Effect of lesser trochanter posteromedial wall defect on the stability of femoral intertrochanteric fracture using 3D simulation

A Novel Internal Fixation Design for the Treatment of AO/OTA-31A3.3 Intertrochanteric Fractures: Finite Element Analysis

OBJECTIVE

AO/OTA 31-A3.3 intertrochanteric fracture is the most unstable type of intertrochanteric fracture, with a high rate of postoperative complications and implant failure. We have designed a new intramedullary fixation, proximal femoral totally bionic nail (PFTBN), for the treatment of A3.3 intertrochanteric fracture. To test its biomechanical performance, we adopted the method of finite element analysis and compared PFTBN with proximal femoral nail antirotation (PFNA) and proximal femoral bionic nail (PFBN, another internal fixation we previously designed for stable intertrochanteric fractures).

METHODS

Mimics, 3-matic, ANSYS, and other software were used to construct a highly precise and realistic 3D digital model of the human femur. An AO/OTA 31-A3.3 intertrochanteric fracture of the femur was constructed according to the 2018 classification of AO/OTA, and then assembled with PFNA, PFBN and PFTBN models, respectively. The stress distribution and displacement distribution of the three groups of constructs were tested under three times the body weight load and one-foot standing configuration.

RESULTS

In terms of maximum stress and maximum displacement, the PFTBN group outperforms the PFBN group, and the PFBN group, in turn, surpasses the PFNA group. The maximum stress of PFTBN group was 408.5 Mpa, that of PFBN group was 525.4 MPa, and that of PFNA group was 764.3 Mpa. Comparatively, the maximum stress in the PFTBN group was reduced by 46.6% when contrasted with the PFNA group. Moreover, the stress dispersion within the PFTBN group was more evenly distributed than PFNA group. Regarding maximum displacement, the PFTBN group displayed the least displacement at 5.15 mm, followed by the PFBN group at 7.32 mm, and the PFNA group at 7.73 mm. Notably, the maximum displacement of the PFTBN group was 33.4% less than that observed in the PFNA group. Additionally, the relative displacement between the fragment and implant at the tip of pressure screw or helical blade was 0.22 mm in the PFTBN group, 0.34 mm in the PFBN group, and substantially higher 0.51 mm in the PFNA group.

CONCLUSION

The "lever-reconstruction-balance" theory provides a new perspective for us to understand the mechanical conduction of the proximal femur. Compared with PFNA, in treating A3.3 intertrochanteric fractures PFTBN can better reconstruct the function of lateral wall, restore physiological mechanical conduction, increase postoperative stability, and finally reduce the risk of postoperative cut-out and implant failure. It might be a better alternative for the treatment of A3.3 intertrochanteric fracture.

Inverse-Vaccines for Rheumatoid Arthritis Re-establish Metabolic and Immunological Homeostasis in Joint Tissues

Rheumatoid arthritis (RA) causes immunological and metabolic imbalances in tissue, exacerbating inflammation in affected joints. Changes in immunological and metabolic tissue homeostasis at different stages of RA are not well understood. Herein, the changes in the immunological and metabolic profiles in different stages in collagen induced arthritis (CIA), namely, early, intermediate, and late stage is examined. Moreover, the efficacy of the inverse-vaccine, paKG(PFK15+bc2) microparticle, to restore tissue homeostasis at different stages is also investigated. Immunological analyses of inverse-vaccine-treated group revealed a significant decrease in the activation of pro-inflammatory immune cells and remarkable increase in regulatory T-cell populations in the intermediate and late stages compared to no treatment. Also, glycolysis in the spleen is normalized in the late stages of CIA in inverse-vaccine-treated mice, which is similar to no-disease tissues. Metabolomics analyses revealed that metabolites UDP-glucuronic acid and L-Glutathione oxidized are significantly altered between treatment groups, and thus might provide new druggable targets for RA treatment. Flux metabolic modeling identified amino acid and carnitine pathways as the central pathways affected in arthritic tissue with CIA progression. Overall, this study shows that the inverse-vaccines initiate early re-establishment of homeostasis, which persists through the disease span.

Lateral wall thickness is not associated with revision risk of medially stable intertrochanteric fractures fixed with a sliding hip screw

Aims

This study aimed to determine whether lateral femoral wall thickness (LWT) < 20.5 mm was associated with increased revision risk of intertrochanteric fracture (ITF) of the hip following sliding hip screw (SHS) fixation when the medial calcar was intact. Additionally, the study assessed the association between LWT and patient mortality.

Methods

This retrospective study included ITF patients aged 50 years and over treated with SHS fixation between 2019 and 2021 at a major trauma centre. Demographic information, fracture type, delirium status, American Society of Anesthesiologists grade, and length of stay were collected. LWT and tip apex distance were measured. Revision surgery and mortality were recorded at a mean follow-up of 19.5 months (1.6 to 48). Cox regression was performed to evaluate independent risk factors associated with revision surgery and mortality.

Results

The cohort consisted of 890 patients with a mean age of 82 years (SD 10.2). Mean LWT was 27.0 mm (SD 8.6), and there were 213 patients (23.9%) with LWT < 20.5 mm. Overall, 20 patients (2.2%) underwent a revision surgery following SHS fixation. Adjusting for covariates, LWT < 20.5 mm was not independently associated with an increased revision or mortality risk. However, factors that were significantly more prevalent in LWT < 20.5 mm group, which included residence in care home (hazard ratio (HR) 1.84; p < 0.001) or hospital (HR 1.65; p = 0.005), and delirium (HR 1.32; p = 0.026), were independently associated with an increased mortality risk. The only independent factor associated with increased risk of revision was older age (HR 1.07; p = 0.030).

Conclusion

LWT was not associated with risk of revision surgery in patients with an ITF fixed with a SHS when the calcar was intact, after adjusting for the independent effect of age. Although LWT < 20.5 mm was not an independent risk factor for mortality, patients with LWT < 20.5 mm were more likely to be from care home or hospital and have delirium on admission, which were associated with a higher mortality rate.

Morphological analysis of posterior-medial intertrochanteric fracture patterns using fracture-mapping technique

Introduction: The purpose of this study was to analyze the fracture patterns of different posterior-medial wall types of intertrochanteric fractures by 3-D fracture-mapping technique and to further assess their clinical utility. Methods: In a retrospective analysis of interochanteric fractures treated in a large trauma center, fractures were classified into predesigned groups based on 3D-CT imaging techniques, and a 3-D template of the intertrochanteric region was graphically superimposed on the fracture line. Fracture characteristics were then summarized based on fracture-mapping. Finally, radiographic parameters, function, and range of motion were recorded in different fracture classification states. Results: A total of 348 intertrochanteric fractures were included. There were 111 patients (31.9%) in the posterolateral + posteromedial + medial group, with the most severe fracture displacement (typically characterized by fragmentation of the posteromedial wall into three isolated fragments). There were 102 cases (29.3%) in the posterolateral + posteromedial + simple medial group, and the most common fracture feature was a complete fragment posteromedially. A total of 81 cases (23.3%) were classified into the posterolateral + medial group, with the medial fracture line extending the anterior fracture line but leaving the lesser trochanter intact. In the isolated medial group of 33 cases (9.5%), the fracture type was similar to type IV, but the integrity of the greater trochanter was ensured. In the posteromedial + medial group of 12 cases (3.4%), the fracture was characterized by an interruption when the fracture line of the anterolateral wall extended to the posteromedial wall, often resulting in a complete isolated fragment posteromedially and medially. There were nine patients (2.6%) in the isolated posterolateral group. In addition, we found significantly different radiographic scores and range of motion scores between groups. Discussion: This morphometric study helps us to further characterize posterior-medial fracture patterns of intertrochanteric fractures, which may be closely related to different clinical outcomes. Further studies are needed to verify the reliability of this classification scheme in clinical application.

Stability of Intertrochanteric Femur Fractures

SUMMARY

The stability of intertrochanteric fractures depends upon multiple factors including the fracture displacement, location and pattern, the type of fixation used for stabilization, and the loading that the fracture undergoes postfixation. Traditional classification systems are of limited utility because they typically stratify intertrochanteric fractures as stable or unstable based purely on the fracture pattern without consideration of the stability after fixation. Biomechanical studies evaluating the stability of various fixation constructs should include physiologic loading, including rotation around the axis of the femoral neck, and reproduce clinical failure modes to be clinically relevant. A growing body of evidence indicates that the type of fixation substantially affects postoperative stability of intertrochanteric fractures.

Accurate reduction of medial arch fracture fragments in intertrochanteric fractures: A novel technical note

Intramedullary fixation is currently used to stabilize intertrochanteric fractures. Surgical reduction of the medial arch cortex is crucial to achieve stabilization of the internal fixation system, however, it is challenging to perform. To ensure anatomical reduction, we developed a novel surgical technique to assist in achieving accurate and convenient reduction. In this technique, right-angle forceps were used to pry and reset medial arch cortex fragments via a mini-helical blade incision. Noteworthily, all patients who underwent this technique achieved anatomical reduction with reduced operation times and bleeding. Our article illustrates intraoperative reduction techniques and summarizes tips and tricks that may be beneficial and educative for orthopedists.

Accuracy and reliability analysis of a machine learning based segmentation tool for intertrochanteric femoral fracture CT

Introduction

Three-dimensional (3D) reconstruction of fracture fragments on hip Computed tomography (CT) may benefit the injury detail evaluation and preoperative planning of the intertrochanteric femoral fracture (IFF). Manually segmentation of bony structures was tedious and time-consuming. The purpose of this study was to propose an artificial intelligence (AI) segmentation tool to achieve semantic segmentation and precise reconstruction of fracture fragments of IFF on hip CTs.

Materials and Methods

A total of 50 labeled CT cases were manually segmented with Slicer 4.11.0. The ratio of training, validation and testing of the 50 labeled dataset was 33:10:7. A simplified V-Net architecture was adopted to build the AI tool named as IFFCT for automatic segmentation of fracture fragments. The Dice score, precision and sensitivity were computed to assess the segmentation performance of IFFCT. The 2D masks of 80 unlabeled CTs segmented by AI tool and human was further assessed to validate the segmentation accuracy. The femoral head diameter (FHD) was measured on 3D models to validate the reliability of 3D reconstruction.

Results

The average Dice score of IFFCT in the local test dataset for “proximal femur”, “fragment” and “distal femur” were 91.62%, 80.42% and 87.05%, respectively. IFFCT showed similar segmentation performance in cross-dataset, and was comparable to that of human expert in human-computer competition with significantly reduced segmentation time (p < 0.01). Significant differences were observed between 2D masks generated from semantic segmentation and conventional threshold-based segmentation (p < 0.01). The average FHD in the automatic segmentation group was 47.5 ± 4.1 mm (41.29∼56.59 mm), and the average FHD in the manual segmentation group was 45.9 ± 6.1 mm (40.34∼64.93 mm). The mean absolute error of FHDs in the two groups were 3.38 mm and 3.52 mm, respectively. No significant differences of FHD measurements were observed between the two groups (p > 0.05). All ICCs were greater than 0.8.

Conclusion

The proposed AI segmentation tool could effectively segment the bony structures from IFF CTs with comparable performance of human experts. The 2D masks and 3D models generated from automatic segmentation were effective and reliable, which could benefit the injury detail evaluation and preoperative planning of IFFs.

When to Reduce and Fix Displaced Lesser Trochanter in Treatment of Trochanteric Fracture: A Systematic Review

Purpose

To systematically evaluate the benefits of reducing and fixing displaced lesser trochanter (LT) of trochanteric fractures and when this procedure is worth the effect.

Methods

From database establishment through March 2021, four online databases (PubMed, Cochrane, Embase, and Web of Science) were searched for relevant literature that investigated reduction and fixation for displaced LT of trochanteric fractures. The papers were then screened by two reviewers independently and in duplicate according to prior inclusion and exclusion criteria. Demographic data as well as data on fracture types, surgical protocols, and surgical outcomes were recorded, analyzed, and interpreted.

Results

Total 10 clinical studies with 928 patients were included, in which 48 cases had intact LT and 880 cases involved the displaced LT, of which 196 (22.27%) cases underwent reduction and fixation for LT while the rest of 684 (77.73%) cases not. In these studies, complications were evaluated as a more applicable predictive parameter for operation than postoperative hip function.

Conclusion

It was beneficial to reduce and fix the displaced LT when one of the conditions below occurred: displacement distance of LT ≥2 cm, quantity of comminuted LT fragments ≥2, and range of LT fragments in medial wall ≥75%; the fracture line of LT fragments reaching or exceeding the midline of the posterior wall.

The clinical efficacy of Shengyu decoction in the treatment of anemia after PFNA for elderly intertrochanteric fracture: A protocol of prospective, randomized, controlled trial

BACKGROUND

Femoral intertrochanteric fractures (ITF) occur frequently in the elderly, accounting for 45% of all hip fractures. Postoperative anemia after fracture tends to cause ischemia, hypoxia in cells, tissues and organs, increasing the rate of blood transfusion, risk of infection, disability and mortality. Meanwhile, traditional Chinese medicine is widely used in the treatment of anemia for activating blood circulation and removing blood stasis.

METHODS

This study is a prospective, outcome assessor-, and data analyst-blinded randomized controlled clinical trial. The objective of this proposed study was to investigate whether Shengyu Decoction could improve the symptoms of anemia after proximal femoral nail antirotation in elderly ITF patients. After qualifying for screening, patients will be randomized into 2 groups with an allocation ratio of 1:1. Hemoglobin concentration, HBL, and HHS score are outcome measurements. The other outcomes also included time to get out of bed, discharge to home, 30-day readmission rates, and mortality.

DISCUSSION

ITF is commonly occurring in senior citizens, and those who are senior in age generally suffer 1 or more basic diseases, whose nutritional status is already poor. Trauma and surgical stimulation not only aggravate the existing disease or induce corresponding cardiovascular complications, but also worsen the nutritional status, which can easily cause postoperative anemia in patients. Because of the limited clinical modalities available for the treatment of postoperative anemia after fracture surgery, and most of them have various side effects that are not easily tolerated by the elderly. Therefore, from a traditional Chinese medicine perspective, we proposed a protocol using mild Chinese herbal decoction to treat postoperative anemia in ITF.Registration number: OSF Registration number: DOI 10.17605/OSF.IO/JQ6ZF.

Early prediction of implant failures in geriatric intertrochanteric fractures with single-screw cephalomedullary nailing fixation

OBJECTIVE

The implant failures of intertrochanteric fractures (ITF) after single-screw cephalomedullary nailing (CMN) were multifactorially associated with various related factors. However, a comprehensive scoring system for the early prediction of implant failures is still lacking. Thus, this study aims to establish a quantification scoring system (QSS) and verify whether the QSS is reliable for predicting implant failures in geriatric ITF patients.

METHODS

We established the QSS of geriatric ITF with single-screw cephalomedullary nailing within three days after surgery. The QSS included eight points totally at eight parameters, including bone quality, fracture type, reduction quality, and internal fixation placement. Then we retrospectively analyzed seventy-seven ITF (seventy-six patients) with surgical treatment between October 2016 and July 2020 in our hospital to verify whether the QSS scoring is suitable for predicting implant failures in ITF patients.

RESULTS

Implant failures were in fifteen fractures (fifteen patients), including six cases of cut-out, eight of pending cut-out, and one of cut-through. There were three cases with 2 points in QSS, three with 3 points, five with 4 points, four with 5 points in these fifteen fractures. No fractures were with 1 point in QSS, and no implant failures when scoring over 5 points in QSS. Except for QSS scoring, no significant difference was in the collected data by binary logistic regression analysis. QSS scoring was significantly associated with implant failures (Adjusted odds ratio (OR) = 7.312; 95% confidence intervals (CI), 2.561 to 20.871; p < 0.001). In the analysis of Spearman's correlation, there was a strong correlation between QSS scoring and the occurrences of implant failures (RQSS = -0.964, p < 0.001). The ROC result indicated that QSS was reliable in predicting implant failures at the cut-off of 5 points (AUC (the area under the curve) = 0.944; 95% CI, 0.866 to 0.983; p < 0.001).

CONCLUSION

The QSS is a useful early prediction of implant failures in geriatric ITF with cephalomedullary nailing fixation. QSS scoring more than 5 points can effectively reduce the risk of implant failures.

Medial Calcar Comminution and Intramedullary Nail Failure in Unstable Geriatric Trochanteric Hip Fractures

Background and Objectives: An increasing global burden of geriatric hip fractures is anticipated. The appropriate treatment for fractures is of ongoing interest and becoming more relevant with an aging population and finite health resources. Trochanteric fractures constitute approximately half of all hip fractures with the medial calcar critical to fracture stability. In the management of unstable trochanteric fractures, it is assumed that intramedullary nails and longer implants will lead to less failure. However, the lack of power, inclusion of older generation femoral nails, and a variable definition of stability complicate interpretation of the literature. Materials and Methods: Between January 2012 and December 2017, a retrospective analysis of operatively treated geriatric trochanteric hip fracture patients were examined at a Level 1 Trauma Centre. The treatment was with a long and short version of one type of trochanteric nail. Unstable trochanteric fractures with medial calcar comminution were examined (AO31A2.3, 2.3 & 3.3). The length of the medial calcar loss, nail length, demographics, fracture morphology, and relevant technical factors were examined in univariate and multivariate analysis using competing risk regression analysis. The primary outcome was failure of fixation with post-operative death the competing event and powered to previously reported failure rates. Results: Unstable patterns with medial calcar comminution loss constituted 617 (56%) of operatively treated trochanteric fractures. Failure occurred in 16 (2.6%) at a median post-operative time of 111 days (40-413). In univariate and multivariate analysis, only younger age was a significant predictor of failure (years; SHR: 0.91, CI 95%: 0.86-0.96, p < 0.001). Nail length, medial calcar loss, varus reduction, and other technical factors did not influence nail failure. Conclusions: In a cohort of unstable geriatric trochanteric hip fractures with medial calcar insufficiency, only younger patient age was predictive of nail failure. Neither the length of the medial calcar fragment or nail was predictive of failure.