Proximal Femoral Nail Antirotation Research Articles

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

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). 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. 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. 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.

Extending the intermedullary nail will not reduce the potential risk of femoral head varus in PFNA patients biomechanically: a clinical review and corresponding numerical simulation

Femoral head varus is an important complication in intertrochanteric fracture patients treated with proximal femoral nail anti-rotation (PFNA) fixation. Theoretically, extending the length of the intramedullary nail could optimize fixation stability by lengthening the force arm. However, whether extending the nail length can optimize patient prognosis is unclear. In this study, a review of imaging data from intertrochanteric fracture patients with PFNA fixation was performed, and the length of the intramedullary nail in the femoral trunk and the distance between the lesser trochanter and the distal locking screw were measured. The femoral neck varus status was judged at the 6-month follow-up. The correlation coefficients between nail length and femoral neck varus angle were computed, and linear regression analysis was used to determine whether a change in nail length was an independent risk factor for femoral neck varus. Moreover, the biomechanical effects of different nail lengths on PFNA fixation stability and local stress distribution have also been verified by numerical mechanical simulations. Clinical review revealed that changes in nail length were not significantly correlated with femoral head varus and were also not an independent risk factor for this complication. In addition, only slight biomechanical changes can be observed in the numerical simulation results. Therefore, commonly used intramedullary nails should be able to meet the needs of PFNA-fixed patients, and additional procedures for longer nail insertion may be unnecessary.

The clinical efficacy of Medial Sustain Nail(MSN) and Proximal femoral nail anti-rotation(PFNA) for fixation of medial comminuted trochanteric fractures: a prospective randomized controlled trial.

To evaluate the clinical efficacy of the Medial Sustain Nail (MSN) for medial comminuted trochanteric fractures fixation in comparison to Proximal Femoral Nail Antirotation (PFNA) through a clinical study. A non-inferiority randomized controlled trial was conducted at a single centre between July 2019 and July 2020. Fifty patients diagnosed comminuted trochanteric fractures were randomly assigned to either the MSN group (n = 25) or the PFNA group (n = 25). A total of forty-three patients were included in the final study analysis. The primary outcome measure was Short Form 36 health surgery physical component summary (SF-36 PCS) score. Secondary outcomes included the Oxford Hip Scores (OHS), weight bearing, complication relate to implant and so on. This study was not blined to surgeons, but to patients and data analysts. The MSN demonstrated significantly better functional outcomes as measured by SF-36 PCS and OHS at sixmonths postoperative compared to PFNA (p < 0.05). Union of fractures in the MSN group reached 90.9% at threemonths after surgery, whereas the PFNA group achieved a union rate of 57.1% (p < 0.05). Furthermore, weight-bearing time of MSN group was earlier than PFNA group (p < 0.05). Additionally, complications related to implant usage were more prevalent in the PFNA group (33.3%) compared to the MSN group (4.5%) (p < 0.05). MSN exhibited superior quality of life outcomes compared to PFNA at sixmonths postoperative. This indicates that MSN effectively reconstructs medial femoral support in patients with comminuted trochanteric fractures, which facilitates early weight-bearing and accelerates the recovery process. Trial registration number: NCT01437176, Date of the trial registration:2011-9-1, Date of commencement of the study:2011-9, Date of enrolment/recruitment of the study subjects:2019-7.

Feasibility biomechanical study of injectable biphasic calcium phosphate bone cement augmentation of the proximal femoral nail antirotation (PFNA) for the treatment of two intertrochanteric fractures using cadaveric femur.

This study evaluated the feasibility of the femoral bone after fixation using biphasic calcium phosphate cement-augmentation of the proximal femoral nail antirotation (PFNA) compared with PFNA without cement. This study presented to compare the stiffness, fatigue testing, and compressive strength between stable (AO31-A2.1) and unstable (AO31-A3.3) intertrochanteric fractures treated by cement augmented PFNA of the cadaveric femoral. Biphasic calcium phosphate cement was injected to align and compatible with PFNA and the reconstructive procedure was monitored the cement placement using X-ray imaging during operation. The testing demonstrated that the cement could be injected through a small needle (13G, 16cm length, 1.8mm inner diameter) within a suitable operating time. The feasibility study of the biomechanical testing was divided into three tests: stiffness test, fatigue cyclic load, and compression test. The results showed that the cement-augmented specimens exhibited higher stiffness than the control specimens without cement. The cement-augmented specimens also showed lower strain energy during the fatigue test, resulting in higher compressive strength (4730.7 N) compared to the control specimens (3857.4 N). There is a correlation between BMD and fracture load and the increase in compression load of the cement-augmented femoral compared to the controls as well as an increase in strain energy of fatigue cyclic testing was found. Biphasic calcium phosphate cement-augmented of the PFNA biomechanically enhanced the cut-out resistance in intertrochanteric fracture. This procedure is especially efficient for unstable intertrochanteric fracture suggesting the potential benefits of using biphasic calcium phosphate cement in medical applications.

A Comparison of the Clinicoradiological Outcomes of Intertrochanteric Fractures Treated Using Proximal Femoral Nail and Proximal Femoral Nail Anti-rotation

A Comparison of the Clinicoradiological Outcomes of Intertrochanteric Fractures Treated Using Proximal Femoral Nail and Proximal Femoral Nail Anti-rotation

Evaluating the Impacts of Proximal Femoral Nail Anti-Rotation (PFNA) Augmentation in Osteoporotic Intertrochanteric Fractures

Surgical interventions are crucial for managing osteoporotic intertrochanteric fractures. Among these interventions, Proximal Femoral Nail Antirotation (PFNA) is preferred due to its advantages in reducing blood loss and surgical duration. This research study examined proximal femoral nail anti-rotation’s clinical and radiological outcomes with augmentation in osteoporotic intertrochanteric fractures. The surgical approach encompassed 50 patients with osteoporotic intertrochanteric fractures treated between November 2012 and April 2014. The surgeries were performed in a supine position on a traction radiolucent table with general, regional, or spinal anesthesia. The incision and nail-blade angle were carefully selected, and postoperative outcomes, including range of motion, infection rates, and complications, were assessed. Results showed a 96% success rate with PFNA, with most patients regaining pre-surgery range of motion within six weeks. Fracture healing was effective in 94% of cases within six months, although some required revision surgery or experienced mechanical failure. Postoperative complications, including superficial infections and nonunion, were observed in a small percentage of cases. In conclusion, PFNA with augmentation is viable for treating osteoporotic intertrochanteric fractures, offering good clinical outcomes and a low complication rate. However, careful patient selection and surgical techniques are essential to minimize risks and ensure optimal results.

Finite Element Analysis of Six Internal Fixations in the Treatment of Pauwels Type III Femoral Neck Fracture.

The current investigation sought to utilize finite element analysis to replicate the biomechanical effects of different fixation methods, with the objective of establishing a theoretical framework for the optimal choice of modalities in managing Pauwels type III femoral neck fractures. The Pauwels type III fracture configuration, characterized by angles of 70°, was simulated in conjunction with six distinct internal fixation methods, including cannulated compression screw (CCS), dynamic hip screw (DHS), DHS with de-rotational screw (DS), CCS with medial buttress plate (MBP), proximal femoral nail anti-rotation (PFNA), and femoral neck system (FNS). These models were developed and refined using Geomagic and SolidWorks software. Subsequently, finite element analysis was conducted utilizing Ansys software, incorporating axial loading, torsional loading, yield loading and cyclic loading. Under axial loading conditions, the peak stress values for internal fixation and the femur were found to be highest for CCS (454.4; 215.4 MPa) and CCS + MBP (797.2; 284.2 MPa), respectively. The corresponding maximum and minimum displacements for internal fixation were recorded as 6.65 mm for CCS and 6.44 mm for CCS + MBP. When subjected to torsional loading, the peak stress values for internal fixation were highest for CCS + MBP (153.6 MPa) and DHS + DS (72.8 MPa), while for the femur, the maximum and minimum peak stress values were observed for CCS + MBP (119.3 MPa) and FNS (17.6 MPa), respectively. Furthermore, the maximum and minimum displacements for internal fixation were measured as 0.249 mm for CCS + MBP and 0.205 mm for PFNA. Additionally, all six internal fixation models showed excellent performance in terms of yield load and fatigue life. CCS + MBP had the best initial mechanical stability in treatment for Pauwels type III fracture. However, the MBP was found to be more susceptible to shear stress, potentially increasing the risk of plate breakage. Furthermore, the DHS + DS exhibited superior biomechanical stability compared to CCS, DHS, and PFNA, thereby offering a more conducive environment for fracture healing. Additionally, it appeared that FNS represented a promising treatment strategy, warranting further validation in future studies.

Finite element analysis of proximal femur bionic nail for treating intertrochanteric fractures in osteoporotic bone

This study compared the biomechanical characteristics of proximal femur bionic nail (PFBN) and proximal femoral nail antirotation (PFNA) in treating osteoporotic femoral intertrochanteric fractures using finite element analysis. Under similar bone density, the PFBN outperforms the PFNA in maximum femoral displacement, internal fixation displacement, stress distribution in the femoral head and internal fixation components, and femoral neck varus angle. As the bone density decreases, the PFBN’s biomechanical advantages over PFNA become more pronounced. This finding suggests that the PFBN is superior for treating osteoporotic intertrochanteric femoral fractures.

Finite element study on the micromechanics of cement-augmented proximal femoral nail anti-rotation (PFNA) for intertrochanteric fracture treatment

Blade cut-out is a common complication when using proximal femoral nail anti-rotation (PFNA) for the treatment of intertrochanteric fractures. Although cement augmentation has been introduced to overcome the cut-out effect, the micromechanics of this approach remain to be clarified. While previous studies have developed finite element (FE) models based on lab-prepared or cadaveric samples to study the cement-trabeculae interface, their demanding nature and inherent disadvantages limit their application. The aim of this study was to develop a novel 'one-step forming' method for creating a cement-trabeculae interface FE model to investigate its micromechanics in relation to PFNA with cement augmentation. A human femoral head was scanned using micro-computed tomography, and four volume of interest (VOI) trabeculae were segmented. The VOI trabeculae were enclosed within a box to represent the encapsulated region of bone cement using ANSYS software. Tetrahedral meshing was performed with Hypermesh software based on Boolean operation. Finally, four cement-trabeculae interface FE models comprising four interdigitated depths and five FE models comprising different volume fraction were established after element removal. The effects of friction contact, frictionless contact, and bond contact properties between the bone and cement were identified. The maximum micromotion and stress in the interdigitated and loading bones were quantified and compared between the pre- and post-augmentation situations. The differences in micromotion and stress with the three contact methods were minimal. Micromotion and stress decreased as the interdigitation depth increased. Stress in the proximal interdigitated bone showed a correlation with the bone volume fraction (R2 = 0.70); both micromotion (R2 = 0.61) and stress (R2 = 0.93) at the most proximal loading region exhibited a similar correlation tendency. When comparing the post- and pre-augmentation situations, micromotion reduction in the interdigitated bone was more effective than stress reduction, particularly near the cement border. The cementation resulted in a significant reduction in micromotion within the loading bone, while the decrease in stress was minimal. Noticeable gradients of displacement and stress reduction can be observed in models with lower bone volume fraction (BV/TV). In summary, cement augmentation is more effective at reducing micromotion rather than stress. Furthermore, the reinforcing impact of bone cement is particularly prominent in cases with a low BV/TV. The utilization of bone cement may contribute to the stabilization of trabecular bone and PFNA primarily by constraining micromotion and partially shielding stress.

Retrospective evaluation of radiological and clinical outcomes after surgical treatment of proximal femoral fractures utilizing PFNA and PFNA augmented.

The primary aim of this study was to evaluate the clinical and radiological outcomes after surgical treatment of proximal femoral fractures utilizing the Proximal Femoral Nail Antirotation (PFNA), with the main focus on complications and reoperations. The secondary aim was to compare the outcomes of patients with and without cement augmentation of the cephalomedullary nails. All patients with an acute proximal femoral fracture consequently treated with a PFNA between January 2011 and Dezember 2018 were evaluated. Clinical and radiological data were assessed for intra- and postoperative complications, including treatment failure. In addition, intra- and postoperative radiographs were used to determine the position of the implant, and any migration, via Tip-Apex-Distance (TAD) and the caput-collum-diaphyseal angle (CCD). The accuracy of the fracture reduction was rated according to Baumgaertners criteria. Two hundred sixty-four consecutive patients (mean age 78.8 ± 12.0; 73.1% female) were included. The predominant OTA/AO fracture classification was 31A1 (153 cases, 58.0%). The average duration of surgery was 63.1 ± 28.0min and showed no significant differences between PFNA and PFNA with augmentation. The implant positioning was rated as good in 222 cases (84.1%). Two hundred sixty-three patients (99.6%) showed evidence of healing within the time frame of three months postoperatively, one case of delayed union healed after secondary dynamization. During the observational period, 18 patients (6.8%) required a total of 23 additional surgeries. Overall, a lower reoperation rate was observed following the use of the augmentation option (2/86 patients (2.3%) vs. 16/178 patients (9.0%), p = 0.04). In particular, there were no cases of cut-out or cut-through among patients who underwent augmentation as part of osteosynthesis. Overall reoperation rate after surgical treatment of proximal femoral fractures utilizing the Proximal Femoral Nail Antirotation (PFNA) was 6.8%, with 23 additional surgeries performed in 18 patients. The usage of the PFNA with augmentation showed equally good implant positioning, excellent healing rates and fewer postoperative complications compared to the PFNA implant alone with a similar overall duration of surgery.

Mechanical effect of changed femoral neck ante-version angles on the stability of an intertrochanteric fracture fixed with PFNA: A finite element analysis

ObjectiveChange of femoral neck ante-version angle postoperatively due to inadequate reduction could result in unsatisfying treatment outcome of intertrochanteric fracture. However, the influence of increased or decreased femoral neck ante-version on the biomechanical stability of the bone-implant complex has rarely been studied. MethodsA finite element model of a complete normal human femur with normal femoral neck ante-version as 13° was established accurately by scanning a 64 year old female femur. The models of 31-A1.1 intertrochanteric fractures with different femoral neck ante-version angles of 3°, 5.5°, 8°, 10.5°, 13°, 15.5°, 18°, 20.5°, 23° were created. They were assembled with a proximal femoral nail anti-rotation (PFNA) device. The biomechanical differences with varying femoral neck ante-version angles were compared using finite element analysis method. ResultsAs the femoral neck ante-version angle gradually increased from 13°to 23°with a gradient of 2.5 °, the peak von Mises stress was gradually increased from 137.82 MPa to 276.02 MPa. Similarly, the peak von Mises stress was gradually increased from 137.82 MPa to 360.12 MPa with the femoral neck ante-version angle decreased from 13° to 3°. When decreased ante-version angle of 7.5° and increased ante-version angle of 10° will exceed the yield strength of femoral (240.32MPa), the risk of femoral fracture will increase significantly. The maximum displacement of the femur was significantly reduced for increased ante-version models than for decreased ante-version models, whether the changes of ante-version angles were 2.5°, 5°, 7.5° or 10°. The maximum stress of PFNA was found in the intersection of main nail and helical blade, and became greater gradually as the ante-version angle increased or decreased with a gradient of 2.5 °. The maximum stress of PFNA was presented in the model 5.5° with the maximum stress of 724.42 MPa (near to the yield strength of titanium alloy of 700-1000MPa), producing the breakage risk of PFNA. The maximum displacement of the PFNA was significantly reduced for increased ante-version models than for decreased ante-version models, whether the changes of ante-version angles were 2.5°, 5°, 7.5° or 10°. ConclusionBased on the results of present study, it was demonstrated that the anatomical reduction of femoral neck ante-version was vital to secure the optimal stability. Abnormal femoral ante-version could increase the potential risk of failure for intertrochanteric fracture after PFNA. The stability of increased femoral ante-version (less than 10°) was superior to the stability of decreased ante-version (less than 5°) for the cases of difficulty to acquire anatomical reduction. The clinical implication of the finding was that increased femoral neck ante-version had an advantage of mechanical stability towards the decreased femoral neck ante-version for the cases of comminuted intertrochanteric fracture and failure of anatomical reduction.

Comparison of PFNA vs Hip Arthroplasty in Patients with Intertrochanteric Fractures

Aims: Intertrochanteric fractures are common types of hip fractures in the elderly population. Different types of surgical treatment options are available for intertrochanteric fractures such as Closed Reduction and Inter Fixation with Proximal Femoral Nail Anti-rotation (PFNA), Open Reduction and internal fixation with Dynamic Hip Screw (DHS), and Hip Arthroplasty. The main purpose of this study is to compare the clinical outcomes of PFNA with Hip arthroplasty in patients with Intertrochanteric Fractures. Materials and Methods: A retrospective cohort study method was used in the current study. The medical record of 101 patients with intertrochanteric fractures was collected. These 101 patients were divided into two groups according to the type of surgical treatment they received, PFNA (n=52) or THA (n=49). The outcome of Hip function was assessed according to the Harris Hip Score (HHS). A simple t-test was performed for statistical analysis. χ2 test used for the analysis of categorical data. P-values &lt;0.05 was considered as significant. Results: Hip Arthroplasty patients had longer surgery duration, length of incision was longer and intraoperative blood loss was more than in those patients who were treated with PFNA (P &lt;0.05). Hip arthroplasty patients could start early weight bearing than those in the PFNA group (P &lt;0.05). There was no any statistical difference between hospital stays in both groups (P &gt;0.05). HHS assessed at those 3 points showed that Hip function in Hip Arthroplasty patients was higher than with those who were treated with PFNA (P &lt;0.05). There was no statistically significant difference between the post-operative complication of both groups, as the P value is &gt;0.05. Conclusion: we concluded that treatment of intertrochanteric fracture with PFNA and Hip Arthroplasty is safe and effective. Each treatment has its advantages and disadvantages but with no significant difference in postoperative complications. Orthopaedic surgeons can choose ........

Unravelling variations: an examination of entry point selection in proximal femoral cephalomedullary nailing

BackgroundThe exact positioning of the cephalomedullary (CM) nail entry point for managing femoral fractures remains debatable, with significant implications for fracture reduction and postoperative complications. This study aimed to explore the variability in the selection of the entry point among trauma surgeons, hypothesizing potential differences and their association with surgeon experience.MethodsIn this prospective multicenter study, 16 participants, ranging from residents to senior specialists, partook in a simulation wherein they determined the optimal entry point for the implantation of a proximal femoral nail antirotation (PFN-A; DePuy Synthes) in various femora. The inter- and intra-observer variability was calculated, along with comprehensive descriptive statistical analysis, to assess the variability in entry point selection and the impact of surgeon experience.ResultsIn this study, the mean distance from the selected entry points to the calculated mean entry point was 3.98 mm, with a smaller distance observed among surgeons with more than 500 implantations (ANOVA, p = 0.050). Intra-surgeon variability for identical femora averaged at 5.14 mm, showing no significant differences across various levels of surgical experience or training. Notably, 13.6% of selected entry points would not allow a proper intramedullary positioning of the implant, thereby rendering anatomical repositioning unfeasible. Among these impossible entry points, a significant skew towards anterior placement was observed (70.6% of the impossible entry points), with a smaller fraction being overly lateral (27.5%) or medial (13.7%). On a patient level, the impossibility rate varied widely from 0 to 35% among the different femora examined, with a significantly higher rate seen in younger patients (mean age 55.02 versus 60.32; t-test for independent samples, p = 0.04).ConclusionsSignificant variations exist in surgeons’ selection of entry points for proximal femoral nailing, underscoring the task’s complexity. Experience does not prevent the choice of unfeasible entry points, emphasizing the inadequacy of a universal approach and pointing towards the necessity for a patient-specific strategy for improved outcomes.Trial registration number: DRKS00032465.

Comparison of the clinical outcomes between proximal femoral nail anti-rotation with cement enhancement and hemiarthroplasty among elderly osteoporotic patients with intertrochanteric fracture

BackgroundThe proximal femoral nail anti-rotation (PFNA) with cement enhancement enhances the anchorage ability of internal fixation in elderly with osteoporotic intertrochanteric fracture. However, whether it is superior to hemiarthroplasty is still controversial. The present study aimed to determine which treatment has better clinical outcomes among older patients.MethodsWe retrospectively analyzed 102 elderly patients with osteoporosis who developed intertrochanteric fractures and underwent PFNA combined with cement-enhanced internal fixation (n = 52, CE group), and hemiarthroplasty (n = 50, HA group) from September 2012 to October 2018. All the intertrochanteric fractures were classified according to the AO/OTA classification. Additionally, the operative time, intraoperative blood loss, intraoperative and postoperative blood transfusion rates, postoperative weight-bearing time, hospitalization time, Barthel Index of Activities Daily Living, Harris score of hip function, visual analog (VAS) pain score, and postoperative complications were compared between the two groups.ResultsThe CE group had significantly shorter operative time, lesser intraoperative blood loss, lower blood transfusion rate, and longer postoperative weight-bearing time than the HA group. The CE group had lower Barthel’s Index of Activities of Daily Living, lower Harris’ score, and higher VAS scores in the first and third months after surgery than the HA group, but no difference was observed between the two groups from 6 months to 12 months. There was no significant difference in the total post-operative complications between the two groups.ConclusionThe use of PFNA combined with a cement-enhanced internal fixation technique led to shorter operative time and lesser intraoperative blood loss and trauma in elderly patients as compared to HA.

A probabilistic approach for assessing the mechanical performance of intertrochanteric fracture stabilized with proximal femoral nail antirotation.

Maintaining post-operative mechanical stability is crucial for successfully healing intertrochanteric fractures treated with the Proximal Femoral Nail Antirotation (PFNA) system. This stability is primarily dependent on the bone mineral density (BMD) and strain on the fracture. Current PFNA failure analyses often overlook the uncertainties related to BMD and body weight (BW). Therefore, this study aimed to develop a probabilistic model using finite element modeling and engineering reliability analysis to assess the post-operative performance of PFNA under various physiological loading conditions. The model predictions were validated through a series of experimental test. The results revealed a negative nonlinear relationship between the BMD and compressive strain. Conversely, the BW was positively and linearly correlated with the compressive strain. Importantly, the compressive strain was more sensitive to BW than to BMD when the BMD exceeded 0.6 g/cm3. Potential trabecular bone compression failure is also indicated if BMD is equal to or below 0.15 g/cm3 and BW increases to approximately 2.5 times the normal or higher. This study emphasizes that variations in the BMD significantly affect the probability of failure of a PFNA system. Thus, careful planning of post-operative physical therapy is essential. For patients aged > 50 years restrictions on high-intensity activities are advised, while limiting strenuous movements is recommended for those aged > 65 years.

Association between increased systemic immune-inflammation index and postoperative delirium in older intertrochanteric fracture patients

Background and purposeThe systemic immune-inflammation index (SII), a novel inflammation index derived from the counts of circulating platelets, neutrophils and lymphocytes, has been studied in the treatment of acute cancer and ischemic stroke (AIS). However, the clinical value of the SII in postoperative delirium patients has not been further investigated. The purpose of our research was to study the incidence and preoperative risk factors for postoperative delirium (POD) and verify whether the SII could serve as a potential marker for POD in older intertrochanteric fracture patients. Finally, we created a novel nomogram for predicting POD in older patients with intertrochanteric fractures.MethodsWe enrolled elderly patients with intertrochanteric fractures who underwent proximal femoral nail antirotation (PFNA) between February 2021 and April 2023. Univariate and multivariate logistic analyses were subsequently performed to confirm the risk factors and construct a nomogram model.Calibration curve and clinical decision curve analysis (DCA) were used to assess the model’s fitting performance. The performance of the nomogram was evaluated for discrimination, calibration, and clinical utility.ResultsA total of 293 patients were eligible for inclusion in the study, 25.6% (75/293) of whom had POD. The POD patients had higher SII values than the non-POD patients. The SII was strongly correlated with POD in older intertrochanteric fracture patients, and the optimal cutoff value was 752.6 × 109. Multivariate analysis revealed that age, diabetes, total albumin, SII > 752.6 × 109 and a CRP > 20.25 mg/L were independent risk factors for POD patients. By incorporating these 5 factors, the model achieved a concordance index of 0.745 (95% CI, 0.683–0.808) and had a well-fitted calibration curve and good clinical application value.ConclusionThe SII is a simple and valuable biomarker for POD, and the new nomogram model can be used to accurately predict the occurrence of POD. They can be utilized in clinical practice to identify those at high risk of POD in older intertrochanteric fracture patients.

Biomechanical evaluation of a modified intramedullary nail for the treatment of unstable femoral trochanteric fractures

BackgroundThe Proximal Femoral Nail Antirotation (PFNA) device is the most commonly used implant to fix unstable femoral trochanteric fractures (UFTFs), but it has a relatively high incidence of complications. Due to this factor, the modified intramedullary nail (MIN) was created to treat patients with UFTFs. The aim was to exhibit the MIN and make a comparison with PFNA and InterTAN using biomechanical methods. MethodsAn adult UFTF model was developed using Mimics software. The PFNA, InterTAN nail, and MIN models were drawn referring to the corresponding parameters and installed in the fracture models. Vertical, anteroposterior (AP) bending, and torsion loads of the femoral head were set in advance and loaded onto the fracture models. The value of maximal displacement and von Mises stress was evaluated via finite element analysis (FEA). ResultsThe MIN model had smaller values for maximal displacement than that of the PFNA model, and the increase in displacement was less pronounced for the MIN compared to PFNA under increasing vertical loads. For the indicator of von Mises stress, the MIN model showed lower stress compared with the PFNA model in vertical loads ranging from 300 N to 2100 N. Except for the maximal stress at implants under AP bending loads, the MIN demonstrated the most superior biomechanical properties under AP bending and torsional loads. ConclusionThe MIN offered obvious advantages in terms of mechanical stability and stress distribution among the three studied implants, providing a promising implant option for patients with UFTFs.

Radiological Differences Following Proximal Femoral Nail Antirotation (PFNA) Compared to the Contralateral Side and Its Correlation with Harris Hip Score (HHS) in Intertrochanteric Femoral Fracture After Three Months

Introduction: The incidence of intertrochanteric femoral fractures, which account for 50% of all hip fractures, is increasing as a result of the aging population. While PFNA surgery typically enhances outcomes, certain individuals continue to have pain, stiffness, and difficulties with their gait. This study aims to determine whether there is a correlation between post-surgical complications and changes in hip joint angles assessed three months following PFNA to lead future advances in PFNA surgery for older persons by comparing impacted and unaffected hips and correlating angles with patients' hip ratings. Methods: This study included 42 individuals who underwent surgery for intertrochanteric fractures aged 50 and above. Eligible participants must possess the ability to walk before to the study, have no history of previous leg fractures, and be capable of participating in rehabilitation. Individuals having comorbidities impacting these aspects or those unable to partake were not included. Result : This study looked at hip angles in 42 people who had surgery intertrochanteric fracture. While the participants varied in age and gender, the surgery itself didn't seem to significantly change the angles of their hip bones or their ability to walk. This suggests that PFNA may not directly affect hip mechanics on its own. Conclusion: This study indicates that attaining acceptable hip angles during the procedure could enhance patients' mobility and post-operative condition. Further investigation involving bigger cohorts and extended periods of observation is necessary to validate these findings and ascertain whether modifying these angles during surgery will result in improved outcomes following PFNA. Keywords: Intertrochanteric fracture; Hip fracture; PFNA

Clinical observation of different intramedullary fixation methods for the treatment of intertrochanteric fracture

To explore clinical efficacy of proximal femoral nail anti-rotation(PFNA),InterTan and proximal femoral bionic intramedullary nail (PFBN) in treating femoral intertrochanteric fracture. Clinical data of 120 patients with intertrochanteric fracture who were underwent closed reduction intramedullary nail-internal fixation from January 2020 to January 2021 were retrospectively analyzed. According to methods of internal fixation,patients were divided into 3 groups. There were 25 patients in PFBN group,including 16 females and 9 males,aged from 69 to 79 years old with an average of (73.67±5.16) years old. There were 55 patients in PFNA group,including 38 females and 17 males,aged from 68 to 80 years old with an average of (74.23±5.57) years old. There were 40 patients in InterTan group,including 26 females and 14 males,aged from 68 to 79 years old with an average of (73.45±5.34) years old. Operative time,intraoperative blood loss,incision length,hospital stay,weight-bearing time,fracture healing time and complications among 3 groups were compared,and clinical effect was evaluated by Harris score of hip function before operation,1,6 and 12 months after opertaion,respectively. Patients among 3 groups were successfully completed operation and were followed up for more than 12 months. There were no significant difference in hospital stay,operative time,intraoperative blood loss and incision length among 3 groups (P>0.05). Weight bearing time of PFBN group (7.98±1.34) d and InterTan group (8.22±0.46) d were earlier than that of PFNA group (10.27±0.66) d(P<0.01). Fracture healing time of PFBN group (10.14±2.33) weeks and InterTan group (11.87±2.48) weeks were earlier than that of PFNA group (13.68±2.36) weeks (P<0.01). One month after operation,Harris score in PFBN group (70.52±5.34) and InterTan group (69.81±6.17) was higher than that of PFNA group (51.46±5.36),and there was no significant difference between PFBN group and InterTan group (P>0.05). There were no significant difference in Harris scores among 3 groups before operation,6 and 12 months after opertaion(P>0.05). Cases of complication of InterTan group and PFNA group were lower than that of PFNA group (P<0.05). PFBN and InterTan for the treatment of intertrochanteric fracture have advantages of faster fracture healing,earlier weight-bearing time and fewer postoperative complications than traditional PFNA,but three operations could achieve higher effective rates without significant difference in long-term results.

Sagittal support rather than medial cortical support matters in geriatric intertrochanteric fracture: A finite element analysis study

Hip fracture, increasing exponentially with age, is osteoporosis's most severe clinical consequence. Intertrochanteric fracture, one of the main types of hip fracture, is associated with higher mortality and morbidity. The current research hotspots lay in improving the treatment effect and optimizing the secondary stability after intertrochanteric fracture surgery. Cortex buttress reduction is a widely accepted method for treating intertrochanteric fracture by allowing the head-neck fragment to slide and rigidly contact the femoral shaft's cortex. Medial cortical support is considered a more effective option in treating young patients. However, osteo-degenerations features, including bone weakness and cortical thickness thinning, affect the performance of cortex support in geriatric intertrochanteric fracture treatment. Literature focusing on the age-specific difference in cortex performance in the fractured hip is scarce. We hypothesized that this osteo-19 degenerative feature affects the performance of cortex support in treating intertrochanteric fractures between the young and the elderly. We established twenty models for the old and the young with intertrochanteric fractures and performed static and dynamic simulations under one-legged stance and walking cycle conditions. The von Mises stress and displacement on the femur, proximal femoral nail anti-rotation (PFNA) implant, fracture plane, and the cutting volume of cancellous bone of the femur were compared. It was observed that defects in the anterior and posterior cortical bone walls significantly increase the stress on the PFNA implant, the displacement of the fracture surface, and cause a greater volume of cancellous bone to be resected. We concluded that ensuring the integrity and alignment of the anterior and posterior cortical bones is essential for elderly patients, and sagittal support is recommended. This finding suggests that the treatment method for intertrochanteric fracture may differ, considering the patient's age difference.