Fibroblast growth factor 23 inhibition attenuates steroid-induced osteonecrosis of the femoral head through pyroptosis.

Steroid-induced osteonecrosis of the femoral head (SONFH) is the predominant cause of non-traumatic osteonecrosis of the femoral head (ONFH). Impaired blood supply and reduced osteogenic activity of the femoral head are the key pathogenic mechanisms of SONFH. Fibroblast growth factor 23 (FGF23) levels are not only a biomarker for early vascular lesions caused by abnormal mineral metabolism, but can also act directly on the peripheral vascular system, leading to vascular pathology. The aim of this study was to observe the role of FGF23 on bone microarchitecture and vascular endothelium, and to investigate activation of pyroptosis in SONFH. Lipopolysaccharide (LPS) combined with methylprednisolone (MPS) was applied for SONFH mouse models, and adenovirus was used to increase or decrease the level of FGF23. Micro-CT and histopathological staining were used to observe the structure of the femoral head, and immunohistochemical staining was used to observe the vascular density. The cells were further cultured in vitro and placed in a hypoxic environment for 12 h to simulate the microenvironment of vascular injury during SONFH. The effect of FGF23 on osteogenic differentiation was evaluated using alkaline phosphatase staining, alizarin red S staining and expression of bone formation-related proteins. Matrigel tube formation assay in vitro and immunofluorescence were used to detect the ability of FGF23 to affect endothelial cell angiogenesis. Steroids activated the pyroptosis signaling pathway, promoted the secretion of inflammatory factors in SONFH models, led to vascular endothelial dysfunction and damaged the femoral head structure. In addition, FGF23 inhibited the HUVECs angiogenesis and BMSCs osteogenic differentiation. FGF23 silencing attenuated steroid-induced osteonecrosis of the femoral head by inhibiting the pyroptosis signaling pathway, and promoting osteogenic differentiation of BMSCs and angiogenesis of HUVECs in vitro.

Deep learning approach to femoral AVN detection in digital radiography: differentiating patients and pre-collapse stages.

OBJECTIVE: This study aimed to evaluate a new deep-learning model for diagnosing avascular necrosis of the femoral head (AVNFH) by analyzing pelvic anteroposterior digital radiography. METHODS: The study sample included 1167 hips. The radiographs were independently classified into 6 stages by a radiologist using their simultaneous MRIs. After that, the radiographs were given to train and test the deep learning models of the project including SVM and ANFIS layer using the Python programming language and TensorFlow library. In the last step, the test set of hip radiographs was provided to two independent radiologists with different work experiences to compare their diagnosis performance to the deep learning models' performance using the F1 score and Mcnemar test analysis. RESULTS: The performance of SVM for AVNFH detection (AUC = 82.88%) was slightly higher than less experienced radiologists (79.68%) and slightly lower than experienced radiologists (88.4%) without reaching significance (p-value > 0.05). Evaluation of the performance of SVM for pre-collapse AVNFH detection with an AUC of 73.58% showed significantly higher performance than less experienced radiologists (AUC = 60.70%, p-value < 0.001). On the other hand, no significant difference is noted between experienced radiologists and SVM for pre-collapse detection. ANFIS algorithm for AVNFH detection with an AUC of 86.60% showed significantly higher performance than less experienced radiologists (AUC = 79.68%, p-value = 0.04). Although reaching less performance compared to experienced radiologists statistically not significant (AUC = 88.40%, p-value = 0.20). CONCLUSIONS: Our study has shed light on the remarkable capabilities of SVM and ANFIS as diagnostic tools for AVNFH detection in radiography. Their ability to achieve high accuracy with remarkable efficiency makes them promising candidates for early detection and intervention, ultimately contributing to improved patient outcomes.

Evaluation of the clinical efficacy of using an inverted triangular cannulated compression screw in combination with positive or negative buttress reduction for the healing of femoral neck fractures.

OBJECTIVE: We aimed to compare the clinical efficacy of inverted triangular cannulated compression screws combined with Gotfried positive or negative buttress reduction in the healing of femoral neck fractures. METHODS: Between October 2017 and March 2021, 55 patients with femoral neck fractures underwent treatment using inverted triangular cannulated compression screws combined with Gotfried positive or negative buttress reduction. Among these patients, 29 received inverted triangular cannulated compression screws combined with Gotfried positive buttress reduction treatment. This group consisted of 16 males and 13 females, with an average age of 43.45 ± 8.23 years. Additionally, 26 patients received inverted triangular cannulated compression nails combined with Gotfried negative buttress reduction treatment. This group included 14 males and 12 females, with an average age of 41.96 ± 8.69 years. Postsurgery, various measurements were taken, including the degree of shortening of the femoral neck, degree of bone nonunion, degree of fixation failure, degree of ischemic necrosis of the femoral head, and Harris score of the hip joint. RESULTS: All patients were followed up for a minimum of 18 months. The group that underwent treatment with an inverted triangular cannulated compression screw combined with Gotfried positive buttress reduction did not experience any cases of bone nonunion, fixation failure, or ischemic necrosis of the femoral head. In the group that received treatment with inverted triangle cannulated compression screws combined with Gotfried negative buttress reduction, there was one case of bone nonunion, three cases of early fixation failure, and one case of ischemic necrosis. Ultimately, five patients (19.23% of the total) underwent joint replacement surgery. The average shortening lengths in the vertical plane were 4.07 ± 1.98 mm and 8.08 ± 3.54 mm, respectively. In the horizontal plane, the average shortening lengths were 3.90 ± 1.57 mm and 7.77 ± 3.31 mm, respectively. At the last follow-up, the group that received Gotfried positive buttress reduction had a greater Harris hip joint score. CONCLUSION: The success rate of combining inverted triangular cannulated compression screws with Gotfried positive buttress reduction surgery is relatively high. This surgical approach effectively prevents femoral neck shortening and improves hip joint function. Moreover, it is crucial to avoid negative buttress reduction when managing femoral neck fractures.

An Unusual Complication Encountered During the Extraction of the Femoral Nail: A Case Report.

Orthopedic implant removal is a common surgery performed either due to patient's complaint of pain, dysfunction or infection or on doctor's advice depending on the nature of the implant and its related future problems. The surgery may range from simple k-wire removal to difficult plate or intramedullary nail removal. Many unforeseen complications are experienced during implant removal, and occasionally, it results in failure of removal, fracture, prolonged per-operative bleeding and damage to nerves and vessels. We report here an unusual complication of coiling of a thick k-wire used during implant extraction surgery to prevent sinking of the nail and the difficulties in removing this coil and the nail, along with the precautions to be taken to avoid such difficulties.

Comparison of the Effects of Adductor Canal and Femoral Nerve Blocks on Postoperative Opioid Consumption and Inflammatory Factor Levels in Elderly Patients After Total Knee Arthroplasty: A Prospective Observational Study.

Purpose: Total Knee Arthroplasty (TKA) is a highly invasive procedure causing severe postoperative pain, which hampers early mobility. Effective pain management is crucial for optimal recovery. This study aimed to evaluate how adductor canal block (ACB) and femoral nerve block (FNB) affect opioid use and inflammation factor levels in elderly TKA patients. Methods: This prospective observational study included 120 patients who received TKA, and divided them into three groups, based on the different nerve block technique: ACB, FNB, and no intervention before general anesthesia (CON). Postoperative opioid consumption, pain assessment, inflammation factor, knee function recovery and other clinical indicators were recorded. Results: The CON group had significantly higher cumulative sufentanil consumption compared to the ACB and FNB groups at both 12 h and 48h postoperative (P<0.001). Compared with the CON group, the ACB and FNB groups persistently had lower pain scores until 12 h at rest and 24 h during motion after surgery. The ACB group showed significantly lower serum concentrations of C-reactive protein (CRP) and interleukin-6 (IL-6) compared to the CON group at 24 h postoperative (P=0.017, P=0.009), and IL-6 levels remained significantly lower at 72 h postoperative (P=0.005). Both ACB and FNB groups achieved earlier ambulation compared to the CON group (P=0.002). On the first day postoperative, both the ACB and FNB groups showed significantly better knee motion (P<0.001), quadriceps strength (P<0.001), and daily mobilization (P<0.001) compared to the CON group. Additionally, the ACB group exhibited superior quadriceps strength (P<0.001) and daily mobilization (P<0.001) compared to the FNB group. Conclusion: The ACB and FNB groups exhibited comparable clinical efficacy outcomes in terms of pain scores and opioid consumption. However, the ACB group experienced reduced postoperative inflammation and improved knee recovery, especially in quadriceps strength.

Serum myostatin is associated with central-to-peripheral arterial stiffness gradient in healthy adolescents. The MACISTE Study.

BACKGROUND: myostatin is a protein compound structurally related to the TGF-beta protein, which plays a pivotal role in regulating muscle growth and extracellular matrix production. exerts both profibrotic and antihypertrophic effects on vascular smooth muscle cells. Aim of the study was to explore the potential association between serum myostatin levels (sMSTN) and carotid-femoral pulse-wave velocity (cf-PWV), carotid-radial pulse wave velocity (cr-PWV), and their ratio (PWVr), in a cohort of healthy adolescents. METHODS: a cohort of 128 healthy subjects (mean age 17±2 years, 59% male) was randomly selected from participants to the MACISTE (Metabolic And Cardiovascular Investigation at School, TErni) study. sMSTN was assessed utilizing an enzyme-linked immunosorbent assay. PWVs were measured in the supine position using high-fidelity applanation tonometry. RESULTS: The mean cf-PWV was 5.1±0.9 m/s, cr-PWV was 6.9±0.9 m/s, PWVr was 0.75±0.12. PWVr exhibited a linear increase across increasing quartiles of sMSTN (0.71±0.1, 0.74±0.1, 0.7±0.1, 0.77±0.1, p for trend=0.03), whereas the association between sMSTN and each single component of PWVr (cf-PWV, cr-PWV) did not attain statistical significance. Quartiles of sMSTN displayed a positive trend with serum HDL-cholesterol (p=0.01) and a negative one with LDL-cholesterol (p=0.01). In a multivariate linear model, the association between PWVr and sMSTN was independent from SBP values, age, sex, heart rate, BMI, HDL-cholesterol and HOMA Index. CONCLUSIONS: In healthy adolescents, sMSTN showed independent associations with PWVr, a measure of central-to-peripheral arterial stiffness gradient. sMSTN may exert differential effects on the structural and functional properties of the arterial wall.

Importance of pseudoaneurysms after TAVI - a retrospective analysis of 2063 patients.

Background: Bifemoral arterial access is common in patients undergoing transcatheter aortic valve implantation (TAVI), with a primary treatment access (TAVI access) and a secondary non-TAVI access. Pseudoaneurysm (PSA) is an important complication of femoral arterial puncture. Major vascular complications after TAVI are well described, but little is known about PSA. Patients and methods: A total of 2063 patients underwent transfemoral TAVI between January 2014 and January 2020. Vascular ultrasound of the common femoral artery was assessed before and after TAVI. We compared patient characteristics, periprocedural risk scores, procedural characteristics, and access site bleeding events according to Valve Academic Research Consortium 3 (VARC-3) criteria, length of stay (LOS), and all-cause mortality at one year between patients with (46) and without (2017) PSA. Results: The incidence of PSA after TAVI was 2.2% (46/2063). All PSA were successfully treated with ultrasound-guided manual compression (UGMC) or thrombin injection (UGTI) without complications. Patients with PSA had lower platelet counts (210×1000/µl vs. 234×1000/µl; p<0.05), more heart failure symptoms on admission (91% vs. 25%; p<0.05), were more often treated with (N)OACs for atrial fibrillation (AF; 54% vs. 38%; p <0.05), and were less often treated with aspirin (35% vs. 51%; p<0.03). Multivariate analysis identified secondary access site (odds ratio [OR] 8.11; p<0.001) and (N)OAC therapy (OR 1.31; p = 0.037) as risk factors for PSA development. PSA is associated with VARC-3 type 1-3 access site bleeding and longer LOS (15.2 ± 11.3 d vs. 11.6 ± 8.9 d; p<0.01), but this did not affect one year mortality (17% vs. 14%; p = 0.53). Conclusions: Pseudoaneurysms are an important complication after TAVI and are associated with access site bleeding and prolonged hospital stay. (N)OAC therapy and secondary access are important risk factors. Pseudoaneurysms can be safely and effectively treated with thrombin injection and do not affect one-year mortality.

The relationship between the femoral artery and vastus medialis muscle coverage at the adductor hiatus during medial closed wedge distal femoral osteotomy in valgus knees.

Purpose: The purpose of this study was to examine the location where the femoral artery contacts the vastus medialis at the adductor tendon hiatus, which is important when using the subvastus approach in medial closed wedge distal femoral osteotomy. We evaluated the correlation between differences in height, vastus medialis morphology, and lower limb alignment. Methods: Sixty knees (16 male, 44 female) that underwent plain computer tomography (CT) were included. Using the radiographic hip-knee-ankle (HKA) angle as a reference, the knees were divided into three groups of 20 knees: valgus, varus, and neutral. The mechanical lateral distal femoral angle (mLDFA) and distance from the medial femoral epicondyle to the centre of the femoral head (D1) were measured on full-length weight-bearing anteroposterior radiographs. The first cross-section on CT where the vastus medialis muscle and femoral artery connect was defined as the cross-sectional image for measurement. The direct distance from the medial epicondyle to the measured cross-sectional image (D2) was measured in the coronal view. The ratio of the vastus medialis muscle width to the femoral posterior wall width was defined as the vastus medialis muscle coverage ratio (CR). Correlations between each measurement and group were evaluated. Results: There was a positive correlation between D1 and D2 in the overall, neutral, and varus groups; however, there was no correlation in the valgus group. A positive correlation was observed in terms of the relationship between CR and D2 in the overall and valgus groups. In addition, there was no statistically significant difference in the correlation between the mLDFA and D2, with patient height as a control variable overall and in all groups. Conclusion: In the valgus group, distance to the adductor hiatus was correlated with vastus medialis coverage. Overhang of the vastus medialis may be an important influencing factor of femoral and popliteus artery position. Level of Evidence: Level III, retrospective cohort study.

Superior accuracy in knee double level osteotomy using a novel hybrid fixation technique compared to conventional double plating.

Purpose: This study aimed to compare two different double-level knee osteotomy (DLO) fixation techniques. The primary outcome reported the radiological coronal plane correction and its accuracy. The secondary outcomes reported the correction outliers, the clinical outcomes, the 5-year postoperative satisfaction and the complications. Methods: A retrospective review of a single surgeon osteotomy database identified 52 cases of DLO between 2011 and 2019, of which 24 cases met the inclusion criteria. Patients were categorised into two groups: the nail-plate (NP) group fixed with a magnetic extendable intramedullary tibial nail and femoral conventional plate, and the double-plate (DP) group fixed with conventional plates (tibia and femur). Radiographic parameters were recorded, including the mechanical femorotibial angle (mFTA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle (mLDFA), joint line convergence angle (JLCA) and weight-bearing line ratio (Mikulicz %). Surgical accuracy was calculated as the difference between the achieved and the planned correction. Outliers were defined as those with a greater than 10% difference from the planned correction. Simple knee value scores and visual analogue scale for pain were recorded preoperatively and postoperatively at 2 and 5 years. Five-year patient satisfaction was recorded. Results: A total of 24 patients were included: the NP group (n = 12) and the DP group (n = 12). Significant coronal plane corrections were achieved in the NP group for the mean mFTA (preoperative 167.9° ± 3.4° to postoperative 182.1° ± 1.4°), the mean MPTA (preoperative 83.5° ± 2.9° to postoperative 91.3° ± 2.8°) and the mean mLDFA (preoperative 89.8° ± 3.4° to postoperative 85.9° ± 4.4°). Similarly, significant coronal plane corrections were achieved in the DP group for the mean mFTA (preoperative 168.6° ± 4.4° to postoperative 182.2° ± 2°), the mean MPTA (preoperative 84.2° ± 2° to postoperative 88.3° ± 4.1°) and the mean mLDFA (preoperative 90.7° ± 2.9° to postoperative 83.9° ± 1.7°) (all p < 0.05). The mean correction accuracy was higher for the NP versus DP group at 3.4 ± 3.4% versus 7.1 ± 3.9% (intergroup p < 0.05). There were no outliers in the NP group versus two outliers (overcorrected) (16.7%) in the DP group. Significant clinical improvement was reported in both groups at 2 and 5 years postoperatively (all p < 0.05). Conclusion: Superior correction accuracy and no outliers were achieved in hybrid fixation double-level knee osteotomy compared to the conventional double-plating technique. The magnetic extendable nail offers the advantage of fine-tuning the correction postoperatively and could be a potential research template for future designs of postoperative correction implants. Level of Evidence: Level III, retrospective cohort study.

Clinical outcomes of total hip arthroplasty after femoral neck fractures vs. osteoarthritis at one year follow up-A comparative, retrospective study.

PURPOSE: The objective of the study is to determine if there was a difference in medical complications and in-hospital mortality among the patients who underwent THA for femoral neck fracture relative to same procedure for elective patients with coxarthrosis. METHODS: We compared characteristics and short-term outcomes during the rehabilitative postsurgical period. We included all patients older than 45 years who underwent THA for primary/secondary hip arthritis and displaced femoral neck fractures type Garden III and IV. Clinical examination, functional outcome and radiographic evaluation were performed during follow-up. Patients were evaluated at the following time points: preoperatively, postoperatively at three days, six weeks, 12 weeks and one year and we registered Visual Analogue Scale (VAS) pain score, Harris Hip Score (HHS), the Western Ontario McMaster Osteoarthritis Index (WOMAC), internal and external rotation of the hip and operated limb length compared with the opposite. RESULTS: There is no significant statistically differences between the two groups regarding the preoperative comorbidities. The frequencies of patients experiencing in-hospital and 30-day postoperative complications were generally low and same in groups we studied. The mean quantity of surgical blood loos during the operation was significantly higher in the hip fracture group compared with elective patient group with OA (340.09 ± 86.03 vs 309.43 ± 102.52). With respect to postoperative recovery the patients with THA after FNF were mobilized by active walking a little bit faster as the patient with OA (2.77 ± 1.18 days vs 3.1 ± 1.14 days). The average inpatient hospital length of stay after THA for OA was 11.07 days compared to 13.41 days following a THA for FNF. CONCLUSION: Our study showed that THA for treatment of an acute fracture of the femoral neck in an elderly patient can provide results comparable to those of patients who received THA for OA and we found that the results are similar.

Heteronymous feedback from quadriceps onto soleus in stroke survivors.

Background: Recent findings suggest increased excitatory heteronymous feedback from quadriceps onto soleus may contribute to abnormal coactivation of knee and ankle extensors after stroke. However, there is lack of consensus on whether persons post-stroke exhibit altered heteronymous reflexes and, when present, the origin of increased excitation (i.e. increased excitation alone and/or decreased inhibition). This study examined heteronymous excitation and inhibition from quadriceps onto soleus in paretic, nonparetic, and age-matched control limbs to determine whether increased excitation was due to excitatory and/or reduced inhibitory reflex circuits. A secondary purpose was to examine whether heteronymous reflex magnitudes were related to clinical measures of lower limb recovery, walking-speed, and dynamic balance. Methods: Heteronymous excitation and inhibition from quadriceps onto soleus were examined in fourteen persons post-stroke and fourteen age-matched unimpaired participants. Heteronymous feedback was elicited by femoral nerve and quadriceps muscle stimulation in separate trials while participants tonically activated soleus at 20% max. Fugl-Myer assessment of lower extremity, 10-meter walk test, and Mini-BESTest were assessed in stroke survivors. Results: Heteronymous excitation and inhibition onsets, durations, and magnitudes were not different between paretic, nonparetic or age-matched unimpaired limbs. Quadriceps stimulation elicited excitation that was half the magnitude of femoral nerve stimulation. Femoral nerve elicited paretic limb heteronymous excitation was positively correlated with walking speed but did not reach significance because only a subset of paretic limbs exhibited excitation (n = 8, Spearman r = 0.69, P = 0.058). Conclusions: Heteronymous feedback from quadriceps onto soleus assessed in a seated posture was not impaired in persons post-stroke. Despite being unable to identify whether reduced inhibition contributes to abnormal excitation reported in prior studies, our results indicate quadriceps stimulation may allow a better estimate of heteronymous inhibition in those that exhibit exaggerated excitation. Heteronymous excitation magnitude in the paretic limb was positively correlated with self-selected walking speed suggesting paretic limb excitation at the higher end of a normal range may facilitate walking ability after stroke. Future studies are needed to identify whether heteronymous feedback from Q onto SOL is altered after stroke in upright postures and during motor tasks as a necessary next step to identify mechanisms underlying motor impairment.

Research Progress on the Treatment of Geriatric Intertrochanteric Femur Fractures with Proximal Femur Bionic Nails (PFBNs).

Intertrochanteric femur fracture is the most common hip fracture in elderly people, and the academic community has reached a consensus that early surgery is imperative. Proximal femoral nail anti-rotation (PFNA) and InterTan are the preferred internal fixation devices for intertrochanteric femur fractures in elderly individuals due to their advantages, such as a short lever arm, minimal stress shielding, and resistance to rotation. However, PFNA is associated with complications such as nail back-out and helical blade cut-out due to stress concentration. As a new internal fixation device for intertrochanteric femur fractures, the proximal femoral biodegradable nail (PFBN) addresses the issue of nail back-out and offers more stable fracture fixation, a shorter lever arm, and stress distribution compared to PFNA and InterTan. Clinical studies have shown that compared to PFNA, PFBNs lead to faster recovery of hip joint function, shorter non-weight-bearing time, and faster fracture healing. This article provides a literature review of the structural characteristics, biomechanical analysis, and clinical studies of PFBNs, aiming to provide a theoretical basis for the selection of internal fixation devices for the treatment of intertrochanteric femur fractures in elderly patients and to improve the quality of life of patients during the postoperative period.

Proximal Femoral Metastasis From Epidermal Growth Factor Receptor-Mutated Lung Adenocarcinoma Mimicking Osteosarcoma on Magnetic Resonance Imaging.

The aggressive nature of lung cancer is frequently accompanied by a high incidence of bone metastasis; however, proximal femoral metastasis from lung cancer is comparatively uncommon when compared to other malignancies. In this report, we present the case of a 53-year-old Asian male who presented with pain in the left thigh and back. Magnetic resonance imaging revealed severe bone destruction with involvement of adjacent soft tissue mass at the left thigh, exhibiting imaging findings that mimic osteosarcoma. Subsequent bone biopsy confirmed the diagnosis of epidermal growth factor receptor (EGFR)-mutated lung adenocarcinoma with bone metastasis. The patient achieved survival following administration of osimertinib and underwent surgery for femoral metastases without palliative surgery for lung cancer. Therefore, proximal femoral metastasis from EGFR-mutated lung adenocarcinoma should be considered as a differential diagnosis in patients suspected to have osteosarcoma. The imaging findings of proximal femoral metastasis from EGFR-mutated lung adenocarcinoma were presented, and their therapeutic management was discussed.

Intraoperative Dissociation and Migration of the Trial Bipolar Cup in Hip Hemiarthroplasty: A Rare Case.

Femoral neck fractures are an ever-increasing pathology, and with the elderly population on the rise, cases of cemented bipolar hemiarthroplasties are also on the rise. This is a rare case of intraoperative dissociation and migration of the trial components of bipolar hemiarthroplasty. Considering the current literature, all junior surgeons should be aware of this possible development during trial reduction. We present the case of an 82-year-old Caucasian woman suffering from a left femoral neck fracture due to a fall. She was treated surgically with a cemented bipolar hemiarthroplasty, but after trial reduction, the trial components dissociated and migrated inside the pelvis. The attempts at recovery through the current approach failed, and a new incision and approach were needed. A small ilioinguinal incision was performed, and the recovery of the trial cup was successful. The patient recovered with no considerable problems. As the reasons for this rare complication are largely unknown, the surgeon should be careful and take measures to prevent this scenario. Moreover, it is wise to weigh the pros and cons of retrieval through other approaches and choose the best course of action for the patient.

Biomechanical analysis of various internal fracture fixation devices used for treating femoral neck fractures: A comparative finite element analysis.

INTRODUCTION: Several internal fixation devices are available for treating Pauwels type I, II and III femoral neck fractures. The present study compared various fixation implants for all Pauwels fracture types using a CT-based subject-specific finite element model of the femur and determined the most effective implant for each fracture type. MATERIALS AND METHODS: The analysis included four different configurations of cannulated screw models, Femoral Neck System, Dynamic Hip Screw and Dynamic Condylar Screw (with and without anti-rotational screw). Ti-alloy was considered as the implant material. Heterogeneous bone material property was assigned based on CT grey value. Frictional contact was assumed in the contact interfaces. Peak loading corresponding to normal walking and stair-climbing were considered. Equivalent strain in bone, equivalent stress in the implants, femoral head deformation and rotation, micromotion in the contact interfaces, and strain-shielding in bone were evaluated for each implanted model. RESULTS: Stresses generated in the implants were within the yield limit of the implant material. In Pauwels I and II, the micromotion predicted at the contact regions in all the implanted models was within 100 µm, which is suitable for bone integration. However, in Pauwels III fracture, most of the implanted models other than DHS with AR-screw model exhibited micromotion of more than 150 µm in the contact regions, which is expected to inhibit bone growth. CONCLUSIONS: The DHS with AR-screw implanted model was identified as the most effective in treating Pauwels I and III fractures. However, for Pauwels type II, DCS with an AR-screw implant was deemed superior to the other configurations.

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

BACKGROUND: Femoral neck fractures (FNF) in young and middle-aged adults are primarily caused by high-energy injuries in traffic accidents. Surgical delays often occur due to transportation issues, preoperative evaluations, and economic burdens. METHODS: A retrospective analysis was conducted on young and middle-aged FNF patients undergoing reduction and internal fixation surgeries from 2010 to 2019 with the use of the National Inpatient Sample database. Logistic regression analysis was used to assess the relationship between surgical delays and complications, and the independent risk factors contributing to delays. Categorical variables were investigated via a chi-square test, while continuous variables including Elixhauser Comorbidity Index (ECI) scores, length of hospital stay (LOS), and total medical costs were analyzed via t-test or rank-sum test. RESULTS: 9,204 patients undergoing reduction and internal fixation surgeries were included. In the delayed group, patients had higher ECI scores, longer hospital stays, higher expenses, and increased inpatient mortality (1.61% vs. 0.28 %, P < 0.0001). Longer surgical delays were associated with higher risks of complications, including femoral head osteonecrosis, internal fixation loosening and breakage, and respiratory complications. Fluid and electrolyte disorders, metastatic cancer, pulmonary circulation disorders, and renal failure were identified as independent risk factors for surgical delays. Except for anemia (OR=2.37, P < 0.0001), no significant differences in early postoperative complications were found between open-reduction and closed-reduction internal fixation (ORIF/CRIF) surgeries. CONCLUSION: Early surgical intervention, within a 2-days period after injury, seems to be crucial for young adults with FNF. If CRIF is challenging in some cases, ORIF can be another choice.

Assessment of implant internal stresses under physiological femoral loading: Translation to a simplified bending load model.

The success of surgical treatment for fractures hinges on various factors, notably accurate surgical indication. The process of developing and certifying a new osteosynthesis device is a lengthy and costly process that requires multiple cycles of review and validation. Current methods, however, often rely on predecessor standards rather than physiological loads in specific anatomical locations. This study aimed to determine actual loads experienced by an osteosynthesis plate, exemplified by a standard locking plate for the femoral shaft, utilizing finite elements analysis (FEA) and to obtain the bending moments for implant development standard tests. A protocol was developed, involving the creation and validation of a fractured femur model fixed with a locking plate, mechanical testing, and FEA. The model's validation demonstrated exceptional accuracy in predicting deformations, and the FEA revealed peak stresses in the fracture bridging zone. Results of a parametric analysis indicate that larger fracture gaps significantly impact implant mechanical behavior, potentially compromising stability. This study underscores the critical need for realistic physiological conditions in implant evaluations, providing an innovative translational approach to identify internal loads and optimize implant designs. In conclusion, this research contributes to enhancing the understanding of implant performance under physiological conditions, promoting improved designs and evaluations in fracture treatments.