Treatment of a femoral neck fracture combined with ipsilateral femoral head and intertrochanteric fractures: A case report

BACKGROUND This article presents a rare case of a complex hip fracture involving the ipsilateral femoral neck,trochanter,and femoral head,that was accompanied by hip dislocation.Currently,there is no established standard treatment method for this specific type of fracture.Therefore,it is crucial to comprehensively consider factors such as patient age,fracture type,and degree of displacement to achieve a successful outcome.CASE SUMMARY A 38-year-old man sustained a comminuted fracture of his right hip as a result of a car accident.The injuries included a fracture of the femoral head,a fracture of the femoral neck,an intertrochanteric fracture of the femur,and a posterior dislocation of the hip on the same side.We opted for a treatment approach combining the use of a proximal femoral locking plate,cannulated screws,and Kirschner wires.Following the surgery,we developed an individualized rehabil-itation program to restore patient limb function.CONCLUSION For this complex fracture,we selected appropriate internal fixation and for-mulated individualized rehabilitation,which ultimately achieved good results.

Finite Element Analysis of Coronal Shear Fractures of the Femoral Neck: Displacement of the Femoral Head and Effect of Osteosynthetic Implants

Coronal shear fractures of the femoral neck (CSFF) are the most challenging to treat among proximal femur fractures, directly affecting the life expectancy of patients with osteoporosis. However, an adequate osteosynthesis method has not been elucidated yet. This study investigated the displacement direction of the femoral head fragment and its effect on the bone using finite element method. A finite element model for CSFF was developed from CT image data of a patient with osteoporosis using Mechanical Finder (ver. 11). Subsequently, finite element analyses were performed on six osteosynthesis models under maximum load applied during walking. The compressive stresses, tensile stresses, and compressive strains of each model were examined. The results suggested that the compressive and tensile stress distributions were concentrated on the anterior side of the femoral neck. Compressive strain distribution in the femoral head and neck was concentrated in four areas: at the tip of the blade or lag screw, the anteroinferior side of the blade or lag screw near the fracture site, and the upper right and lower left near the junction of the blade or lag screw and nail. Thus, the distribution of both these stresses revealed that the femoral head fragment was prone to anterior and inferior displacement. Distribution of compressive strains revealed the direction of the stress exerted by the osteosynthetic implant on the bone. The same results were observed in all osteosynthetic implants;thus, the findings could lay the foundation for developing methods for placing osteosynthetic implants less prone to displacement and the osteosynthetic implants themselves. In particular, the study provides insight into the optimal treatment of CSFF.

Evaluation of the bone metabolism balance and traumatic reaction of minimally invasive mippo intramedullary nail internal fixation treatment of femoral shaft fractures

Objective:To evaluate the bone metabolism balance and traumatic reaction of minimally invasive mippo intramedullary nail internal fixation treatment of femoral shaft fractures. Methods:80 patients with femoral shaft fractures who were treated in our hospital between May 2011 and December 2016 were collected and divided into control group (n=40) and observation group (n=40) according to random number table, control group received conventional steel plate internal fixation treatment, and observation group received minimally invasive mippo intramedullary nail internal fixation treatment. Differences in serum levels of bone formation indexes, bone resorption indexes, inflammatory factors, and pain mediators and so on were compared between two groups of patients before operation and 1 week after treatment.Results: Before operation, differences in serum levels of bone formation indexes, bone resorption indexes, inflammatory factors and pain mediators were not statistically significant between two groups of patients. After operation, serum bone formation indexes P ICP, BGP, BALP and ALP levels in observation group were higher than those in control group;serum bone resorption indexesβ-CTX and OPG levels were lower than those in control group;serum inflammatory factors IL-1β, IL-6, IL-8 and CRP levels were lower than those in control group;serum pain mediators SP, PGE2 and 5-HT levels were lower than those in control group.Conclusion:Minimally invasive mippo intramedullary nail internal fixation treatment of femoral shaft fractures can promote the bone formation, relatively inhibit bone resorption and cause less traumatic reaction.

PFNA2 versus 95 Degree Condylar Blade Plate in the Management of Unstable Trochanteric Fractures

Purpose: The proximal femoral nail anti-rotation (PFNA) is known to have advantages in enhancing the anchorage ability of internal fixation in elderly unstable osteoporotic intertrochanteric fracture patients. However whether it is superior to condylar blade fixation is not clear. This study aimed to determine which treatment has better clinical outcomes in older patients. Materials and Methods: A total of 86 patients over the age of 60 with unstable trochanteric fractures within the past 3 weeks, were included in this prospective study conducted from June 1, 2018, to May 31, 2021. All the intertrochanteric fractures were classified according to AO/OTA classification. Among them, 44 cases were treated with the Proximal Femoral Nail (PFNA2) with or without an augmentation screw, and 42 cases were treated with the Condylar Blade Plate. In addition, the operative time, intraoperative blood loss, intraoperative and postoperative blood transfusion, postoperative weight-bearing time, hospitalization time, Harris score of hip function, Kyle’s criteria and postoperative complications were compared between the two groups. Results: The mean duration of surgery for the PFN group was 66.8 minutes (on average), whereas for the condylar blade plate group, it was 99.30 minutes (on average). The PFNA2 group experienced less blood loss (average of 80 mL) compared to the condylar blade plate group (average of 120 mL). Union and partial weight-bearing occurred earlier in the PFNA2 group (14.1 weeks and 10.6 weeks, respectively) compared to the Condylar blade plate group (18.7 weeks and 15.8 weeks). In two patients from the PFNA2 group, screw backing out and varus collapse complications were encountered;however, these patients remained asymptomatic and did not require revision surgery. In two other patients, screw cut out and breakage of the nail at the helical screw hole leading to non-union of the proximal femur were observed during the nine-month follow-up, necessitating revision surgery with prosthetic replacement. Among the condylar blade plate group, three patients experienced complications, including blade breakage at the blade and plate junction. In two cases, the fracture united in varus, and in one case, the blade cut through, resulting in non-union of the femoral head, which required revision surgery. According to the Harris hip score and Kyle’s criteria, a good-excellent outcome was observed in 92.85% of cases in the PFNA2 group and 90.90% of cases in the condylar blade plate group. Conclusion: Both the Proximal Femoral Nail A2 and Condylar blade plate are effective implants for the treatment of unstable trochanteric fractures. The intramedullary implant promotes biological healing and allows for early ambulation with minimal complications. Similarly satisfactory restoration of anatomy and favorable radiological and functional results can be achieved with the biological fixation provided by the 95-degree condylar blade plate. However, the use of PFNA2 internal fixation technique has the advantage of less trauma in elderly patients than the 95-degree condylar blade plate.

Selection of internal fixation method for femoral intertrochanteric fractures using a finite element method

BACKGROUND Failure to fix unstable intertrochanteric fractures impairs return to daily activities.AIM To simulate five different internal fixation methods for unstable proximal femoral fractures.METHODS A three-dimensional model of the femur was established from sectional computed tomography images,and an internal fixation model was established.Finite element analysis of the femur model was established,and three intertrochanteric fracture models,medial defect,lateral defect,and medial-lateral defects,were simulated.Displacement and stress distribution after fixation with a proximal femoral anti-rotation intramedullary nail(PFNA),integrated dual-screw fixation(ITN),PFNA+wire,PFNA+plate,and PFNA+wire+plate were compared during daily activities.RESULTS The maximum displacement and stress of PFNA and ITN were 3.51 mm/473 MPa and 2.80 mm/588 MPa for medial defects;2.55 mm/288 MPa and 2.10 mm/307 MPa for lateral defects;and 3.84 mm/653 MPa and 3.44 mm/641 MPa for mediallateral defects,respectively.For medial-lateral defects,reconstructing the medial side alone changed the maximum displacement and stress to 2.79 mm/515 MPa;reconstructing the lateral side changed them to 3.72 mm/608 MPa,when both sides were reconstructed,they changed to 2.42 mm/309 MPa.CONCLUSION For medial defects,intramedullary fixation would allow early low-intensity rehabilitation exercise,and ITN rather than PFNA reduces the risk of varus and cut-out;for lateral wall defects or weakness,intram-edullary fixation allows higher-intensity rehabilitation exercise,and ITN reduces the risk of varus.For both medial and lateral defects,intramedullary fixation alone will not allow early functional exercise,but locating lateral or medial reconstruction will.For defects in both the inner and outer sides,if reconstruction cannot be completed,ITN is more stable.

Bone metabolism and trauma degree of magnetic-guided intramedullary nail fixation for femoral shaft fracture

Objective:To explore the effect of magnetic-guided intramedullary nail fixation on bone metabolism and trauma degree in patients with femoral shaft fracture.Methods: A total of 128 patients with femoral shaft fractures who received surgical treatment in the hospital between April 2016 and November 2017 were divided into control group (n=64) and study group (n=64) according to the random number table method. Control group received the traditional intramedullary nail treatment, and study group received magnetic-guided intramedullary nail treatment. The differences in serum levels of bone metabolism indexes and inflammatory factors were compared between the two groups 48 h after surgery.Results: 48 h after surgery, serum bone formation indexes BGP, PⅠNP, PⅠCP and BAP levels of study group were higher than those of control group whereas bone resorption indexesβ-CTX, TRACP5b and NTX levels were lower than those of control group;serum inflammatory factors TGF-β, hs-CRP, IL-1β, IL-6 and IL-17 levels were lower than those of control group.Conclusion:Compared with traditional intramedullary nail therapy, magnetic-guided intramedullary nail fixation can more effectively balance the bone metabolism status and reduce the fracture end trauma in patients with femoral shaft fracture.

Effect comparison of knee-chest elastic bandage fixation and Pavlik harness fixation on the treatment of femoral shaft fractures in newborns

Objective:To study and analyze the clinical efficacy of fixation of the elastic bandage of immobilization of knee-chest position and Pavlik harness fixation in the treatment of neonatal femoral shaft fractures.Methods:A retrospective analysis was conducted from May 2010 to March 2017 with a total of 37 cases of femoral shaft fracture of the newborn.Among them,17 newborns with femur shaft fracture were treated using this fixation of the elastic bandage of immobilization of knee-chest position,and 20 newborns were treated utilizing Pavlik harness fixation.All patients were followed up for 24 months.It was compared between the two groups in length of hospitalization,hospitalization cost,the incidence of complications,fracture healing rate and post-operation angulation,rotation and shortening indexes.Results:Compared with the Pavlik harness fixation group,the hospitalization cost of knee-chest elastic bandage fixation group was lower(P<0.05),the difference was statistically significant.There is no significant difference between the two groups in terms of length of hospitalization,complications and fracture healing.The two groups of treatment methods compared in angle formation,rotation and shortness(P>0.05),with no statistical difference.Conclusions:Both knee-chest elastic bandage fixation and Pavlik harness fixation are effective methods for the treatment of neonatal femoral shaft fractures.But the former has lower cost and simpler operation,which is worthy of clinical application.

Trauma and bone metabolism of magnetic navigation intramedullary nail and traditional intramedullary nail fixation treatment of femoral shaft fracture

Objective:To analyze the trauma and bone metabolism of magnetic navigation intramedullary nail and traditional intramedullary nail fixation treatment of femoral shaft fracture. Methods:58 patients with femoral shaft fracture treated in our hospital between December 2011 and December 2015 were divided into observation group and control group by random number table (n=29). Control group received conventional intramedullary nail fixation treatment, and observation group received magnetic navigation intramedullary nail fixation treatment. 24 h after surgery, blood coagulation indexes, enzymology indexes, bone metabolism indexes and angiogenesis indexes were determined;6 months after surgery, bone mineral density levels were determined. Results:24 h after surgery, peripheral blood thrombin time (TT), prothrombin time (PT), and activated partial thromboplastin time (APTT) levels of observation group were significantly higher than those of control group, and serum fibrinogen (FIB), D-Dimer (D-D), lactate dehydrogenase (LDH), creatine kinase (CK), creatine kinase isoenzyme (CKMB), glutamic oxalacetic transaminase (GOT), sex hormone-binding globulin type I (SHBG), collagen cross-linked carboxyl-terminal telopeptide (CTX) and deoxypyridinoline (DPD) content were lower than those of control group while bone gla protein (BGP), insulin-like growth factor (IGF-1), hypoxia-inducible factor-1α (HIF-α), angiogenin 1 (Ang-1), recombinant basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) content were higher than those of control group;6 months after surgery, fracture end bone mineral density (BMD) value of observation group was higher than that of control group. Conclusions:Magnetic navigation intramedullary nail treatment of femoral shaft fracture can more effectively reduce the surgical trauma, improve bone metabolism and increase bone mineral density.

A comparison of three fixations for intertrochanteric femoral fractures in the elderly

Objective To compare the efficacy of 3 internal fixations,locking proximal femoral plate (LPFP),ASI-AN IMHS and InterTAN,for intertrochanteric femoral fractures in elderly patients.Methods A retrospective study was done to analyse

A Biomechanical Comparison of Conventional versus an Anatomic Plate and Compression Bolts for Fixation of Intra-articular Calcaneal Fractures

The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures.Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-Ⅲ calcaneal fracture model by using osteotomy.The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws.Reduction of fracture was evaluated through X radiographs.Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N,representing the partial weight bearing and full weight bearing,respectively,and then the specimens were loaded to failure.Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test.No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading(P=0.06),while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading(P=0.008).The load achieved at loss of fixation of the constructs for the two groups had significant difference:anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N(P=0.008).There was no significant difference between the ultimate displacements.Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading.The study supports the mechanical viability of using our plate and compression bolts for the fixation of calcaneal fracture.

Titanium elastic nailing in diaphyseal femoral fractures of children below six years of age

AIM To report the clinical and radiographic results of titanium elastic nail(TEN) in diaphyseal femoral fractures of children below age of six years.METHODS A retrospective analysis of 27 diaphyseal femoral fractures in children younger than six years treated with TEN between 2005 and 2015 was conducted. Patients were immobilized in a cast for 5 wk and the nails were removed from 6 to 12 wk after surgery. Twenty-four cases were clinically and radiographically re-evaluated using the Flynn's scoring criteria, focusing on: Limb length discrepancy, rotational deformity, angulation, hip and knee range of motion(ROM), functional status, complications, and parent's satisfaction.RESULTS Sixteen males and eight females with a mean age of 3.2 years at the time of treatment were re-evaluated at an average follow-up of 58.9 mo. No cases of delayed union were observed. The mean limb lengthening was 0.3 cm. Four cases experienced limb lengthening greater than 1 cm and always minor than 2 cm. Twelve point five percent of the cases showed an angulation < 10°. Complete functional recovery(hip and knee ROM, ability to run and jump on the operated limb) occurred in 95.7% of cases. Complications included two cases of superficial infection of the TEN entry point, one case of refracture following a new trauma, and one TEN mobilization. According to the Flynn's scoring criteria, excellent results were obtained in 79.2% of patients and satisfactory results in the remaining 20.8%, with an average parent's satisfaction level of 9.1/10.CONCLUSION TEN is as a safe, mini-invasive and surgeon-friendly technique and, considering specific inclusion criteria, it represents a useful and efficacy option for the treatment of diaphyseal femoral fractures even in patients younger than six years of age.

Revisiting Pauwels' classification of femoral neck fractures

Pauwels’femoral neck fracture classification is based on the biomechanical principle that shear stress and varus force increase along more vertically oriented fractures,resulting in higher risk of fracture displacement and ultimately nonunion.This principle continues to guide construct selection for femoral neck fracture internal fixation and is the foundation for treating non-union with valgus osteotomy.However,with poor inter-and intra-rater reliability,dated treatment recommendations,and unreliable prognostic value,the Pauwels classification cannot be directly applied in its entirety to the management of femoral neck fractures in modern practice.

Current concepts in the management of bisphosphonate associated atypical femoral fractures

Bisphosphonates are a class of drugs used as the mainstay of treatment for osteoporosis.Bisphosphonates function by binding to hydroxyapatite,and subsequently targeting osteoclasts by altering their ability to resorb and remodel bone.Whilst aiming to reduce the risk of fragility fractures,bisphosphonates have been associated with atypical insufficiency fractures,specifically in the femur.Atypical femoral fractures occur distal to the lesser trochanter,until the supracondylar flare.There are a number of the differing clinical and radiological features between atypical femoral fractures and osteoporotic femoral fractures,indicating that there is a distinct difference in the respective underlying pathophysiology.At the point of presentation of an atypical femoral fracture,bisphosphonate should be discontinued.This is due to the proposed inhibition of osteoclasts and apoptosis,resulting in impaired callus healing.Conservative management consists primarily of cessation of bisphosphonate therapy and partial weightbearing activity.Nutritional deficiencies should be investigated and appro-priately corrected,most notably dietary calcium and vitamin D.Currently there is no established treatment guidelines for either complete or incomplete fractures.There is agreement in the literature that nonoperative management of bisphosphonate-associated femoral fractures conveys poor outcomes.Currently,the favoured methods of surgical fixation are cephalomedullary nailing and plate fixation.Newer techniques advocate the use of both modalities as it gives the plate advantage of best reducing the fracture and compressing the lateral cortex,with the support of the intramedullary nail to stabilise an atypical fracture with increased ability to load-share,and a reduced bending moment across the fracture site.The evidence suggests that cephalomedullary nailing of the fracture has lower revision rates.However,it is important to appreciate that the anatomical location and patient factors may not always allow for this.Although causation between bisphosphonates and atypical fractures is yet to be demonstrated,there is a growing evidence base to suggest a higher incidence to atypical femoral fractures in patients who take bisphosphonates.As we encounter a growing comorbid elderly population,the prevalence of this fracture-type will likely increase.Therefore,it is imperative clinicians continue to be attentive of atypical femoral fractures and treat them effectively.

The effect of moment arm length on high angled femoral neck fractures (Pauwels’ III)

This study investigated loads among five fixation types (FT) [three cannulated screws (CS), dynamic hip screws with and without derotational screws (DHS-DS and DHS), and dynamic helical hip screws with and without derotational screws (DHHS-DS and DHHS)] across three fracture moment lengths (ML) in Pauwels’ Type III fractures. Methods: Seventy-five sawbones were tested (5 FT × 5 trials × 3 ML). The study hypothesis was that significant differences in axial loading to failure would be demonstrated when CS was compared with the other four FT at the three MLs. Each construct was exposed to an axial compressive load to failure. Construct failure was defined as 5 mm of migration at the fracture site or fixation failure. Shapiro-Wilk was used to test for data normality. Subsequently, independent t-tests with Bonferroni correction was used for paired comparisons. Results: At fracture Moments A and B there were no statistical differences between CS and the other FT. At fracture Moment C all four FT yielded significantly higher (p ≤ 0.001) loads compared with CS. Conclusions: for basicervical fractures CS is a suboptimal form of fixation compared with DHS and DHHS both with and without derotation screws.

Intraprosthetic fixation techniques in the treatment of periprosthetic fractures: A biomechanical study

AIM: To develop new fixation techniques for the treatment of periprosthetic fractures using intraprosthetic screw fixation with inserted threaded liners. METHODS: A Vancouver B1 periprosthetic fracture was simulated in femur prosthesis constructs using sawbones and cemented regular straight hip stems. Fixation was then performed with either unicortical locked-screw plating using the less invasive stabilization system-plate or with intraprosthetic screw fixation using inserted liners. Two experimental groups were formed using either prostheses made of titanium alloy or prostheses made of cobalt chrome alloy. Fixation stability was compared in an axial load-to-failure model. Drilling was performed using a specially invented prosthesis drill with constantly applied internal cooling.RESULTS: The intraprosthetic fixation model with titanium prostheses was superior to the unicortical lockedscrew fixation in all tested devices. The intraprosthetic fixation model required 10 456 N ± 1892 N for failure and the unicortical locked-screw plating required 7649 N ± 653 N(P < 0.05). There was no significant difference between the second experimental group and the control group.CONCLUSION: Intraprosthetic screw anchorage with special threaded liners enhances the primary stability in treating periprosthetic fractures by internal fixation.

Managing extremely distal periprosthetic femoral supracondylar fractures of total knee replacements-a new PHILOS-ophy

We report two cases where a proximal humeral locking plate was used for the fixation of an extremely distal, type Ⅲ peri-prosthetic femoral fractures in relation to a total knee replacement(TKR). In each case there was concern regarding the fixation that could be achieved using the available anatomic distal femoral plates due to the size and bone quality of distal fragment. The design of the Proximal Humeral Internal Locking System(PHILOS) allows nine 3.5-mm locking screws to be placed over a small area in multiple directions. This allowed a greater number of fixation points to be achieved in the distal fragment. Clinical and radiological short-term follow-up(6-12 mo) has been satisfactory in both cases with no complications. We suggest the use of this implant for extremely distal femoral fractures arising in relation to the femoral component of a TKR.

Hybrid External Fixation for Open Severe Comminuted Fractures of the Distal Femur

Background: The treatment of distal femoral open comminuted fractures is a major problem for orthopedic surgeon. The basic and important aim in treatment of these fractures is to assemble the condylar fragments and then fix the condyles to the femoral shaft by minimum handling of the bone and soft tissues. Objectives: To evaluate the treatment of distal femoral open comminuted fractures (type C2 and C3) with hybrid external fixator. Methods: Thirty-four patients with distal femur open comminuted fracture (type C2 and C3) were treated by hybrid external fixator between January 2005 and December 2008. All of the fractures were opened with extension to joint surface. 30 patients were male and 4 were female. Their average age was 30.5 years (17 to 72 years). Average follow up period was 36 months. 12 patients had isolated fracture and 22 patients had multiple fractures. The bony and functional results were evaluated by the association for the study and application of the method of Ilizarov (ASAMI) protocol and knee society score. Results: 29 out of 34 fractures (85%) had union without bone grafts. Average time of union was 6.1 months (4 - 19 ms). The average knee range of motion was 87.5 degrees (30 - 115 degrees). The bony results were excellent in 24 patients (70.5%), good in 6 (17.7%), fair in 2 (5.9%), and poor in 2 (5.9%), and the functional results were excellent in 10 (29.4%) patients, good in 14 (41.2%), fair in 6 (17.6%), and poor in 4 (11.8%), and the functional results were excellent in 10 (29.4%) patients, good in 14 (41.2%), fair in 6 (17.6%), and poor in 4 (11.8%) according to ASAMI protocol. According to the knee society score the functional results were excellent in 9 (26.44%) patients, good in 13 (38.26%), fair in 7 (20.6%), and poor in 5 (14.7%). Conclusion: Hybrid external fixator is an effective method for treatment of distal femoral open comminuted fractures (type C2 and C3) and may be considered as an alternative surgical methods in the management of these fractures.

Proximal Femoral Nail in Reverse Trochanteric Femoral Fractures: An Analysis of 53 Cases at One Year Follow-Up

Treatment of reverse oblique trochanteric femoral fractures poses a lot of challenges. There have been proponents of intramedullary devices as well as extramedullary devices. We present the results of proximal femoral nailing surgery performed for reverse obliquity intertrochanteric fractures using two proximal lag screws and a nail of 250 mm. There is prospective study of fifty three patients with AO/OTA 31 A-A3 fractures being treated by proximal femoral nailing in our institute after seeking approval from the Hospital ethics board. The quality of the reduction, the operative time, complications and the functional status of the patients were the parameters on which the results were evaluated. The mean Harris hip score was 76.66 (range 70 - 93) and the mean Barthel activity score was 16.21 (range 12 - 20). The average surgical time was 50 minutes and the mean consolidation time was 11.5 weeks. Intramedullary nailing with proximal femoral nails seems to be a good option in the treatment of reverse obliquity intertrochanteric fractures as against the various existing options available for the management.

Proximal Femur Bionic Nail (PFBN): A Panacea for Unstable Intertrochanteric Femur Fracture

With the aging population,intertrochanteric femur fracture in the elderly has become one of the most serious public health issues and a hot topic of research in trauma orthopedics.Due to the limitations of internal fixation techniques and the insufficient mechanical design of nails,the occurrence of complications delays patient recovery after surgical treatment.Design of a proximal femur bionic nail(PFBN)based on Zhang’s N triangle theory provides triangular supporting fixation,which dramatically decreases the occurrence of complications and has been widely used for clinical treatment of unstable intertrochanteric femur fracture worldwide.In this work,we developed an equivalent biomechanical model to analyze improvement in bone remodeling of unstable intertrochanteric femur fracture through PFBN use.The results show that compared with proximal femoral nail antirotation(PFNA)and InterTan,PFBN can dramatically decrease the maximum strain in the proximal femur.Based on Frost’s mechanostat theory,the local mechanical environment in the proximal femur can be regulated into the medium overload region by using a PFBN,which may render the proximal femur in a state of physiological overload,favoring post-operative recovery of intertrochanteric femur fracture in the elderly.This work shows that PFBN may constitute a panacea for unstable intertrochanteric femur fracture and provides insights into improving methods of internal fixation.

Conversion hip arthroplasty for failed nailing of intertrochanteric fracture: Reflections on some important aspects

In this editorial,I present my comments on the article by Solarino et al.Conversion hip arthroplasty,which is an optional salvage procedure performed following unsuccessful fixation of intertrochanteric femur fractures in elderly pati-ents,entails more complex processes and higher rates of operative complications than primary arthroplasty.Hence,it is important to consider the appropriateness of the primary treatment choice,as well as the adequacy of nailing fixation for intertrochanteric fractures.This article briefly analyzes the possible factors contributing to the nailing failure of intertrochanteric fractures and attempts to find corresponding countermeasures to prevent fixation failures.It also analyzes the choice of treatment between nailing fixation and primary arthroplasty for intertrochanteric fractures.