Anteromedial cortical support reduction in unstable pertrochanteric fractures: a comparison of intra-operative fluoroscopy and post-operative three dimensional computerised tomography reconstruction

Flexible reamer use to overcome entry point errors in proximal femoral nail application in severe obese intertrochanteric fracture patients

INTRODUCTION

Proximal femoral nailing (PFN) offers biomechanical benefits for intertrochanteric fractures but can lead to higher complication rates from poor reduction and technique errors, particularly in obese patients. Incorrect entry points may cause reduction loss, iatrogenic fractures, and misplaced lag screws. The study aims to investigate the effect of using an oriented flexible reamer instead of a rigid reamer on clinical and radiological results to obtain a medial entry point and better positioning of the nail in the intramedullary area in obese intertrochanteric fracture patients.

MATERIALS AND METHODS

A retrospective analysis was conducted on patients aged 65 years and older who underwent PFN treatment between March 2020 and June 2022 at a single institution, with at least 1-year postoperative follow-up. Patients were divided into two groups: those applied with a flexible reamer and a rigid reamer. Parameters analyzed from postoperative radiographs included tip-apex distance (TAD), calcar-referenced tip-apex distance (CalTAD), reduction quality, femoral neck-shaft angle, and lag screw placement. Complication rates and types were recorded for each group.

RESULT

The analysis included 91 patients, with 45 treated using a flexible reamer and 46 treated using a rigid reamer. There was no statistical difference between the two groups regarding age, gender, BMI, and AO class distributions of the patients (p > 0.05). The Femur neck shaft angle was significantly higher in the flexible reamer group (p < 0.001). As a result of the reduction types analysis, medial type reduction was significantly higher in the group where the flexible reamer was applied (p < 0.001). The CalTAD was shorter in the Flexible reamer group (p = 0.005). Complications and the need for reoperation were statistically significantly higher in the rigid reamer group (p < 0.048).

CONCLUSION

The oriented flexible reamer reduces application-related errors in patients undergoing proximal femoral nail (PFN) treatment due to intertrochanteric fracture. The oriented flexible reamer technique allows a more medial entry point. Oriented flexible reamer creates enough space on both fracture sides at the level of intertrochanteric fracture to avoid nail pass-related complications.

LEVEL OF EVIDENCE

Level III, Case-control study.

Anteromedial cortical support reduction of intertrochanteric fractures-A review

The intertrochanteric fracture is a common fragility fracture typically resulting from low-energy falls. The functional outcome of intertrochanteric fractures is closely linked to the patient's underlying physical condition, intraoperative procedures, and postoperative complications. In terms of surgery, while timely surgery and appropriate internal fixation have demonstrated favorable outcomes, attention to intraoperative reduction is crucial. In recent years, there have been further developments in the evaluation of reduction of intertrochanteric fractures, particularly in the anteromedial cortical reduction, and these advances have been further scientifically elucidated in terms of their ability to provide stable fracture reduction and resist loss of reduction. In order to gain a comprehensive understanding of the anteromedial cortex theory, this article reviewed the anatomy, related theoretical progress, and controversies in recent years.

Cement Filling Technique to Prevent Greater Trochanter Displacement in Hip Arthroplasty for Femoral Intertrochanteric Fracture: A Technical Note

With the increasing use of primary hip arthroplasty for management of intertrochanteric fractures, firm fixation and union of the greater trochanteric (GT) fragment are required during hip arthroplasty for management of intertrochanteric fractures. Various methods have been suggested to address this issue. However, displacement of the GT is a frequent occurrence. We have introduced a cement-filling technique for performance of hip arthroplasty of the proximal femur for achievement of immediate firm fixation of the GT. Cement filling during performance of hip arthroplasty for management of femoral intertrochanteric fractures is a valuable technique for preventing displacement of the GT and to encourage early mobilization.

Finite element analysis of fixation stability according to reduction position for internal fixation of intertrochanteric fractures

In recent years, finite element analysis (FEA) has been instrumental in comparing the biomechanical stability of various implants for femur fracture treatment and in studying the advantages and disadvantages of different surgical techniques. This analysis has proven helpful for enhancing clinical treatment outcomes. Therefore, this study aimed to numerically analyze fixed stability according to location using FEA. In this study, a virtual finite element model was created based on a clinically anatomically reduced patient. It incorporated positive and negative support derived from intramedullary and extramedullary reduction from the anteroposterior (AP) view and neutral support from the lateral view. The generated model was analyzed to understand the biomechanical behavior occurring in each region under applied physiological loads. The simulation results of this study showed that the average von Mises stress (AVMS) of the nail when performing intramedullary reduction for femoral fixation was 187% of the anatomical reduction and 171% of the extramedullary reduction, and individually up to 2.5 times higher. In other words, intramedullary reduction had a very high possibility of fixation failure compared to other reduction methods. This risk is amplified significantly, especially in situations where bone strength is compromised due to factors such as old age or osteoporosis, which substantially affects the stability of fixation. Extramedullary reduction, when appropriately positioned, demonstrates greater stability than anatomical reduction. It exhibits stable fixation even in scenarios with diminished bone strength. In instances in which the bone density was low in the support position, as observed in the lateral view, the AVMS on the nail appeared to be relatively low, particularly in cases of positive support. Additionally, the femur experienced lower equivalent stress only in the extramedullary reduction-negative position. Moreover, by comparing different reduction methods and bone stiffness values using the same femoral shape, this study offers insights into the selection of appropriate reduction methods. These insights could significantly inform decision making regarding surgical strategies for intertrochanteric fractures.

Anteromedial Cortical Support in Reduction of Trochanteric Hip Fractures: From Definition to Application

➤ The concept of anteromedial cortical support (AMCS) serves as valuable guidance for the intraoperative reduction of trochanteric hip fractures.➤ Positive medial cortical support (MCS) and positive or neutral anterior cortical support (ACS) are desirable. Some evidence has suggested that positive MCS is potentially superior to neutral MCS.➤ Experimental studies underscore the vital importance of the anteromedial wall and reveal why positive MCS potentially outperforms neutral MCS.➤ Incorporating the AMCS concept, the Chang reduction quality criteria (CRQC) are a reliable alternative approach to evaluate the reduction quality of trochanteric hip fractures.

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.

Role of Anteromedial Cortical Support for Unstable Intertrochanteric Fractures Being Treated With Cephalomedullary Nails

INTRODUCTION

Reduction quality is of paramount importance for an optimal outcome in unstable pertrochanteric fractures. The non-anatomical functional anteromedial buttress is proposed to prevent impending mechanical complications. We aimed to evaluate the role of anteromedial cortical support in preventing mechanical complications following fixation with the cephalomedullary nail.

MATERIALS AND METHODS

A prospective, single-arm interventional study was conducted in the Orthopaedics Department of a Combined Military Hospital (CMH) in Rawalpindi. The duration of the study was 24 months. Patients were recruited by the purposive sampling technique as per inclusion/exclusion criteria. Preoperatively, the reduction was categorized as per Baumgartner's and Chang's criteria. Post-operatively, weight bearing as tolerated was advised. Radiographs prior to discharge for loss of reduction were evaluated. Follow-up radiographic measurements of neck length, neck shaft angle, and their loss as per protocol were done at three and six months.

RESULTS

A total of 202 patients were operated on from October 21 until August 23. Mortality at six months in 39 patients (19.3%) and loss to follow-up in 31 patients (15.3%) resulted in 132 patients with complete follow-up and having developed complications in 12 patients (9.09%). The mean age was 76.3 ± 7.98 years; males were 105 (79.5%), and females were 27 (20.5%). Closed reduction was 58 (43.9%), and additional manoeuvres were required in 74 (56.1%). The mean tip apex distance (TAD) was 24.56 ± 2.76, and the Calcar gap was 5.16 ± 1.27. Cleveland zone centre-centre in 54 (40.9%), inferior-centre in 65 (49.2%), and inferior-posterior (9.9%) were statistically significant for mechanical complications (p≤0.001). There was a significant association between the grading of Chang's and Baumgartner's poor groups for the development of mechanical complications (p≤0.001). The mean time to full weight bearing without support was 21 ± 1.22 weeks. The mean Hip Harris score at six months was 69.27 ± 7.68.

CONCLUSION

Results suggest that anteromedial cortical support can lead to fewer potential mechanical complications at six months. A higher Chang's grade drives surgeons to engage in additional manoeuvres. Anteromedial cortical support is worth consideration for unstable pertrochanteric fractures.

Geriatric trauma: there is more to it than just the implant!

Geriatric trauma continues to rise, corresponding with the continuing growth of the older population. These fractures continue to expand, demonstrated by the incidence of hip fractures having grown to 1.5 million adults worldwide per year. This patient population and their associated fracture patterns present unique challenges to the surgeon, as well as having a profound economic impact on the health care system. Pharmacologic treatment has focused on prevention, with aging adults having impaired fracture healing in addition to diminished bone mineral density. Intraoperatively, novel ideas to assess fracture reduction to facilitate decreased fracture collapse have recently been explored. Postoperatively, pharmacologic avenues have focused on future fracture prevention, while shared care models between geriatrics and orthopaedics have shown promise regarding decreasing mortality and length of stay. As geriatric trauma continues to grow, it is imperative that we look to optimize all phases of care, from preoperative to postoperative.

The Role of Computed Tomography and Radiographs in the Management of Intertrochanteric Fractures

Introduction

The Intertrochanteric fracture is a common hip trauma encountered in elderly patients. There is a lack of general agreement regarding its surgical management and choice of implant. Purpose of this study to conclude the final decision matrix regarding surgical management of intertrochanteric fractures based on parameters assessed on plain radiographs and CT scan.

Materials and methods

We have retrospectively evaluated 55 patients with intertrochanteric fractures presented to our institute after informed consent with radiographs and CT scans between July 2017 to July 2018. Assessment of various parameters regarding fracture geometry and classification as well as measurement was done.

Results

Mean lateral wall thickness in present study was 20.76mm. Incidence of coronal fragments was 90.9% and absence of coronal fragment in 5 patients. We noted the cases with anterior comminution had also a posterior comminution rendered the fracture unstable in almost 20 % cases.

Conclusion

Better understanding of fracture geometry by combined used of radiograph and CT scan enhanced preoperative planning, choice of suitable implant, helps in reduction manoeuvre and improving quality of osteosynthesis.

Preventing the Slide in High-Energy Intertrochanteric Fractures With Intramedullary Nails

LEVEL OF EVIDENCE

Therapeutic Level V.

Positive medial cortical support versus anatomical reduction for trochanteric hip fractures: Finite element analysis and biomechanical testing

BACKGROUND AND OBJECTIVES

The anatomical reduction (AR) is usually considered the best option for fractures. Nevertheless, in unstable trochanteric hip fractures (UTHF), previous clinical reports found that the positive medial cortical support (PMCS, an over-reduction technique) attained higher mechanical stability, but this challenging clinical finding still needs experimental validation.

METHODS

This study constructed in-silico and biomechanical PMCS and AR models, with the use of the most clinically-representative geometry design of fracture models, the multi-directional design in FE analysis, and the subject-specific (osteoporotic) bone material properties, to make the models better mimic the actual condition in clinical settings. Then multiple performance variables (von-Mises stress, strain, integral axial stiffness, displacement, structural changes, etc.) were assessed to uncover details of integral and regional stability.

RESULTS

Among in-silico comparison, PMCS models showed significantly lower maximum displacement than AR models, and the maximum von Mises stress of implants (MVMS-I) was significantly lower in PMCS models than in AR models (highest MVMS-I in -30°-A3-AR of 1055.80 ± 93.37 MPa). Besides, PMCS models had significantly lower maximum von Mises stress along fracture surfaces (MVMS-F) (highest MVMS-F in 30°-A2-AR of 416.40 ± 38.01 MPa). Among biomechanical testing comparison, PMCS models showed significantly lower axial displacement. Significantly lower change of neck-shaft angle (CNSA) was observed in A2-PMCS models. A fair amount of AR models converted into the obvious negative medial cortical support (NMCS) condition, whereas all PMCS models kept the PMCS condition. The results were also validated through comparison to previous clinical data.

CONCLUSIONS

The PMCS is superior to the AR in the UTHF surgery. The current study opens up the second thought of the role of over-reduction technique in bone surgery.

Relative instability ratios of bone wall defects in trochanteric hip fractures: A finite element analysis

Background: For decades, medial and lateral wall fragments of trochanteric hip fractures were considered two pivotal factors that could influence the stability of postoperative femur-implant complex. However, most studies seemed to misunderstand the concept of the posteromedial fragment and equated it with the medial wall, which overlooked vital roles of the anteromedial wall. Roles of the posterior coronal bone fragment were also highlighted in some research. However, influences of the bone walls above the trochanteric fracture instability are yet to be investigated and quantified by means of finite element analysis. Methods: Eight trochanteric fracture fixation models with different wall defects were constructed. Outcome indicators were the von Mises stress of the implant models, the maximum/minimum principal strain, the risky tensile/compressive volume and the volume ratios of the bone models, the femoral head vertex displacement, and the fracture surface gap. Based on these indicator values, the relative instability ratios were computed. Results: Outcome indicators, absolute values, and nephograms of all models showed the same upward and concentrating trends with exerted hip contact loads shifting from static walking to dynamic climbing. Similarly, these indicators also exhibited the same trends when the eight models were solved in sequence. Moreover, the relative instability ratio of the medial wall (100%), particularly the anteromedial part (78.7%), was higher than the figure for the lateral wall (36.6%). Conclusion: The anteromedial wall played relatively pivotal stabilizing roles in trochanteric hip fractures compared with the posteromedial wall and the lateral wall, which indicated that orthopedic surgeons should attach more importance to the anteromedial cortex support in an operating theatre.

Strategies for Pertrochanteric Fracture Reduction and Intramedullary Nail Placement: Technical Tips and Tricks

The incidence of pertrochanteric hip fractures continues to rise as the aging population expands. Despite advancements in techniques and implants, failure rates remain up to 16% in the literature. The recognition of challenging fracture patterns and the use of meticulous preoperative planning can help to avoid common pitfalls. Understanding fluoroscopic views for reduction assessment and implant placement is instrumental in preventing fixation failure. In addition, adjunctive techniques including the use of a bone hook, cerclage wire, and colinear clamps can facilitate reduction efforts. It is imperative for the surgeon to recognize common pitfalls and to consider a wide array of techniques to manage these challenging and common fractures.

A sophisticated fracture classification system of the proximal femur trochanteric region (AO/OTA-31A) based on 3D-CT images

Objective

Fracture classification evolves dynamically with new and enhanced imaging modalities. This paper aims to introduce a novel hypothesis of a sophisticated fracture classification system for the proximal femur trochanteric region (AO/OTA-31A) based on 3D-CT images and accommodate the clinical requirement of the worldwide outbreak of geriatric hip fractures with large amounts of surgical operations.

Methods

In the current practice of widely preoperative 3D-CT application and cephalomedullary nailing, we attempt to propose a new comprehensive classification system to describe the fracture characteristics in a more detailed and sophisticated architecture, and pay the most important concern to the parameters that contribute to fracture stability reconstruction in osteosynthesis.

Results

The new four-by-four comprehensive classification system, followed the structure of the AO/OTA system, incorporates many fracture characteristics as dividing indexes into multiple grade levels, such as fracture line direction, the number of fragments, the lesser trochanter fragment and its distal extension (>2 cm), the posterior coronal fragment and its anterior expansion (to the entry portal of head–neck implant at the lateral cortex), the lateral wall and anterior cortex fracture, and the anteromedial inferior corner comminution. From a panoramic perspective, there are four types and each type has four subtypes. A1 is simple two-part fractures (20%), A2 is characterized by lesser trochanter fragment and posterior coronal fractures (62.5%), A3 is reverse obliquity and transverse fractures with complete lateral wall broken (15.5%), and A4 is medial wall comminution which further lacks anteromedial cortex transmission of compression force (2%). For subtypes, A2.2 is with a banana-like posterior coronal fragment, A2.4 is with distal cortex extension >2 cm of the lesser trochanter and anterior expansion of the posterior coronal fragment(s) to the entry portal of head–neck implants, A3.4 is a primary pantrochanteric fracture, and A4.4 is a concomitant ipsilateral segmental fracture of the neck and trochanter region.

Conclusion

Classification represents diversity under consistency. The four-by-four sophisticated classification system delineates fracture characteristics in more detail. It is applicable in the time of rapid outbreak of trochanteric fractures in the older population, the large amounts of surgical operations, and incorporates various rare and/or more complicated subtypes which is unclassifiable before.

Letter to the editor: Calcar fracture gapping: a reliable predictor of anteromedial cortical support failure after cephalomedullary nailing for pertrochanteric femur fractures

A recently published article by Song H et al. investigated the risk factors for anteromedial cortical support loss in pertrochanteric fractures treated with cephalomedullary nails. In this Correspondence, we would like to raise some concerns. Specifically, calcar fracture gap and anteromedial cortical support are different concepts in evaluating reduction quality. In addition, calcar fracture gap using immediate postoperative radiographic images has measurement bias. Lastly, explanatory variables selected for multivariable analysis are inappropriate. We would like to discuss and suggest solutions for these problems.

Calcar fracture gapping: a reliable predictor of anteromedial cortical support failure after cephalomedullary nailing for pertrochanteric femur fractures

Background

Maintaining anteromedial cortical support is essential for controlling sliding and decreasing postoperative implant-related complications. However, adequate fracture reduction with cortical support in immediate postoperative fluoroscopy is not invariable in postoperative follow-ups. This study was conducted to investigate the risk factors leading to anteromedial cortical support failure in follow up for pertrochanteric femur fractures treated with cephalomedullary nails.

Methods

This retrospective study enrolled 159 patients with pertrochanteric fractures (AO/OTA- 31A1 and 31A2) that fixed with cephalomedullary nails. All patients were evaluated as adequate fracture reduction in immediate postoperative fluoroscopy before leaving the operation theater. The patients were separated into two groups based on the condition of the anteromedial cortex in the postoperative 3D CT with full-range observation: those with calcar support maintained in Group 1 and those with calcar support lost in Group 2. Demographic information, fracture classification, TAD (tip-apex distance), Cal-TAD, Parker ratio, NSA (neck-shaft angle), reduction quality score, and calcar fracture gapping were collected and compared. Logistic regression analysis was conducted to explore the risk factors leading to anteromedial cortex change.

Results

Anteromedial cortical support failure was noted in 46 cases (29%). There was no significant difference between the two groups concerning age, sex, side injury, TAD, Cal-TAD, Parker ratio, or NSA. There was a significant difference in the AO/OTA fracture classification in univariate analysis but no difference in the multivariable analysis. The reduction quality score, calcar fracture gapping in the AP (anteroposterior), and lateral views were significantly associated with anteromedial cortical support failure in follow-up after cephalomedullary nailing in the multivariable analysis. The threshold value of calcar fracture gapping for the risk of loss was 4.2 mm in the AP and 3.8 mm in the lateral fluoroscopies. Mechanical complications (lateral sliding and varus) were frequently observed in the negative anteromedial cortical support group.

Conclusions

Good reduction quality was a protective factor, and larger calcar fracture gapping in the AP and lateral views were risk factors leading to the postoperative loss of anteromedial cortical support. Therefore, we should pay close attention to fracture reduction and minimize the calcar fracture gap during surgery.

Low filling ratio of the distal nail segment to the medullary canal is a risk factor for loss of anteromedial cortical support: a case control study

Background

Anteromedial cortical support apposition (positive and/or neutral cortical relations) is crucial for surgical stability reconstruction in the treatment of trochanteric femur fractures. However, the loss of fracture reduction is frequent in follow-ups after cephalomedullary nail fixation. This paper aimed to investigate the possible predictive risk factors for postoperative loss of anteromedial cortex buttress after nail fixation.

Methods

A retrospective analysis of 122 patients with AO/OTA 31A1 and A2 trochanteric femur fractures treated with cephalomedullary nails between January 2017 and December 2019 was performed. The patients were classified into two groups according to the postoperative status of the anteromedial cortical apposition in 3D CT images: Group 1 with contact “yes” (positive or anatomic) and Group 2 with contact “No” (negative, loss of contact). The fracture reduction quality score, tip-apex distance (TAD), calcar-referenced TAD (Cal-TAD), Parker ratio, neck-shaft angle (NSA), and the filling ratio of the distal nail segment to medullary canal diameter in anteroposterior (AP) and lateral fluoroscopies (taken immediately after the operation) were examined in univariate and multivariate analyses. Mechanical complications were measured and compared in follow-up radiographs.

Results

According to the postoperative 3D CT, 84 individuals (69%) were categorized into Group 1, and 38 individuals (31%) were classified as Group 2. The multivariate logistic regression analysis showed that the poor fracture reduction quality score (P < 0.001) and decreasing filling ratio in the lateral view (P < 0.001) were significant risk factors for the loss of anteromedial cortical contact. The threshold value for the distal nail filling ratio in lateral fluoroscopy predicting fracture reduction re-displacement was found to be 53%, with 89.3% sensitivity and 78.9% specificity. The mechanical complication (varus and over lateral sliding) rate was higher in Group 2.

Conclusions

The fracture reduction quality score and the decreasing filling ratio of the distal nail to the medullary canal in the lateral view (a novel parameter causing pendulum-like movement of the nail) were possible risk factors for postoperative loss of anteromedial cortical support.

Comparison of sliding distance of lag screw and nonunion rate according to anteromedial cortical support in intertrochanteric fracture fixation: A systematic review and meta-analysis

INTRODUCTION

We compared the sliding distance of the lag screw, change in neck-shaft angle (NSA), and nonunion rates according to the anteromedial cortical support on anteroposterior (AP) and lateral view radiographs post intertrochanteric fracture reduction.

MATERIAL AND METHODS

In this systematic review and meta-analysis, MEDLINE, Embase, and Cochrane Library databases were searched systematically for studies published before September 26, 2020. We performed synthetic analyses of the amount of lag screw sliding, change in NSA, and incidence of nonunion following reduction of intertrochanteric fractures by extramedullary reduction (EMR), neutral reduction (NR), and intramedullary reduction (IMR). The combined data of EMR and NR comprised the non-IMR group.

RESULTS

Our study enrolled eight studies, representing 1,363 patients who underwent surgery for intertrochanteric fractures. A pooled analysis showed a larger sliding distance in the IMR group than in the non-IMR group (standard mean difference [SMD] = 1.47, 95% confidence interval [CI]: 0.73-2.20; P < 0.0001 and SMD = 1.27, 95% CI: 0.56-1.99; P = 0.0005, respectively) in both AP and lateral views. The pooled mean difference of change in NSA in the IMR group was -3.11° and differed significantly from that of the non-IMR group (95% CI: -4.07 to -2.16; P < 0.0001). In the lateral view, the nonunion rate was significantly higher in the IMR group than in the non-IMR group (odds ratio [OR] = 11.61; 95% CI, 3.32-40.62; P = 0.0001). In the subgroup analysis, the NR group showed a larger sliding distance than that of the EMR group in the AP view (SMD = 0.40, 95% CI: 0.04-0.76; P = 0.03); however, the reverse was true in the lateral view (SMD = 0.68, 95% CI: 0.38-0.97; P < 0.00001).

CONCLUSION

In the current meta-analysis, larger sliding distances, more varus in NSA, and higher nonunion rates were observed in the IMR group than the non-IMR group, in both AP and lateral views. However, in the comparison between EMR and NR, it was difficult to conclude which of them was the ideal reduction method because of inconsistent results.

Reduction of trochanteric fractures in lateral view is significant predictor for radiological and functional result after six months

OBJECTIVES

The goal of our retrospective study was to determine which radiological parameter after fixation of trochanteric fractures type AO 31 A2 is most important for the position of the fracture after six months. The additional goal was to find how the end position influences mechanical failure and the mobility of the patients.

PATIENTS AND METHODS

We analysed 92 patients operated in one-year period for A 2 type trochanteric fractures with sliding hip screw or proximal femur intramedullary nail. They were divided in two groups according to the radiological position of the proximal fragment six months after the surgery. In group A we had 46 patients with satisfactory and in group B 46 patients with unsatisfactory position. In anteroposterior view we evaluated neck-shaft angle (NSA) and medial cortical support (MCS) and in lateral view anterior cortical support (ACS). Unsatisfactory position was recognized if NSA was in varus or ACS or MCS were negative. We compared the groups regarding basic patients characteristics (age, gender, ASA score, preinjury mobility, and degree of osteoporosis), type and quality of fixation, the position of the fracture (postoperatively and after 6 months), mechanical failure and mobility after 6 months. Statistical significance level was set to p ≤ 0.05.

RESULTS

Basic patients' characteristics as well as type and quality of fixation did not significantly differ between the groups. After the injury the difference between the groups in reduction quality was significant in lateral view (ACS; p=0.001), while after half a year there were significant differences in both views: NSA (p=0.003), ACS and MCS (both p<0.001). Proximal fragment position after six months statistically significant correlated with postoperative ACS in B group (r = 0.386, p = 0.008), but not with NCA nor with MCS. There were also significantly more fixation failures in group B (p<0.001) and less patients regain preinjury mobility (p=0.029).

CONCLUSIONS

In trochanteric fractures reduction in lateral view is the most important prognostic factor for favourable radiological result after half a year. Unsatisfactory position of the proximal fragment after six months influences mechanical failures and walking ability.

[Reasons of the guide pin eccentricity of helical blade during proximal femoral nail anti-rotation internal fixation for femoral intertrochanteric fractures]

Objective

To analyze the reasons and the influence of internal fixation about the guide pin eccentricity of helical blade during proximal femoral nail anti-rotation (PFNA) internal fixation for femoral intertrochanteric fractures.

Methods

A retrospective analysis of the intraoperative imaging data of 175 patients with femoral intertrochanteric fractures, who underwent closed reduction and PFNA internal fixation between January 2018 and January 2020, was performed. There were 76 males and 99 females with an average age of 79.8 years (mean, 61-103 years). The internal between admission and operation was 12-141 hours (median, 32 hours). According to AO/Orthopaedic Trauma Association (AO/OTA) classification, the fractures were rated as type 31-A1 in 64 cases and type 31-A2 in 111 cases. In the intraoperative fluoroscopy image by C-arm X-ray machine, the caputcollum-diaphysis (CCD) was measured after closed reduction and internal fixation, respectively; the angles between the center line of the head nail hole and the axis of proximal nail and between the axis of guide pin and proximal nail were measured, and the difference between the two angles was evaluated; the quality of fracture reduction was evaluated according to the alignment of the medial cortex, anterior cortex of the head and neck bone block, and femoral shaft cortex; the position of the helical blade in the femoral head was evaluated according to the Cleveland method.

Results

The CCDs of proximal femur were (134.6±6.8)° after closed reduction and (134.9±4.3)° after internal fixation. There was no significant difference between pre- and post-internal fixation ( t=0.432, P=0.766). The angles between the center line of the head nail hole and the axis of proximal nail and between the axis of guide pin and proximal nail were (125.4±2.44)° and (126.3±2.3)°, respectively, showing significant difference ( t=2.809, P=0.044). The difference between the two angles was (0.8±2.2)°. The guide pin eccentricity of helical blade occurred in 47 cases. After tapping the helical blade along the eccentric guide pin, 10 cases had fracture reduction loss, and 5 cases had a poor position of the helical blade in the femoral head.

Conclusion

During PFNA internal fixation, a variety of reasons can lead to the eccentric position of the guide pin of helical blade, including unstable fracture, soft tissue inserted, severe osteoporosis, mismatched tool, and fluoroscopic imaging factors. It is possible that the fracture end would be displaced again and the helical blade position may be poor when knocking into the helical blade along the eccentric guide pin. During operation, it should be judged whether the direction of the guide pin needs to be adjusted according to the eccentric angle.

Postoperative computed tomography assessment of anteromedial cortex reduction is a predictor for reoperation after intramedullary nail fixation for pertrochanteric fractures

PURPOSE

Postoperative radiographs are routinely used to assess fracture reduction following intramedullary nail fixation for pertrochanteric fractures, even though computed tomography (CT) is a superior modality. We aimed to determine the association between reduction quality assessed by CT and rates of reoperation and to evaluate the association of reoperation and reduction quality according to the assessment modality (plain radiographs vs. CT).

METHODS

A retrospective analysis of 299 consecutive patients treated with intramedullary nail fixation for pertrochanteric fractures was conducted. Fracture reduction measured by postoperative radiographs and CT was categorized as anatomical type, extramedullary type, or intramedullary type. Postoperative data for analysis included reduction status, tip-apex distance (TAD), screw position in the femoral head, sliding distance, and conditions associated with reoperation.

RESULTS

Of the 299 patients included with a mean age of 83.1 ± 8.2 years, there were six patients who required reoperation (2.0%). According to the CT assessments, there were 42 intramedullary reductions (14.0%). Patients with a non-intramedullary reduction based on postoperative CT images were significantly more likely to have proper placement of the screw, a reduced TAD, a reduced sliding distance, and a lower reoperation rate than those with an intramedullary reduction (P < 0.05). The reduction quality assessed by postoperative CT was significantly associated with reoperation (95% CI, 1.45-29.31).

CONCLUSIONS

Intramedullary reduction assessed by CT was associated with reoperation. The reduction quality based on CT findings was more predictive for reoperation than that from plain radiographs.

Positive or negative anteromedial cortical support of unstable pertrochanteric femoral fractures: A finite element analysis study

OBJECTIVE

To explore the mechanical stability of unstable pertrochanteric fractures with proximal femoral nail anti-rotation (PFNA-Ⅱ) fixation under different anteromedial cortical support reduction patterns.

METHODS

A 65-year-old healthy male volunteer with no history of hip or systemic disease was recruited. High-resolution computed tomography images with a slice thickness of 0.67 mm of his right femur were obtained. These images were used to establish three-dimensional (3D) models. The lesser trochanter and lateral femoral wall were cut off to create an AO Foundation/Orthopaedic Trauma Association type 31-A2 unstable pertrochanteric fracture model. PFNA-Ⅱ was used to simulate fixation. Nine different fracture reduction patterns, which included positive-positive, positive-neutral, positive-negative, neutral-positive, neutral-neutral, neutral-negative, negative-positive, negative-neutral, and negative-negative cortical support reductions, were simulated. A load of 700 N was applied to simulate a 70 kg elderly patient standing on one leg. The models were subjected to finite element analysis. The displacement and von Mises stress distributions were analyzed.

RESULTS

The positive-positive cortical support reduction pattern showed minimal stress and the negative-negative reduction pattern showed maximal stress on the intramedullary nail. The stress was mainly concentrated at the junction of the helical blade and the main nail and at the site of the lateral aspect of the insertion point of the nail in the great trochanter. The positive cortical support reduction patterns seemed to have smaller maximum displacements of the entire fragment-implant assembly and relative displacements between the head-neck and shaft fragments. Meanwhile, the negative reduction patterns seemed to have larger displacements.

CONCLUSION

The positive-positive support reduction pattern showed better mechanical stability for unstable pertrochanteric fractures. The negative-negative support reduction pattern was prone to fixation failure and should be avoided during an operation.

Radiological findings and outcomes of anterior wall fractures in pertrochanteric fractures

BACKGROUND

Anterior wall fractures with comminution at the anterior cortex in pertrochanteric fractures are relatively rare. We aimed to investigate the prevalence and clinical findings of anterior wall fractures in this comparative cohort study.

METHODS

We reviewed 516 consecutive patients who underwent internal fixation. Anterior wall fractures were classified into three types: proximal, distal, and proximal/distal. Outcome measures included demographic data, residual anterior cortex length, fracture reduction, tip-apex distance (TAD), sliding distance, bone union, and revision surgery. We compared radiological outcomes between patients with anterior wall fractures and posterior comminuted fractures without an anterior wall fracture. The groups were matched for age and sex.

RESULTS

Anterior wall fractures were noted in 44 patients (8.5%). Residual anterior cortex length was shorter for the proximal/distal type. The distal type was the most common, was the most difficult to achieve an acceptable reduction status for, and was associated with the longest sliding distance. The proportion of unacceptable reduction status was higher for anterior wall fractures. However, there were no statistically significant differences between anterior wall fractures and posterior comminuted fractures without an anterior wall fracture in terms of TAD, sliding distance, bone union, and revision rate.

CONCLUSIONS

This study suggests that anterior wall fracture is not a significant predictor of over-sliding distance.

The Role of Preoperative Computed Tomography on the Quality of Reduction and Outcomes in Intertrochanteric Fracture: A Controlled Trial

Purpose

The study is aimed at assessing the role of preoperative computerised tomography (CT) examination in the quality of reduction and outcomes in elderly patients with intertrochanteric fracture.

Methods

The elderly patients with an intertrochanteric fracture who were treated with proximal femoral nail antirotation were included. The patients were divided into the CT group and the no-CT group according to the presence of preoperative CT examination. Patients' baseline characteristics, quality of reduction, and function were recorded at follow-up. Functional outcomes were evaluated using the Harris hip scores (HHS).

Results

Totally, the study included 182 patients with intertrochanteric fractures, with 85 in the CT group and 97 in the no-CT group, admitted between January 2018 and June 2019. There was no difference in the quality of reduction, HHS, the fracture healing, or postoperative complications between the CT group and the no-CT group. However, the CT group experienced the shorter mean operative time and blood transfusion, compared to the no-CT group.

Conclusions

The preoperative CT examination seems to be excessive for elderly patients with an intertrochanteric fracture.

The Pre-Loaded Set-Screw in InterTAN Nail: Should It Be Tightened or Not Tightened in Pertrochanteric Hip Fractures

Background:

InterTAN is a specific type of cephalomedullary nail with a twin interlocking de-rotation and compression screw, which has inherent ability of anti-rotation. Whether to tighten or not to tighten the preloaded setscrew to allow or not allow secondary sliding in InterTan nail is controversial in clinical practice.

Methods:

We retrospectively collected 4 nonunion cases of unstable pertrochanteric femur fractures (AO/OTA-31A2), all were treated with InterTan nail and the preloaded setscrew was tightened in order to prevent further secondary sliding and femoral neck shortening.

Results:

After 6 months to 2 years follow-up, the fractures showed nonunion in radiography and the patients complained slight to middle degrees of pain, and had to use walking stick assistant in activities of daily life. Tightening the pre-loaded setscrew to prevent postoperative secondary sliding as static constructs might keep the femoral neck length, but lose the opportunity of telescoping for fracture impaction, and take the risk of healing complications, such as fracture nonunion, femoral head cutout or nail breakage.

Conclusions:

As the harm outweighs benefit, we advocate the preloaded setscrew in InterTan nail should not be tightened in standard-obliquity pertrochanteric hip fractures (AO/OTA-31A1 and A2).

Nonanatomical Reduction of Femoral Neck Fractures in Young Patients (≤65 Years Old) with Internal Fixation Using Three Parallel Cannulated Screws

Purpose

The study is aimed at investigating the association between different reduction classifications (anatomic reduction, positive buttress position reduction, and negative buttress position reduction) and two end points (complications and reoperations).

Methods

The study retrospectively analyzed 110 patients undergoing internal fixation with three parallel cannulated screws from January 2012 to January 2019 in Huashan Hospital. Based on the principles of the “Gotfried reduction,” all enrolled patients were divided into three groups: anatomic reduction, positive buttress position reduction, and negative buttress position reduction intraoperatively or immediately after surgery. Clinical characteristics including age, sex, side, Garden classification, Pauwels classification, fracture level, reduction classification, Garden alignment index angles, cortical thickness index (CTI), tip-caput distance (TCD), angle of the inferior screw, and the two ending points (complications and reoperations) were included in the statistical analysis. The Mann-Whitney U-test, the chi-square test, Fisher's exact test, and multiple logistic regression analysis were used in the study.

Results

Of the 110 patients included in our study, the mean ± standard deviation (SD) of age was 51.4 ± 10.4 years; 41 patients showed anatomic reduction, 35 patients showed positive buttress position reduction, and 34 patients showed negative buttress position reduction. For the outcomes, 24 patients (anatomic reduction: 6 [14.6%]; positive buttress position reduction: 5 [14.3%]; negative buttress position reduction: 13 [38.2%]) had complications, while 18 patients (anatomic reduction: 5 [12.2%]; positive buttress position reduction: 3 [8.6%]; negative buttress position reduction: 10 [29.4%]) underwent reoperations after surgery. In the multivariate logistic regression analysis of complications, negative buttress position reduction (negative buttress position reduction vs. anatomic reduction, OR = 4.309, 95%CI = 1.137 to 16.322, and p = 0.032) was found to be correlated with higher risk of complications. The same variable (negative buttress position reduction vs. anatomic reduction, OR = 5.744, 95%CI = 1.177 to 28.042, and p = 0.031) was also identified as risk factor in the multivariate logistic regression analysis of reoperations. However, no significant difference between positive reduction and anatomical reduction was investigated in the analysis of risk factors for complications, not reoperations.

Conclusion

Positive buttress position reduction of femoral neck fractures in young patients showed a similar incidence of complications and reoperations compared with those of anatomic reduction. For irreversible femoral neck fractures, if positive buttress position reduction has been achieved intraoperatively, it is not necessary to pursue anatomical reduction; however, negative reduction needs to be avoided.

A new fluoroscopic view for evaluation of anteromedial cortex reduction quality during cephalomedullary nailing for intertrochanteric femur fractures: the 30° oblique tangential projection

Background

Anteromedial cortex-to-cortex reduction is a key parameter for stable reconstruction of the fracture fragments during the intertrochanteric fracture fixation. This paper introduces the oblique fluoroscopic projection as a novel method to evaluate the quality of anteromedial cortical apposition.

Methods

Three proximal femur specimens were marked with steel wires along five anatomic landmarks: Greater trochanter, Lesser trochanter, Intertrochanteric line, Anterolateral tubercle and the Anteromedial cortical line. After obtaining the standard femoral neck AP and lateral fluoroscopic images, the C-arm was rotated by every 5°increments until a clear tangential view of the antero-medial-inferior corner cortex was observed. 98 cases of intertrochanteric hip fractures were enrolled from April 2018 to October 2019. After fixation with the nails, the intra-operative anteromedial cortex reduction quality was evaluated from the AP, the true lateral, and the new anteromedial oblique fluoroscopic images. The fluoroscopic results were compared with the post-operative 3D-CT reconstruction images.

Results

The specimen study showed that internal rotation of the C-arm to approximately 30 ° can remove all the obscure shadows and clearly display the antero-medial-inferior cortical tangent line. Clinically,the positive, neutral and negative apposition of different cortices via intra-operative fluoroscopic images showed79, 19 and 0 cases of medial cortical apposition in AP views; 2, 68 and 28 cases of anterior cortices in lateral views;and 22, 51 and 25cases of anteromedial cortical apposition in oblique views respectively. The post-operative 3D-CT reconstruction images revealed that the final anteromedial cortical contact was noted in 62 cases (63.3%), and lost in 36 cases (36.7%). The overall coincidence rate between intra-operative fluoroscopy and post-operative 3D-CT was 63.3% (62/98) in AP view,79.6% (78/98) in lateral view, and 86.7% (85/98) in oblique view(p < 0.001). Negative cortical apposition in oblique view was highly predictive of a final loss of cortical support on 3D CT (24/25 cases, 96%).And non-negative cortical apposition in oblique view was highly associated with true cortical support on 3D CT images (61/73 cases, 83.6%) (p < 0.001).

Conclusions

Besides the AP and lateral projections, an anteromedial oblique view of 30° certifies to be a very useful means for evaluation of the fracture reduction quality of anteromedial cortical apposition.

Three-Dimensional Computed Tomography (CT) Mapping of Intertrochanteric Fractures in Elderly Patients

Background

The complex anatomy of the trochanter and the diversity in mechanisms of injury to it complicate intertrochanteric fracture patterns. Using digital technology, we created three-dimensional (3D) computed tomography (CT) mapping to show the relevant characteristics of intertrochanteric fractures in elderly patients.

Material/Methods

This was a retrospective analysis of a case series of closed intertrochanteric fractures in patients older than age 60 years who had sustained single-sided injuries less than 1 week previously. High-quality CT scans of the cases were used to create a 3D reconstruction fracture model, and fracture maps of the proximal femur were created by overlapping the fracture lines.

Results

A total of 115 patients were enrolled in this study, with mean age of 78 years (SD 7.98 years; range, 60 to 96 years). The essential features of the fracture lines were recorded in each case. Fracture maps revealed that the fracture lines were mainly concentrated in the area of the lesser and greater trochanter, intertrochanteric line, and intertrochanteric crest. As for fracture subtypes, results between patients were similar for Types A1 and A2 fractures, and differed for Type A3 fractures.

Conclusions

Detailed analysis of essential features of fracture lines revealed fracture fragments, some of which may be difficult to see using traditional imaging methods. Fracture maps composed of interindividual fracture lines revealed the relevant characteristics of intertrochanteric fractures in elderly patients. The resulting information about characteristics of distribution of fracture lines may be helpful in clinical practice.

Three-Dimensional Mapping of Medial Wall in Unstable Pertrochanteric Fractures

OBJECTIVE

Unstable pertrochanteric fractures are usually treated with internal fixation, and the integrity of the anteromedial cortex is an important factor for stability and healing. In this study, we described and analyzed the three-dimensional mapping technology and morphological characteristics of pertrochanteric fractures.

METHODS

Fifty-nine pertrochanteric fractures (OTA/AO 2007 types 31A2) were retrospectively reviewed. Computed tomographic (CT) images for all fractures were superimposed on a standard template. Medial wall integrity was analyzed, and three-dimensional fracture maps were created.

RESULTS

Pertrochanteric fractures always have a posterior defect in the medial cortex. The mean width of the defect, in our study, was 21.5 mm (SD: 6.1 mm, range: 10-40 mm), 56.3% (SD: 13.7%, range: 27.5-100%). Bone segments that contact by the anteromedial cortex were 16.5 mm (SD: 5.3 mm, range: 0-29 mm).

CONCLUSION

The integrity of the anteromedial cortex should be considered during internal fixation of femoral trochanteric fractures. These morphological characteristics could be used to form postoperative cortical contact and improve stability of the fixation. Three-dimensional mapping technology can help establish a typical fracture model, thereby improving doctors' understanding of fracture characteristics.

Intertrochanteric Femur Fracture Treatment in Asia: What We Know and What the World Can Learn

Hip fractures are of great interest worldwide as the geriatric population continues to increase rapidly. Currently, surgeons prefer to use cephalomedullary nail for internal fixation of pertrochanteric/intertrochanteric fractures. This article summarizes 10 concepts in hip fracture treatment over the past 20 years, including fracture line mapping, proximal lateral wall and anterior cortex, posteromedial lesser trochanter-calcar fragment, anteromedial cortex support reduction, changes of fracture reduction after sliding and secondary stability, nail entry point and wedge-open deformity, tip-apex distance and calcar-referenced tip-apex distance, femoral anterior bowing and nail modification, long nails for wide medullary canal and large posterior coronal fragment, and postoperative stability score.

[Concept evolution and research progress of stability reconstruction for intertrochanteric fracture]

Objective

To summarize the evolving concept and research progress on stability reconstruction in the surgical treatment of intertrochanteric fracture.

Methods

Related literature and author's own experience concerning the surgical treatment of intertrochanteric fracture were reviewed and analyzed in terms of fracture pathoanatomy, stable and unstable pattern, adequate and in-adequate reduction, primary and secondary stability, postoperative stability evaluation, and early weight-bearing.

Results

Intertrochanteric fracture occur at the translational area of cervico-trochanteric junction, which has a nature tendency to varus instability. Fracture reduction quality is the paramount factor and is evaluated by two views, the anteroposterior and lateral Garden alignment and cortex apposition between the head-neck fragment and the femoral shaft. Rather than the posteromedial lesser trochanteric frag ment, the cortical support concept (positive, neutral, negative) emphasizes the reduction of anteromedial cortex to a nonanatomic positive apposition or an "anatomic" neutral apposition in intraoperative fluoroscopy. Postoperative radiographic stability score provides a quantitative assessment for early weight-bearing standing and walking. However, some fractures may lose cortical contact and buttress (negative) during the process of postoperative telescoping and secondary stability. Further studies are needed to elucidate the risk factors such as tilting, swing or rotation of the head-neck fragment, and propose new preventive methods.

Conclusion

Stability reconstruction of intertrochanteric fracture requires adequate fracture reduction with Garden alignment and anteromedial cortical support apposition, and reliable sustainment by internal fixation implants. Early weight-bearing standing and walking is safe in patients with perfect postoperative stability score.

[Feasibility study of Kirschner wire-fixation-cortical bone technique in treatment of intertrochanteric fracture]

Objective

To explore the feasibility and effectiveness of maintaining the reduction of unstable intertrochanteric fractures by Kirschner wire-fixation-cortical bone technique.

Methods

Forty patients with intertrochanteric fracture [AO/Orthopaedic Trauma Association (AO/OTA) type 31-A2.2] admitted between May 2015 and January 2017 and requiring closed reduction and proximal femoral nail antirotation (PFNA) were randomly divided into trial group (intraoperative Kirschner wire-fixation-cortical bone technique group, 20 cases) and control group (conventional treatment group, 20 cases). There was no significant difference in general data of gender, age, side, body mass index, cause of injury, time from injury to operation between the two groups ( P>0.05). The operation time, intraoperative blood loss, and intraoperative fluoroscopy times of the two groups were recorded; the reduction quality of fracture was observed according to the corresponding relationship between medial and anterior cortex (positive, neutral, and negative support) of intraoperative fluoroscopy proposed by ZHANG Shimin, and the stability of internal fixation and fracture healing were observed; Harris score was used to evaluate the recovery of hip function at 12 months after operation.

Results

In the trial group, 6 cases (30%) had 2 Kirschner wires implanted less than 4 times, 7 cases (35%) had 5-8 times, and 7 cases (35%) had 9 times or more. There was no significant difference in operation time and intraoperative blood loss between the two groups ( P>0.05), but the blood transfusion volume and intraoperative fluoroscopy times in the trial group were significantly less than those in the control group ( P<0.05). Both groups were followed up 13-21 months, with an average of 17 months. There was no complications such as wound infection, deep venous thrombosis of lower extremities, refracture, and internal fixation-related complications. The quality of intraoperative reduction in the trial group was significantly better than that in the control group ( Z=-2.794, P=0.024). The Harris score of the trial group was significantly better than that of the control group at 12 months after operation ( t=2.98, P=0.01).

Conclusion

The use of Kirschner wire-fixation-cortical bone technique during intertrochanteric fracture closed reduction and PFNA internal fixation surgery can effectively maintain the reduction effect, reduce the number of fluoroscopy, improve the reduction quality, reduce allogeneic blood input, obtain better hip function, and do not increase the operation time and intraoperative blood loss.

[Image study of anteromedial cortical morphology of intertrochanteric fractures]

Objective

To study the anteromedial cortical morphology of intertrochanteric fracture with CT three-dimensional reconstruction technique, and to provide a reference for further study of cortical buttress reduction theory.

Methods

CT data of 75 patients with unstable intertrochanteric fracture with complete imaging data treated between January 2016 and January 2019 were retrospectively analyzed, including 32 males and 43 females, aged 65-98 years (mean, 79.8 years). According to AO/Orthopaedic Trauma Association typing of 2018 edition, there were 46 cases of 31-A2.2 type and 29 cases of 31-A2.3 type. The image processing techniques such as segmentation modeling and virtual reset were performed. The thickness of the cortex at the anteromedial corner, the angle between the anterior wall fracture line and the coronal horizontal line, the angle between the medial wall fracture line and the sagittal horizontal line, the width of the cortex supported by the medial wall were measured, and the morphology of the cortical bone at the anteromedial corner were observed.

Results

The angle between the anterior wall fracture line and the coronal horizontal line was 51.8-72.6°, with an average of 62.4°; the angle between the medial wall fracture line and the sagittal horizontal line ranged from 17.6° to -47.3°, with an average of -15.8°; the thickness of the cortex at the anteromedial angle was 3.6-6.1 mm, with an average of 4.4 mm; and the width of the cortex supported by the medial wall was 14.3-21.2 mm, with an average of 16.8 mm. The morphology of the cortical bone at the anteromedial corner had 3 forms: angle with femoral neck axis >90°, 57 cases (76.0%); perpendicular to femoral neck axis, 7 cases (9.3%); angle with femoral neck axis <90° (including reverse angle), 11 cases (14.7%).

Conclusion

CT three-dimensional reconstruction can clearly show the cortical morphology and the direction of the fracture line of intertrochanteric fracture, which can indicate the stability of the intertrochanteric fracture after reduction, and has a good guiding on the form of cortical buttress reduction.

[Research progress on anteromedial cortical positive support reduction in treatment of intertrochanteric fracture]

Objective

To introduce the reduction concept of anteromedial cortical support in the treatment of intertrochanteric fracture, summarize the history, characteristics, biomechanics, and clinical applications, discuss the unsolved problems and prospect the future directions.

Methods

Relevant domestic and foreign studies on cortical support reduction of intertrochanteric fracture in recent years were reviewed. Conclusions were drawn combined with clinical experience.

Results

The positive cortical supportive reduction of intertrochanteric fracture, as a stable non-anatomical fracture reduction technique, has dual effects on mechanical buttress and biological bone healing. It does not increase the difficulty of doctors' surgical procedure. For patients, it decreases the loss of femoral neck length, the loss of neck-shaft angle, the incidence rate of coxa vara, and maintains stable mechanical structure of the pelvis. It also shows a lower rate of instrument-related complications, and higher limb function scores. The mechanical stability of medial cortex apposition is more important than that of anterior cortex. For the best stability of the fracture, both sides should get positive support reduction pattern.

Conclusion

Anteromedial cortical support reduction can improve the postoperative stability of intertrochanteric fracture, enable better imaging and functional prognosis. As a kind of non-anatomic form of functional reduction, it can be used as a suboptimal choice secondary to anatomic reduction.

[The measurement and clinical significance of the rotation angles of head-neck fragments after cephalomedullary nail fixation in intertrochanteric fractures]

OBJECTIVE

To measure the rotation angle of the head-neck fragment of intertrochanteric fracture after cephalomedullary nail fixation by three-dimensional CT imaging, and to explore its clinical significance.

METHODS

The clinical data of 68 patients with unstable intertrochanteric fracture of AO/Orthopaedic Trauma Association (AO-OTA) type 31-A2 treated with cephalomedullary nail fixation and with complete intraoperative fluoroscopy and postoperative three-dimensional CT imaging data between July 2016 and October 2018 were retrospectively analyzed. Among them, there were 21 males and 47 females, aged 68-93 years, with an average age of 81.8 years. There were 31 cases of AO/OTA type 31-A2.2 and 37 cases of 31-A2.3. Fracture reduction quality was evaluated according to Baumgaertner et al. and Chang et al. criteria. The anteromedial cortical contact or not of each patient was observed by three-dimensional CT imaging on T3DView software after operation. The rotation of head-neck fragments were divided into three types: non-rotation, flexion rotation, and hyperextension rotation. The rotation angles of each type were measured and the relationship between the rotation type of the head-neck fragments and the contact of the anteromedial cortex was analyzed.

RESULTS

The reduction and fixation of the small trochanter were not performed in 68 patients. According to Baumgaertner et al. criteria, the quality of fracture reduction was excellent in 15 cases (22.1%), acceptable in 50 cases (73.5%), and poor in 3 cases (4.4%). According to Chang et al. criteria, 31 cases were excellent (45.6%), 33 cases were acceptable (48.5%), and 4 cases were poor (5.9%). Thirty-nine cases (57.4%) received anteromedial cortical support and 29 cases (42.6%) did not receive cortical support. Three-dimensional CT imaging showed non-rotation in 12 cases (17.6%), flexion rotation in 39 cases (57.4%), and hyperextension rotation in 17 cases (25.0%). There were 7 cases (58.3%), 30 cases (76.9%), and 2 cases (11.8%) of cortical support in non-rotation group, flexion rotation group, and hyperextension rotation group, respectively. The rotation angles were (1.05±0.61), (13.96±6.17), (8.21±3.88)°, respectively. There were significant differences between groups ( P<0.05).

CONCLUSION

In the unstable intertrochanteric fracture after cephalomedullary nail fixation, the rotation of head-neck fragment exists in most patients, and the types of flexion rotation and non-rotation can easily obtain cortical support reduction.

The Effect of Valgus Reduction on the Position of the Blade of the Proximal Femoral Nail Antirotation in Intertrochanteric Hip Fractures

Background

The purpose of this study was to evaluate the quantitative association between the degree of reduction and the position of the blade of the proximal femoral nail antirotation (PFNA) in intertrochanteric hip fractures.

Methods

From March 2009 to April 2015, 530 patients treated with PFNA for intertrochanteric hip fractures were retrospectively reviewed. Patients were divided into a valgus reduced group (group 1) and a non-valgus reduced group (group 2), and the "valgus reduced" was defined as valgus reduction over 5°. We compared the calcar referenced tip-apex distance (calTAD) and the area between the blade of PFNA and the medial cortex of the femoral neck between the two groups.

Results

The calTAD was measured as 22.5 ± 4.1 mm in group 1 and 24.8 ± 3.8 mm in group 2 (p < 0.05). The area between the blade and the medial femoral neck was measured as 135.5 ± 49.8 mm² in group 1 and 145.1 ± 54.8 mm² in group 2 (p = 0.074). The area corrected for the length difference in the femoral neck was 0.55 ± 0.16 in group 1 and 0.79 ± 0.19 in group 2 (p < 0.05).

Conclusions

Valgus reduction resulted in less calTAD and inferior position of the blade at the femoral neck in the treatment of intertrochanteric hip fractures with PFNA.

[Comparative study of proximal femoral shortening after the third generation of Gamma nail versus proximal femoral nail anti-rotation in treatment of intertrochanteric fracture]

Objective

To explore the difference of the proximal femoral shortening (PFS) between the third generation of Gamma nail (TGN) and the proximal femoral nail anti-rotation (PFNA) in treating intertrochanteric fracture of femur.

Methods

The clinical data of 158 patients with intertrochanteric fracture of femur who were treated with TGN internal fixation or PFNA internal fixation between January 2014 and December 2015 were retrospectively analysed. The patients were divided into TGN group (69 cases) and PFNA group (89 cases) according to surgical operation. There was no significant difference in gender, age, bone mineral density, causes of injury, AO/Association for the Study of Internal Fixation (AO/ASIF) classification, accompanied disease, and the time from injury to operation between 2 groups ( P>0.05). The result of fracture reduction was divided into 3 types: positive medial cortex support, neutral position cortex support, and negative medial cortex support according to the method of Chang et al. At 18 months postoperatively, bilateral hip anteroposterior X-ray films were taken to measure horizontal PFS values (marked as X), vertical PFS values (marked as Y), and calculate the total PFS values (marked as Z). The PFS values were divided into 4 grades according to the criteria (≤1.0 mm, 1.0-4.9 mm, 5.0-9.9 mm, and ≥10.0 mm), and the constituent ratio was calculated and compared between 2 groups. The X, Y, and Z values and the collodiaphyseal angles of 2 groups at 18 months postoperatively were compared. The X, Y, and Z values of 2 groups of patients with failed fixation and normal healing within 18 months after operation were recorded and compared. The X, Y, and Z values of 2 groups of the patients with different cortex support types were also compared.

Results

There were 34 cases of positive medial cortex support, 30 cases of neutral position cortex support, and 5 cases of negative medial cortex support in TGN group, and there were 45, 33, and 11 cases in PFNA group respectively, showing no significant difference between 2 groups ( Z=-1.06, P=0.29). All patients were followed up 18 months after operation. At 18 months after operation, the constituent ratios of PFS values (X, Y, Z) had significant differences between 2 groups ( P<0.05). The patients of shortening of 1.0-4.9 mm and 5.0-9.9 mm were obviously more in TGN group than in PFNA group; the patients of shortening of ≥10.0 mm were obviously more in PFNA group than in TGN group. There were significant differences in X, Y, and Z values between 2 groups ( P<0.05), but no significant difference of the collodiaphysial angle was found between 2 groups ( t=0.47, P=0.64). Six cases of internal fixation failed in TGN group and PFNA group respectively within 3 months after operation, and there was no significant difference of X, Y, and Z values between failed fixation and normal healing patients within 2 groups ( P>0.05). When the reposition effect was the positive medial cortex support, the X, Y, and Z values were significantly lower in TGN group than in PFNA group ( P<0.05); but no significant difference was found between 2 groups when the reposition effect was the neutral position cortex support or negative medial cortex support ( P>0.05). At 18 months after operation, the X, Y, and Z values of the negative medial cortex support patients were significantly higher than those of the positive medial cortex support or the neutral position cortex support patients within 2 groups ( P<0.05).

Conclusion

PFS is a common complication of the intertrochanteric fracture of the femur after internal fixation. During operation, the selection of internal fixation should be based on the results of intraoperative reduction. TGN should be applied to reduce PFS if positive medial cortex support happened.