Fixation Of Femoral Neck Fractures Research Articles

The Effects and Risk Factors of Femoral Neck Shortening after Internal Fixation of Femoral Neck Fractures.

Internal fixation has been established as a treatment of choice in relatively young patients with femoral neck fractures. Due to the characteristics of femoral neck anatomy and blood supply, complications such as malunion, nonunion, avascular necrosis, and femoral neck shortening can occur after internal fixation of femoral neck fractures. Unlike other complications such as avascular necrosis or nonunion, femoral neck shortening has not been relatively well studied. This study aimed to investigate the risk factors and clinical outcomes of femoral neck shortening after internal fixation of femoral neck fractures. From June 2012 to July 2022, among 102 patients who underwent internal fixation of femoral neck fractures, 94 patients who met inclusion and exclusion criteria were retrospectively analyzed. Internal fixation of the femoral neck was done with cannulated compression screws or a femoral neck system. Patients were divided into 2 groups; femoral neck shortening (≥ 5 mm) and no shortening (< 5 mm) according to measurement on follow-up hip anteroposterior (AP) simple radiographs compared with postoperative hip AP simple radiographs. Demographic and radiographic data were compared between the 2 groups. The modified Harris Hip Score (mHHS) and a visual analog scale (VAS) were used to evaluate the clinical outcomes. Among 94 patients, femoral neck shortening was observed in 33 (35.1%). In chi-square test, Pauwels angle, Garden type III or IV (displacement), and cortical comminution were significantly correlated with neck shortening (p < 0.05). In the multifactorial logistic regression test, cortical comminution was significantly correlated with femoral neck shortening (p < 0.01). The shortening group showed significantly lower clinical scores in terms of mHHS and VAS (p < 0.01). The femoral neck shortening group showed significantly lower clinical scores of mHHS and VAS than the no-shortening group. The presence of cortical comminution in preoperative hip computed tomography is a risk factor of femoral neck shortening after internal fixation of femoral neck fractures.

FIJACIÓN DE LAS FRACTURAS DE CUELLO FEMORAL DEL ADULTO: COMPARACIÓN RETROSPECTIVA ENTRE TORNILLOS CANULADOS Y EL SISTEMA DE CUELLO FEMORAL (FNS)

The FNS System DePuy Synthes® (EEUU, 2018) represents a recent alternative treatment for the fixation of femoral neck fractures, providing biomechanical advantages with respect to cannulated screws (3CS). The objective of this study is to compare the clinical results of both fixation methods. A retrospective collection of the 36 subcapital fractures treated with the FNS system was carried out compared with a retrospective search of the last 35 patients treated with 3CS. Age, sex, fracture pattern, delay until the intervention, lenght of intervention, hospital length stay, and haemoglobin loss were analyzed. In addition, the rate of avascular necrosis, nonunion, symptomatic femoral neck shortening, and material protrusion with or without its removal were recorded during a minimum follow-up of 6 months. No significant differences were found in age (p-value 0.32), fracture patterns (p-value 0.77), surgical delay (p-value 0.28), surgical time (p-value 0.226), length of hospital stay (p-value 0.921) and blood loss (p-value 0.086) between the two groups. A significantly higher overall complication rate was observed in the group treated with cannulated screws (p-value 0.004). Analysed separately, a higher rate of avascular necrosis, symptomatic shortening of the femoral neck, protrusion of the osteosynthesis material with or without removal was observed in the group treated with cannulated screws. The FNS system represents a safe and reproductible alternative for the fixation of femoral neck fractures, showing non-inferior outcomes to treatment with cannulated screws.

Biomechanical evaluation of Gamma 3 nail with anti-rotation screw fixation for unstable femoral neck fractures: a biomechanical study

This study aims to evaluate the biomechanical performance of the Gamma 3 nail with an anti-rotation screw (GNS) and compare it to two established gold-standard methods for treating unstable femoral neck fractures (UFNFs). Synthetic bone models were prepared with Pauwels’ type III osteotomy and an additional posterior wedge. Three different implant configurations were tested: three cannulated crews (3CS) in an inverted triangle configuration, a dynamic hip screw with an anti-rotation screw (DHSS), and GNS. Non-destructive cyclic axial loading was applied at 7° adduction, with 1000 cycles ranging from 100 to 1000 N. Subsequently, a construct failure test was conducted using progressive axial compression, and fracture reduction loss was recorded. The average axial stiffness was 321 ± 52 N/mm for 3CS, 430 ± 71 N/mm for DHSS, and 519 ± 104 N/mm for GNS. The average ultimate failure loads were 2699.3 N for 3CS, 3427.1 N for DHSS, and 3758.9 N for GNS. GNS demonstrated significantly greater axial stiffness compared to the other two groups (P < 0.05). Both DHSS and GNS exhibited similar failure loading, which were greater than those of 3CS (P < 0.05). GNS offers the advantages of a minimally invasive and intramedullary implant with comparable stability to the DHSS system. Moreover, GNS demonstrated superior biomechanical performance compared to 3 CS configuration.

The use of fully threaded headless cannulated screws for femoral neck fracture fixation in small-breed dogs show promise in cadaveric study.

To biomechanically evaluate the stability of internal fixation methods for femoral neck fractures in small-breed dogs. Furthermore, the possibility of replacing the headed screw with fully threaded headless cannulated screws in the fixation method was assessed. The study was conducted from December 12, 2023, to February 7, 2024. A total of 18 femurs from 9 canine cadavers were used in this study. After a simple neck fracture was created, in group A (n = 6), the fracture was stabilized with three 1.1-mm parallel Kirschner wires (K-wires). In group B (n = 6), a 3.0-mm partially threaded cannulated screw and an antirotation pin were used. In group C (n = 6), a 2.5-mm fully threaded headless cannulated screw and an antirotation pin were used. A mechanical test was conducted to apply a single axial compressive load to the femoral head. 9 adult small-breed dogs weighing 3.6 to 8.3 kg (mean ± SD; 5.9 ± 1.6). The mean maximum failure load was highest in group C (495 ± 81 N), followed by group B (454 ± 50.4 N), and then group A (222 ± 21.6 N). Significant differences in maximum failure load were observed between groups A and B as well as groups A and C but not between groups B and C. The use of fully threaded headless cannulated screws presents a promising method for internal fixation of canine femoral neck fractures. To demonstrate the potential stability and reliability of fully threaded headless cannulated screws.

Biomechanical comparison of two fixation methods for pediatric femoral neck fractures: an in vitro study using ovis aries lambs.

In pediatric patients, femoral neck fracture is a relatively rare injury with a high complication rate despite proper diagnosis and treatment. Fixation of femoral neck fractures is usually performed with screws placed along the neck axis. In this study, we aim to compare two different implants and methods in terms of biomechanics. Twenty-eight right-left fresh femur bones of 6-month-old male Ovis aries lambs grown on the same farm were used. Bones were randomly divided into 4 groups (n=7). In group 1, the Delbet type III femoral neck fracture model was fixed with two 4.5 mm cannulated screws, one screw crossing the physis. In group 2, two 4.5 mm cannulated screws, which did not cross the physis, were used. In group 3, Delbet type III femoral neck fracture model was fixed with a 3.5 mm proximal femoral anatomical plate and five screws, one screw crossing the physis. Finally, in group 4, Delbet type III femoral neck fracture model was fixed with one 3.5 mm proximal femoral anatomical plate and five screws that did not exceed the physis. Biomechanical tests were performed using a Zwick/Roell AllroundLine 100 kN device. While axial failure burden (F = 6.819, p<.05, d = .46) and axial stiffness (F = 3.576, p<.05, d = .30) have been found to be significantly different between the independent treatment groups, axial failure displacement (F = .622, p>.05) and axial failure energy (F = .727, p>.05) have been found not to be significant between the independent groups. The effect sizes of the axial failure load and axial stiffness variables were 0.46 and 0.30, respectively, suggesting a moderate clinical effect. The highest axial failure load was recorded in group 3, while the smallest load was recorded in group 2. Similarly, the axial stiffness level in group 3 was statistically higher than the axial stiffness measurement recorded in group 2, p<.05. Consequently, we found that the biomechanical fixation success was the highest with a 3.5 mm proximal femoral anatomical plate, a 3.5 mm locking screw crossing the physis, and five 3.5 mm screws.

In Vitro Biomechanical Study of Femoral Neck Fracture Fixation with Two or Three Cannulated Screws in Dogs.

To evaluate the in vitro mechanical properties of basilar fractures of the femoral neck stabilized with two or three titanium-cannulated screws in dogs. Ex vivo study. Cadaveric canine femur (n = 21). The bones were divided as follows: Group 1: control (no osteotomy); Group 2: osteotomy and stabilization with two cannulated screws; and Group 3: osteotomy and stabilization with three cannulated screws. All groups were tested with destructive axial compression with load applied to the femoral head. The stiffness, load, and displacement were evaluated at the failure of Group 1, and the yield load and displacement of Groups 2 and 3. The placement of the three cannulated screws was more demanding than two cannulated screws because of the risk of cortical perforation, especially in the trochanteric fossa area. The smaller the width of the femoral neck, the higher the risk of cortical bone wall perforation. The intact control bones were stiffer (674 N/mm) than both the two-screw repair (90 N/mm) and three-screw repair (120 N/mm) groups (p < 0.05). The failure load was greatest for Group 1 (2692 N). The yield loads for Groups 3 and 2 were 586 and 303 N, respectively. There was no difference between groups for displacement. In vitro cadaveric models of femoral neck basilar fractures repaired with three cannulated screws were significantly stronger than two cannulated screws, but the clinical efficacy must be evaluated by comparing them in vitro with noncannulated stainless steel screws.

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

IntroductionThe dynamic hip screw (DHS) and cannulated compression screws (CCS) have been the two implants most frequently employed for the fixation of femoral neck fractures. The objective of this study is to compare clinical and radiographic outcomes between patients treated with the FNS and those treated with CCS.Material and methodsWe conducted a retrospective analysis of a consecutive series of femoral neck fractures treated with FNS or CCS between May 2019 and June 2022. The study included 144 patients who met the inclusion criteria. Collected data encompassed age, sex, Garden fracture classification, Pauwels classification, duration of surgery, length of hospital stays, Harris Hip Score (HHS), complications, and injured side.ResultsThe FNS group comprised 70 patients, while the CCS group consisted of 74 patients. The operation time was 43.6 ± 12.09 min for the FNS group and 56.47 ± 22.42 min for the CCS group. At the end of the follow-up, the mean HHS was 87.07 ± 11.77 for the FNS group and 76.20 ± 13.64 for the CCS group. The mean reduction in hemoglobin levels from pre- to post-surgery was 1.05 mg/dl in the FNS group and 0.87 mg/dl in the CCS group. The reintervention rate was 8.1% for the CCS group and 2.85% for the FNS group.ConclusionThe FNS does not demonstrate superiority over CCS regarding femoral neck shortening, complication rate, and reduction in hemoglobin levels. However, FNS does appear superior to CCS in terms HHS, operation time, and reoperation rate.

926 Long-Term Outcomes of Internal Fixation vs Hemiarthroplasty for Femoral Neck Fractures: A Quantitative Analysis of the Correlation Between Harris Hip Score and Mortality in Elderly Patients

926 Long-Term Outcomes of Internal Fixation vs Hemiarthroplasty for Femoral Neck Fractures: A Quantitative Analysis of the Correlation Between Harris Hip Score and Mortality in Elderly Patients

Should a low starting point be abandoned for cannulated screw fixation of femoral neck fractures?

A validated femoral neck fracture model stabilized with three inverted cannulated screws was used to consider different intraoperative scenarios when the inferior screw hole is inadvertently started too inferiorly. These scenarios were to: (1) abandon the misplaced inferior screw hole and restart this hole more proximally, or (2) accept the mispositioned placement of the inferior screw and insert the remaining superior screws parallel or convergent to the inferior screw. Utilizing the second option and accepting the errant hole was associated with the greatest interfragmentary motion and stresses in the bone and hardware. In contrast, the first option created an improved mechanical environment for healing.

Biomechanical comparison of the therapeutic effect of a novel proximal femoral bionic intramedullary nail and traditional inverted triangle hollow screw on femoral neck fracture

ObjectiveA novel Proximal Femoral Bionic Nail (PFBN) has been developed by a research team for the treatment of femoral neck fractures. This study aims to compare the biomechanical properties of the innovative PFBN with those of the conventional Inverted Triangular Cannulated Screw (ITCS) fixation method through biomechanical testing.MethodsSixteen male femoral specimens preserved in formalin were selected, with the donors’ age at death averaging 56.1 ± 6.3 years (range 47–64 years), and a mean age of 51.4 years. The femurs showed no visible damage and were examined by X-rays to exclude diseases affecting bone quality such as tumors, severe osteoporosis, and deformities. The 16 femoral specimens were randomly divided into an experimental group (n = 8) and a control group (n = 8). All femurs were prepared with Pauwels type III femoral neck fractures, fixed with PFBN in the experimental group and ITCS in the control group. Displacement and stress limits of each specimen were measured through cyclic compression tests and failure experiments, and vertical displacement and strain values under a 600 N vertical load were measured in all specimens through vertical compression tests.ResultsIn the vertical compression test, the average displacement at the anterior head region of the femur was 0.362 mm for the PFBN group, significantly less than the 0.480 mm for the ITCS group (p < 0.001). At the fracture line area, the average displacement for the PFBN group was also lower than that of the ITCS group (0.196 mm vs. 0.324 mm, p < 0.001). The difference in displacement in the shaft area was smaller, but the average displacement for the PFBN group (0.049 mm) was still significantly less than that for the ITCS group (0.062 mm, p = 0.016). The situation was similar on the posterior side of the femur. The average displacements in the head area, fracture line area, and shaft area for the PFBN group were 0.300 mm, 0.168 mm, and 0.081 mm, respectively, while those for the ITCS group were 0.558 mm, 0.274 mm, and 0.041 mm, with significant differences in all areas (p < 0.001). The average strain in the anterior head area for the PFBN group was 4947 μm/m, significantly less than the 1540 μm/m for the ITCS group (p < 0.001). Likewise, in the fracture line and shaft areas, the average strains for the PFBN group were significantly less than those for the ITCS group (p < 0.05). In the posterior head area, the average strain for the PFBN group was 4861 μm/m, significantly less than the 1442 μm/m for the ITCS group (p < 0.001). The strain conditions in the fracture line and shaft areas also showed the PFBN group was superior to the ITCS group (p < 0.001). In cyclic loading experiments, the PFBN fixation showed smaller maximum displacement (1.269 mm vs. 1.808 mm, p < 0.001), indicating better stability. In the failure experiments, the maximum failure load that the PFBN-fixated fracture block could withstand was significantly higher than that for the ITCS fixation (1817 N vs. 1116 N, p < 0.001).ConclusionThe PFBN can meet the biomechanical requirements for internal fixation of femoral neck fractures. PFBN is superior in biomechanical stability compared to ITCS, particularly showing less displacement and higher failure resistance in cyclic load and failure experiments. While there are differences in strain performance in different regions between the two fixation methods, overall, PFBN provides superior stability.

Integrated proteomics and metabolomics analysis of sclerosis-related proteins and femoral head necrosis following internal fixation of femoral neck fractures

Femoral head necrosis (FHN) is a serious complication after femoral neck fractures (FNF), often linked to sclerosis around screw paths. Our study aimed to uncover the proteomic and metabolomic underpinnings of FHN and sclerosis using integrated proteomics and metabolomics analyses. We identified differentially expressed proteins (DEPs) and metabolites (DEMs) among three groups: patients with FNF (Group A), sclerosis (Group B), and FHN (Group C). Using the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology enrichment analyses, we examined the roles of these proteins and metabolites. Our findings highlight the significant differences across the groups, with 218 DEPs and 44 DEMs identified between the sclerosis and FNF groups, 247 DEPs and 31 DEMs between the FHN and sclerosis groups, and a stark 682 DEPs and 94 DEMs between the FHN and FNF groups. Activities related to carbonate dehydratase and hydrolase were similar in the FHN and sclerosis groups, whereas extracellular region and lysosome were prevalent in the FHN and FNF groups. Our study also emphasized the involvement of the PI3K-Akt pathway in sclerosis and FHN. Moreover, the key metabolic pathways were implicated in glycerophospholipid metabolism and retrograde endocannabinoid signaling. Using western blotting, we confirmed the pivotal role of specific genes/proteins such as ITGB5, TNXB, CA II, and CA III in sclerosis and acid phosphatase 5 and cathepsin K in FHN. This comprehensive analyses elucidates the molecular mechanisms behind sclerosis and FHN and suggests potential biomarkers and therapeutic targets, paving the way for improved treatment strategies. Further validation of the findings is necessary to strengthen the robustness and reliability of the results.

Femoral neck osteosynthesis using interfragmentary compression or position screw in synthetic bones. What are the mechanical differences?

We aim to compare interfragmentary compression with the position osteosynthesis in the fixation of different femoral neck fractures (FN)in synthetic bones subjected to vertical load. Forty-two synthetic femurs were subjected to neck fractures and separated into 3 groups according to the Pauwels classification: Pauwels I had 6 units (PI); Pauwels II, 24 units, with and without comminution (PII); and Pauwels III, 12 units, with and without comminution (PIII). After, they were fixed with 2 different ways: three 7, 0mm cannulated lag screws (CSs) versus three 6, 5mm solid fully threaded screws (SSs). Screws positioning was oriented by the Pauwels classification: inverted triangle or crossed screws. All specimens were submitted to vertical loading until failure. The average force was 79.4 ± 22.6Kgf. The greatest one was recorded in model 1 (135.6Kgf), and the lowest in model 41 (39.6Kgf). CSs and SSs had similar resistance until failure (p = 0.2). PI showed heightened resistance and PIII showed a worse response (p < 0,01). CSs had better performance in PIII (p = 0.048). Comminution and screws orientation caused no difference on peak force (p = 0.918 and p = 0.340, respectively). In synthetic bones, the resistance of a femoral neck fracture osteosynthesis using a 7, 0mm cannulated lag screw or 6, 5mm solid fully threaded screw are similar. There was no loss of efficiency with comminution in the femoral neck. Osteosynthesis resistance decreased with the verticalization of the fracture line and, in the more vertical ones, interfragmentary compression with CSs was more resistant than positional osteosynthesis with SSs.

Cannulated screws fixation for nondisplaced femoral neck fractures: early versus late weight-bearing-a prospective analysis.

Nondisplaced intracapsular fractures (Garden I/II) are predominantly treated with an internal fixation technique. The purpose of the study is to identify the best rehabilitation protocol after internal fixation with 3 parallel cannulated screws. All patients operated on from 2016 to 2021 for femoral neck fractures by internal fixation with 3 cannulated screws were enrolled into this prospective study. The population was divided into two groups: Group A (n = 34) who followed a postoperative rehabilitation protocol involving full and immediate loading, and Group B (n = 22) who followed a postoperative rehabilitation protocol involving late full loading (after 30days). The two groups were compared with each other by mortality rate, postoperative complications and need for re-interventions. Functional outcome and quality of life were assessed at the minimum follow-up of 1year using the modified Harris Hip Score(HHS) and the Short form health survey (SF-12) questionnaire. Group A showed a lower complication rate (2.9% vs. 18.2%), a lower 1-year mortality rate (5.9% vs. 9.1%), a better perception of mental health status (SF12-MCS 56.2 vs. 51.4, p = 0.03) but a worse perception of one's physical health status (SF12-PCS 48.1 vs. 56.7, p < 0.01). The two groups were also statistically overlapping in terms of the functional outcome achieved after the intervention (HHS was 90.94 in Group A vs. 93.15 in Group B, p = 0.32). Postoperative complications, mortality and revision rate were higher in patients who followed a late-loaded rather than early loaded rehabilitation protocol. Functional outcome at 1-year survival is not significantly different. In nondisplaced intracapsular hip fractures treated with cannulated screws, an immediate full load should be preferred. Query.

Equivalence in osteoporosis workup and management after femoral neck fracture fixation and vertebral compression fracture cement augmentation: A single-center retrospective study highlighting persistent underdiagnosis and undertreatment

BackgroundThe purpose of this study was to evaluate pre- and post-fracture medical management of osteoporosis among patients who underwent surgical fixation of femoral neck fractures (FNF) and vertebral compression fractures (VCF), and to investigate if there is a difference in treatment, management, and subsequent fractures between FNF and VCF patients. MethodsPatients who underwent surgical fixation of FNF or VCF were retrospectively reviewed at a minimum 1 year follow up. Patients were excluded if their fracture was caused by high energy trauma or malignancy, <50 years-old, deceased, or lost to follow up. Patient demographics such as age, sex, BMI, American Society of Anesthesiology Physical Status Classification System and Charleston Comorbidity index were recorded. Management of osteoporosis, including medication regimen and dual-energy X-ray absorptiometry (DEXA) scans were assessed preoperatively and at minimum one year follow up. Subsequent fractures were also recorded. ResultsIn the analysis of 370 patients (74.7% FNF, 25.2% VCF), demographics showed a predominantly female population (mean age 78.1). Preoperatively, 21.6% were diagnosed with osteoporosis, consistent between FNF and VCF. Postoperatively, there were no significant differences in new osteoporosis diagnoses, bisphosphonate use, or subsequent fractures. VCF patients, however, were more likely to receive denosumab and post-operative DEXA scans (p < 0.05). Within a year, 6.2% experienced subsequent fractures, with no significant FNF-VCF difference. Only 12.7% received appropriate post-operative osteoporosis treatment, 27.1% had DEXA scans, and 25% had a recorded osteoporosis diagnosis. Multivariable analysis highlighted pre-fracture osteoporosis diagnosis as the sole predictor for post-operative DEXA scans and anti-osteoporotic medication (p < 0.001). ConclusionsThis study suggests that factors beyond the type of fragility fracture may influence subsequent fracture risk and anti-osteoporotic medication administration in elderly patients. These findings underscore the importance of a comprehensive approach to fracture risk assessment and treatment decisions in this population. Level of evidenceIII.

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

Operative fixation of femoral neck fractures (FNFs) remains challenging. Complications are not infrequent, especially in displaced patterns. Numerous fixation techniques have been previously described in the literature; however, there remains a paucity of data regarding outcomes of these injuries treated with the femoral neck system (FNS). Patients with a displaced FNF (OTA/AO 31B) treated with the FNS at a single level 1 academic trauma center between 1/1/2019 and 1/1/2023 were identified. Radiographs were reviewed to assess fracture displacement, location, and characteristics. Patient records were further reviewed to assess for complications, reoperations, and osseous union. Forty-three patients (65% male) with 44 FNFs were identified with a mean age of 35.0years (range, 13-61years). Two patients developed a deep infection requiring surgical debridement, four patients underwent a total hip arthroplasty, and one patient underwent a valgus intertrochanteric osteotomy for nonunion. There were three cases of femoral head AVN. Mean follow-up was 482.5days among all patients, and 36 fractures had at least 6months of follow-up or reached bony union. Here, we present a series of patients treated with the FNS for internal fixation and report a 18% reoperation rate. This is lower than the average rate that has been previously reported in similar patient populations in the literature treated with alternative methods of internal fixation. Thus, the FNS appears to be a safe and effective option for treatment of these injuries.

Low avascular necrosis rates in femoral neck fractures: efficacy of cannulated screw fixation.

Cannulated screw fixation for femoral neck fractures is often limited by concerns of avascular necrosis (AVN) occurring, historically seen in 5-40% of fixed intracapsular fractures. This study aims to assess the outcomes, particularly the AVN rate, associated with current surgical techniques within our unit. We conducted a single-center cross-sectional study, manually searching operative records between July 14, 2014, and December 1, 2018, identifying patients with intracapsular fractured neck of femur fixed with cannulated screws, with a minimum of two years follow-up. Patient records and radiographs were reviewed for clinical and radiographic diagnoses of AVN, non-union, post-operative metalwork infection, and screw penetration of the head. Additionally, fracture pattern and displacement, screw configuration, reduction techniques, and adequacy of reduction were recorded, with radiographs independently analyzed by four orthopedic surgeons. Fifty-six patients were included; average age of 67 years (range 30-100). Forty-two patients (75%) sustained displaced fractures and 14 patients (25%) had undisplaced fractures. Two (4%) patients developed AVN, with no cases of non-union, post-operative metalwork infection or screw penetration of the head. Eight patients (14%) sustained a high-energy injury, though none of these patients developed AVN. All fractures required closed reduction; no open reductions performed. Twenty-seven (64%) of reductions were adequate. Our observed AVN rate is notably lower than the widely reported figures, even among a significant proportion of displaced fractures that were fixed. This study underscores that with adequate fixation, cannulated screws represent an excellent option for treating intracapsular neck of femur fractures, even in cases of displaced fracture patterns with imperfect reduction.

Multiple fluoroscopic views, including an external rotation-adduction view, are required to detect uncontained screws in the femoral neck

Introduction: Peripheral screws in the femoral neck are often used for fixation of femoral neck fractures. The posterior-cranial screw can violate the femoral head blood supply if it is extra-osseous, and can be difficult to image intraoperatively. The purpose of this study was to identify whether any specific radiographic views were superior at detecting an uncontained screw in the femoral neck. Additionally, the external rotation-adduction view was defined and its efficacy at detecting an unsafe posterior cranial screw assessed. Methods: A radiographic study using three-dimensional (3D) computed tomography scanswas performed at a single institution academic hospital. Forty-six patients with normal CT scans of the pelvis were included. Cannulated screws were digitally templated on 3D renderings of the femoral neck in an inverted triangle configuration. Each screw was systematically moved to a position where it was uncontained. Ghost images were created, and the pelvis rotated to simulate obtaining various iterations of a lateral view of the proximal femur. The ability of a given radiographic view to detect an uncontained screw was determined. Results: A flat-lateral view detected 72% of unsafe anterior screw, while a neck-shaft colinear view detected 98%. The flat lateral view detected 61% of unsafe posterior cranial screws, while a new external rotation-adduction view identified 100% of unsafe posterior cranial screws. Conclusions: Multiple radiographic views should be obtained to assess screw safety when treating femoral neck fractures with peripherally placed screws. The external rotation-adduction view may be useful for detection of uncontained posterior cranial screws. Level of evidence: III

Contralateral Neck-shaft Angle Lower Than 130° Is Associated With Clinical Failure in Nongeriatric Individuals: Analysis of the National Femoral Neck Fracture Database of 1066 Patients.

Treatment of femoral neck fractures in patients who are nongeriatric (≤ 60 years) is challenging because of high failure rates. Anatomic parameters influence the biomechanical environment for fracture healing, but their associations with clinical prognosis remains unclear. (1) Which anatomic parameter that is identifiable on pelvic radiographs shows a statistical correlation with a higher risk of clinical failure defined as nonunion, avascular necrosis (AVN), reoperation, and functional failure (decrease in Harris hip score reaching the minimum clinically important difference) in the screw fixation of femoral neck fractures among nongeriatric patients? (2) How does the influence of anatomic parameters on clinical prognosis manifest: directly or mediated by additional mechanisms? This retrospective, multicenter study used a nationwide database in China. Between January 2014 and December 2020, we evaluated 1066 patients with femoral neck fractures with a median age of 53 years (interquartile range 46 to 56) and median follow-up period of 62 months. Anatomic parameters including femoral neck-shaft angle (NSA), femoral head radius, femoral neck width, femoral offset, acetabular center-edge angle, and acetabular sharp angle were variables of interest. The primary outcome was clinical failure including nonunion, AVN, reoperation, and functional failure (decrease in Harris hip score reaching the minimum clinically important difference). Risk factors for failure were first filtered using the Bayesian information criterion and then assessed with multiple regression adjusting for confounders. The mediation effect was further explored using model-based causal mediation analysis with a quasi-Bayesian Monte Carlo method. Of all anatomic parameters we assessed, the contralateral NSA was associated with clinical failure, after adjusting for all potential covariates and confounding variables (adjusted odds ratio 0.92 [95% confidence interval 0.89 to 0.95]; p < 0.001). The optimal threshold for the NSA was 130°, with the highest Youden index of 0.27. Patients with an NSA < 130° (41% [441 of 1066]) demonstrated an increased occurrence of nonunion (15% [68 of 441] versus 5% [33 of 625]; p < 0.001), AVN (32% [141 of 441] versus 22% [136 of 625]; p < 0.001), functional failure (25% [110 of 441] versus 15% [93 of 625]), and reoperations (28% [122 of 441] versus 13% [79 of 625]). The impact of an NSA less than 130° on clinical failure was direct and substantially mediated by the type of displaced fracture (mediation proportion: 18.7%). In our study of screw fixations for femoral neck fractures among nongeriatric patients, we identified that a contralateral NSA < 130° correlates with an increased risk of clinical failure including nonunion, AVN, functional failure, and reoperation. The effect is either direct or mediated through displaced fracture types. This is important for surgeons in order to recognize the elevated rate of clinical failure and nature of the challenging biomechanical environment, which should guide them in refining surgical details and selecting appropriate fixation and rehabilitation plans. Approaches to managing these fractures require further validation with large-scale clinical trials. Level III, prognostic study.

Correlation between combined deflection angle classification adduction typing and complications after internal fixation of adduction femoral neck fracture

To analyze the correlation between postoperative complications and combined deflection angle classification adduction type (CDAC-ADT) of femoral neck fractures after cannulated screw internal fixation. The clinical data of 121 patients with CDAC-ADT femoral neck fracture admitted between January 2018 and December 2021 and met the selected criteria were retrospectively analyzed. There were 69 males and 52 females, the age ranged from 19 to 79 years (mean, 48.1 years). The causes of injury included 52 cases of traffic accident, 24 cases of falling from height, and 45 cases of fall. The time from injury to operation ranged from 2 to 12 days, with an average of 6.0 days. Among them, there were 18 cases of CDAC-ADT type Ⅰ, 46 cases of type Ⅱ, and 57 cases of type Ⅲ; 6 cases of Garden type Ⅱ, 103 cases of type Ⅲ, and 12 cases of type Ⅳ; and according to the location of the fracture line, there were 26 cases of subcapitate type, 88 cases of transcervical type, and 7 cases of basal type. All patients were treated with cannulated screw internal fixation. The occurrence of complications (including internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head) was recorded, and the correlation between complications and CDAC-ADT typing, Garden typing, and fracture line location were analyzed. The patients were followed up 8-44 months, with a mean of 24.9 months. There were 10 cases of internal fixation failure, 7 cases of fracture nonunion, and 30 cases of osteonecrosis of the femoral head after operation. Correlation analysis showed that patients' CDAC-ADT typing was significantly correlated with the overall incidence of complication and the incidence of internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head ( P<0.05), and the Pearson coefficient of contingency were 0.435, 0.251, 0.254, and 0.241, respectively. Garden typing did not correlate with the overall incidence of complication and the incidence of internal fixation failure and fracture nonunion ( P>0.05), but correlated with the incidence of osteonecrosis of the femoral head ( P<0.05), and the Pearson coefficient of contingency was 0.251. Fracture line position typing had no correlation with the overall incidence of complication and the incidence of internal fixation failure, fracture nonunion, and osteonecrosis of the femoral head ( P>0.05). CDAC-ADT typing has obvious correlation with postoperative complications of femoral neck fracture and can be used to predict complications of femoral neck fracture.

Effectiveness of cannulated screw fixation for femoral neck fracture assisted by three-dimensional printing navigation template in middle-aged and elderly patients.

We sought to explore the effectiveness of cannulated screw fixation for femoral neck fractures in middle-aged and elderly patients assisted by a three-dimensional printing navigation template. A total of 98 middle-aged and elderly patients who underwent cannulated screw fixation for femoral neck fractures were retrospectively analyzed. They were allocated into two groups, each comprising 49 patients. Surgical indexes, hip function, and pain levels were compared between the two groups. The study group, assisted by the three-dimensional printing navigation template, exhibited significantly reduced nail insertion, fewer instances of C-arm fluoroscopy, shorter operation time, quicker time to bone union, earlier initiation of walking exercise, shorter time to weight-bearing walking, and reduced hospital stay than those in the control group (all p<0.001). However, the study group also experienced higher blood loss compared to the control group (p<0.001). Postoperatively, at 3 months and 12 months, the study group demonstrated significantly higher scores compared to the control group (both p<0.001) and reported significantly lower pain scores than that in the other group at 1 week and 12 months post-surgery (both p<0.001). Furthermore, the study group experienced significantly fewer postoperative complications than the control group (p=0.029). Cannulated screw fixation for femoral neck fractures assisted by a 3D printing navigation template is more effective and safer than traditional fixation methods. This approach represents a promising alternative for surgical management.