Impact of the nail insertion angle on the wedge effect in intramedullary nail fixation of intertrochanteric hip fractures.

BACKGROUND: The wedge effect is known to be influenced by the insertion of the proximal femoral intramedullary nail through the fracture line and the large proximal diameter of the nail. However, the impact of the nail insertion angle (NIA) on the wedge effect remains unclear. This study aimed to investigate: (1) how to evaluate the NIA intraoperatively, (2) whether the NIA is associated with the wedge effect, (3) whether the NIA can serve as a reliable predictor of the wedge effect, (4) which factors affect the NIA, and (5) which surgical techniques can prevent the occurrence of the wedge effect associated with the NIA. HYPOTHESIS: We hypothesized that an excessive NIA is related to the wedge effect and that lateral deviation of the entry point is associated with an excessive NIA. PATIENTS AND METHODS: Intraoperative fluoroscopy images of patients who underwent intramedullary nail fixation for intertrochanteric hip fractures between 2013 and 2023 were analyzed. NIA and insertion point distance (IPD) were measured on hip anteroposterior radiographs with the guidewire inserted. Femoral shaft lateralization (FSL) and neck-shaft angle (NSA) were measured on hip anteroposterior radiographs before and after nail insertion; differences in FSL and NSA were calculated. A negative difference in FSL combined with a positive difference in NSA indicated the occurrence of the wedge effect. Pearson's correlation test was used to determine relationships between continuous variables (NIA, FSL, NSA, and IPD). Binary logistic regression analyzed the association between NIA and the wedge effect. Receiver operating characteristic (ROC) curve analysis was used to determine the threshold value of NIA, with predictive performance assessed using the area under the ROC curve (AUC). Other potential factors influencing the wedge effect were also examined. RESULTS: A total of 408 patients were included. The mean NIA was 15.61 ± 4.49 °. Post-nail insertion, the average increase in FSL was 3.20 mm, and the average decrease in NSA was 1.90 °. Pearson's correlation test revealed that NIA was negatively correlated with the difference in FSL (R = 0.565, P < 0.001) and positively correlated with the difference in NSA (R = 0.509, P < 0.001). Binary logistic regression showed a significant correlation between NIA and the wedge effect (P < 0.001). ROC analysis indicated that the AUC for NIA was 0.813, with an optimal cutoff point of 14.85 °. IPD was positively correlated with NIA (R = 0.519, P < 0.001). Unstable fractures were associated with increased lateralization of the femoral shaft after nail insertion (P = 0.003). DISCUSSION: The NIA is positively correlated with the wedge effect in intramedullary nail fixation of intertrochanteric hip fractures. The wedge effect tends to occur when the NIA is >14.85 °, particularly in unstable fractures. Lateral deviation of the entry point is associated with an excessive NIA. Adducting the affected limb, moving the entry point slightly medial and using a medial pusher may help control the NIA to less than 14.85 ° to reduce the wedge effect. LEVEL OF EVIDENCE: III.

The incidence and risk factors of perioperative recurrent stroke in elderly patients with previous ischemic stroke receiving hip fracture surgery.

BACKGROUND: Data are currently lacking regarding perioperative stroke recurrence in hip fracture patients with previous stroke. We aimed to analyze the incidence and risk factors of perioperative stroke recurrence in elderly patients with previous stroke who underwent hip fracture surgery. METHODS: We used 2019 and 2020 data from the United States National Inpatient Sample database. We identified elderly patients with previous ischemic stroke who had undergone hip fracture surgery to analyze the incidence of stroke recurrence. A 1:4 propensity score matching was used to balance confounding factors related to demographic data and matched the control group with the stroke recurrence group. Risk factors for stroke recurrence were determined using univariate and multivariate logistic analysis. RESULTS: The incidence of perioperative stroke recurrence in elderly patients with previous stroke who underwent hip fracture surgery was 5.7% (51/882). Multivariate logistic regression analysis showed that intertrochanteric fracture (odds ratio 2.24, 95% confidence interval 1.14-4.57; p = 0.021), hypertension (odds ratio 2.49, 95% confidence interval 1.26-5.02; p = 0.009), and postoperative pneumonia (odds ratio 4.35, 95% confidence interval 1.59-11.82; p = 0.004) were independently associated with stroke recurrence. CONCLUSIONS: The perioperative stroke recurrence rate in elderly hip fracture patients with previous stroke was 5.7%. Intertrochanteric fracture, hypertension, and postoperative pneumonia were identified as factors significantly associated with stroke recurrence in this study. Adequate systemic support post-fracture, effective blood pressure management, and proactive infection prevention may help reduce stroke recurrence, especially in patients with intertrochanteric fractures.

Type 2 diabetic mellitus related osteoporosis: focusing on ferroptosis.

With the aging global population, type 2 diabetes mellitus (T2DM) and osteoporosis(OP) are becoming increasingly prevalent. Diabetic osteoporosis (DOP) is a metabolic bone disorder characterized by abnormal bone tissue structure and reduced bone strength in patients with diabetes. Studies have revealed a close association among diabetes, increased fracture risk, and disturbances in iron metabolism. This review explores the concept of ferroptosis, a non-apoptotic cell death process dependent on intracellular iron, focusing on its role in DOP. Iron-dependent lipid peroxidation, particularly impacting pancreatic ß-cells, osteoblasts (OBs) and osteoclasts (OCs), contributes to DOP. The intricate interplay between iron dysregulation, which comprises deficiency and overload, and DOP has been discussed, emphasizing how excessive iron accumulation triggers ferroptosis in DOP. This concise overview highlights the need to understand the complex relationship between T2DM and OP, particularly ferroptosis. This review aimed to elucidate the pathogenesis of ferroptosis in DOP and provide a prospective for future research targeting interventions in the field of ferroptosis.

[Genetic analysis of a Chinese pedigree affected with atypical Charcot-Marie-Tooth disease type 1A due to duplication of PMP22 gene].

OBJECTIVE: To explore the clinical manifestations and genetic basis for a Chinese pedigree affected with atypical Charcot-Marie-Tooth disease type 1 A (CMT1A). METHODS: A patient admitted to the Department of Neurology, Xijing Hospital Affiliated to Air Force Medical University in June 2022 was selected as the study subject. Clinical data of the patient was collected, and 17 family members from four generations of this pedigree were traced based on pes arcuatus and atypical clinical symptoms. Neuroultrasound and genetic testing were carried out on available family members. Whole exome sequencing and multiple ligation-dependent probe amplification assay were carried out for the proband and some of the affected members of the pedigree. RESULTS: The proband, a 15-year-old male, had presented with paroxystic limb pain with weakness, accompanied by pes cavus and hypertrophy of gastrocnemius muscles, without stork leg sign caused by muscles atrophy in the distal lower extremities. MRI has revealed no sign of fat infiltration in the muscles of both legs. Nerve conduction examination had indicated damages of the sensory and motor nerves of the limbs, mainly with demyelinating changes. Seven members of the pedigree had pes arcuatus, including 5 presenting with paroxysmal neuropathic pain and myasthenia in the limbs, whilst 2 were without any clinical symptoms. Neurosonography of the proband, his brother, father and aunt showed thickened peripheral nerves of the extremities with unclear bundle structure. Genetic analysis revealed a large repeat encompassing exons 1 to 5 of the PMP22 gene and flanking regions (chr17: 15133768_15502298) in some of the affected members, which was predicted to be pathogenic. CONCLUSION: The duplication of PMP22 gene was considered to be pathogenic for this CMT1A pedigree.

Environmental factors affecting the risk of generalization for ocular-onset myasthenia gravis: a nationwide cohort study.

BACKGROUND: The environmental effects on the prognosis of ocular myasthenia gravis (OMG) remain largely unexplored. AIM: To investigate the association between specific environmental factors and the generalization of OMG. DESIGN: The cohort study was conducted in China based on a nationwide multicenter database. METHODS: Adult patients with OMG at onset, who were followed up for at least 2 years until May 2022, were included. We collected data on demographic and clinical factors, as well as environmental factors, including latitude, socioeconomic status (per capita disposable income [PDI] at provincial level and education) and smoking. The study outcome was the time to the development of generalized myasthenia gravis (GMG). Cox models were employed to examine the association between environmental exposures and generalization. Restricted cubic spline was used to model the association of latitude with generalization risk. RESULTS: A total of 1396 participants were included. During a median follow-up of 5.15 (interquartile range [IQR] 3.37-9.03) years, 735 patients developed GMG within a median of 5.69 (IQR 1.10-15.66) years. Latitude of 20-50°N showed a U-shaped relation with generalization risk, with the lowest risk at around 30°N; both higher and lower latitudes were associated with the increased risk (P for non-linearity <0.001). Living in areas with lower PDI had 1.28-2.11 times higher risk of generalization. No significant association was observed with education or smoking. CONCLUSIONS: Latitude and provincial-level PDI were associated with the generalization of OMG in China. Further studies are warranted to validate our findings and investigate their potential applications in clinical practice and health policy.

Regression of a large prolapsed lumbar disc herniation achieved by conservative treatment: A case report and literature review.

A common spinal condition known as lumbar disc herniation (LDH) can result in radicular and low back discomfort. A 27-year-old man was admitted to our hospital with a 6-year history of persistent low back pain, and his low back pain had recurred with radiation to his lower extremities over the last two months. An extensive right-sided paracentral disc herniation in the L5/S1 intervertebral region, which compressed the nerve root, was discovered by magnetic resonance imaging (MRI) of his lumbar spine. After receiving conservative treatment, the patient reported that his lower back discomfort and neurogenic claudication had gradually subsided after 4 months. After one year, a follow-up MRI showed that the massive, prolapsed disc herniation at the L5/S1 level had totally disappeared. The sagittal protrusion length of the L5/S1 intervertebral disc shrank from 12.35 mm to 3.49 mm. However, there remained a chance of vertebral height loss. During the course of treatment, the height of the L5/S1 intervertebral space was still slightly reduced. The intervertebral space height declined from 7.705 mm to 7.201 mm after one year of treatment. The current case and a review of the literature demonstrate that LDH can decrease with conservative therapy over a short period of time. We stress the effectiveness of conservative treatment in very select LDH cases that lack a clear surgical justification.

A biomechanical investigation of a novel intramedullary nail used to salvage failed internal fixations in intertrochanteric fractures.

PURPOSE: The ideal approach for revision surgery following femoral head salvage treatments for an intertrochanteric fracture is still up for debate. A novel variety of proximal femoral bionic intramedullary nail (PFBN) has been created in clinical practice. We aimed to compare the biomechanical results of the novel implant to conventional intramedullary and extramedullary fixation in the treatment of intertrochanteric fracture following primary internal fixation failure. METHODS: Using finite element analysis, we created a three-dimensional model of the intertrochanteric fracture's helical blade cut-out for this investigation. The PFBN 1 group, the PFBN 2 group, the PFNA group, and the DHS group were our four test groups. For each fracture group, the von Mises stress and displacements of the femur and internal fixation components were measured under 2100 N axial loads. RESULTS: The values for the femoral displacement in the PFBN1 group, PFBN2 group, PFNA group, and DHS group were 6.802 mm, 6.716 mm, 8.080 mm, and 8.679 mm, respectively. The internal implant displacement values were 6.201 mm, 6.138 mm, 7.396 mm, and 8.075 mm in the PFBN1 group, PFBN2 group, PFNA group, and DHS group, respectively. The maximum von Mises Stress in the femoral was 187.2 MPa, 85.18 MPa, 106.6 MPa, and 386.2 MPa in the PFBN1 groups, PFBN2 groups, PFNA groups, and DHS groups, respectively. In the PFBN1 groups, PFBN2 groups, PFNA groups, and DHS groups, the maximum von Mises Stress in internal fixation was 586.7 MPa, 559.8 MPa, 370.7 MPa, and 928.4.8 MPa, respectively. CONCLUSION: Our biomechanical research demonstrates that intramedullary fixation is more stable than extramedullary fixation when salvaging failed internal fixations in intertrochanteric fracture. Compared with PFNA and DHS, PFBN showed better biomechanical stability in the treatment of patients with revised intertrochanteric fractures. In light of this, we advocate PFBN fixation as the method of choice for intertrochanteric fracture revision. This result still has to be confirmed in more clinical research.

Comparison between mono-tacrolimus and mono-glucocorticoid in the treatment of myasthenia gravis.

OBJECTIVE: Use of tacrolimus in mild to moderate myasthenia gravis (MG) is generally limited to glucocorticoid-refractory cases; the advantage of mono-tacrolimus over mono-glucocorticoids is unknown. METHODS: We included mild to moderate MG patients treated with mono-tacrolimus (mono-TAC) or mono-glucocorticoids (mono-GC). The correlation between the immunotherapy options and the treatment efficacy and side effects were examined in 1:1 propensity-score matching. The main outcome was time to minimal manifestations status or better (MMS or better). Secondary outcomes include time to relapse, the mean changes in Myasthenia Gravis-specific Activities of Daily Living (MG-ADL) scores and the rate of adverse events. RESULTS: Baseline characteristics showed no difference between matched groups (49 matched pairs). There were no differences in median time to MMS or better between the mono-TAC group and mono-GC group (5.1 vs. 2.8 months: unadjusted hazard ratio [HR], 0.73; 95% CI, 0.46-1.16; p = 0.180), as well as in median time to relapse (data unavailable for the mono-TAC group since 44 of 49 [89.8%] participants remained in MMS or better; 39.7 months in mono-GC group: unadjusted HR, 0.67; 95% CI, 0.23-1.97; p = 0.464). Changes in MG-ADL scores between the two groups were similar (mean differences, 0.3; 95% CI, -0.4 to 1.0; p = 0.462). The rate of adverse events was lower in the mono-TAC group compared to the mono-GC group (24.5% vs. 55.1%, p = 0.002). INTERPRETATION: Mono-tacrolimus performs superior tolerability with non-inferior efficacy compared to mono-glucocorticoids in mild to moderate myasthenia gravis patients who refuse or have a contraindication to glucocorticoids.

Biomechanical study of femoral neck system for young patients with nonanatomically reduced femoral neck fractures: a finite element.

BACKGROUND: A consensus regarding the optimal approach for treating femoral neck fractures is lacking. We aimed to investigate the biomechanical outcomes of Femoral Neck System (FNS) internal fixation components in the treatment of nonanatomically reduced femoral neck fractures. METHOD: We constructed two types of femoral neck fractures of the Pauwels classification with angles of 30° and 50°, and three models of anatomic reduction, positive buttress reduction and negative buttress reduction were constructed. Subgroups of 1 to 4 mm were divided according to the distance of displacement in the positive buttress reduction and negative buttress reduction models. The von Mises stress and displacements of the femur and FNS internal fixation components were measured for each fracture group under 2100-N axial loads. RESULTS: When the Pauwels angle was 30°, the positive 1-mm and 2-mm models had lower FNS stress than the negative buttress model. The positive 3- and 4-mm models showed FNS stress similar to that of the negative buttress model. But the four positive buttress models had similar stresses on the femur as the negative buttress model. When the Pauwels angle was 50°, the four positive buttress models had higher FNS stress than the negative buttress model. Three positive buttress models (2 mm, 3 and 4 mm) resulted in lower stress of the femur than the negative buttress model, though the 1-mm model did not. When the Pauwels angle was 30°, the positive buttress model had a lower displacement of the FNS than the negative buttress model and a similar displacement of the femur with the negative buttress model. When the Pauwels angle was 50°, the positive buttress model had a higher displacement of the FNS and femur than the negative buttress model. Our study also showed that the von Mises stress and displacement of the internal fixation and the femur increased as the fracture angle increased. CONCLUSION: From the perspective of biomechanics, when the Pauwels angle was 30°, positive buttress was more stable to negative buttress. However, when the Pauwels angle was 50°, this advantage weakens. In our opinion, the clinical efficacy of FNS internal fixation with positive buttress may be related to the fracture angle, neck-shaft angle and alignment in the lateral view. This result needs verification in further clinical studies.