixation approach remains controversial among orthopedic surgeons. This study aimed to evaluate the postoperative outcomes and complications of femoral neck fracture in adolescents with open physis, following transphyseal fixation using a combined cannulated cancellous screw and Kirschner wire fixation.

Methods

Data of 19 patients aged between 12 and 19 years from January 2010 to January 2021 were retrospectively studied. The follow-up period was 1-11 years (5.83 ± 3.76 years). The variables of interest including demographic and clinical variables [age, BMI, gender, side of injury, fracture classification, operation time, time to surgery, and length of hospital stay (LOS)], postoperative outcomes, and complications (fracture healing time, nonunion, coxa vara, osteoarthritis, avascular necrosis, screw loosening, and femoral shortening) were analyzed. The assessment of the hip function was done on the final follow-up using the Ratliff scoring system.

Results

There was a male predominance of 76%; the mean age was 16.14 ± 1.57 years and the most frequent mechanism of injury was fall from a height. Delbet type II and III were the most encountered. The mean intraoperative time was 54.71 ± 7.85 min, the LOS was 8.34 ± 1.81days, and the time to surgery was 2.60 ± 1.16 days; the fracture healing time was 3.31 ± 1.04 months. The postoperative complications encountered were coxa vara osteoarthritis, spontaneous dislocation, and neck shortening. Clinical assessment revealed good results in 89% of patients and fair results in 11% of patients.

Conclusion

Transphyseal fixation using cannulated cancellous screw combined with Kirschner wire in our patients provided acceptable results. Thus, this approach can be a viable alternative in the management of adolescent femoral neck fracture with open physis.

Total hip arthroplasty for failed internal fixation of femoral neck fracture: a retrospective study with 2-14 years' follow-up of 345 patients

OBJECTIVES

The purpose of this study was to analyze mid- to long-term outcomes of total hip arthroplasty (THA) following failed internal fixation of femoral neck fracture.

METHODS

This study retrospectively analyzed 345 patients with femoral neck fracture who underwent THA after failure of internal fixation at our hospital between January, 2003 and December, 2019. Patients older than 55 years (n = 175) and patients no older than 55 years (n = 170) were compared in terms of complications and survival rates during follow-up, which lasted a mean of 6 years.

RESULTS

The two age groups showed similarly low incidence of complications and similarly long periods of survival without revision surgery. Only three younger patients and two older patients underwent revision surgery during follow-up. The two groups showed similarly high survival rates at the end of follow-up (> 93%). Younger patients showed significantly bettter Harris hip score at last follow-up (90.2 vs. 88.1 points, p < 0.001) without clinically significant difference, but they required THA significantly earlier after internal fixation (4.4 vs. 6.8 years, p < 0.001).

CONCLUSIONS

THA after failed internal fixation of femoral neck fracture is a well tolerated and effective procedure in older and younger patients.

Comparison of femoral neck system vs. dynamic hip system blade for the treatment of femoral neck fracture in young patients: A retrospective study

Background

Femoral neck fracture is a common fracture in orthopedic practice. This study aimed to compare the clinical outcomes between the femoral neck system and dynamic hip system blade for the treatment of femoral neck fracture in young patients.

Methods

This retrospective study included 43 and 52 patients who underwent treatment for femoral neck fracture with the femoral neck system and dynamic hip system blade, respectively, between August 2019 and August 2020. Operative indexes, including operation duration, blood loss, incision length, postoperative complications (femoral neck shortening, non-union, screw pull-out, femoral head necrosis), and Harris scale scores were recorded and analyzed.

Results

Compared to that with the dynamic hip system blade, the femoral neck system showed significantly less operation duration (femoral neck system vs. dynamic hip system blade: 47.09 ± 9.19 vs. 52.90 ± 9.64, P = 0.004), less blood loss (48.53 ± 10.69 vs. 65.31 ± 17.91, P < 0.001), and shorter incision length (4.04 ± 0.43 vs. 4.93 ± 0.53, P < 0.001). Femoral neck shortening was significantly lower with the femoral neck system than with the dynamic hip system blade (3.93 ± 2.40, n = 39 vs. 5.22 ± 2.89, n = 44, P = 0.031). No statistical differences were observed between the two groups in nonunion, screw pull-out, and femoral head necrosis. In addition, the latest follow-up Harris scale score was significantly higher with the femoral neck system than with the dynamic hip system blade (92.3 ± 4.5 vs. 89. 9 ± 4.9, P = 0.015).

Conclusion

The femoral neck system results in less trauma, less femoral neck shortening, and better hip joint function than the dynamic hip system blade for the treatment of femoral neck fracture in young patients.

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.

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.

Finite element analysis of necessity of reduction and selection of internal fixation for valgus-impacted femoral neck fracture

This study compared the biomechanical characteristics of different treatment strategies based on finite element analysis. Posterior tilt and valgus angle were measured on X-ray from ten valgus-impacted femoral neck fractures, and 7 finite element models that were generated to compare the stress and displacement. The results showed that in the intact femur, von Mises stress was concentrated at the medial and inferior sides of the femoral neck. In valgus-impacted femoral neck fractures, von Mises stress was at the same locations but was 5.66 times higher than that in the intact femur. When 3 cannulated screws were used for internal fixation, anatomic reduction diminished the stress at the fracture end from 140.6 to 59.14 MPa, although displacement increased from 0.228 to 0.450 mm. When the fracture was fixed with a sliding hip screw (SHS) + cannulated screw, there was less stress at the fracture end and greater displacement with anatomic reduction than that without reduction (stress: 15.9 vs 37.9 MPa; displacement: 0.329 vs 0.168 mm). Therefore, the SHS + cannulated screw has superior biomechanical stability than 3 cannulated screws, and is recommended following anatomic reduction to treat valgus-compacted femoral neck fractures.

Biomechanical comparison of the femoral neck system versus InterTan nail and three cannulated screws for unstable Pauwels type III femoral neck fracture

BACKGROUND

There are a variety of internal fixation methods for unstable femoral neck fractures (FNFs), but the best method is still unclear. Femoral neck system (FNS) is a dynamic angular stabilization system with cross screws, and is a new internal fixation implant designed for minimally invasive fixation of FNFs. In this study, we conducted a biomechanical comparison of FNS, InterTan nail and three cannulated screws for the treatment of Pauwels III FNFs and investigate the biomechanical properties of FNS.

METHODS

A total of 18 left artificial femurs were selected and randomly divide into Group A (fixation with FNS), Group B (fixation with InterTan nail) and Group C (fixation with three cannulated screws), with 6 specimens in each group. After creating Pauwels type III FNF models, the specimens in each were tested with non-destructive quasi-static tests, including torsion, A-P bending and axial compression tests. The average slope of the linear load-deformation curve obtained from quasi-static tests defines the initial torsional stiffness, A-P bending stiffness, and axial compression stiffness. After cyclic loading test was applied, the overall deformation of models and local deformation of implant holes in each group were assessed. The overall deformation was estimated as the displacement recorded by the software of the mechanical testing apparatus. Local deformation was defined as interfragmental displacement. Data were analyzed by one-way analysis of variance (ANOVA) followed by Bonferroni post hoc test using the SPSS software (version 24.0, IBM, New York, NY, USA). Correlation analysis was performed using Pearson's correlation analysis.

RESULTS

Group B exhibited significantly higher axial stiffness and A-P bending stiffness than the other two groups (P < 0.01), while Group A had significantly higher axial stiffness and A-P bending stiffness than Group C (P < 0.01). Groups A and B exhibited significantly higher torsional stiffness than Group C (P < 0.01), no statistical significance was observed between Groups A and B (P > 0.05). Group B exhibited significantly lower overall and local deformations than the other two groups (P < 0.01), while Group A had significantly lower overall and local deformations than Group C (P < 0.01). Correlation analysis revealed positive correlation between axial stiffness and A-P bending stiffness (r = 0.925, P < 0.01), torsional stiffness (r = 0.727, P < 0.01), between torsional stiffness and A-P bending stiffness; negative correlation between overall, local deformations and axial stiffness (r = - 0.889, - 0.901, respectively, both P < 0.01), and positive correlation between the two deformations (r = - 0.978, P < 0.01).

CONCLUSION

For fixation of unstable FNFs, InterTan nail showed the highest axial stiffness and A-P bending stiffness, followed by FNS, and then three cannulated screws. Torsional stiffness of FNS was comparable to that of the InterTan nail. FNS, as a novel minimally invasive implant, can create good mechanical environment for the healing of unstable FNFs. Clinical studies are needed to confirm the potential advantages of FNS observed in this biomechanical study.

Treatment Failure in Femoral Neck Fractures in Adults Less Than 50 Years of Age: Analysis of 492 Patients Repaired at 26 North American Trauma Centers

OBJECTIVES

To assess the operative results of femoral neck fractures (FNFs) in young adults in a large multicenter series, specifically focusing on risk factors for treatment failure.

DESIGN

Large multicenter retrospective cohort series.

SETTING

Twenty-six North American Level 1 trauma centers.

PATIENTS

Skeletally mature patients younger than 50 years with displaced and nondisplaced FNFs treated between 2005 and 2017.

INTERVENTION

Operative repair of FNF.

MAIN OUTCOME MEASUREMENTS

The main outcome measure is treatment failure: nonunion and/or failed fixation, osteonecrosis, malunion, and need for subsequent major reconstructive surgery (arthroplasty or proximal femoral osteotomy). Logistic regression models were conducted to examine factors associated with treatment failure.

RESULTS

Of 492 patients with FNFs studied, a major complication and/or subsequent major reconstructive surgery occurred in 45% (52% of 377 displaced fractures and 21% of 115 nondisplaced fractures). Overall, 23% of patients had nonunion/failure of fixation, 12% osteonecrosis type 2b or worse, 15% malunion (>10 mm), and 32% required major reconstructive surgery. Odds of failure were increased with fair-to-poor reduction [odds ratio (OR) = 5.29, 95% confidence interval (CI) = 2.41-13.31], chronic alcohol misuse (OR = 3.08, 95% CI = 1.59-6.38), comminution (OR = 2.63, 95% CI = 1.69-4.13), multiple screw constructs (vs. fixed-angle devices, OR = 1.95, 95% CI = 1.30-2.95), metabolic bone disease (OR = 1.77, 95% CI = 1.17-2.67), and increasing age (OR = 1.03, 95% CI = 1.01-1.06). Women (OR = 0.57, 95% CI = 0.37-0.88), Pauwels angle ≤50 degrees (type 1 or 2; OR = 0.64, 95% CI = 0.41-0.98), or associated femoral shaft fracture (OR = 0.19, 95% CI = 0.10-0.33) had lower odds of failure.

CONCLUSIONS

FNFs in adults <50 years old remain a difficult clinical and surgical problem, with 45% of patients experiencing major complications and 32% undergoing subsequent major reconstructive surgery. Risk factors for complications after treatment of displaced FNFs were numerous.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

[Comparison of effectiveness of femoral neck system and cannulate compression screw in treatment of femoral neck fracture in young and middle-aged patients]

OBJECTIVE

To compare the effectiveness of femoral neck system (FNS) and cannulate compression screw (CCS) in the treatment of femoral neck fractures in young and middle-aged patients.

METHODS

The clinical data of 82 young and middle-aged patients with femoral neck fracture treated between January 2018 and September 2020 were retrospectively analyzed. They were divided into FNS group (24 cases) and CCS group (58 cases) according to different surgical methods. There was no significant difference between the two groups ( P>0.05) in general data such as gender, age, height, body mass, cause of injury, complications, fracture location, and fracture classification (Garden classification and Pauwells classification). The operation time, intraoperative blood loss, complications (nonunion, osteonecrosis of the femoral head, shortening of femoral neck, etc.), visual analogue scale (VAS) score at 2 days after operation, clinical healing time of fracture, and Harris score of hip joint after operation were recorded and compared between the two groups.

RESULTS

The operation time and VAS score at 2 days after operation in FNS group were significantly lower than those in CCS group ( P<0.05); there was no significant difference in intraoperative blood loss between the two groups ( t=0.263, P=0.796). The patients in CCS group were followed up 6-18 months, with an average of 13.6 months; and the follow-up time in FNS group was 3-12 months, with an average of 7.3 months. There was no complication of internal fixator loosening in both groups. There were 2 cases of osteonecrosis of the femoral head, 1 case of bone nonunion, and 13 cases of femoral neck shortening in CCS group and only 2 cases of femoral neck shortening in FNS group. The difference in the incidence of complications between the two groups (27.6% vs. 8.3%) was significant ( χ 2=36.670, P=0.015). In CCS group, 3 cases underwent secondary artificial hip arthroplasty due to bone nonunion and osteonecrosis of the femoral head, and the remaining 55 cases achieved clinical healing; in FNS group, 6 patients excluded in the statistics because the follow-up time was less than 6 months, and the remaining 18 fractures healed clinically; there was significant difference in fracture healing time between the two groups ( t=4.481, P=0.000). The difference of Harris score of hip joint between 9 months and 6 months after operation in FNS group was significantly higher than that in CCS group ( P<0.05), and the Harris score at 9 months after operation was significantly higher than that at 6 months after operation in both groups ( P<0.05).

CONCLUSION

FNS can accelerate the healing of femoral neck fractures in young and middle-aged patients, so that patients can start functional exercise as soon as possible, thereby reducing the incidence of related complications.

Fixation using Alternative Implants for the Treatment of Hip Fractures (FAITH-2): The Exploratory Health-Related Quality of Life and Patient-Reported Functional Outcomes of a Multi-Centre 2 × 2 Factorial Randomized Controlled Pilot Trial in Young Femoral Neck Fracture Patients

PURPOSE

Femoral neck fractures in young patients are typically managed with internal fixation using either cancellous screws or a sliding hip screw (SHS). Although fixation preserves the hip joint, patients are still at risk of complications and poor clinical outcomes which lead to diminished function and health related quality of life (HRQL). The Fixation using Alternative Implants for the Treatment of Hip Fractures (FAITH-2) pilot randomized controlled factorial trial evaluated the effect of surgical fixation (cancellous screws vs. SHS) and vitamin D supplementation vs. placebo on patient-reported function and HRQL.

METHODS

Patients between the ages of 18-60 years with a femoral neck fracture requiring surgical fixation were eligible. Eligible patients were randomized to receive either a sliding hip screw or cancellous screws for fracture fixation AND vitamin D₃ 4,000 IU or placebo daily for 6 months. Patient-reported function (Hip Outcome Score) and HRQL (Short Form-12) were assessed at standardized time points in the 12 months following their fixation surgery. Patient-reported function and HRQL were summarized using means, SD, and 95% confidence intervals (CIs), or percentages and counts. Longitudinal data analysis with mixed models was used to explore the effect of treatment group and time on the patient-reported function and HRQL.

RESULTS

86 of the 91 patients randomized into the FAITH-2 pilot study were deemed eligible. There were no significant differences in patient-reported function or HRQL between the treatment groups at 12 months post-fracture. At the 6- and 9-month assessments, a potential benefit in hip function was seen in the cancellous screw group. In all treatment groups, participants reported lower function and HRQL at 12 months post-fracture as compared to their pre-injury assessment.

CONCLUSIONS

Few differences were found in function and HRQL among the treatment groups in the FAITH-2 pilot study. Despite modern implants and vitamin D supplementation, neither function nor HRQL returns to baseline in this population. Additional efforts to improve the outcomes of these challenging injuries are still needed.

LEVEL OF EVIDENCE

Therapeutic Level II.

Femoral neck system versus inverted cannulated cancellous screw for the treatment of femoral neck fractures in adults: a preliminary comparative study

BACKGROUND

The femoral neck system (FNS) may be a valid alternative for treating femoral neck fractures, but few studies have compared the outcomes between FNS and cannulated cancellous screws. This study aimed to compare the clinical efficacy and complications of FNS with those of inverted cannulated cancellous screws (ICCS) for the treatment of femoral neck fractures in adults.

METHODS

This retrospective study evaluated patients with femoral neck fractures who underwent FNS or ICCS internal fixation between June 2019 and January 2020. The operative time, intraoperative blood loss, number of fluoroscopies, length of surgical incision, length of hospital stay, time to fracture healing, and other indicators were compared between the two groups. The incidence of complications such as nonunion, avascular necrosis of the femoral head, loosening of the internal fixation, and shortening of the femoral neck during follow-up was also assessed in both groups.

RESULTS

Among the 92 patients included, 47 and 45 patients were categorized into the FNS and ICCS groups, respectively. Follow-up ranged from 14 to 24 months. There were no significant between-group differences in sex, age, side of the injured limb, and type of fracture and in operative time, intraoperative blood loss, incision length, and length of hospital stay (all P > 0.05). The incidence of complications such as fracture nonunion, avascular necrosis of the femoral head, and screw loosening was also comparable between the two groups. However, the number of fluoroscopies was significantly lower in the FNS group than in the ICCS group (P < 0.05). The fracture healing time was also significantly lower in the FNS group than in the ICCS group (P < 0.05). Furthermore, the femoral neck shortening and Harris hip score at the last follow-up were significantly better in the FNS group than in the ICCS group (P < 0.05).

CONCLUSIONS

FNS for femoral neck fractures improves hip functional recovery and reduces the femoral neck shortening rate and fluoroscopy exposure postoperatively. Thus, FNS can be an alternative to ICCS for the treatment of femoral neck fractures.

Medial femoral plate with cannulated screw for Pauwels type III femoral neck fracture: A meta-analysis

BACKGROUND

Femoral neck fractures often occur in the elderly, which usually results in hip pain.

OBJECTIVE

The purpose of this study was to evaluate the difference in the treatment of Pauwels type III femoral neck fractures with medial femoral support plate combined with cannulated screws and cannulated screws alone.

METHODS

PubMed, ScienceDirect, China Academic Journals Full-text Database (CNKI), Wanfang Database, Chinese Biomedical Literature Database (CBM), Embase and Cochrane Library were used to collect clinical controlled trials of the medial femoral support plate combined with hollow screw internal fixation and simple hollow screw internal fixation for Pauwels type III femoral neck fracture.

RESULTS

Seven articles (n= 409 cases) were evaluated for quality and included in this meta-analysis. Four hundred and nine patients with Pauwels type III femoral neck fractures were included: 202 in the experimental group and 207 in the control group. The results showed that, compared with simple hollow screw internal fixation, the medial femoral support plate combined with hollow screw internal fixation has a longer operation time (MD= 23.05, 95% CI= 13.86-32.24), and more intraoperative blood loss (MD= 91.55, 95% CI= 50.72-132.39), shorter healing time (MD=-1.48, 95% CI (-1.71, -1.26)), lower incidence of complications (RR= 0.34, 95% CI= 0.19-0.61), lower VAS score (MD=-1.28, 95% CI (-1.83, -0.72)), and higher Harris score (MD= 8.49, 95% CI (4.15, 12.83)).

CONCLUSION

Medial femoral plate combined with cannulated screw for Pauwels type III femoral neck fracture can shorten healing time, reduce postoperative complications, and improve the postoperative Harris score.

Clinical outcome of femoral neck system versus cannulated compression screws for fixation of femoral neck fracture in younger patients

Background

The clinical outcome of a new fixation device (femoral neck system, FNS) for femoral neck fractures remains unclear. The main purpose of this study was to evaluate two different internal fixation methods for the treatment of femoral neck fractures in patients aged under 60 years.

Methods

We retrospectively studied patients who underwent internal fixation surgery in our hospital for femoral neck fractures between January 2017 and January 2020. Cannulated compression screws (CCS) and FNS groups were divided according to different internal fixation methods. General data (such as sex, age, body mass index, type of fracture) of all patienFemoral neck shorteningts were collected, and joint function was evaluated using the Harris Hip Score (HHS) before and 1 year after surgery. We recorded related surgical complications, including femoral head necrosis, nonunion, and femoral neck shortening.

Results

There were no significant differences in age, sex, or body mass index between the two groups. There was no statistical difference in HHSs between the two groups before surgery. Patients who underwent FNS treatment had longer surgery time (79.75 ± 26.35 min vs. 64.58 ± 18.56 min, p = 0.031) and more blood loss (69.45 ± 50.47 mL vs. 23.71 ± 28.13 mL, p < 0.001). The degree of femoral neck shortening in the FNS group was significantly lower than that in the CCS group (10.0% vs 37.5%, p = 0.036). Regarding postoperative complications, there was no statistical difference in the incidence of femoral head necrosis and fracture nonunion between the two groups.

Conclusion

Patients younger than 60 with femoral neck fractures can obtain satisfactory clinical results with CCS or FNS treatment. FNS has excellent biomechanical properties and shows significantly higher overall construct stability.

Development and validation of a predictive nomogram for postoperative osteonecrosis of the femoral head with cannulated screws fixation

Background

Osteonecrosis of the femoral head (ONFH) remains a major complication of femoral neck fractures. Early interventions require preliminary prediction and detection. In this study, we aimed to evaluate the perioperative variables of postoperative ONFH in femoral neck fracture patients with closed reduction and cannulated screw fixation. We also established and validated an individualized nomogram for the prediction of postoperative ONFH.

Methods

We included 470 patients with ONFH from two hospitals [First Affiliated Hospital of University of Science and Technology of China (n=360) and Southern Branch of the First Affiliated Hospital of the University of Science and Technology of China (n=110)]. We evaluated the prognostic value of multiple perioperative variables using a Cox regression model in the training cohort. We developed a nomogram for the prediction of ONFH using a logistic regression model. We assessed the performance of this nomogram in a validation cohort and evaluated its clinical value.

Results

Of the 470 patients who met the inclusion criteria, 141 (30.0%) developed postoperative ONFH. We found alcohol use [odds ratio (OR), 1.743, 95% confidence interval (CI), 1.042-2.901, P=0.033], cerebrovascular disease (OR, 5.357, 95% CI, 2.318-13.13, P<0.001), interval to surgery (OR, 5.273, 95% CI, 2.724-10.43, P<0.001), Garden classification (OR, 23.17, 95% CI, 6.812-145.3, P<0.001), Garden index (OR, 5.935, 95% CI, 2.670-14.184, P<0.001), interval to partial weight-bearing (OR, 0.053, 95% CI, 0.006-0.296, P=0.002), and six-month Harris hip score (OR, 0.856; 95% CI, 0.792-0.919, P<0.001) were independent predictors of postoperative development of ONFH. Based on these variables, we developed a nomogram that showed good discrimination in both the training [area under the curve (AUC) =0.865] and the validation cohort (AUC =0.877). The favorable performance of this nomogram was also confirmed in the validation cohort.

Conclusions

We developed and validated an easy-to-use nomogram for predicting postoperative ONFH. This nomogram can aid decision-making of intraoperative interventions and postoperative rehabilitation plans for patients, surgeons, and osteo-rehabilitative physicians.

Assessing the effect of Gotfried reduction with positive buttress pattern in the young femoral neck fracture

BACKGROUND

Although many available surgical procedures for displaced femoral neck fractures in young patients, there are still many challenges to achieve satisfactory results. The incidence of avascular necrosis and nonunion rates remains relatively high despite the progress in our understanding and surgical technique. The purpose of this study was to evaluate the clinical efficacy of Gotfried reduction and cannulated screw fixation in the treatment of femoral neck fracture for young adults.

METHODS

A retrospective analysis was made on 67 cases from May 2013 to March 2019. They were divided into three groups according to the first postoperative anteroposterior view of hip X-ray: Anatomic reduction (group A), Gotfried positive buttress reduction (group B), and Gotfried negative buttress reduction (group C). The incidence of avascular osteonecrosis of the femoral head (AVN) and the Harris scores of hip joints were compared in three groups at the last follow-up.

RESULTS

The mean follow-up period after surgery was 22.5 ± 11.3 (range, 11-34) months. There were 21 cases (mean age, 49.7 ± 11.6) in group A, 24 cases (mean age, 48.6 ± 11.3) in group B, 22 cases (mean age, 48.3 ± 12.4) in group C. No significant difference in general preoperative demographics (P > 0.05). The incidence of avascular necrosis of femoral head in group A, B, and C was 19.05%, 20.83%, and 22.73%, respectively, showing no significant difference between groups (P = 0.156). The mean Harris hip scores at the final follow-up for groups A (85.6 ± 6.7) and B (84.5 ± 6.2) were significantly higher than group C (74.3 ± 8.3), and the difference was statistically significant (P = 0.043). The incidence of femoral neck shortening in group A and group B was significantly lower than that in group C in postoperative 1 year, and the difference was statistically significant (P < 0.05).

CONCLUSIONS

Gotfried positive buttress reduction and fixation for femoral neck fracture may lead to similar clinical results with anatomic reduction, but much better than Gotfried negative buttress reduction. For the patients of femoral neck fracture with severe displacement and difficulty reduction, it is not necessary to pursue anatomical reduction. Achieving positive valgus reduction can also obtain satisfactory clinical results, and should try to avoid negative buttress.

Early Radiographic Union Score for Hip Is Predictive of Femoral Neck Fracture Complications Within 2 Years

OBJECTIVES

To determine if the Radiographic Union Score for Hip (RUSH) measured at 3 and 6 months after femoral neck fracture were predictive of reoperation for infection, nonunion, delayed union, avascular necrosis, or implant failure within 24 months of initial surgery.

DESIGN

Secondary analysis of a randomized controlled trial. Logistic regression was performed to investigate associations between lower RUSH and reoperation. Results were reported as odds ratios (OR), 95% confidence intervals (CIs), and associated P values. All tests were 2 tailed with alpha = 0.05.

SETTING

Eighty-one clinical sites across 8 countries.

PATIENTS/PARTICIPANTS

Data from 734 of the clinical trial participants with radiographs at 3 and 6 months after fracture fixation were included.

INTERVENTION

A reviewer blinded to patients' outcomes independently assigned a RUSH at each follow-up time point.

MAIN OUTCOME MEASURES

Revision surgery rate related to intervention.

RESULTS

Lower RUSH at 3 and 6 months were associated with increased odds of reoperation within 24 months of fracture fixation. For every 2-point decrease in RUSH at 3 months, there was a 16% increase in the odds of a patient experiencing a re-operation (OR, 1.16; 95% CI, 1.10-1.22; P < 0.0001). A similar association was observed at the 6-month assessment for every 2-point decrease (OR = 1.05; 95% CI, 1.01-1.09; P = 0.005).

CONCLUSIONS

Decreased radiographic healing as early as 3 months post fracture fixation is associated with developing patient important femoral neck fracture reoperations. This relationship may guide early treatment decisions, suggesting that 3- and 6-month RUSH are a useful surrogate measure of reoperations within 24 months of fracture fixation.

LEVEL OF EVIDENCE

Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Dynamic compression locking system versus multiple cannulated compression screw for the treatment of femoral neck fractures: a comparative study

BACKGROUND

Femoral neck fractures are one of the problems in clinical treatment. The prognosis is uncertain. Currently, No internal fixation method is superior to other internal fixation methods in the treatment of femoral neck fractures. Therefore, the internal fixation system needs to be further explored. The aim of this study was to compare clinical outcomes of femoral neck dynamic compression locking system (DCLS) and multiple cannulated compression screws(MCCS) in the treatment of femoral neck fractures.

METHODS

A prospective analysis of 54 cases of femoral neck fractures treated with either a DCLS (n = 28) or MCCS (n = 26) was conducted between December 2015 and November 2017 in authors' hospitals. The perioperative and postoperative parameters of the two groups were recorded and evaluated.

RESULTS

Fifty-four patients were followed up for 24-47 months. The etiology was caused by a fall. There was no significant difference in follow-up time, operation time, incision length, surgical blood loss, the incidence of perioperative and postoperative healing complications, and mobility in the two groups (all P > 0.05). The Harris score, fracture healing time, femoral neck shortening, partial weight-bearing time and complete weight-bearing time were significantly better in the DCLS group than in the MCCS group (all P < 0.05). The fracture healing rate in the DCLS group was higher than that in the MCCS group.

CONCLUSIONS

The DCLS and MCCS might be equally effective in terms of operation time, incision length, surgical blood loss, the incidence of perioperative and postoperative healing complications, and mobility in the treatment of femoral neck fractures. However, the DCLS is superior to the MCCS in Harris score, fracture healing time, femoral neck shortening, weight-bearing time and fracture healing rate. So, DCLS deserves further study.

The effect of bone morphogenetic protein 2 composite materials combined with cannulated screws in treatment of acute displaced femoral neck fractures

The risk of avascular necrosis (AVN) and nonunion after treatment of displaced femoral neck fractures is increased in patients aged <60 years. Therefore we established a new protocol for closed reduction and internal fixation (CRIF) using cannulated screws combined with bone morphogenetic protein 2 (BMP-2) composite materials to treat acute femoral neck fractures.This study enrolled 78 patients with acute femoral neck fractures between April 2014 and September 2016. We treated 46 patients with a mean age of 43.8 years in study group. These patients were treated by CRIF combined with BMP-2 composite materials. In control group, there were 32 patients with a mean age of 42.09 years. The patients were treated by CRIF without BMP-2. The duration between presentation and surgery, operative time, Harris score and complications were recorded.In study group, 43 patients were followed up with an average of 31.3 months. One patient suffered nonunion and three patients presented AVN. In control group, 28 patients were followed up with an average of 32.3 months, the rate of AVN and fracture nonunion were 25% (7/28) and 21.4% (6/28) respectively, significantly higher than those in study group (P < .05).Acute displaced femoral neck fractures can be treated with CRIF and BMP-2 composite materials in a minimally invasive manner. This technique was reproducible and had fewer complications.

Correlation Between Reduction Quality of Femoral Neck Fracture and Femoral Head Necrosis Based on Biomechanics

Objective

To investigate the biomechanical effects of reduction quality on patients after femoral neck fracture internal fixation.

Methods

The data of individual patients with femoral neck fractures were reviewed. Data for patients with simple unilateral femoral neck fractures whose reduction quality was evaluated as good by hip X‐ray films after internal fixation were collected from January 2013 to January 2017. The CT data of the patients was used to reconstruct 3D models of the femur and the screw. The spatial displacement after the operation of femoral neck fracture was measured, which included the displacement of the deepest portion of the femoral head fovea, the displacement of the center of the femoral head, and the rotational angle. The cases were followed up by telephone consultation and clinical review to determine whether the osteonecrosis of the femoral head occurred. Follow‐up time should be more than 18 months after surgery. The cases were grouped according to the results into an osteonecrosis of the femoral head group and a non‐osteonecrosis of the femoral head group. Finally, the differences in postoperative spatial displacement between the two groups were compared and analyzed. In addition, a mechanical analysis of femoral force during gait was performed via finite element analysis.

Results

Data for 241 patients with femoral neck fractures who were treated with closed reduction and internal fixation were collected. 3D measurement showed the average displacement value, including the center of the femoral head (5.90 ± 3.4 mm), the deepest portion of the femoral head fovea (9.32 ± 4.8 mm), and the rotational angle (16.1° ± 9.4°). After telephone consultation and clinical review, osteonecrosis of the femoral head was diagnosed in 28 (11.62%) of the patients. In the osteonecrosis of the femoral head (ONFH) group, the displacement of the deepest portion of the femoral head fovea was 10.92 ± 9.18 mm; the displacement was 8.86 ± 6.29 mm in the non‐ONFH group. The displacement of the center of the femoral head in the ONFH group was 7.575 ± 5.69 mm and 5.31 ± 4.05 mm in non‐ONFH group. The rotational angle was 20.11° ± 10.27° in the ONFH group and 14.19° ± 11.09° in the non‐ONFH group. The statistical analysis showed that the postoperative spatial displacements, including the displacement of the deepest portion of the femoral head fovea, the displacement of the center of the femoral head, and the rotational angle between the two groups, had statistical differences. Finite element analysis showed that as the spatial displacement increased, the stress, the displacement, and the equivalent strain of the proximal femur also increased.

Conclusion

Poor reduction quality after femoral neck fracture is a risk factor for re‐fracture and femoral head necrosis, and the measurement method of this study can be used to predict the occurrence of femoral head necrosis early after femoral neck fracture.

Fixation using alternative implants for the treatment of hip fractures (FAITH-2): design and rationale for a pilot multi-centre 2 × 2 factorial randomized controlled trial in young femoral neck fracture patients

BACKGROUND

Femoral neck fractures in patients ≤ 60 years of age are often very different injuries compared to low-energy, hip fractures in elderly patients and are difficult to manage because of inherent problems associated with high-energy trauma mechanisms and increased functional demands for recovery. Internal fixation, with multiple cancellous screws or a sliding hip screw (SHS), is the most common treatment for this injury in young patients. However, there is no clinical consensus regarding which surgical technique is optimal. Additionally, there is compelling rationale to use vitamin D supplementation to nutritionally optimize bone healing in young patients. This pilot trial will determine feasibility and provide preliminary clinical data for a larger definitive trial.

METHODS

We will conduct a multicenter, concealed randomized controlled pilot study, using a 2 × 2 factorial design in 60 patients aged 18-60 years with a femoral neck fracture. Eligible patients will be randomized in equal proportions to one of four groups: 1) SHS and vitamin D supplementation (4000 international units (IU) daily dose) for 6 months, 2) cancellous screws and vitamin D supplementation (4000 IU daily dose) for 6 months, 3) SHS and placebo, and 4) cancellous screws and placebo. Participants will be followed for 12 months post-fracture. Feasibility outcomes include initiation of clinical sites, recruitment, follow-up, data quality, and protocol adherence. Clinical outcomes, for both the pilot and planned definitive trials, include a composite of patient-important outcomes (re-operation, femoral head osteonecrosis, severe femoral neck malunion, and nonunion), health-related quality of life and patient-reported function, fracture healing complications, and radiographic fracture healing. A priori success criteria have been established. If the pilot study is deemed successful, study participants will be included in the definitive trial and clinical outcomes for the pilot will not be analyzed. If the pilot study is not deemed successful, clinical outcome data will be analyzed.

DISCUSSION

Results of this study will inform the feasibility of a definitive trial. If clinical outcome data are analyzed, they will be disseminated through a publication and presentations.

TRIAL REGISTRATION

The FAITH-2 trial, described as a definitive trial, was registered at ClinicalTrials.gov (NCT01908751) prior to enrollment of the first participant.

The effect of patient, fracture and surgery on outcomes of high energy neck of femur fractures in patients aged 15-50

INTRODUCTION:

High-energy femoral neck fractures in young patients can be devastating, with the risk of osteonecrosis, nonunion, malunion and lifelong morbidity. The aim of this study is to define the effects of patient, fracture and surgical factors on the outcome of high-energy femoral neck fractures in patients aged from 15 to 50 years.

METHODS:

A retrospective review was conducted of high-energy femoral neck fractures in patients aged 15-50 managed surgically at a Level 1 Trauma Centre, using a prospectively recorded trauma database. Low energy trauma (including falls from <1 m), medical conditions adversely affecting bone density, and pathological fractures were excluded. A clinical and radiological review was performed. The primary outcome measures were the development of osteonecrosis or nonunion leading to total hip arthroplasty (THA). Secondary outcome measures included osteotomy or other surgical procedures, quality of reduction and malunion.

RESULTS:

32 patients meeting the inclusion criteria were identified between January 2008 and July 2015. The mean follow-up was 58.5 months (range 980-3,048 days). 3 patients (9.4%) required THA. No other surgical procedures were performed. None of the 29 other patients developed radiologically apparent osteonecrosis. Fracture type, displacement, anatomical reduction and fixation type were not statistically significant risk factors affecting these outcomes. For all patients, an average of 8% loss of femoral neck height and 10% femoral neck offset were seen.

CONCLUSIONS:

At a mean 4.9-year follow-up, the incidence of high-energy femoral neck fractures leading to THA was 9.4%, as a consequence of osteonecrosis or nonunion. Malunion was common.

Chronic kidney disease predicts a lower probability of improvement in patient-reported experience measures among patients with fractures: a prospective multicenter cohort study

Patient-reported experience measures (PREMs) are integral component of care for fracture patients. Using a multicenter cohort, we showed that the presence of chronic kidney disease (CKD) attenuated the probability of PREM improvement in fracture patients.

INTRODUCTION

Assessing PREM can assist physicians in improving patients' experiences. Patients with CKD are at an increased risk of exhibiting poor PREM and developing fractures. We aimed to assess whether CKD influences the probability of PREM improvement during follow-up among patients with fractures.

METHODS

We prospectively enrolled patients with hip or vertebral fractures from different institutes into a fracture liaison service program. After registering clinical histories, they received a baseline PREM assessment based on EuroQol group-5 dimension content, including self-care, daily activity, and pain severity using a 5-point Likert scale. A follow-up PREM assessment was arranged 4 months later, and we evaluated whether baseline CKD was predictive of PREM improvement.

RESULTS

Among 593 fracture patients (18% with CKD), 37.3% and 62.7% presented with hip and vertebral fractures, respectively. Self-care, daily activity, and pain severity improved after follow-up in 32%, 27%, and 43% participants; those with CKD exhibited worse self-care ability and daily activity than those without. Multivariate logistic regression analyses showed that baseline CKD was significantly associated with lower possibility of improvement in daily activity (odds ratio [OR] 0.58, p = 0.049) and pain severity (OR 0.52, p = 0.01), and an insignificant change in the possibility of improvement in self-care ability (OR 0.61, p = 0.09).

CONCLUSIONS

The presence of CKD predicts a significantly lower probability of PREM improvement among fracture patients. An early emphasis on renal function during fracture care should be considered.

Using Naive Bayes Classifier to predict osteonecrosis of the femoral head with cannulated screw fixation

Predictive models permitting personalized prognostication for patients with cannulated screw fixation for the femoral neck fracture before operation are lacking. The objective of this study was to train, test, and cross-validate a Naive Bayes Classifier to predict the occurrence of postoperative osteonecrosis of cannulated screw fixation before the patient underwent the operation. The data for the classifier model were obtained from a ambispective cohort of 120 patients who had undergone closed reduction and cannulated screw fixation from January 2011 to June 2013. Three spatial displaced parameters of femoral neck: displacement of centre of femoral head, displacement of deepest of femoral head foveae and rotational displacement were measured from preoperative CT scans using a 3-dimensional software. The Naive Bayes Classifier was modelled with age, gender, side of fractures, mechanism of injury, preoperative traction, Pauwels angle and the three spatial parameters. After modelling, the ten-fold cross-validation method was used in this study to validate its performance. The ten-fold cross-validation method uses the whole dataset to be trained and tested by the given algorithm. Two of the three spatial parameters of femoral neck (displacement of center of femoral head and rotational displacement) were included successfully in the final Naive Bayes Classifier. The Classifier achieved good performance of the accuracy (74.4%), sensitivity (74.2%), specificity (75%), positive predictive value (92%), negative predictive value (42.9%) and AUC (0.746). We showed that the Naive Bayes Classifier have the potential utility to be used to predict the osteonecrosis of femoral head within 5 years after surgery. Although this study population was restricted to patients treated with cannulated screws fixation, Bayesian-derived models may be developed for application to patients with other surgical procedures at risk of osteonecrosis.

Biomechanics-Hot Topics Part I

This study summarizes presentations of a symposium on biomechanically related hot topics of the 2015 Basic Science Focus Forum. Each topic emphasizes a biomechanical challenge common to all 4 of these presentations: an ideal fixation technique should deliver ample stability and sufficient flexibility to prevent fixation failure and to restore normal function.