Biomechanics of Femoral Neck Fractures and Implications for Fixation

MRI characteristics of radiographically occult femoral neck fractures in trauma patients with ipsilateral femoral shaft fractures

PURPOSE

Ipsilateral femoral neck fractures can be seen alongside femoral shaft fractures in high-velocity trauma patients. These neck fractures are often occult on radiographs and CT, and can have a significant impact on patient outcomes if not treated promptly. Limited protocol pelvic MRI has been used to increase sensitivity for these occult fractures. Detailed characterization of these fractures on MRI is lacking.

METHODS

427 consecutive trauma patients presenting to our emergency department who had known femoral diaphyseal fractures but no ipsilateral femoral neck fracture on radiographs or CT were included in this study. These patients were scanned using a limited protocol MRI with coronal T1 and coronal STIR sequences. Presence of an ipsilateral femoral neck fracture and imaging characteristics of the fracture were obtained.

RESULTS

31 radiographically occult ipsilateral femoral neck fractures were found, representing 7% of all cases. All neck fractures were incomplete. All fractures originated along the lateral cortex of the femoral neck and extended medially towards the junction of the medial femoral neck and the lesser trochanter. 58% (18/31) were vertical in orientation. 61% (19/31) did not demonstrate any appreciate edema on STIR images.

CONCLUSION

Implementation of limited protocol MRI protocol increases sensitivity for detection of femoral neck fractures in the setting of ipsilateral femoral shaft fractures not seen on radiograph or CT imaging. We describe the characteristic MR imaging features of these fractures.

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

BACKGROUND

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

RESULTS

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

CONCLUSION

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

Biomechanical study of a biplanar double support screw (BDSF) technique based on Pauwels angle in femoral neck fractures: finite element analysis

Objective

The objective of the present study is to conduct a comparative analysis of the biomechanical advantages and disadvantages associated with a biplanar double support screw (BDSF) internal fixation device.

Methods

Two distinct femoral neck fracture models, one with a 30° angle and the other with a 70° angle, were created using a verified and effective finite element model. Accordingly, a total of eight groups of finite element models were utilized, each implanted with different configurations of fixation devices, including distal screw 150° BDSF, distal screw 165° BDSF, 3 CLS arranged in an inverted triangle configuration, and 4 CLS arranged in a "α" configuration. Subsequently, the displacement and distribution of Von Mises stress (VMS) in the femur and internal fixation device were assessed in each fracture group under an axial load of 2100 N.

Results

At Pauwels 30° Angle, the femur with a 150°-BDSF orientation exhibited a maximum displacement of 3.17 mm, while the femur with a 165°-BDSF orientation displayed a maximum displacement of 3.13 mm. When compared with the femoral neck fracture model characterized by a Pauwels Angle of 70°, the shear force observed in the 70° model was significantly higher than that in the 30° model. Conversely, the stability of the 30° model was significantly superior to that of the 70° model. Furthermore, in the 70° model, the BDSF group exhibited a maximum femur displacement that was lower than both the 3CCS (3.46 mm) and 4CCS (3.43 mm) thresholds.

Conclusion

The biomechanical properties of the BDSF internal fixation device are superior to the other two hollow screw internal fixation devices. Correspondingly, superior biomechanical outcomes can be achieved through the implementation of distal screw insertion at an angle of 165°. Thus, the BDSF internal fixation technique can be considered as a viable closed reduction internal fixation technique for managing femoral neck fractures at varying Pauwels angles.

Effects of Cerclage Cabling on Preventing Periprosthetic Femoral Fractures When Using Cementless Stems for Unstable Femoral Neck Fractures

BACKGROUND

Periprosthetic femoral fractures (PFFs) are serious complications in hip arthroplasty for femoral neck fractures. The rates of intraoperative (iPFFs) and postoperative PFFs (pPFFs) are higher in cementless stem cases than in cemented cases. This study aimed to investigate the effects of cerclage cabling on PFF prevention in cementless arthroplasty for femoral neck fractures.

METHODS

This retrospective study included 329 consecutive patients who underwent hip arthroplasty using a cementless stem for femoral neck fractures. A total of 159 and 170 patients were in the non-cabling and cabling groups, respectively. Patient characteristics were comparable in both groups. The PFF occurrence (iPFF and pPFF) rates, reoperation rates, operative time, and blood loss volume were compared between the groups.

RESULTS

The iPFF rate was significantly higher in the noncabling group (6.3%) than in the cabling group (0%, P < .001). The rate of pPFF was significantly higher in the non-cabling group (5.1%) than in the cabling group (0.6%; P = .016). All patients in the non-cabling group required reoperation (5.1%), whereas the patient in the cabling group was an ambulatory case and required no reoperation (0%, P = .003). No significant difference in either operative time or blood loss volume was observed between the non-cabling (50 minutes, 133 mL) and cabling (52 minutes, P = .244; 149 mL, P = .212, respectively) groups.

CONCLUSIONS

When a cementless stem is used to treat unstable femoral neck fractures, cerclage cabling effectively prevents iPPF and pPPF without increasing surgical time or blood loss volume.

Diagnostic Accuracy of Artificial Intelligence-Based Algorithms in Automated Detection of Neck of Femur Fracture on a Plain Radiograph: A Systematic Review and Meta-analysis

Objectives

To evaluate the diagnostic accuracy of artificial intelligence-based algorithms in identifying neck of femur fracture on a plain radiograph.

Design

Systematic review and meta-analysis.

Data sources

PubMed, Web of science, Scopus, IEEE, and the Science direct databases were searched from inception to 30 July 2023.

Eligibility criteria for study selection

Eligible article types were descriptive, analytical, or trial studies published in the English language providing data on the utility of artificial intelligence (AI) based algorithms in the detection of the neck of the femur (NOF) fracture on plain X-ray.

Main outcome measures

The prespecified primary outcome was to calculate the sensitivity, specificity, accuracy, Youden index, and positive and negative likelihood ratios. Two teams of reviewers (each consisting of two members) extracted the data from available information in each study. The risk of bias was assessed using a mix of the CLAIM (the Checklist for AI in Medical Imaging) and QUADAS-2 (A Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies) criteria.

Results

Of the 437 articles retrieved, five were eligible for inclusion, and the pooled sensitivity of AIs in diagnosing the fracture NOF was 85%, with a specificity of 87%. For all studies, the pooled Youden index (YI) was 0.73. The average positive likelihood ratio (PLR) was 19.88, whereas the negative likelihood ratio (NLR) was 0.17. The random effects model showed an overall odds of 1.16 (0.84-1.61) in the forest plot, comparing the AI system with those of human diagnosis. The overall heterogeneity of the studies was marginal (I2 = 51%). The CLAIM criteria for risk of bias assessment had an overall >70% score.

Conclusion

Artificial intelligence (AI)-based algorithms can be used as a diagnostic adjunct, benefiting clinicians by taking less time and effort in neck of the femur (NOF) fracture diagnosis.

Study registration

PROSPERO CRD42022375449.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43465-024-01130-6.

Mechanical Complications of Proximal Femur Fractures Treated with Intramedullary Nailing: A Retrospective Study

Background and Objectives: This retrospective cohort study analyzes mechanical complications in hip fracture surgery using the Trochanteric Fixation Nail-Advanced (TFNA) implant. It investigates the correlation of these complications with demographic, intraoperative, and radiological factors, aiming to identify associated risk factors and suggest improvements in clinical surveillance and treatment strategies. Materials and Methods: We enrolled 253 patients diagnosed with pertrochanteric hip fractures treated between 2017 and 2021, with 126 meeting the criteria for a minimum 6-month follow-up. Data on demographics, American Anesthesia Association Classification (ASA), comorbidities, AO/OTA [AO (Arbeitsgemeinschaft für Osteosynthesefragen)/OTA (Orthopedic Trauma Association)] fracture classification, procedural details, and time to failure were collected. Radiographs were evaluated for reduction quality, the tip-apex distance (TAD), progressive varus deviation, and identification of mechanical complications. Statistical analysis was performed using SPSS software. Results: The predominant AO/OTA fracture classification was 31A2 in 67 cases (52.7%). Reduction quality was deemed good or acceptable in 123 cases (97.6%). The mean time to failure was 4.5 months (range: 2.2-6). The average TAD was 18 mm (range: 1.2-36), with a mean progressive varus deviation of 2.44° (range: 1.30-4.14). A good or acceptable reduction quality was observed in 97.6% of cases. Mechanical complications occurred in 21.4% of patients, with significant associations found with the lateral cortex fracture, use of a TFNA implant with a 130° angle, open reduction, and absence of prior osteoporosis treatment. Conclusions: The study provides insights into mechanical complications in proximal femur fractures treated with the TFNA nail, emphasizing the need for enhanced clinical and radiographic surveillance, especially in patients without osteoporosis treatment. Our findings support the necessity for further clinical studies comparing these outcomes with other implant designs and underscore the importance of personalized treatment strategies to reduce complication rates.

Biomechanical Stability of Femoral Neck System for Pauwels Type III Femoral Neck Fractures Based on Different Reduction Quality

To further investigate the biomechanics of a femoral neck system (FNS) for Pauwels type III femoral fractures based on three different reductions.We constructed three different reduction (anatomical reduction, negative buttress reduction, and positive buttress reduction) models of Pauwels type III femoral neck fractures. Then, three cannulated screws (3CS), dynamic hip screws (DHS), dynamic hip screws combined with an anti-rotation screw (DHS + ARS), one-hole femoral neck system (1HFNS), and two-hole femoral neck system (2HFNS) were assembled with the reduction models, respectively, to simulate the internal fixation surgical procedure. All models had a load of 2100 N in line with the femoral mechanical axis applied. The implant stress, the head and implant displacements, and the rotational angles of all models were recorded and analyzed.Compared to 3CS and 2HFNS, 1HFNS had higher implant stress (higher than 92.5 MPa and 46.3 MPa, respectively) and displacement (higher than 0.9 mm and 0.8 mm, respectively) in the anatomical reduction. 2HFNS exhibited the highest stress values (225.5 MPa) in the anatomical reduction but the lowest values (159.8 MPa) in the positive buttress reduction when compared to the other implants. 2HFNS showed the best rotational stability in the negative and positive buttress reduction (rotational angels of 0.8° and 0.6°, respectively).Based on the outcome of this computational study, it might be concluded that 2HFNS was an alternative fixation for the treatment of Pauwels type III femoral neck fracture, especially when anatomical reduction cannot be perfectly attained. More relevant clinical and biomechanical studies are needed in the future.

Revision ratio after Femoral Neck System implantation for hip fracture treatment: a retrospective cohort analysis

The aim of the study is to determine the revision ratio after implantation of the femoral neck system (FNS) for the treatment of femoral neck fractures. A retrospective single center cohort analysis with a total of 71 patients who underwent the implantation of the FNS between December 2019 and December 2021, was performed. 31 males and 40 females were included. There was no exclusion based on BMI, ASA score, Garden classification or Pauwels classification. Primary outcome was the revision rate after FNS implantation. Secondary outcomes comprise the reason for revision surgery as well as the time toward revision surgery and the 30-day mortality. The revision ratio was 11 out of 71 patients (15.5%) with an average time to revision surgery of 10 months. Most common reason for revision was avascular necrosis (AVN) in 45.5%. Other reasons for revision surgery were implant failure due to a secondary fall on to the hip with the FNS implant in place, cut-out, cut-through and malunion in respectively 27.3%, 9%, 9% and 9% of the revision patients. The one- hole plate was used in 72% of the patients. Mean follow-up was 18.07 months (range 6-30 months). Full weight bearing instruction was given to 85.9% of the patients. Partial weight bearing in 14.1% of the patients. In conclusion, the FNS has similar revision ratio when used for femoral neck fractures compared to cannulated screw fixation in literature. The predominant reason for revision is AVN and implant failure with no difference between the use of the one- or-two-hole plate in this study.

Single-plane osteotomy model is inaccurate for evaluating the optimal strategy in treating vertical femoral neck fractures: A finite element analysis

BACKGROUND AND OBJECTIVES

The conventional method for simulating vertical femoral neck fractures (vFNFs) is via a vertical single-plane osteotomy (SPO) across the entire femur. However, the accuracy of SPO for evaluating the optimal internal fixation strategy (IFS) and the appropriate assessment parameters is not clear. This study thus aimed to examine the accuracy of SPO in evaluating IFSs and to identify appropriate evaluation parameters using finite element analysis.

METHODS

Eighty patient-specific finite element models were developed based on CT images from eight vFNF patients. The natural fracture model was built using structural features of the affected side, while the SPO was simulated on the healthy side. Five different IFSs were applied to both the natural fracture and SPO groups. Thirteen parameters, including stress, displacement, and stiffness, were subjected to a two-way repeated measures ANOVA to determine the effect of IFSs and fracture morphology on stability. A Pearson correlation analysis was performed on varied parameters with various IFSs to identify independent parameters. Based on these independent parameters, the entropy evaluation method (EEM) score was used to rank the performance of IFSs for each patient.

RESULTS

Eight of the thirteen parameters were significantly influenced by IFSs (p < 0.05), two by fracture morphology (p < 0.01), and none by the interaction between IFS and fracture morphology. In the natural fracture group, parameters including screw stress and displacement, bone cut rate (BCR), and compression effects varied independently with distinct IFSs. In the SPO group, trunk displacement, BCR, cut-out risk, and compression effects parameters changed independently. The BCR of the Alpha strategy was significantly higher than that of the Inverted strategy in the natural fracture group (p = 0.002), whereas the opposite was observed in the SPO group (p = 0.016). Regarding compression effects, two IFS pairings in the natural fracture group and seven IFS pairings in the SPO group exhibited significant differences. None of the five IFSs achieved the optimal EEM score for each patient.

CONCLUSIONS

The single-plane osteotomy model may have limitations in assessing IFSs, particularly when the bone cut rate and compression effects are the main influencing factors. Parameters of the screw stress and displacement, BCR, and compression effects appear to be relevant in evaluating IFSs for natural fracture models. It indicates that individualized natural fracture models could provide more comprehensive insights for determining the optimal IFS in treating vFNFs.

Morphological characteristics of femoral neck fractures in young and middle-aged population: a retrospective descriptive study

BACKGROUND

A understanding of morphological characteristics are important to femoral neck fractures (FNFs) resulting in high rates of complications in the young and middle-aged adults and the detailed data is lack in the literature. We aimed to report on the detailed morphological characteristics and the relationship between them in young and middle-aged adults with femoral neck fractures (FNFs).

METHODS

The postoperative CT images of one hundred and fifty-two adults with FNFs were retrospectively reviewed. After image standardization, morphological characteristics including fracture orientation, cortex comminution, and intraosseous bone defects were measured and analyzed. Additionally, the distribution and correlation of these morphological features were analyzed using Pauwels classification, the right angle of the neck axis (VNA) classification, and the anteromedial oblique angle (AMA).

RESULTS

Pauwels III fractures accounted for approximately half (55.2%) of the FNFs analyzed. Pauwels II and III could be detected in all four VNA types, and the distribution of the Pauwels types in VNA classification showed significant differences (χ2 = 106.363, p < 0.001). The VNA (9.0° ± 12.1) showed positive correlation with the neck-shaft angle (139.5° ± 6.3) and modified Pauwels angle (49.8° ± 10.6) (r = 0.441, r = 0.855, all p < 0.001). Cortical comminutions were commonly observed in the posterior (86.7%) and the inferior (80.7%). AMAs within the cases without posterior and inferior cortex comminutions were significantly larger than those with comminution (t = 2.594, 2.1196; p = 0.01, 0.036), but no difference could be detected after the AMA being divided into three groups (< 85°, 85°-95°, > 95°). The MPA, VNA and AMA of the group with an intraosseous defect were significantly different compared with those without (t = 2.847, 2.314, 2.268; p = 0.005, 0.022,0.025). The incidence of intraosseous defects within the groups with coronal and axial cortex comminutions were significantly higher than those within the groups without comminutions (χ2 = 34.87, 25.303; p < 0.001).

CONCLUSIONS

The present study highlights the morphological diversity and complexity within FNFs in young and middle-aged adults, which allows for more accurate simulation of FNF patterns in the future biomechanical studies.

Proximal femoral bionic nail-a novel internal fixation system for the treatment of femoral neck fractures: a finite element analysis

Introduction: Currently, cannulated screws (CSs) and dynamic hip screws (DHSs) are widely used for the treatment of femoral neck fractures, but the postoperative complications associated with these internal fixations remain high. In response to this challenge, our team proposes a new approach involving triangular-supported fixation and the development of the proximal femoral bionic nail (PFBN). The primary objective of this study is to investigate the biomechanical differences among CSs, DHSs, and the PFBN in their capacity to stabilize femoral neck fractures. Methods: A normal proximal femur model was constructed according to the CT data of a normal healthy adult. A femoral neck fracture model was constructed and fixed with CSs, DHSs, and the PFBN to simulate the fracture fixation model. Abaqus 6.14 software was used to compare the biomechanical characters of the three fracture fixation models. Results: The maximum stresses and displacements of the normal proximal femur were 45.35 MPa and 2.83 mm, respectively. Under axial loading, the PFBN was more effective than DHSs and CSs in improving the stress concentration of the internal fixation and reducing the peak values of von Mises stress, maximum principal stress, and minimum principal stress. The PFBN fixation model exhibits superior overall and fracture section stability in comparison to both the DHS fixation model and the CS fixation model under axial loading. Notably, the maximum stress and peak displacement of the PFBN and bone were lower than those of the DHS and CS fixation models under bending and torsional loading. Conclusion: The PFBN shows considerable improvement in reducing stress concentration, propagating stress, and enhancing the overall stability in the femoral neck fracture fixation model compared to DHSs and CSs. These enhancements more closely correspond to the tissue structure and biomechanical characteristics of the proximal femur, demonstrating that the PFBN has great potential for therapeutic purposes in treating femoral neck fractures.

In vitro biomechanical analysis of a locking self-compression screw model applied to Pauwels III and comminuted femoral neck fractures

Femoral neck fractures (FNFs) affect the young adult population and are intimately related to high-energy trauma. Despite innovations in osteosynthesis materials, the rate of complications remains at 10%-59% in Pauwels type III (PIII) fractures. The authors thus propose a fixation model with a novel self-compression screw, comparing it to a sliding hip screw plate associated with a derotation screw in the fixation of a PIII fracture with posterior inferior comminution. The finite element method (FEM) was used in this comparison along with a virtual femur model with structural characteristics similar to those of a healthy young human bone. We formed 4 groups: Group 1 (GC), intact bone; Group 2 (SHS+S), sliding hip screw plate with derotation screw; Group 3 (XS), X-pin + SS (self-compression model with superior positioning screw); Group 4 (XI), X-pin + IS (self-compression model with inferior positioning screw). A 700 N monotonic load was applied to the apex of the femur head towards the ground so that stress was mainly focused on the fracture site and osteosynthesis. Analyses included total displacement and maximum principal stress and were performed for all groups. Fracture displacement, rotation, and von Mises were assessed only in groups that underwent osteosynthesis. Total displacement values in groups with self-compression screws (XS and XI) were closer to those for healthy femurs, with a 38.5% reduction when comparing the XS group with the SHS+S group. Fracture displacement and rotation values presented reductions of over 60% when comparing the XS and XI groups with the SHS+S group. Equivalent Von Mises stress values were similar between XS and XI and presented a reduction of approximately 5.25% when compared with the SHS+S group. Our FEM analyses demonstrated that the self-compression screw model has potential biomechanical advantages over the SHS+S model.

What is the best method of fixation for minimally displaced subcapital neck of femur fractures? A systematic review

BACKGROUND

Femoral neck fractures are a common cause of morbidity and mortality in the community. Minimally displaced subcapital necks of femoral fractures are usually managed with internal fixation, although there is debate as to which method is superior. This systematic review aimed to compare the outcomes of different fixation methods in the management of this common fracture.

METHODS

This systematic review was conducted in accordance with PRISMA statement guidelines. The databases searched were MEDLINE (Ovid), Cochrane Central Register of Controlled Trials, and EMBASE (Ovid). The study quality and risk of bias were assessed using the Newcastle-Ottawa Quality Assessment Scale, and relevant data were extracted and synthesised.

RESULTS

Nine articles met the inclusion criteria. A total of 819 patients were included in this study. Eight of the nine studies were case series, and one was a randomised control trial. The mean risk of bias was 7.4/9 for non-randomised articles. The fixation methods used in the included studies were dynamic hip screw (DHS), cannulated screws, Smith-Peterson nail, hooknail, Moore's pins, and Knowle's pins. DHS was found to be a superior method of fixation and was supported by a clinical trial. It has high rates of union (99 %), low rates of avascular necrosis (<1 %), and low rates of fixation failure (<1 %).

CONCLUSIONS

Based on the available data, DHS appears to be the superior method of fixation for the minimally displaced subcapital neck of femoral fractures. Given the general low level of evidence currently available, additional clinical trials are needed in this area.

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

BACKGROUND

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

CASE PRESENTATION

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

CONCLUSIONS

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

A biomechanical comparison of three fixation methods for unstable femoral neck fractures with medial calcar defect

BACKGROUND

Unstable femoral neck fractures with medial calcar defects are difficult to manage. The optimal fixation methods for these fractures have been a subject of ongoing debate among orthopedic surgeons. In this study, three different fixation techniques for vertical, medial defected femoral neck fractures were compared.

METHODS

In this study, a biomechanical analysis was conducted to compare three fixation methods: cannulated screws (Group 1), cannulated screws combined with a medial buttress plate (Group 2), and intramedullary nails (Group 3). Synthetic composite bone models representing vertical collum femoris fractures with medial calcar defects were used. Each group consisted of seven specimens, and, to maintain consistency, a single surgeon performed the surgical procedure. Biomechanical testing involved subjecting the specimens to axial loading until failure, and the load to failure, stiffness, and displacement values were recorded. Normality was tested using the Shapiro-Wilk test. One-way ANOVA and Tukey's HSD post hoc test were used for comparisons.

RESULTS

The difference in the load to failure values was statistically significant among the groups, with Group 2 exhibiting the highest load to failure value, followed by Group 3 and Group 1. Stiffness values were significantly higher in Group 2 than in the other groups. Displacement values were not significantly different between the groups. Fracture and displacement patterns at the point of failure varied across the groups.

CONCLUSION

The results of this study indicate that fixation with a medial buttress plate in combination with cannulated screws provides additional biomechanical stability for vertical femoral neck fractures with medial calcar defects. Intramedullary nail fixation also demonstrated durable stability in these fractures. These findings can be used to better understand current management strategies for these challenging fractures to promote the identification of better evidence-based recommendations.

Bone Grafting Can Promote the Prognosis of Displaced Femoral Neck Fractures: A Follow-up of the Clinical Significance of Bone Defects

Background

Femoral neck fractures (FNFs) comprise a large proportion of osteoporotic fractures in Asia. However, the full range of prognostic variables that affect prognosis remains unclear. Here, we aimed to determine whether the severity of bone defects at the fracture site and other variables impact the prognosis of displaced FNFs.

Methods

We evaluated the incidence of FNF internal fixation failures at regular intervals after surgery in data collected retrospectively. Digital Imaging and Communications in Medicine (DICOM) magnetic resonance imaging data of the displaced FNFs of 204 patients (> 20 years old; mean age, 52.3 years; men, 55.4%) who underwent internal fixation were used to construct three-dimensional (3D) virtual models of the femoral neck region. We calculated the position and volume of bone defect (VBD) using our independently developed algorithm and Mimics software. Each participant was followed up for at least 24 months; complications were noted and correlated with VBD and demographic and clinical variables.

Results

On the basis of VBD values calculated from virtual reduction models, 57 patients were categorized as having a mild defect, 100 as having a moderate defect, and 47 as having a severe defect. Age (p = 0.046) and VBD (p < 0.001) were significantly correlated with internal fixation failure. Multivariate analysis revealed that severe bone defects were associated with internal fixation failure (adjusted odds ratio [aOR], 23.073; 95% confidence interval [CI], 2.791-190.732) and complications (aOR, 8.945; 95% CI, 1.829-43.749). In patients with a severe defect, bone grafting was inversely associated with internal fixation failure (aOR, 0.022; 95% CI, 0.002-0.268) and complications (aOR, 0.023; 95% CI, 0.002-0.299).

Conclusions

Bone defect severity was associated with internal fixation failure and other complications. For young adults with large VBDs, bone grafting of the defect can reduce the risk of internal fixation failure. These results provide useful new quantitative information for precisely classifying displaced FNFs and guiding subsequent optimal treatments.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Exploration of the synergistic role of cortical thickness asymmetry ("Trabecular Eccentricity" concept) in reducing fracture risk in the human femoral neck and a control bone (Artiodactyl Calcaneus)

The mechanobiology of the human femoral neck is a focus of research for many reasons including studies that aim to curb age-related bone loss that contributes to a near-exponential rate of hip fractures. Many believe that the femoral neck is often loaded in rather simple bending, which causes net tension stress in the upper (superior) femoral neck and net compression stress in its inferior aspect ("T/C paradigm"). This T/C loading regime lacks in vivo proof. The "C/C paradigm" is a plausible alternative simplified load history that is characterized by a gradient of net compression across the entire femoral neck; action of the gluteus medius and external rotators of the hip are important in this context. It is unclear which paradigm is at play in natural loading due to lack of in vivo bone strain data and deficiencies in understanding mechanisms and manifestations of bone adaptation in tension vs. compression. For these reasons, studies of the femoral neck would benefit from being compared to a 'control bone' that has been proven, by strain data, to be habitually loaded in bending. The artiodactyl (sheep and deer) calcaneus model has been shown to be a very suitable control in this context. However, the application of this control in understanding the load history of the femoral neck has only been attempted in two prior studies, which did not examine the interplay between cortical and trabecular bone, or potential load-sharing influences of tendons and ligaments. Our first goal is to compare fracture risk factors of the femoral neck in both paradigms. Our second goal is to compare and contrast the deer calcaneus to the human femoral neck in terms of fracture risk factors in the T/C paradigm (the C/C paradigm is not applicable in the artiodactyl calcaneus due to its highly constrained loading). Our third goal explores interplay between dorsal/compression and plantar/tension regions of the deer calcaneus and the load-sharing roles of a nearby ligament and tendon, with insights for translation to the femoral neck. These goals were achieved by employing the analytical model of Fox and Keaveny (J. Theoretical Biology 2001, 2003) that estimates fracture risk factors of the femoral neck. This model focuses on biomechanical advantages of the asymmetric distribution of cortical bone in the direction of habitual loading. The cortical thickness asymmetry of the femoral neck (thin superior cortex, thick inferior cortex) reflects the superior-inferior placement of trabecular bone (i.e., "trabecular eccentricity," TE). TE helps the femoral neck adapt to typical stresses and strains through load-sharing between superior and inferior cortices. Our goals were evaluated in the context of TE. Results showed the C/C paradigm has lower risk factors for the superior cortex and for the overall femoral neck, which is clinically relevant. TE analyses of the deer calcaneus revealed important synergism in load-sharing between the plantar/tension cortex and adjacent ligament/tendon, which challenges conventional understanding of how this control bone achieves functional adaptation. Comparisons with the control bone also exposed important deficiencies in current understanding of human femoral neck loading and its potential histocompositional adaptations.

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.

Mechanical study of the application of compression screw nails in the cross-inverted triangular pattern for internal fixation of femoral neck fractures

OBJECTIVE

To design a cross-inverted triangular pattern to insert compression screw nails for the treatment of femoral neck fractures and to compare the biomechanics of inserting compression screw nails in cross-inverted triangular patterns and inverted triangular patterns. I am very sorry that a corresponding author needs to be added to the article. I do not know how to insert it, so I make a note here. Please check the attachment I uploaded.

METHODS

The reasonableness of the model is first analyzed using finite elements. A total of 6 adult human specimens were selected, of which 3 males and 3 females were divided into the A1, B1, and C1 groups and the A2, B2, and C2 groups by the random number table method. The A1 and A2 groups were made into subhead femoral neck fracture models, the B1 and B2 groups were made into trans-neck femoral neck fracture models, and the C1 and C2 groups were made into basal femoral neck fracture models. The right femur of each group had a compression screw nail inserted in the crossed-inverted triangular pattern, and the left femur of each group had a compression screw nail inserted in the inverted triangular pattern. The static compression test was performed by an electronic universal testing machine. The maximum load of the femoral neck and the load of 3.00 mm axial displacement of the femoral head were read according to the pressure-displacement curve drawn in the experiment.

RESULTS

The finite element analysis showed that the cross-inverted triangular hollow threaded nail has better conductivity and more stable fixation than the inverted triangular hollow threaded nail. The maximum load of the femoral neck and the load of 3.00 mm axial displacement of the femoral head of the left femur were greater than those of the right femur in the A1, A2, B1, B2 and C2 groups, while the maximum load of the femoral neck and the load of 3.00 mm axial displacement of the femoral head of the left femur were smaller than those of the right femur in the C1 group. There was no statistically significant difference in the maximum load of the femoral neck or the load of 3.00 mm axial displacement of the femoral head between the A1 and A2 groups, the B1 and B2 groups, or the C1 and C2 groups (P > 0.05). After the K-S test, the maximum load of the femoral neck and the load of 3.00 mm axial displacement of the femoral head were normally distributed (P = 0.20), and the LSD-t test was conducted for the two load data; the difference was not statistically significant (P = 0.235).

CONCLUSION

The effect of compression screw nails in the cross-inverted triangular pattern was the same in males and females, and stability was better in the fixation of subhead and trans-neck femoral neck fractures. However, its stability in fixation of basal femoral neck fracture is worse than that of the inverted triangular pattern. The cross-inverted triangular hollow threaded nail has better conductivity and more stable fixation than the inverted triangular hollow threaded nail.

Biomechanical effects of internal fixation with self-lock compression anti-rotation blade for Pauwels type III femoral neck fractures: a comparative finite element analysis

BACKGROUND

Self-lock compression anti-rotation blade (SCAB) is a novel internal fixation implant for femoral neck fractures (FNF). We conducted this finite element analysis study to evaluate the biomechanical performances of SCAB combined with a cannulated screw for fixation of Pauwels type III FNF.

METHODS

Three finite element models of Pauwels type III FNF treated with various internal fixations were established: a: the inverted triangular parallel cannulated screw (3CS) model, b: the biplane double-supported screw fixation (BDSF) model, c: the SCAB combined with a cannulated screw model. Displacement and Von Mises stress of femurs and internal fixations under increasing loads as well as the average stress on fracture surfaces and maximum displacements on the X and Z axis of proximal fracture fragments at maximum load were measured and compared.

RESULT

The SCAB-based internal fixation exhibited superior biomechanical performances compared with 3CS and BDSF configurations, as the former resulted in lower parameters including displacement of the femur, Von Mises stress of internal fixation, stress on fracture surfaces as well as X and Z axis displacement of fracture fragments.

CONCLUSION

Internal fixation using SCAB combined with a cannulated screw for Pauwels type III FNFs shows enough stability, with satisfied resistance to varus and shearing forces, which may provide a new option for the treatment of FNFs.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

II, Systematic review and Meta-analysis.

TRIAL REGISTRATION

PROSPERO CRD42021283646.

The comparison of femoral neck system and cancellous screws internal fixation for femoral neck fracture

BACKGROUND

The clinical efficacy of cancellous screws (CS) and femoral neck system (FNS) internal fixation in the treatment of femoral neck fracture (FNF) was compared in this research.

METHODS

Ninety-six patients with FNF were enrolled in this study. There were 47 cases in FNS group and 49 cases in CS group. The data of operation time, intraoperative bleeding, bed days and complication were recorded. Patients' joint function was evaluated by Harris score. At the last follow-up, the cost-effectiveness analysis of the two methods was analyzed according to the total cost of patients and hip function.

RESULTS

The intraoperative blood loss of the patients in FNS group was significantly higher than that in the CS group, but the length of hospitalization was significantly lower. There was no significant difference in the incidence of complications between FNS and CS. The joint function of FNS group was significantly better than that of CS group at 3 months after operation. There was no significant difference in Harris score between the two groups at the last follow-up. The overall medical cost of FNS group in 1 year is high. Cost-effectiveness analysis showed that compared with CS group, FNS group needs to pay 5761.1 yuan more for each additional Harris score.

CONCLUSION

FNS and CS internal fixation can achieve satisfactory clinical results in the treatment of FNF. FNS treatment is helpful to the early functional recovery of patients, but the overall medical cost is high.

Risk factors associated with periprosthetic infection in patients with femoral neck fracture: A case-control study

BACKGROUND

Infection is one of the most important local complications in the patient with femoral neck fracture treated with arthroplasty. The aim of the present study is to describe and analyze possible risk factors that could be involved in periprosthetic infection in the patient with femoral neck fracture.

METHODS

A retrospective case-control study was performed including patients with femoral neck fractures treated with arthroplasty in the period between January 2015 and December 2017. Cases were defined as patients with femoral neck fracture who after undergoing arthroplasty (hemiarthroplasty or total hip arthroplasty) had a periprosthetic infection, whose diagnosis was carried out according to the major and minor criteria described in the International Consensus on Musculoskeletal Infections (Philadelphia 2018). In order to mitigate the influence of variables that could be considered confounding variables, a multivariate analysis was carried out.

OUTCOMES

A statistically significant association was found between periprosthetic infection and certain variables present at the time of admission, including the presence of moderate or severe anaemia (OR: 10.91; 95%CI: 1.07-111.50; P=.007), thrombocytopenia (OR: 27.72; 95%CI: 3.48-221.01; P=.002), history of thromboembolism event (OR: 8.80; 95%CI: 1.31-59.38; P=.026), anxious-depressive disorder in treatment with two or three drugs (OR: 21.36; 95%CI: 3.65-125.12; P=.001) and liver disease (OR: 32.04; 95%CI: 2.59-396.29; P=.007).

CONCLUSIONS

Periprosthetic infection in the patient with femoral neck fracture treated with arthroplasty could be related to the presence of certain variables at the time of hospital admission, including moderate or severe anaemia, thrombocytopenia, history of thromboembolic event, anxious-depressive disorder in treatment with two or three drugs or liver disease.

Quick and Accurate Placement of Cannulated Screws to Internal Fixation of Femoral Neck Fractures Using a Novel Guide Device

INTRODUCTION

Fixation of femoral neck fractures with cannulated screws is an accepted method. This study aimed to compare a novel guide device and conventional technique with regard to the accuracy, operation time, fluoroscopy numbers, and drilling attempts during the insertion of cannulated screws to internal fixation of femoral neck fractures.

METHODS

This retrospective study included 60 patients with intracapsular femoral neck fractures who were treated with cannulated screws from January 2020 to June 2021. Three screws were inserted into the femoral neck by conventional technique or using the novel guide device. The operative time, total drilling attempts, and fluoroscopy numbers were evaluated. The precision of implant placement was evaluated by screw parallelism and spread. The patients were followed for 12-24 months.

RESULTS

The fluoroscopy numbers and operation time of the guide-device-assisted group were shorter than for the conventional group (p < 0.05). The total drilling attempts were significantly lower with the guide device than in the conventional group (p < 0.05). The guide-device-assisted group had better screw parallelism and greater spread than the conventional group (p < 0.05).

CONCLUSIONS

The novel guide device may be an effective assistant instrument for internal fixation of femoral neck fracture with cannulated screws.

[Translated article] Risk factors associated with periprosthetic infection in patients with femoral neck fracture: A case-control study

BACKGROUND

Infection is one of the most important local complications in the patient with femoral neck fracture treated with arthroplasty. The aim of the present study is to describe and analyze possible risk factors that could be involved in periprosthetic infection in the patient with femoral neck fracture.

METHODS

A retrospective case-control study was performed including patients with femoral neck fractures treated with arthroplasty in the period between January 2015 and December 2017. Cases were defined as patients with femoral neck fracture who after undergoing arthroplasty (hemiarthroplasty or total hip arthroplasty) had a periprosthetic infection, whose diagnosis was carried out according to the major and minor criteria described in the International Consensus on Musculoskeletal Infections (Philadelphia 2018). In order to mitigate the influence of variables that could be considered confounding variables, a multivariate analysis was carried out.

OUTCOMES

A statistically significant association was found between periprosthetic infection and certain variables present at the time of admission, including the presence of moderate or severe anaemia (OR: 10.91; 95% CI: 1.07-111.50; P = .007), thrombocytopenia (OR: 27.72;95% CI: 3.48-221.01; P = .002), history of thromboembolism event (OR: 8.80; 95% CI: 1.31-59.38; P = .026), anxious-depressive disorder in treatment with two or three drugs (OR: 21.36; 95% CI: 3.65-125.12; P = .001) and liver disease (OR: 32.04; 95% CI: 2.59-396.29; P = .007).

CONCLUSIONS

Periprosthetic infection in the patient with femoral neck fracture treated with arthroplasty could be related to the presence of certain variables at the time of hospital admission, including moderate or severe anaemia, thrombocytopenia, history of thromboembolic event, anxious-depressive disorder in treatment with two or three drugs or liver disease.

Gamma Nail Combined with One Cannulated Compression Screw Fixation for Treating Pauwels Type III Femoral Neck Fractures in Young and Middle-Aged Adults: Clinical Follow-Up and Biomechanical Studies

OBJECTIVE

Recently, some clinical studies have reported the use of an intramedullary nailing system for treating unstable femoral neck fractures or femoral neck fractures combined with femoral shaft fractures in young adults, and the results have indicated certain advantages. However, no study has investigated the mechanical properties of this method. We aimed to evaluate the mechanical stability and clinical efficacy of the Gamma nail combined with one cannulated compression screw (CCS) fixation for treating Pauwels type III femoral neck fracture in young and middle-aged adults.

METHODS

This study consists of two parts: a clinical retrospective study and randomized controlled biomechanical test. Twelve adult cadaver femora were used to test and compare the biomechanical properties among three fixation methods: three parallel CCS (group A), Gamma nail (group B), and Gamma nail combined with one cannulated compression screw (group C). The single continuous compression test, cyclic load test, and ultimate vertical load test were used to evaluate the biomechanical performance of the three fixation methods. We also conducted a retrospective study of 31 patients with Pauwels type III femoral neck fractures, including 16 patients with fractures fixed with three parallel CCS (CCS group) and 15 patients with fractures fixed with Gamma nail combined with one CCS (Gamma nail + CCS group). The patients were followed up for at least 3 years, and all were evaluated for surgical time (from skin incision to closure), surgical blood loss, hospital stay, and the Harris hip score.

RESULTS

In mechanical experiments, we have found that the mechanical advantages of Gamma nail fixation are not as good as those of conventional CCS fixation. However, the mechanical properties of Gamma nail fixation combined with one cannulated screw perpendicular to the fracture line are much better than those of Gamma nail fixation and CCS fixation. No significant difference was found in the incidence of femoral head necrosis and nonunion between the CCS and Gamma nail + CCS groups. Moreover, there was no statistically significant difference in the Harris hip scores between the two groups. One patient in the CCS group showed significant withdrawal of cannulated screws at 5 months after surgery, whereas in the Gamma nail + CCS group, all patients, including those with femoral neck necrosis, showed no loss of stability of the fixation.

CONCLUSION

Among the two fixation methods evaluated in this study, Gamma nail combined with one CCS fixation showed better biomechanical properties and may reduce complications associated with unstable fixation devices.

Combined Deflection Angle Classification: A Novel Typing System of Adult Femoral Neck Fracture

OBJECTIVE

Femoral neck fracture (FNF) is a common clinical trauma with high mortality and disability rates. Furthermore, its incidence increases exponentially with increasing age. Existing classifications have some disadvantages. Thus, this study aimed to establish a novel typing system for FNF.

METHODS

We retrospectively analyzed all adult patients with FNF admitted to our hospital between December 2015 and November 2017 for cannulated screw internal fixation. The study population was divided into the femoral varus offset group (VAR) and the valgus offset group (VAL). The data collected included sex, age, affected side, injury mode, body mass index, complications, pelvic incidence (PI), hip deflection angle (HDA), combined deflection angle (CDA), and neck shaft angle. Statistical analysis was conducted to determine the correlation between complications and deviation angles. A novel typing system was developed and compared with the Garden classification to detect its superiority.

RESULTS

A total of 108 patients were recruited, with 59 patients in the VAR and 49 patients in the VAL groups. The incidence of complications in the VAR group was significantly higher than that in the VAL group (P < 0.05). Moreover, there were more male participants in the VAR group. Compared with the VAL group, the VAR group had significantly higher PI, HDA, and CDA (P < 0.05). The CDA classification (CDAC) was defined, with CDA as the main criterion and HDA as the supplementary criterion. Furthermore, there was a hierarchical correlation between the actual incidence of complications and the typing level, which was increased in CDAC but not in the Garden classification. This showed that CDAC was more accurate.

CONCLUSION

A novel typing system, CDAC, for FNF was established, which was more accurate than the Garden classification. We suggest combining CDAC and Garden classifications for the preoperative diagnosis, treatment selection, and prognostic evaluation for patients with FNF.

Biomechanical evaluation of compression buttress screw and medial plate fixation for the treatment of vertical femoral neck fractures

OBJECTIVE

To compare the biomechanical properties of compression buttress screw (CBS) fixation with three plate fixation methods for the treatment of vertical femoral neck fractures (FNFs).

METHODS

A total of forty synthetic femoral models with simulated Pauwels type III fractures (angle of 70°) were equally assigned to one of four fixation groups: CBS fixation, anteromedial plate fixation (AMP), medial buttress plate fixation (MBP) and medial buttress plate fixation without proximal screw (MBPw). Within each group, half of the specimens were randomly assigned to two loading settings, an axial compression loading test and a hip-flexion torsion test.

RESULTS

There were no significant differences in axial load to failure, axial stiffness, torsional strength, or torsional stiffness when comparing CBS with MBP (p>0.05). In the axial compression loading test, both CBS and MBP showed higher load to failure and axial stiffness than MBPw (p<0.05). In torsional testing, AMP exhibited superior torsional strength and torsional stiffness than both MBPw and MBP (all p<0.05) and a higher torsional strength than CBS fixation (p<0.05). There were no significant differences in torsional stiffness between the CBS and AMP fixation groups (p>0.05).

CONCLUSION

The biomechanical parameters of CBS fixation are comparable to that of AMP and MBP, and demonstrate superior axial stiffness than MBPw fixation. Although the CBS method for surgical fixation of vertical FNF holds promise as a less invasive surgical technique than plate fixation with similar biomechanical assessments, further clinical evaluation is warranted.

The incidence of focal osteonecrosis of the femoral head and its impact on conversion hip arthroplasty after screw fixation of femoral neck fractures: a multicenter retrospective study based on postoperative magnetic resonance imaging

PURPOSE

Osteonecrosis of the femoral head (ONFH) and subsequent head collapse is a major concern after internal fixation of femoral neck fracture (FNF). Previous studies focused on ONFH incidence using plain radiography; postoperative magnetic resonance imaging (MRI) was rarely performed. We performed a multicenter retrospective study to investigate the incidence of ONFH and the need for conversion hip arthroplasty after FNF screw fixation.

METHODS

We reviewed 195 patients who underwent screw fixation during closed FNF reduction between 2012 and 2017 at three institutions. Except for patients who did not consent to MRI, all patients underwent postoperative MRI either 1-3 years after screw fixation. The occurrence of ONFH was investigated through plain radiography and MRI.

RESULTS

Thirty patients were diagnosed with ONFH through plain radiography, and an additional 33 patients were diagnosed with MRI, resulting in a total of 63 patients (32.3%) diagnosed with ONFH. The mean time to ONFH diagnosis was 18.9 months and the conversion rate to hip arthroplasty was 10.2%. Of the 33 patients who were normal on hip radiography but exhibited ONFH on MRI, all had small focal lesions not associated with head collapse at the last follow-up. The ONFH group diagnosed through plain radiography had more unstable FNFs than the group diagnosed through MRI.

CONCLUSION

Although postoperative MRI revealed a higher incidence of ONFH after FNF screw fixation than reported previously, the small focal MRI lesions were not associated with increased risks of femoral head collapse or conversion to arthroplasty.

Finite element comparative analysis of three different internal fixation methods in the treatment of Pauwels type III femoral neck fractures

BACKGROUND

Comparison of 4 cannulated lag screws (3 inverted triangular cannulated screws + anti-rotating screws;4 CLS), dynamic hip screws + derotational screws (DHS + DS), and femoral neck fixation system (FNS) in the treatment of Biomechanical properties of middle-aged Pauwels type III femoral neck fractures.

METHODS

The femur CT data of a healthy young volunteer was selected and imported into Mimics software to construct a three-dimensional model of a normal femur. Pauwels type III femoral neck fractures were simulated according to the 70° fracture line. Use Geomagic and SolidWorks software to optimize and build CLS, DHS + DS, and FNS fracture internal fixation models. Finally, Ansys software was used to analyze the stress distribution, peak value, and maximum displacement of the proximal fracture fragment and internal fixation; the displacement distribution, and peak value of the fracture surface at the fracture end.

RESULTS

① The stress peaks of the proximal fracture fragments in the three groups were concentrated near the femoral calcar. The peak stress of the FNS group was the largest, and the DHS + DS group was the smallest. ②The displacement of the fracture fragments was all located at the top of the femur. The peak displacement of the FNS group was the largest, and the DHS + DS group was the smallest. ③ The internal fixation stress of the three groups is concentrated in the middle part of the device. The stress distribution of the first two groups of models is more uniform than that of FNS. The peak stress of FNS is the largest and the CLS is the smallest. ④ The internal fixed displacements are all located at the top of the model. The peak displacement of the CLS is the largest, and the DHS + DS is the smallest. ⑤ The displacement of the fracture surface is in the upper part of the fractured end. The peak displacement of the FNS group was the largest, and the DHS + DS group was the smallest.

CONCLUSION

Compared with the other two internal fixation methods, dynamic hip screw + derotational screw (DHS + DS) showed good biomechanical stability. When Pauwels type III femoral neck fracture occurs in young adults, DHS + DS can be given priority as the preferred treatment for this type of fracture.

Reoperation rate and implants’ position variation features of displaced femoral neck fractures with sliding compression or length-stable fixation in young and middle-aged population

Introduction

Sliding compression fixation and length-stable fixation are two basic internal fixation concepts in the treatment of displaced femoral neck fractures. In this study, we aimed to compare the reoperation rates for different methodologies of internal fixation for femoral neck fractures in young and middle-aged population.

Materials and methods

This a retrospective study. A total of 215 patients with displaced femoral neck fractures treated with cannulated screw fixation were enrolled and divided into the sliding compression and length-stable groups according to the fixation pattern. The occurrence of and reason for revision surgery within one year were recorded. Forty-five patients with complete CT data (including CT scanning on the first postoperative day and at the last follow up) were selected from the total sample. A newly established computerized image processing method was used to evaluate variations in the spatial location of screws.

Results

The reoperation rate was significantly higher in the length-stable group (23.8%) than in the sliding compression group (7.3%). The rate of revision surgery due to nonunion was also higher in the length-stable group (11.4%) than in the sliding compression group (1.8%). However, no significant difference was observed in terms of joint penetration or soft tissue irritation. The sliding compression group (6.58 ± 3.18 mm) showed higher femoral neck shortening than length-stable group (4.16 ± 3.65 mm). When analyzing the spatial variations, a significantly greater screw withdrawal distance was observed in the sliding compression group than in the length-stable group, but with a smaller rotation angle.

Conclusion

Length-stable internal fixation of displaced femoral neck fractures may lead to an increased reoperation rate in young and middle-aged population.

Trial registration

Name of the registry: Chinese Clinical Trial Registry.

Trial registration number: ChiCTR2000032327.

Trial registration date: 2020–4-26.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Internal Fixation of Garden Type III Femoral Neck Fractures with Sliding Hip Screw and Anti-Rotation Screw: Does Increased Valgus Improve Healing?

Background and Objectives: The aim of this study was to compare the effect of valgus versus anatomic reduction on internal fixation of Garden type III femoral neck fractures using the sliding hip screw (SHS) and anti-rotation screw (ARS) regarding the radiographic and therapeutic outcome. Patients and Methods: A retrospective case-controlled study was performed in a level I trauma center. All patients between 2006 and 2020 aged younger than 70 years with a Garden type III femoral neck fracture and a Kellgren-Lawrence score under grade III stabilized using SHS and ARS were identified. One-hundred and nine patients were included, with a group distribution of sixty-eight patients in group A (anatomic reduction) and forty-one patients in group B (valgus reduction). Results: Mean age was 55 years, and the mean Kellgren-Lawrence score was 1 in both groups. Mean femoral neck angle was 130.5 ± 3.8° in group A and 142.8 ± 4.3° in group B (p = 0.001), with an over-correction of 12° in group B. Tip-apex distance was 10.0 ± 2.8 mm in group A versus 9.3 ± 2.8 mm in group B (p = 0.89). Healing time was 9 weeks in group A compared to 12 weeks in group B (p = 0.001). Failure rate was 4.4% in group A and 17.1% in group B (p = 0.027). Conclusions: Anatomic reduction of Garden type III femoral neck fractures in patients younger than 70 years treated using SHS and ARS resulted in significantly lower failure rates and shorter healing times than after valgus reduction. Therefore, it can be recommended to achieve anatomic reduction.

[Influence of medical outliers in patients with femoral neck fracture]

OBJECTIVES

The objective is to describe and analyze how outlier admission influences hospital stay and the appearance of complications in patients with a femoral neck fracture treated with arthroplasty.

MATERIAL AND METHOD

A historical cohort study was carried out in which the group of patients with a displaced fracture of the femoral neck who had an outlier admission was defined as an exposed cohort, that is, they were admitted to a hospitalization area not belonging to the Orthopedic Surgery and Traumatology department, unlike the unexposed cohort, that included patients admitted to a hospitalization area assigned to the Orthopedic Surgery and Traumatology department.

RESULTS

Outlier admission was a risk factor for requiring a postoperative transfusion (RR 1.52, 95% CI 1.05-2.21; P=.035), to have a postoperative stay longer than 5 days (RR 1.35, 95% CI 1.04-1.74; P=.038) and to suffer general postoperative complications (RR 1.35, 95% CI 1.02-1.78; P=.048).

CONCLUSIONS

Outlier admission is a threat to the quality and safety of health care. In patients over 80 years of age, medical outliers is a risk factor for postoperative transfusion and systemic postoperative complications.

Broken pin removal from hip joint using arthroscopic grasper - A technical note and review of literature

Guidewire breakage during a surgical procedure is uncommon but still challenging for orthopedic surgeons. Due to the potential for harmful complications, surgeons prefer to remove broken wires near the joint surface or neurovascular bundle in the hip region. Due to the depth of the location, the retrieval procedure is arduous, time-consuming, and potentially dangerous. This study describes a case of a sub-capital femoral neck fracture that was fixed with a cannulated screw. However, three years later, the distal portion of the guidewire broke and migrated into the hip joint, where it became entrapped. This study describes a method for removing a broken wire from the hip region and a relevant literature review. In brief, initially, we untightened the screw and removed it. Afterward, the broken wire was reached by reaming in the direction of the screw. Ultimately, we advanced the arthroscopic grasper to the broken wire for removal under fluoroscopic guidance. The study's findings indicate that this method could provide a promising outcome with minimal complications.

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

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

Biomechanical comparison of four different fixation methods in the management of Pauwels type III femoral neck fractures: Is there a clear winner?

BACKGROUND

Cannulated screws augmented with the medial buttress plate could confer greater biomechanical stability and higher union rates than the screw fixation alone for treating young patients with Pauwels type III femoral neck fractures (FNFs). No study has evaluated the effects of distal bicortical screw fixation and biomechanical properties of buttress plate augmentation under simultaneous vertical and rotational forces, physiologically acting on the hip joint. This study aimed to compare the biomechanical properties of four methods of three cannulated screw fixation under the combined axial and torsional loading in a synthetic femur model of type III FNF.

METHODS

Twenty-four third-generation composite femora were divided into four groups (6 femora in each group) based on the screw fixation configuration: inverted triangle configuration (Group A),  Pauwels' configuration (Group B), inverted triangle configuration combined with medial buttress plate using distal unicortical (Group C), and distal bicortical screw placement (Group D). A Pauwels type III FNF was simulated on the sawbones. Each model was subjected to the combined axial and torsional cyclic loading and subsequently tested to failure.

RESULT

Significant differences were determined in axial stiffness (AS) among the four groups (p = 0.024), whereas there was no significant difference in torsional stiffness (p = 0.147). The mean AS was higher in group D (639.5 ± 86.2 N/mm) than in group A (430.6 ± 94.8 N/mm), group B (426.2 ± 41.9 N/mm), and group C (451.2 ± 156.7 N/mm). Failure forces (FFs) were significantly different among four groups (p = 0.007), while there was no considerable difference in failure moment values (p = 0.555). The mean FF was significantly higher in group D (1307.1 ± 96.4 N) than in group A  (1076.9 ± 371.2 N) and group B (1075.5 ± 348.3 N) (p = 0.014 and p = 0.018, respectively). There was no significant difference in the mean FF between groups D and C.

CONCLUSION

Regardless of the medial plate use, multiple cannulated systems could provide similar biomechanical results regarding torsional stiffness and failure moments. Bicortical placement of the most distal screw in medial buttress plate application could improve axial stability but not significantly affect the rotational stability of the inverted triangle screw fixation system in managing type III FNFs.

Global Research Status and Trends of Femoral Neck Fracture Over the Past 27 Years: A Historical Review and Bibliometric Analysis

Background

Femoral neck fracture (FNF) is a commonly encountered injury in orthopedic practice, and many studies have been conducted in this field. However, no bibliometric studies regarding the global research trend concerning FNF have been performed. This study aims to analyze the knowledge framework, research hotspots, and theme trends in the field of FNF research.

Methods

The scientific outputs related to FNF from 1994 to 2021 were retrieved from the Web of Science Core Collection. Three bibliometric tools were used for this study. The main analyses include publication and citation counts, contributions of countries, institutions, authors, funding agencies and journals, and clustering of keywords.

Results

In total, 3,553 articles were identified. The annual publication counts of FNF showed an ascending tendency as a whole. The United States has the most prominent contributions, with the most number of publications and the highest H-index. Karolinska Institutet devoted the most in this domain. Professors Bhandari M, Schemitsch EH, Frihagen F, Parker MJ, and Rogmark C were the core authors in this field. The most productive journal was Injury International Journal of the Care of the Injured. Keywords were divided into four clusters: epidemiology and mortality, fracture prevention, internal-fixation and risk factors, and hip replacement. A trend of balanced and diversified development existed in these clusters. Keywords with the ongoing bursts, including “outcome,” “reoperation,” “complication,” “revision,” “displaced intracapsular,” “fracture,” and “adult,” are considered as the research hotspots in the future and deserve more attention.

Conclusions

The management of FNF in young patients is drawing more attention from orthopedic surgeons, and it is expected that these research topics may continue to be the research hotspots and focus in the near future.

Multiple cannulated screw fixation of femoral neck fractures with comminution in young- and middle-aged patients

Objective

To investigate the distribution and influence of comminution in femoral neck fracture (FNF) patients after cannulated screw fixation (CSF).

Methods

From January 2019 to June 2020, a total of 473 patients aged 23–65 years with FNF treated by CSF were included in the present study. Based on location of the cortical comminution, FNF patients were assigned to two groups: the comminution group (anterior comminution, posterior comminution, superior comminution, inferior comminution, multiple comminutions) or the without comminution group. The incidence of postoperative complications, quality of life and functional outcomes was recorded at 1-year follow-up.

Results

Comminution was more likely to appear in displaced FNF patients (86.8%) compared with non-displaced FNF patients (8.9%), and the rate of comminution was closely associated with Pauwels classification (3.2% vs 53.5% vs 83.9%, P < 0.05). The incidence of osteonecrosis of the femoral head (ONFH, 11.3% vs 2.9%, P < 0.05), nonunion (7.5% vs 1.7%, P < 0.05), femoral neck shortening (21.6% vs 13.4%, P < 0.05) and internal fixation failure (11.8% vs 2.9%, P < 0.05) was significantly higher in FNF patients with comminutions, especially with multiple comminutions, than those without. Furthermore, there was a significant difference in the Harris hip score (HHS, 85.6 ± 15.6 vs 91.3 ± 10.8, P < 0.05) and EuroQol five dimensions questionnaire (EQ-5D, 0.85 ± 0.17 vs 0.91 ± 0.18, P < 0.05) between FNF patients with comminution and those without. There was no significant difference in Visual analogue scale scores (VAS, 1.46 ± 2.49 vs 1.13 ± 1.80, P > 0.05) between two groups at 1 year post-surgery.

Conclusion

Comminution is a risk factor for postoperative complications in young- and middle-aged patients with displaced and Pauwels type III FNF who undergo CSF. This can influence the recovery of hip function, thereby impacting quality of life. Further evaluation with a more comprehensive study design, larger sample and long-term follow-up is needed.

A Novel Fluoroscopic View for Improved Assessment of the Safety of the Posterosuperior Screw in Femoral Neck Fracture Fixation

BACKGROUND

The purpose of the present study was to determine specific fluoroscopic views of the femoral neck to accurately identify partially extraosseous ("in-out-in"; IOI) placement of the posterosuperior screw for fixation of femoral neck fractures.

METHODS

A 3.2-mm guide pin was placed in the posterosuperior aspect of 2 synthetic femur models: 1 entirely intraosseous and 1 IOI. Sequential fluoroscopic images were made at 5° intervals in order to identify which fluoroscopic projections identified IOI guide pin placement. These images were utilized to inform screw placement and assessment in the second phase of the study, which involved the use of cadaveric specimens. In Phase II, the posterosuperior screw of the inverted triangle was placed in 10 cadaveric specimens with use of a standard posteroanterior fluoroscopic view and 1 of 2 lateral views, either (1) neck in line with the shaft, i.e., 0° lateral; or (2) a -15° rollunder view. The final fluoroscopic views (i.e., the posteroanterior and multiple lateral and oblique views) were randomized and blinded for review by 10 orthopaedic residents and 5 attending orthopaedic traumatologists. Specimens were stripped of soft tissue and inspected for screw perforation.

RESULTS

Overall accuracy of respondents was 68.8%, with no difference between the attending traumatologists (71.8%) and resident surgeons (67.4%; p = 0.173). Interobserver reliability was moderate (κ = 0.496). Dissection identified that 4 (40%) of 10 screws were extraosseous. All of the extraosseous screws were placed with use of the 0° lateral view. The -15° rollunder lateral view was the most sensitive (81.7%) and specific (92.2%) view for identifying IOI screw placement.

CONCLUSIONS

Surgeons often utilize the standard posteroanterior and 0° lateral fluoroscopic views to safely place screws; however, many of these screws are IOI. The addition of a -15° rollunder lateral view significantly improved identification of IOI screws in the posterosuperior femoral neck. Unidentified IOI screw placement may result in damage to the blood supply of the femoral head.

Challenging the dogma to "always operate" acute hip fractures: a proof-of-concept pilot study for nonoperative management of undisplaced femoral neck fractures

Background

The notion that all acute hip fractures are a surgical entity requiring either surgical fracture fixation or hip replacement represents a historic dogma, particularly within the orthopaedic community of the United States. The present study from a European regional trauma center was designed to challenge the notion that stable and undisplaced femoral neck fractures represent an absolute indication for surgical management.

Methods

The purpose of this study was to investigate the hypothesis that stable and undisplaced femoral neck fractures of the Garden types 1 and 2 can be safely managed nonoperatively. A retrospective observational cohort study was carried out at a regional orthopaedic trauma center in Germany from January 1, 2016 to June 30, 2021. The inclusion criteria specified patients older than 18 years suffering a < 24 h, traumatic, femoral neck fracture Garden types 1 and 2. Exclusion criteria included Garden types 3 and 4 femoral neck fractures, pregnancy, active infection or previous surgery, tumor-associated fractures, medical history of femoral neck necrosis, vascular injury associated with femoral neck fractures, nerve injury associated to a femoral neck fracture and ≥ 24 h femoral neck fracture. The primary intention of this research was to identify deterioration of fracture retention with an ensuing unplanned trip to the operating room in femoral neck fractures Garden types 1 and 2. Secondary were included unplanned readmissions and complications such as surgical site infection.

Results

A total of 41 undisplaced femoral neck fractures (Garden types 1 and 2) were included in this study; n = 20 were in the resulting admission operatively treated (group 1) and n = 21 were treated conservatively. The mean age in group 1 was 76 years; women (70%). In group 2 it was 81 years with a female dominance (71.4%). Admission status: Garden types 1 and 2, group 1 n = 13/7 and group 2 n = 15/6. Subsequent femoral neck fracture displacement (Y/N) (in case of operation, before operation) group 1 n = 14/6 and group 2 n = 6/15.

Conclusion

According with our results, patients sustaining Garden type 1 femoral neck fractures, depending on age and comorbidities, should be treated conservatively with weight bearing and under physiotherapeutic instructions. In case of femoral neck fractures Garden type 2, a surgical treatment should be performed in order to avoid femoral neck fractures to slip after weight bearing by lacking of fracture impaction.

Patient-specific risk factors for adverse outcomes following geriatric proximal femur fractures

BACKGROUND

Proximal femur fractures (PFFs) occur frequently among geriatric patients due to diverse risk factors, such as a lower bone mineral density and the increased risk of falls.

METHODS

In this review, we focus on recent literature of patient-specific risk factors and their impact on common complications and outcome parameters in patients with PFF.

RESULTS

Patient- and treatment related factors have a significant impact on outcome and are associated with an increased risk of mortality, impairments in functional rehabilitation and complicative courses.

CONCLUSION

Geriatric patients at high risk for complications are nursing home inhabitants suffering from severe osteoporosis, dementia and sarcopenia. The early and ongoing assessment for these individual risk factors is crucial. Strategies including interdisciplinary approaches, addressing comorbidities and facilitating an optimal risk factor evaluation result in a beneficial outcome. The ongoing ambulant assessment and therapy of complicating factors (e.g., malnutrition, sarcopenia, frailty or osteoporosis) have to be improved.

Effect of Psychological Support Therapy on Psychological State, Pain, and Quality of Life of Elderly Patients With Femoral Neck Fracture

Purpose

To explore the intervention effect of psychological support therapy (PST) on elderly patients with femoral neck fracture.

Methods

A total of 82 elderly patients with femoral neck fractures admitted to our hospital from July 2020 to June 2021 were selected. Patients were randomly divided into conventional group (n = 41) and intervention group (n = 41). The conventional group received routine nursing care. The intervention group was given PST on the basis of the conventional group. The joint function, psychological state, pain, quality of life, and nursing satisfaction of both groups were observed.

Results

Compared with before intervention, the Harris hip joint score and the General Quality-of-Life Inventory-74 scores of both groups increased after the intervention, and the increase was more obvious in the intervention group (p < 0.05). Compared with before intervention, the self-rating anxiety scale, the self-rating depression scale scores, and the visual analog scales score in both groups decreased after the intervention, and the decrease was more obvious in the intervention group (p < 0.05). The total satisfaction of the intervention group (92.68%) was higher than that of the conventional group (75.61%) (p < 0.05).

Conclusion

Psychological support therapy has a certain intervention effect on elderly patients with femoral neck fracture, which can improve psychological state, reduce pain, improve quality of life, and improve nursing satisfaction.

Biomechanical study of extramedullary and intramedullary fixation in the treatment of unstable intertrochanteric reversed-tilt fractures of the femur

Background

To investigate the efficacy of the 135° hip screw, 95° intramedullary hip screw (IMHS) and 95° hip screw in the treatment of intertrochanteric reverse dip fracture of the femur.

Methods

We retrospectively analyzed 125 matched pairs of human femurs (median age 64 years) which were osteotomized at a 33° angle in the left femur and extended downward from the minor trochanter to simulate a reverse oblique intertrochanteric fracture. The right femur served as a control. The left femur (n=4) was implanted with a 135° hip screw, 95° hip screw, or IMHS. A strain detector was placed distal to the fracture site to monitor fragment strain. The lateral displacement of the proximal femur was measured by a linear variable differential transformer. An Instron tester measured stiffness, strain, and lateral displacement at 25° adduction, and 90° adduction with vertical loads on the femoral head. A 2 cm gap was then formed at the fracture site to simulate comminution and the mechanical test was repeated.

Results

Before the formation of the gap, there was no significant difference in stiffness among different bone structures (P>0.05), but after the formation of the gap, the stiffness of all the adduction structures decreased (P=0.03), and the difference in adduction was statistically significant (135° hip screw: 46.6%±3%; 95° hip screw: 22.9%±2%; IMHS: 53.7%±7.8%; P<0.05). Similar results were found for the abduction and buckling positions. There was no significant difference in the lateral displacement of the gap before (P=0.92) and after (P=0.26), but a significant difference in the failure load was found (135° hip screw: 1,222±560 N; 95° hip screw: 2,566±283 N; IMHS: 4,644±518 N; P=0.02).

Conclusions

There was no statistically significant difference in stiffness among different structures (P>0.05). However, in the presence of gaps, IMHS bone implant structures are much stiffer than 135° and 95° structures and have a greater destructive load.

A Comparative Study between Proximal Femoral Locking Plate and Multiple Cannulated Screws for Fixation of Femoral Neck Fractures in Young Adults

OBJECTIVE

To compare the clinical effect of proximal femoral locking plate (PFLP) versus multiple cancellous screw (MCS) for FNF.

METHODS

FNF patients were treated with the PFLP implant or multiple cancellous screws (MCSs). Patient has been followed up for at least 12 months after surgery nonunion, and the occurrence of complications, femoral neck shortening, fracture healing time, and Harris hip score were recorded and compared.

RESULTS

77 FNF patients were treated with the PFLP (36 patients) or MCS (41 patients). The sex, age, side of the injured limb, type of Garden fracture, time from injury to surgery, and fracture healing time of two groups patients were comparable. The operation time and intraoperative blood loss in the PFLP group were worse than those in the MCS group. Two patients with the PFLP (5%) and nine patients (21%) with the MCS experienced cut out of the lag screw or avascular necrosis of the femoral head or nonunion and received hip replacement. However, the number of fluoroscopies in the PFLP group was significantly lower than that in the MCS group. Additionally, the femoral neck shortening and Harris hip score were all strongly better in the PFLP group than in the MCS group.

CONCLUSIONS

Compared with the MCS, PFLP treatment for FNF in young adults can decrease the fluoroscopy times, improve hip functional recovery, and reduce the complications rate and femoral neck shortening.

Experimental evaluation of the primary fixation stability of uncemented ceramic hip resurfacing implants

Hip resurfacing arthroplasty is associated with increased frictional moments compared to standard heads owing to their large diameter. High frictional moments may harbor the risk of the implant loosening if the frictional moments exceed the fixation stability of the hip resurfacing arthroplasty. Therefore, the aim of this experimental study was to evaluate the fixation stability of ceramic hip resurfacing implants through a turn-off test. The test specimens, made of alumina toughened zirconia (ATZ) ceramics with an inner titanium-coated surface and square base bodies for better application to the test setup, were pushed on artificial bone materials until a predefined seating depth was achieved. Thereafter, the specimens were turned off from the artificial bone material by using a lever-arm and the turn-off moments were calculated. The density of the artificial bone material utilized (15 and 25 pcf), the press-fit (0.4 and 0.8 mm) and the size of the test specimens varied. The push-on forces ranged from 0.6 ± 0.1 kN to 5.6 ± 0.5 kN depending on the press-fit and artificial bone material. The turn-off moments relied on the respective press-fit, artificial bone material and size of the specimen. They belonged between the range of 8.5 ± 0.4 Nm and 105.4 ± 0.2 Nm. Most of the previously described frictional moments are lower compared to the turn-off moments determined in this study. However, in the worst-case scenario, the turn-off moments of the hip resurfacing implants may be reduced, especially when the adjacent bone stock has a low mineral density.

The role of the medial buttress plate in the treatment of Pauwels type II and III femoral neck fracture in nonelderly patients: a retrospective study and preliminary results

Background

The purpose of this study was to compare the effectiveness of multiple cannulated screws combined with medial buttress plate or not for the treatment of unstable femoral neck fracture in nonelderly patients.

Methods

Sixty-nine nonelderly patients with Garden type III-IV femoral neck fracture were retrospectively analyzed. The patients were divided into MCS (multiple cannulated screws) group and CMBP (combined with medial buttress plate) group according to the surgical method. Patient’s demographic data, Harris Hip Score, EQ-5D index and complications at a minimum of 2 years follow-up were analyzed.

Results

There were 47 patients in the MCS group (35 male and 12 females) with a mean age of 40.28 ± 12.64 years, whereas 22 patients in the CMBP group (17 male and 5 females) with a mean age of 43.86 ± 12.55 years. In the MCS group, there were 1 (2.1%) avascular necrosis, 5 (10.6%) postoperative nonunion, 5 (10.6%) implant failure, and 2 (4.3%) femoral neck shortening. While 1 (4.5%) implant failure, 2 (9.1%) postoperative nonunion and 2 (9.1%) impingement in the CMBP group. For patients with Pauwels type II and III femoral neck fracture, the CMBP group had higher HHS scores at 3 months after surgery than the MCS group (P < 0.05), whereas there was no statistical significance at 6 months, 1 year, and 2 years (P > 0.05). The same results were found in the EQ-5D index.

Conclusions

In our cohort, we observed better outcomes in the CMBP group at 3 and 6 months, with later results similar between groups. However, there were fewer complications in the CMBP group, without obviously blood-supply disruption, especially in Pauwels type II and III. Further, anatomic reduction and stable fixation may contribute to satisfactory outcomes in the treatment of nonelderly displaced femoral neck fractures.

The oblique triangle configuration of three parallel screws for femoral neck fracture fixation using computer-aided design modules

Closed reduction and internal fixation with three cannulated compression screws is a common method for treating femoral neck fractures in young and middle-aged patients. Protocols including the inverted triangle configuration and dispersion of the screws still needed further supports. The purpose of this study was to explore a novel oblique triangle configuration (OTC) of three screws in fixing femoral neck fractures based on the morphology of the femoral neck isthmus (FNI). The computer-aided design modules were used to explore the ideal spatial configuration with largest triangle by three parallel screws. A univariate evaluation model was established based on the oval-like cross-section of the FNI. When the three screws were positioned by the OTC, Inverted Equilateral Triangle Configuration (IETC), and the Maximum Area Inverted Isosceles Triangle Configuration (MA-IITC) respectively, the proportion of area and circumference in the cross-section of FNI and the changing trend of proportion were compared under various torsion angles, eccentricity, and cross-sectional area of FNI. The area and circumference ratios of the parallel screws using the OTC method were significantly higher than in the IETC and MA-IITC groups. In the univariate evaluation model, the OTC area ratio and circumference ratio remained stable under the different femoral neck torsion angles, FNI cross-sectional area, and eccentricity. The OTC method provided an ideal spatial configuration for the FNA fixation with the largest area using three parallel screws. The position of the posterior screw was also away from the metaphyseal artery, potentially reducing the possibility of vascular injury and screw penetrating.

The Effect of Vertical and Oblique Inclinations on Fracture Stability and Reoperation Risks in Femoral-Neck Fractures of Nongeriatric Patient

Background: For nongeriatric patients with femoral neck fractures (FNFs), preoperative evaluation of fracture three-dimensional inclination is essential to identify fracture stability, select appropriate fixation strategies, and improved clinical prognoses. However, there is lack of evaluation system which takes into account both vertical and oblique inclinations. The purpose of this study was to comprehensively investigate the effect of vertical and oblique inclinations on fracture stability and reoperation risks.

Methods: We retrospectively reviewed the medical records of 755 FNFs patients with over 2 years follow-up. The 3-D inclination angle in vertical (α) and oblique plane (β) were measured based on CT images. The optimal threshold for unstable 3-D inclination were identified by seeking the highest Youden Index in predicting reoperation and validated in the biomechanical test. According to the cut-off value proposed in the diagnostic analysis, forty-two bone models were divided into seven groups, and were all fixed with traditional three parallel screws. Interfragmentary motion (IFM) was used for comparison among seven groups. The association between reoperation outcome and 3-D inclination was analysed with a multivariate model.

Results and Conclusion: The overall reoperation rate was 13.2%. Unstable 3-D inclination angles with an optimally determined Youden index (0.39) included vertical (α > 70°) and oblique (50°<α < 70° and β > 20°/β < −20°) types. Biomechanical validation showed these fractures had significantly greater (p < 0.05) interfragmentary motion (1.374–2.387 mm vs. 0.330–0.681 mm). The reoperation rate in 3-D unstable group (32.7%) is significantly (p < 0.001) higher than that in 3-D stable group (7.9%). Multivariate analysis demonstrated that 3-D inclination angle was significantly (OR = 4.699, p < 0.001) associated with reoperation. FNFs with α > 70°; 50°<α < 70° and β > 20°/β < −20° are real unstable types with significantly worse interfragmentary stability and higher reoperation risks. Fracture inclination in vertical and oblique planes is closely related to reoperation outcomes and may be a useful complement to the way FNFs are currently evaluated.