A finite element analysis of a low-profile femoral neck system of screws in sleeves in a vertical femoral neck fracture model.

BACKGROUND: Femoral neck system (FNS) has exhibited some drawbacks, such as non-fit of the plate with the lateral femoral cortex, postoperative pain, and the potential risk of subtrochanteric fractures. We have developed a low-profile FNS system that addresses some compatibility issues in FNS. In this study, we conducted finite element analysis on the 1-hole FNS (1 H-FNS), 2-holes FNS (2 H-FNS), and low-profile FNS (LP-FNS) and compared their biomechanical performance. METHODS: After the mesh convergence analysis, we established three groups of 1 H-FNS, 2 H-FNS, and LP-FNS. The interfragmentary gap, sliding distance, shear stress, and compressive stress and the bone-implant interface compression stress, stiffness, and displacement were determined under the neutral, flexion, or extension conditions of the hip joint, respectively. The stress and displacement of the femur after the implant removal were also investigated. RESULTS: (1) There were no obvious differences among the three FNS groups in terms of the IFM distance. However, the LP-FNS group showed less rotational angle compared with conventional FNS (neutral: 1 H-FNS, -61.64%; 2 H-FNS, -45.40%). Also, the maximum bone-implant interface compression stress was obviously decreased under the neutral, flexion, or extension conditions of the hip joint (1 H-FNS: -6.47%, -20.59%, or -4.49%; 2 H-FNS: -3.11%, 16.70%, or -7.03%; respectively). (2) After the implant removal, there was no notable difference in the maximum displacement between the three groups, but the maximum von Mises stress displayed a notable difference between LP-FNS and 1 H-FNS groups (-15.27%) except for the difference between LP-FNS and 2 H-FNS groups (-4.57%). CONCLUSIONS: The LP-FNS may not only provide the same biomechanical stabilities as the 1 H-FNS and 2 H-FNS, but also have more advantages in rotational resistance especially under the neutral condition of the hip joint, in the bone-implant interface compression stress, and after the implant removal. In addition, the 1 H-FNS and 2 H-FNS have similar biomechanical stabilities except for the maximum von Mises stress after the implant removal. The femur after the LP-FNS removal not only is subjected to relatively little stress but also minimizes stress concentration areas.

Posterior Approach and Inferior Capsulotomy in Bipolar Hemiarthroplasty for Femoral Neck Fractures: Comparison with Superior Capsulotomy.

Background: Hemiarthroplasty is frequently used to treat displaced femoral neck fractures in elderly patients, but it has a higher risk of postoperative dislocation. We introduced the posterior approach and inferior capsulotomy (PAICO) to enhance joint stability after bipolar hemiarthroplasty for femoral neck fracture. We evaluated whether the PAICO would have a lower dislocation rate than the conventional posterior approach with superior capsulotomy. Methods: From January 2021 to December 2021, we prospectively recruited 25 patients (25 hips) aged 50 years or older who underwent bipolar hemiarthroplasty for femoral neck fractures due to low-energy trauma as the PAICO group. We compared the PAICO group with a historical control group who had undergone hemiarthroplasty in 7 institutes between 2010 and 2020. The primary endpoint was dislocation within 1 year after the surgery. We compared data from the PAICO group with the data from the historical control group from the Korean Hip Fracture Registry which was carried out in South Korea. Results: A total of 25 patients (25 hips) were enrolled in the present study; 3,477 patients (3,571 hips) who underwent bipolar hemiarthroplasty were reviewed as the historical control group. In the PAICO group, we observed no dislocation, whereas the dislocation rate in the control group was 1.3%. Conclusions: In patients with displaced femoral neck fractures, the PAICO approach demonstrated comparable results in operation time and complication rates when compared to bipolar hemiarthroplasty using superior capsulotomy. Notably, there were no observed cases of dislocation among patients who underwent the PAICO approach. We recommend this PAICO approach to surgeons using the posterior approach, hoping to prevent dislocation in bipolar hemiarthroplasty.

Phosphaturic mesenchymal tumor-induced bilateral osteomalacia femoral neck fractures: a case report.

Phosphaturic mesenchymal tumors (PMT) are rare and distinctive tumors that typically result in paraneoplastic syndrome known as tumor-induced osteomalacia (TIO). We report a case of bilateral osteoporotic femoral neck fracture caused by PMT. PMT was surgically resected, followed by sequential treatment of bilateral femoral neck fractures with total hip arthroplasty (THA). A 49-year-old perimenopausal woman experienced consistent bone pain with limb weakness persisting for over 2 years. Initially, she was diagnosed with early osteonecrosis of the femoral head and received nonsurgical treatment. However, from 2020 to 2022, her pain extended to the bilateral shoulders and knees with increased intensity. She had no positive family history or any other genetic diseases, and her menstrual cycles were regular. Physical examination revealed tenderness at the midpoints of the bilateral groin and restricted bilateral hip range of motion, with grade 3/5 muscle strength in both lower extremities. Laboratory findings revealed moderate anemia (hemoglobin 66 g/L), leukopenia (2.70 × 109/L), neutropenia (1.28 × 109/L), hypophosphatemia (0.36 mmol/L), high alkaline phosphatase activity (308.00 U/L), and normal serum calcium (2.22 mmol/L). After surgery, additional examinations were performed to explore the cause of hypophosphatemic osteomalacia. After definitive diagnosis, the patient underwent tumor resection via T11 laminectomy on August 6, 2022. Six months after the second THA, the patient regained normal gait with satisfactory hip movement function without recurrence of PMT-associated osteomalacia or prosthesis loosening. By providing detailed clinical data and a diagnostic and treatment approach, we aimed to improve the clinical understanding of femoral neck fractures caused by TIO.

Association of osteoporotic fractures of femoral neck and femoral neck geometric parameters in native Chinese women.

BACKGROUND: Although it is generally believed that the femoral neck fracture is related to the femoral neck geometric parameters (FNGPs), the association between the risk of osteoporotic fracture of the femoral neck and FNGPs in native Chinese women is still unclear. METHODS: A total of 374 female patients (mean age 70.2 ± 9.32 years) with osteoporotic fracture of the femoral neck, and 374 non-fracture control groups were completely matched with the case group according to the age ratio of 1:1. Using DXA bone densitometer to measured eight FNGPs: the outer diameter (OD), cross-sectional area (CSA), cortical thickness (CT), endocortical diameter (ED), buckling ratio (BR), section modulus (SM), cross-sectional moment of inertia (CSMI), and compressive strength index (CSI) at the narrowest point of the femoral neck. RESULTS: Compared with the control group, the average values of OD (2.9%), ED (4.5%), and BR (26.1%) in the patient group significantly increased (p = 0.015 to < 0.001), while CSA (‒15.3%), CT (‒18.2%), SM (‒10.3%), CSMI (‒6.4%), and CSI (‒10.8%) significantly decreased (all p < 0.001). The prevalence of osteoporosis in the lumbar spine, femoral neck, and total hip was, respectively, 82%, 81%, and 65% in fracture patients. Cox proportional hazard model analysis showed that in the age adjusted model, the fracture hazard ratio (HR) of CSA, CT, BR, SM, and CSI significantly increased (HRs = 1.60‒8.33; 95% CI = 1.08‒16.6; all p < 0.001). In the model adjusted for age and femoral neck BMD, HRs of CT (HRs = 3.90‒8.03; 95% CI = 2.45‒15.1; all p < 0.001) and BR (HRs = 1.62‒2.60; 95% CI = 1.20‒5.44; all p < 0.001) were still significantly increased. CONCLUSION: These results suggest that the majority of osteoporotic fractures of the femoral neck of native Chinese women occur in patients with osteoporosis. CT thinning or BR increase of FNGPs may be independent predictors of fragility fracture of femoral neck in native Chinese women unrelated to BMD.

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

OBJECTIVE: 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. PATIENTS AND METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Outcomes in Arthroplasty Procedures Performed for Femoral Neck Fractures Does Approach Affect Outcome?

BACKGROUND: The surgical approach used for arthroplasty in the setting of hip fracture has traditionally been decided based on surgeon preference. This study analyzed the ef-fect of the surgical approach on hospital quality measures, complications, and mortality in patients treated with hip arthroplasty for fracture fixation. METHODS: A cohort of consecutive acute hip fracture pa-tients who were 60 years of age or older and who underwent hemiarthroplasty (HA) or total hip arthroplasty (THA) at one academic medical center between January 2014 and January 2018 was included. Patient demographics, length of stay (LOS), surgery details, complications, ambulation at dis-charge, discharge location, readmission, and mortality were recorded. Two cohorts were included based on the surgical approach: the anterior-based cohort included the direct an-terior and anterolateral approaches and the posterior-based cohort included direct lateral and posterior approaches. RESULTS: Two hundred five patients were included: 146 underwent HA (81 anterior-based and 65 posterior-based) and 79 underwent THA (37 anterior-based and 42 posterior-based). The mean age of the HA and THA cohorts was 84.1 ± 7.5 and 73.7 ± 8.0 years, respectively. There was no dif-ference in LOS, time to surgery, or surgical time between the two cohorts for HA and THA. There were no differences in perioperative complications, including dislocation, ob-served based on surgical approach. No difference was found between readmission rates and mortality. CONCLUSION: In this cohort of hip fracture arthroplasty patients, there was no difference observed in hospital quality measures, readmission, or mortality in patients based on sur-gical approach. These results are in contrast with literature in elective arthroplasty patients supporting the use of an anterior approach for potential improved short-term outcomes.

Basicervical femoral neck fractures: an observational study derived from the Swedish Fracture Register.

BACKGROUND AND PURPOSE: Limited research has been conducted on basicervical femoral neck fractures (bFNFs). The importance of displacement in clinical outcomes remains unclear. We aimed to characterize patient demographics, degree of displacement, treatment, treatment failures, and reoperations in a cohort of fractures from the Swedish Fracture Register (SFR). METHODS: 1,260 fractures in 1,185 individuals ≥ 60 years who had a bFNF registered in the SFR at 6 orthopedic departments from 2011 to 2020 were screened through radiographic review. The final sample included 291 patients with a confirmed bFNF. The medical records of these 291 patients were reviewed. We assessed baseline characteristics, initial fracture dislocation, treatment methods, tip-apex distance, failures, reoperations, and mortality. RESULTS: The mean age was 82 years (range 60-101, 55% women). 98 (34%) were undisplaced and 193 (66%) displaced. All patients underwent operative treatment. In the undisplaced group 95 (97%) patients received internal fixation (IF) and 3 (3%) had primary hip arthroplasty. In the displaced group 149 (77%) received IF and 41 (21%) had primary hip arthroplasty. 33 (11%) suffered treatment failure. When treating an undisplaced bFNF with IF, only 3 (3%) experienced treatment failure, in contrast to the 24 (16%) failure rate for a displaced bFNF. CONCLUSION: Undisplaced bFNFs have a low failure rate when treated with IF. For displaced bFNF treated with IF the failure rate is considerably higher. There is a need for further investigation of classification, treatment, and outcome of bFNF.

[Clinical study on the incidence of femoral head posterior tilt angle in non-displaced femoral neck fractures].

OBJECTIVE: To investigate the occurrence of posterior femoral head tilt after clinical non-displaced femoral neck fracture, and to provide a reference basis for clinical surgery and improvement of disease prognosis. METHODS: Total of 165 patients with non-displaced femoral neck fractures of Garden typeⅠandⅡfrom January 2018 to June 2022 were selected as study subjects including 48 males and 117 females, with an average age of (71.5±8.5) years old ranging from 53 to 89, involving 97 cases of typeⅠand 68 of typeⅡ. On the patient's preoperative sagittal or axial CT film of the hip, the angle formed by the radius line of the femoral head and the midline of the femoral neck was used as the posterior tilt angle of the femoral head (α), and the posterior tilt femoral head angle was measured using the method proposed by Palm. The measured data were divided into 6 groups:α<0°, 0°<α< 5°, 5°≤α<10°, 10°≤α<15°, 15°≤α<20°, α≥20°, and the incidence of different ranges of posterior tilt angle was compared. The sex composition ratio of 165 patients were analyzed and compared, and the age of 65 was used as the cut-off point to compare the incidence of fractures between genders. Patients were divided into the posterior tilt <20° group for 135 cases and the posterior tilt ≥20°group for 30 cases according to the preoperative posterior tilt angle, the differences between two groups in terms of gender and age were analyzed. RESULTS: Among 165 patients with non-displaced femoral neck fractures, 143 cases with poaterior tilt of the femoral head occurred with an incidence of 86.7%. Posterior tilt 0°<α<5° accounted for 36 cases with an incidence of 21.8%;5°≤α<10° accounted for 40 cases with an incidence of 24.2%;10°≤α<15° accounted for 27 cases with an incidence of 16.4%;15°≤α<20° accounted for 10 cases with an incidence of 6.1%;posterior tilt angle α≥20° accounted for 30 cases, the incidence was 18.2%, of which the maximum posterior tilt angle was 42.7°. Statistical analysis showed that the percentage of fractures in the 165 patients selected for this study was significantly higher in female than in male, and that the female group was more likely to have fractures before the age of 65 years compared to the male group. However, gender, age and fracture subtypes (GardenⅠ, Ⅱ) were not influential factors for femoral neck fractures with a preoperative posterior femoral head tilt angle >20°(P>0.05). CONCLUSION: The incidence of femoral head posterior tile in non-displaced femoral neck fractures is relatively high, in which severe posterior tile occurs, and the femoral head posterior tile angle≥20° can reach 18.2%. In patients with closed reduction internal fixation, the fracture end needs to be repositioned as much as possible to reduce the risk of postoperative avascular necrosis of the femoral head. In order to prevent femoral neck fractures, special attention should be paid to anti-osteoporosis treatment for female. Preoperative assessment of posterior tilt is critical for patients of different ages, genders and fracture subtypes (GardenⅠ, Ⅱ).

[Short term follow-up of femoral neck dynamic cross screw system and threaded cannulated screw in the treatment of vertically unstable femoral neck fractures].

OBJECTIVE: To analyze and compare the clinical effects of femoral neck dynamic cross screw system (FNS) and cannulated screws(CS) in the treatment of vertically unstable femoral neck fractures. METHODS: The clinical data and short-term follow-up results of 40 patients with vertically unstable femoral neck fractures admitted from July 2020 to August 2021 were retrospectively analyzed. According to different internal fixation methods, 40 patients were divided into two groups, 20 cases in FNS group included 11 males and 9 females with a median of 58.5(50.3, 62.5) years old, and 20 in CS group included 9 males and 11 females with a median of 52.0(40.5, 58.0) years old. The operation time, knife edge length, blood loss and treatment cost of two gruops were observed and compared. The postoperative fracture healing and internal fixation were evaluated with X-ray imaging data, and the femoral neck shortening of the affected side was measured. The incidence of thigh irritation, the time of partial weight bearing and full weight bearing, early necrosis of femoral head, reoperation revision and Harris scores were compared between two groups. RESULTS: FNS group was followed up for 18.0(15.0, 19.0) months, CS group for 17.0(15.0, 18.8) months. There was no significant difference in operation time, incision length and blood loss between two groups(P>0.05). The cost of diagnosis and treatment in FNS group was higher than that in CS group(P<0.001). In FNS group, there was no irritation sign of the affected side thigh, while in CS group, there were 6 cases with discomfort or irritation sign of the lateral thigh(P<0.05). The average time of partial weight bearing activity in CS group was later than that in FNS group(P<0.05); However, there was no significant difference in the activity time of complete weight bearing between two groups(P=0.011>0.05). At the last follow-up, the shortened length of the affected femoral neck in CS group was greater than that in FNS group(P<0.05). There was no early necrosis of femoral head and reoperation in both groups. There was no significant difference in Harris score between two groups 12 months after operation(P>0.05). CONCLUSION: FNS treatment of vertically unstable femoral neck fractures can significantly reduce the incidence of lateral thigh irritation sign, and effectively reduce the postoperative shortening rate of vertically unstable femoral neck fractures, which can provide a relatively stable anti rotation force and anti cutting force, so that patients can go to the ground relatively early, which is conducive to the recovery of the affected hip joint function after surgery. It is a new option for the surgical treatment of vertically unstable femoral neck fractures. However, due to the high cost of treatment, In clinical practice, appropriate surgical treatment is selected according to the actual situation.

Direct Anterior Approach Total Hip Arthroplasty for Femoral Neck Fractures in the Lateral Position.

Objective: To compare the clinical efficacy of artificial total hip arthroplasty(THA) for femoral neck fracture between direct anterior approach(DAA) in lateral position and posterior lateral approach(PLA). Methods: Comparison of 200 cases of patients who underwent THA collected between September 2019 and August 2021 was done. Incision length, intraoperative bleeding, operative time, difference in postoperative haemoglobin from preoperative levels, length of hospital stay, postoperative time to get off the floor, visual analogue score (VAS) for pain, preoperative and postoperative Harris scores for the hip, and measurements of the acetabular abduction angle and anterior acetabular tilt angle at 6 months postoperatively were collected, and all the cases were followed up for at least 2 years. Results: Compared with the PLA group, the DAA group had a shorter incision length, less intraoperative blood loss, less postoperative haemoglobin reduction compared with the preoperative period, a shorter hospital stay and an earlier first time to get off the floor after surgery, however, the comparison of operative times was not statistically significant; Patients in the DAA group had a lower VAS in the early postoperative period compared to PLA; Patients in the DAA group had higher hip Harris scores at 6 weeks and 6 months postoperatively; There was no significant difference in acetabular abduction angle and acetabular anterior tilt angle between the two groups at 6 months postoperatively. Conclusion: Compared to PLA, DAA in THA is minimally invasive, has less pain, less bleeding, earlier time out of bed, shorter hospital stay, better early hip function, faster rehabilitation, and better joint stability.

The influence of operation time for hip hemiarthroplasty on complication rates and mortality in patients with femoral neck fracture: a retrospective data analysis.

BACKGROUND: The aim of the present study was to investigate the influence of various factors, in particular operation time, on mortality and complication rates in patients with femoral neck fractures who have undergone hip hemiarthroplasty (HHA) and to determine a cut-off value above which mortality and complication rates increase significantly. METHODS: Cases of patients with femoral neck fracture treated with HHA between 1 January 2017 and 31 December 2023 were screened for eligibility. Multiple logistic regressions were calculated to determine which factors (patient age, experience of surgeon, patient sex, ASA score, time to surgery, operation time) influenced the incidence of complications and mortality. The exact cut-off value for complications and mortality was determined using the Youden index of the ROC curve (sensitivity vs. specificity) of logistic regression. RESULTS: A total of 552 patients were considered eligible for this study. During the 90-day follow-up period after HHA, 50 deaths and 34 complications were recorded, giving a mortality rate of 9.1%, and a complication rate of 6.2%. Of the 34 complications recorded, 32.3% were infections, 14.7% dislocations, 20.7% trochanteric avulsions, 11.8% periprosthetic fractures, 11.8% nerve injuries, and 8.8% deep vein thrombosis. The odds ratio (OR) of a patient experiencing a complication is 2.2% higher for every minute increase in operation time (Exponential Beta - 1 = 0.022; p = 0.0363). The OR of a patient dying is 8.8% higher for each year increase in age (Exponential Beta - 1 = 0.088; p = 0.0007). When surgery was performed by a certified orthopaedic surgeon the mortality rate lowered by 61.5% in comparison to the surgery performed by a trainee (1 - Exponential Beta = 0.594; p = 0.0120). Male patients have a 168.7% higher OR for mortality than female patients (Exponential Beta - 1 = 1.687; p = 0.0017). Patients with an operation time of ≥ 86 min. have a 111.8% higher OR for mortality than patients with an operation time of < 86 min. (Exponential Beta - 1 = 1.118). CONCLUSION: This retrospective data analysis found that the risk of a patient experiencing a complication was 2.2% higher for every minute increase in operation time. Patients with an operation time above the cut-off of 86 min had a 111.8% higher risk of mortality than those with an operation time below the cut-off. Other influencing factors that operators should be aware of include patient age, male sex, and operator experience.

Clinical efficacy of Femoral Neck System for treatment of unstable femoral neck fractures in young adults.

OBJECTIVE: This study was performed to evaluate the mid-term clinical efficacy of the Femoral Neck System (FNS) (DePuy Synthes, Zuchwil, Switzerland) in treating young patients with unstable Pauwels type III femoral neck fractures. METHODS: We performed a retrospective observational analysis of 21 young adults treated with the FNS. Clinical outcomes were assessed based on fracture reduction quality, Harris hip scores, and postoperative complication rates. RESULTS: The study comprised 21 patients with a mean age of 35 years (range, 20-50 years) who were followed for a mean duration of 22.8 months (range, 16-30 months). Closed reduction was unfeasible in three (14.3%) patients, each of whom required open reduction. Notable postoperative complications were avascular necrosis in two (9.5%) patients, nonunion in one (4.7%), and implant failure in one (4.7%). Each of these complications led to the requirement for total hip arthroplasty. CONCLUSION: The favorable mid-term clinical outcomes of this study indicate that the FNS is a potentially effective treatment modality for young individuals with unstable Pauwels type III femoral neck fractures.

Biomechanical changes in the proximal femur before and after removal of femoral neck system.

BACKGROUND: As an innovative internal fixation system, FNS (femoral neck system) is increasingly being utilized by surgeons for the treatment of femoral neck fractures. At present, there have been numerous finite element analysis experiments studying the immediate stability of FNS and CSS in treating femoral neck fractures. However, there is scarce mechanical analysis available regarding the effects post internal fixation removal. This study aimed to investigate the alterations in mechanical parameters of the proximal femur before and after the removal of FNS (femoral neck system), and to assess potential distinctions in indicators following the extraction of CSS (Cannulated Screws). METHODS: A proximal femur model was reconstructed using finite element numerical techniques. The models for CSS and FNS were formulated utilizing characteristics and parametric definitions. The internal fixation was combined with a normal proximal femur model to simulate the healing state after fracture surgery. Within the framework of static analysis, consistent stress burdens were applied across the entirety of the models. The total deformation and equivalent stress of the proximal femur were recorded before and after the removal of internal fixation. RESULTS: Under the standing condition, the total deformation of the model before and after removing CSS was 0.99 mm and 1.10 mm, respectively, indicating an increase of 12%. The total deformation of the model before and after removing FNS was 0.65 mm and 0.76 mm, respectively, indicating an increase of 17%. The equivalent stress for CSS and FNS were 55.21 MPa and 250.67 MPa, respectively. The average equivalent stress on the cross-section of the femoral neck before and after removal of CSS was 7.76 MPa and 6.11 MPa, respectively. The average equivalent stress on the cross-section of the femoral neck before and after removal of FNS was 9.89 MPa and 8.79 MPa, respectively. CONCLUSIONS: The retention of internal fixation may contribute to improved stability of the proximal femur. However, there still existed risks of stress concentration in internal fixation and stress shielding in the proximal femur. Compared to CSS, the removal of FNS results in larger bone tunnels and insufficient model stability. Further clinical interventions are recommended to address this issue.

Structural characteristics, biomechanics and clinical significance of calcar femorale: A review.

The calcar femorale, first identified by Merkel in 1874, plays a pivotal role in the weight-bearing capacity of the proximal femur, and its structural integrity is crucial for the efficient distribution of mechanical loads. Originating at the vertical ridge where the pubofemoral ligament anchors, this bony prominence extends laterally behind the neutral axis from the medial to lateral aspects. Its presence is not merely an anatomical curiosity but significantly influences the biomechanics of the hip joint by providing additional strength and support against compressive forces encountered during activities such as walking or jumping. Despite its clear description in orthopedic texts, misconceptions persist about its exact function and importance. This article delves into the nuanced anatomy and biomechanical properties of the calcar femorale, offering a detailed literature-based examination that demonstrates its relevance in clinical practice. The review highlights how the robustness of the calcar femorale contributes to the prevention of femoral neck fractures as well as the stabilization of hip prostheses. Furthermore, the indispensable role of the calcar femorale in surgical outcomes is discussed, especially in the context of fracture repair and joint replacement, thus illustrating its enduring significance in contemporary medical applications.

Comparison of the Surgical Outcome between the Multiple Screw Fixation and Fixed Angle Devices for the Basicervical Femoral Neck Fractures.

Introduction: Basicervical femoral neck fracture (FNF) is an uncommon type of femoral neck fracture and is associated with an increased risk of fixation failure due to its inherent instability. The purpose of this study was to compare the surgical parameters and reoperation rate between the use of a multiple cannulated screw (MCS) and fixed angle device (FAD) in treating basicervical FNFs. Methods: We retrospectively reviewed the records of 885 patients who underwent internal fixation between May 2004 and August 2019 to determine basicervical FNF with at least 12 months of follow-up. Among the identified 77 patients with basicervical FNF, 17 patients who underwent multiple cannulated screw (MCS) fixation and 36 patients who underwent fixed angle device (FAD) fixation were included. We compared the rates of fracture-site collapse and reoperations according to the fixation device. Results: Among the 53 patients with basicervical FNF, 13 patients (24.5%) sustained surgical complications (8 collapses of fracture site and 5 reoperations). The reoperation rate in the MCS group was significantly higher than that in the FAD group (23.5% vs. 2.8%, p = 0.016), without any significant difference in the collapse of the fracture site (11.8% vs. 16.7%, p = 0.642). Conclusions: Although basicervical FNF was rare among hip fractures, fracture site collapse was prevalent and prone to fixation failure. Surgeons should keep this in mind, and consider FAD for basicervical FNF.

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

Background: Femoral neck fractures need to be treated in their early stages with accurate reduction and stable fixation to reduce complications. The authors compared the early radiologic outcomes of femoral neck fractures treated with the recently introduced Femoral Neck System (FNS, Depuy-Synthes) with conventional cannulated screws (CS) in a multicenter design. Furthermore, the factors associated with early failure after FNS were analyzed. Methods: The FNS group included 40 patients treated between June 2019 and January 2020, and the CS group included 65 patients treated between January 2015 and May 2019. The operation was performed in 3 university hospitals. Patient demographics, fracture classification, postoperative reduction quality, sliding distance of FNS or CS, union and time to union, and complication rates were examined. Logistic regression analysis was performed on candidate factors for early failure of the FNS group. Results: The FNS group had a 90% union rate and a mean time to union of 4.4 months, while the CS group had similar results with an 83.1% union rate and a mean time to union of 5.1 months. In the subgroup analysis of Pauwels type III fractures, the union rates were 75.0% and 58.8% in the FNS and CS groups, respectively, and the time to union was significantly shorter in the FNS group with 4.8 months compared to 6.8 months in the CS group. Early failure rate within 6 months of FNS fixation was observed to be 10%, which included 3 reduction failures and 1 excessive sliding with a broken implant. Risk factors for early failure after FNS were identified as displaced fractures (Garden classification type III or IV), poor reduction quality, longer tip-apex distance, greater sliding distance, and 1-hole implants, of which sliding distance was the only significant risk factor in multivariate analysis. Conclusions: In femoral neck fractures, FNS and CS did not show significant differences for short-term radiologic results. FNS resulted in shorter operative time than cannulated screw fixation and favorable outcomes in Pauwels type III femoral neck fractures. The FNS could be considered a reliable and safe alternative to CS when treating femoral neck fractures.

Comparative Interrupted Time Series Analysis of Direct Medical Expense and Length of Stay in Elderly Patients with Femoral Neck Fractures Who Underwent Total Hip Arthroplasty and Hemiarthroplasty: A Real World Nationwide Database Study.

Background: The objective of our study was to analyze the postoperative direct medical expenses and hospital lengths of stay (LOS) of elderly patients who had undergone either hemiarthroplasty (HA) or total hip arthroplasty (THA) for femoral neck fractures and to determine the indication of THA by comparing those variables between the 2 groups by time. Methods: In this comparative large-sample cohort study, we analyzed data from the 2011 to 2018 Korean National Health Insurance Review and Assessment Service database. The included patients were defined as elderly individuals aged 60 years or older who underwent HA or THA for a femoral neck fracture. A 1:1 risk-set matching was performed on the propensity score, using a nearest-neighbor matching algorithm with a maximum caliper of 0.01 of the hazard components. In comparative interrupted time series analysis, time series were constructed using the time unit of one-quarter before and after 3 years from time zero. For the segmented regression analysis, we utilized a generalized linear model with a gamma distribution and logarithmic link function. Results: A total of 4,246 patients who received THA were matched and included with 4,246 control patients who underwent HA. Although there was no statistically significant difference in direct medical expense and hospital LOS for the first 6 months after surgery, direct medical expenses and hospital LOS in THA were relatively reduced compared to the HA up to 24 months after surgery (p < 0.05). In the subgroup analysis, the THA group's hospital LOS decreased significantly compared to that of the HA group during the 7 to 36 months postoperative period in the 65 ≤ age < 80 age group (p < 0.05). Direct medical expenses of the THA group significantly decreased compared to those of the HA group during the period from 7 to 24 months after surgery in the men group (p < 0.05). Conclusions: When performing THA in elderly patients with femoral neck fractures, the possibility of survival for at least 2 years should be considered from the perspective of medical expense and medical utilization. Additionally, in healthy and active male femoral neck fracture patients under the age of 80 years, THA may be more recommended than HA.

Low Hand Grip Strength, Mid-Upper Arm Muscle Area, Calf Circumference, Serum Albumin Level, and Muscle Fiber Diameter as Risk Factors for Independent Walking Inability in Patients with Hip Fracture 6 Weeks after Bipolar Hemiarthroplasty Surgery.

Background: Bipolar hemiarthroplasty, one of the main treatment modalities for hip fracture, does not always promise the ability to walk independently after surgery. Patients with the same fracture characteristics and comorbidities, implants, and operators may also have different outcomes. Sarcopenia is thought to be one of the causes of the inability to walk independently after this operation; however, it has not been widely studied and is often overlooked. Methods: This study used a case-control design with 23 patients in the case group (patients unable to walk independently) and 23 patients in the control group (patients able to walk independently). Sampling was carried out consecutively according to the inclusion and exclusion criteria based on the medical records of patients with hip fractures after bipolar hemiarthroplasty at our hospital. In the preoperative period, hand grip strength (HGS), mid-upper arm muscle area (MUAMA), calf circumference (CC), serum albumin level, and total lymphocyte count were measured. A muscle biopsy was performed intraoperatively from the gluteus muscle with the amount of 200-350 mg. The patient's walking ability was assessed in the polyclinic using the Timed Up and Go test 6 weeks postoperatively. The statistical tests used were descriptive statistics, proportion comparison analysis with the chi-square test, and multiple logistic regression test. Results: Univariate analysis using chi-square test proved HGS, MUAMA, CC, serum albumin level, and muscle fiber diameter as risk factors for inability to walk independently 6 weeks after bipolar hemiarthroplasty (p = 0.003, p = 0.003, p = 0.006, p = 0.044, and p = 0.000, respectively). Logistic regression test proved 3 direct risk factors for the inability to walk independently 6 weeks after bipolar hemiarthroplasty, namely MUAMA, serum albumin level, and muscle fiber diameter, as the strongest predictive factor (adjusted odds ratio, 63.12). Conclusions: Low MUAMA, serum albumin levels, and muscle fiber diameter are direct risk factors for the inability to walk independently in hip fracture patients 6 weeks after bipolar hemiarthroplasty.

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

OBJECTIVE: To investigate the efficacy of using pre-sliding technique to prevent postoperative shortening of displaced femoral neck fracture fixed with femoral neck system (FNS). METHODS: Retrospective analysis of 110 cases of displaced femoral neck fracture treated with femoral neck system from September 2019 to November 2022 in our center, which were divided into 56 cases in the pre-sliding group and 54 cases in the traditional group. The baseline data such as gender, age, side, mechanism of injury, fracture type, operation time, intraoperative bleeding were recorded and compared between the two groups, and the quality of fracture reduction, shortening distance, Tip Apex Distance (TAD), union time, Harris score of the hip were also compared between the two groups. RESULTS: The TAD value of the pre-sliding group was smaller than that of the traditional group, and the difference was statistically significant (P < 0.001). The shortening distance in both groups on postoperative day 1 was smaller in the pre-sliding group than in the traditional group, but the difference was not statistically significant (P = 0.07), and the shortening distance was smaller than in the traditional group at 1, 3, 6, and 12 months postoperatively, and the difference was statistically significant (all P < 0.001). Of the 110 cases, 34 (30.9%) had moderate or severe shortening, of which 24 (44.4%) were in the traditional group and 10 (17.9%) in the pre-sliding group, and the difference was statistically significant (P < 0.001), and the Harris score at 1 year, which was higher in the pre-sliding group than in the traditional group, and the difference between the two groups was statistically significant (P < 0.001). There was no statistically significant difference in the comparison of baseline data such as gender, age, side, mechanism of injury, fracture type, operation time, intraoperative bleeding, and quality of reduction between the two groups (all P > 0.05), and no statistically significant difference in fracture healing time between the two groups (P = 0.113). CONCLUSION: The use of the pre-sliding technique of displaced femoral neck fracture fixed with FNS reduces the incidence of moderate and severe shortening, improves the postoperative TAD value, and improves the hip function scores, with a satisfactory midterm efficacy.

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

Objective: 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. Methods: 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. Results: 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). Conclusion: CDAC-ADT typing has obvious correlation with postoperative complications of femoral neck fracture and can be used to predict complications of femoral neck fracture.