Clustering of morphological fracture lines for identifying intertrochanteric fracture classification with Hausdorff distance-based K-means approach

Six-Part Classification of Femoral Intertrochanteric Fractures: A Classification Method to Improve the Diagnosis Rate of Unstable Fractures

OBJECTIVE

Three-dimensional (3D)-CT data is currently insufficient for classifying femoral trochanter fractures. Fracture classification based on fracture stability analysis is helpful to evaluate the prognosis of patients after internal fixation. Currently, there is a lack of fracture classification methods based on 3D-CT images and fracture stability analysis. The aim of this study was to propose a new six-part classification method for intertrochanteric fractures of femur based on 3D-CT images and fracture stability analysis to improve the diagnosis rate of unstable fractures.

METHOD

From January 2009 to December 2019, 320 patients receiving intramedullary nail surgery for femoral intertrochanteric fractures at Chengdu University's Affiliated Hospital were studied retrospectively. AO and six-part classifications were undertaken according to the 3D-CT image data of the patients, and the stability rates of two classifications were compared. According to the six-part classification stability criteria, the patients were divided into a stable and an unstable fracture group. The perioperative and follow-up indicators of the two groups were statistically analyzed, and the six-part classification's inter-observer and internal reliability was examined.

RESULTS

There were 107 men and 213 females women the 320 patients, with an average age of 79.32 ± 11.26 years and an osteoporosis rate of 55.63% (178/320). The fracture stability rate of 39.69% (127/320) was studied using a six-part classification method. The AO classification fracture stability rate was 42.50% (136/320), with no significant difference (χ2  = 0.523, p = 0.470 > 0.05). There is no statistically significant difference between the two classification techniques in the examination of fracture stability (McNemer difference test p = 0.306 > 0.05; Kappa consistency test p < 0.001). According to the six-part classification, fracture stability and instability group were divided into two groups. The following indicators were compared between the two groups: The surgery time (p = 0.280), fracture reduction quality (p = 0.062); function independent measurement (p = 0.075); timed up and go test (TUG) (p = 0.191), and Parker-Palmer score (p = 0.146). Were as compared according to the six-part classification of stable and unstable fracture groups. Perioperative blood loss (p < 0.001), the Harris score excellent and good rate (p = 0.043), fracture healing time (p < 0.001), and the entire weight-bearing duration (p = 0.002) were statistically significant. The difference in femoral head height (FHH) (p = 0.046), the change in femoral neck shaft angle (p = 0.003), the change in medial cephalic nail length (p = 0.033), and the change in tip-apex distance (TAD) (p = 0.002) were statistically significant compared to the relevant markers of imaging stability. Fracture stability had a substantial influence on Harris ratings at 3, 6, and 12 months following surgery, according to repeated measures analysis of variance (F(1,126)  = 32.604, p < 0.001). The effect of time on the Harris score was similarly significant (F(1.893,238.508)  = 202.771, p < 0.001). The observer intra-observer inter-group correlation coefficient (ICC) value was 0.941 > 0.75, the inter-observer ICC value was 0.921 > 0.75, and the intra-observer and inter-observer reliability were both good.

CONCLUSION

The six-part classification of femoral intertrochanteric fractures based on 3D-CT images has broader guiding relevance for femoral intertrochanteric fracture stability analysis. Clinicians will find this classification simpler and more consistent than the AO classification.

The remnant axial cortical length of the proximal femur in pertrochanteric fractures: a three-dimensional computed tomography study and its clinical implications

BACKGROUND

Cortical buttress are important factors for postoperative stable reconstruction of per/inter-trochanteric fractures. The study aimed to measure the remnant axial cortical length (RACL) of the proximal circumference of the femur, and to determine which part of the RACL can be used reliably to postoperatively sustain the head-neck fragment as a cortical support pattern.

METHODS

Eighty patients with trochanteric hip fractures admitted from January 2015 to January 2016 were included in a retrospective study. Their pre-operative computed tomography (CT) images were used to form 3D-CT reconstructions via Mimics software. After simulated rotation and movement for fracture reduction, the RACL, its three component parts-namely, the remnant anterior cortex (RAC), remnant lateral cortex (RLC), and remnant posterior cortex (RPC) -the γ angle between the anterior and posterior cortex, and the Hsu's lateral wall thickness (LWT) were evaluated.

RESULTS

Patients with an A1 fracture (21/80) had a longer RACL (88.8 ± 15.8 mm) than those with an A2 fracture (60.0 ± 11.9 mm; P < 0.01). The RAC, RLC, and RPC of the RACL in A1 fractures were also significantly longer than those in A2 fractures (P < 0.001). However, the most significant difference among the three components of the RACL was in the RPC, which was 27.3 ± 7.8 mm in A1 fractures and 9.2 ± 6.6 mm in A2 fractures. In addition, the coefficient of variation of the RAC was only 20.0%, while that of the RPC was 75.5%. The average γ angle in A1 fractures was 16.2 ± 13.1°, which was significantly smaller than that in A2 fractures, which was 40.3 ± 14.5° (P < 0.001). There was a significant statistical difference in the LWT between A1 and A2 fractures (P < 0.001). There were significant differences in the RACL, RAC, RLC, RPC, γ angle, and LWT among the five subtypes (P < 0.001).

CONCLUSIONS

The RAC is relatively stable in pertrochanteric fractures. Fracture reduction through a RAC buttress may help to enhance the postoperative stable reconstruction of per/inter-trochanteric fractures and make possible good mechanical support for fracture healing.

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

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

The PFNA in treatment of intertrochanteric fractures with or without lateral wall fracture in elderly patients: a retrospective cohort study

BACKGROUND

There is no consensus about intertrochanteric fractures with lateral wall treated with intramedullary nail-proximal femoral nail antirotation (PFNA). The aim of the present study was to compare function outcomes between lateral wall and no lateral wall fractures after surgery by PFNA.

METHODS

This retrospective study evaluated patients with or without lateral wall fractures who underwent PFNA between January 2015 and June 2018. The operative time, intraoperative blood loss, time to fracture healing, complications and functional outcomes qualified by Harris hip score and Parker - Palmer mobility score (PPMS) were compared between the two groups.

RESULTS

Two groups were comparable with regard to patient age, sexual distribution, mechanism of injury, fracture type, body mass index (BMI), Time to surgery, American Society of Anesthesiologists (ASA) score and quality of reduction. The incomplete group had a longer operation time (54.1 ± 8.74 min vs. 51.0 ± 9.86 min) and more intraoperative blood loss (228.4 ± 48.8 ml vs. 151.3 ± 43.5 ml) in comparison with the control group (P < 0.01). Regarding functional outcome, the HHSs of the two groups were 76.2 ± 11.6 vs 75.6 ± 12.5 at the 3 months (P = 0.603), 81.9 ± 9.4 vs 82.6 ± 8.7 at the six months (P = 0.224), 83.8 ± 6.6 vs 84.5 ± 6.0 at the twelve months 85.2 ± 5.5 vs 86.0 ± 5.8 at the twenty-four months (P > 0.05), respectively. Similar results were obtained about PPMS. We found no difference in Weight bearing time, Time of fracture healing, and Complications between incomplete group and intact group.

CONCLUSIONS

There is no substantial difference in functional results or complication rates for intertrochanteric fractures with lateral wall fractures, except from increased blood loss and operation time. We believe that an intramedullary nail will be sufficient to repair an intertrochanteric fracture with or without a lateral wall fracture.

Dynamic evaluation of the sternoclavicular and acromioclavicular joints using an upright four-dimensional computed tomography

In the analysis of the shoulder complex, the sequential changes occurring in the sternoclavicular and acromioclavicular joints during active shoulder motion are challenging to track. This study aimed to investigate the in vivo sternoclavicular and acromioclavicular joint motions during active elevation, including the sequential changes in these joint spaces using upright four-dimensional computed tomography (4DCT). Bilateral shoulders of 12 healthy volunteers upright 4DCT were obtained during active elevation similar to a "hands up" motion. The sternoclavicular and acromioclavicular rotation angles, joint distances, and closest points on the clavicle relative to the thorax and scapula were evaluated during 10°-140° of humerothoracic elevation. During humerothoracic elevation, the clavicle elevated, retracted, and rotated posteriorly relative to the thorax, whereas the scapula rotated upwardly, internally, and posteriorly relative to the clavicle. All the sternoclavicular and acromioclavicular joint rotation angles were significantly different at ≥ 30°-50° of humerothoracic elevation compared with 10° of humerothoracic elevation. The mean sternoclavicular and acromioclavicular joint distances were 2.2 ± 1.1 mm and 1.6 ± 0.9 mm, respectively. The closest points were located on the anteroinferior part of the medial and lateral clavicle in the sternoclavicular and acromioclavicular joints, respectively. Significant differences were observed in the acromioclavicular joint distance and anterior/posterior movements of the closest points in the sternoclavicular and acromioclavicular joints compared with 10° of humerothoracic elevation. Our sternoclavicular and acromioclavicular closest point results indicate that the impingement tends to occur at the anteroinferior part of the medial and lateral aspects of the clavicle and may be related to osteoarthritis.

Pathoanatomy of pertrochanteric fractures - a postmortem study

BACKGROUND

Recent pathoanatomic studies based on 3D CT reconstructions have questioned validity of AO/OTA classification because it does not reflect the reality and requires revision. These 3D CT studies, however, do not allow analysis of all details. Therefore, we have exploited the possibility to analyze the pathoanatomy of pertrochanteric fractures on postmortem specimens.

MATERIAL AND METHODS

From the collection of the Institute of Anatomy, the authors obtained 16 specimens of hip joints of individuals who had sustained a pertrochanteric fracture and died within 30 days of the injury, with anteroposterior radiographs of the injured hip available in all of them. The number of major fragments and their shape, and the courses of the main fracture lines were studied.

RESULTS

Three major fragments (a proximal head and neck fragment, a distal diaphyseal fragment and a posterior flat fragment), separated by three types of fracture lines (primary, secondary and tertiary lines) were identified. The primary line separated the proximal fragment (head and neck) from the distal diaphyseal fragment. The secondary fracture line separated the posterior flat fragment from the distal diaphyseal fragment. The tertiary fracture line split the posterior fragment into two parts. A key factor for fracture instability is the defect of the posterior cortex, which depends on the size and shape of the posterior fragment. Avulsion of the lesser trochanter and the adjacent cortex results in an unstable configuration of fracture lines on the medial side, while on the lateral side a large posterior fragment weakens the lateral trochanteric wall.

CONCLUSION

In agreement with recent CT studies, the findings of this pathoanatomical study change, in a number of aspects, the traditional view of the pathoanatomy and classification of pertrochanteric fractures, and introduces the concept of three, instead of the traditional four, main fragments.

Predicting Corrosion Damage in the Human Body Using Artificial Intelligence: In Vitro Progress and Future Applications

Artificial intelligence (AI) is used in the clinic to improve patient care. While the successes illustrate AI's impact, few studies have led to improved clinical outcomes. In this review, we focus on how AI models implemented in nonorthopedic fields of corrosion science may apply to the study of orthopedic alloys. We first define and introduce fundamental AI concepts and models, as well as physiologically relevant corrosion damage modes. We then systematically review the corrosion/AI literature. Finally, we identify several AI models that may be implemented to study fretting, crevice, and pitting corrosion of titanium and cobalt chrome alloys.

Prediction of osteoporosis from proximal femoral cortical bone thickness and Hounsfield unit value with clinical significance

Background

Utilizing dual-energy x-ray absorptiometry (DXA) to assess bone mineral density (BMD) was not routine in many clinical scenarios, leading to missed diagnoses of osteoporosis. The objective of this study is to obtain effective parameters from hip computer tomography (CT) to screen patients with osteoporosis and predict their clinical outcomes.

Methods

A total of 375 patients with hip CT scans for intertrochanteric fracture were included. Among them, 56 patients possessed the data of both hip CT scans and DXA and were settled as a training group. The cortical bone thickness (CTh) and Hounsfield unit (HU) values were abstracted from 31 regions of interest (ROIs) of the proximal femur. In the training group, the correlations between these parameters and BMD were investigated, and their diagnostic efficiency of osteoporosis was assessed. Finally, 375 patients were divided into osteoporotic and nonosteoporotic groups based on the optimal cut-off values, and the clinical difference between subgroups was evaluated.

Results

The CTh value of ROI 21 and the HU value of ROI 14 were moderately correlated with the hip BMD [r = 0.475 and 0.445 (p < 0.001), respectively]. The best diagnostic effect could be obtained by defining osteoporosis as CTh value < 3.19 mm in ROI 21 or HU value < 424.97 HU in ROI 14, with accuracies of 0.821 and 0.883, sensitivities of 84% and 76%, and specificities of 71% and 87%, respectively. The clinical outcome of the nonosteoporotic group was better than that of the osteoporotic group regardless of the division criteria.

Conclusion

The CTh and HU values of specific cortex sites in the proximal femur were positively correlated with BMD of DXA at the hip. Thresholds for osteoporosis based on CTh and HU values could be utilized to screen osteoporosis and predict clinical outcomes.

Finite-Element Analysis of a Novel Cephalomedullary Nail for Restricted Sliding to Reduce Risk of Implant Failure in Unstable Intertrochanteric Fractures

Objective

How to restrict sliding of cephalomedullary nail and rigid reconstruct medial support for unstable intertrochanteric fractures remains a challenge. This study aims to explore the feasibility of a novel cephalomedullary nail for restriction sliding and reconstruction of medial femoral support to prevent failure in unstable trochanteric fractures through finite element analysis.

Methods

The DICOM files of a unilateral femur spiral computed tomography (CT) scans from a elderly female were converted into STL files, and the most common clinical trochanteric fracture model with the absence of medial support, AO/OTA 31‐A2.3 was simulated by removing the posterior medial femur. The model of a novel medial sustain nail (MSN‐II) and a widely used nail (proximal femoral nail anti‐rotation PFNA‐II) were modeled according to the manufacturer‐provided engineering drawing. Different loads were applied to the femoral head to simulate the postoperative weight bearing gait. The sliding distance of helical blade in femoral neck, maximum stress of femur and nail, displacement of proximal fragment were analyzed to revealing the mechanical stability of unstable trochanteric fracture stabilized by different implant.

Results

The sliding distance of helical blade in the femoral neck, the maximum stress on the femur and nail, the displacement of proximal fragment in MSN‐II under 2100N axial load were 0.65 mm, 689 MPa, 1271 MPa, 16.84 mm respectively, while that were 1.43 mm, 720.8 MPa, 1444 MPa, 18.18 mm, respectively in PFNA‐II. The difference between the two groups was statistically significant (P < 0.05) and the stress was mainly distributed in medial distal side of nail but helical blade and the proximal aperture for the nail in MSN‐II. Compared to PFNA‐II, MSN‐II demonstrates biomechanical merit against femur medialization, cut‐out and coax varus.

Conclusion

The sliding distance of helical blade in femoral neck, the maximum stress on the femur and nail, and the displacement of proximal fragment of MSN‐II were less than those of PFNA‐II in the treatment of unstable intertrochanteric fractures. Therefore MSN‐II has better stability than PFNA‐II and it may have the potential to avoid femur medialization and cut out. It might be an option in unstable trochanteric fracture because of its superiority in restricted sliding and medial support reconstruction.

[Proposal of a novel comprehensive classification for femoral intertrochanteric fractures]

OBJECTIVE

To introduce a novel comprehensive classification for femoral intertrochanteric fractures, and to accommodate the clinical requirement for the world-wide outbreak of geriatric hip fractures and surgical operations.

METHODS

On the basis of reviewing the history of classification of femoral intertrochanteric fractures and analyzing the advantages and disadvantages of AO/Orthopaedic Trauma Association (AO/OTA) classification in different periods, combined with the current situation of extensive preoperative CT scan and three-dimensional reconstruction and widespread use of intramedullary nail fixation in China, the "Elderly Hip Fracture" Research Group of the Reparative and Reconstructive Surgery Committee of the Chinese Rehabilitation Medical Association proposed a novel comprehensive classification for femoral intertrochanteric fractures, focusing on the structure of fracture stability reconstruction during internal fixation.

RESULTS

The novel comprehensive classification of femoral intertrochanteric fractures incorporates multiple indicators of fracture classification, including the orientation of the fracture line, the degree of fracture fragmentation, the lesser trochanteric bone fragment and its distal extension length (>2 cm), the posterior coronal bone fragment and its anterior extension width (involving the lateral cortex of the head and neck implant entry point), transverse fracture of the lateral and anterior wall and its relationship with the implant entry point in the head and neck, and whether the cortex of the anteromedial inferior corner can be directly reduced to contact, etc. The femoral intertrochanteric fractures are divided into 4 types (type A1 is simple two-part fractures, type A2 is characterized by lesser trochanter fragment and posterior coronal fractures, type A3 is reverse obliquity and transverse fractures, type A4 is medial comminution which lacks anteromedial cortex transmission of compression force), each of which is subdivided into 4 subtypes and further subdivide into finer subgroups. In a review of 550 trochanteric hip fracture cases by three-dimensional CT, type A1 accounted for 20.0%, type A2 for 62.5%, type A3 for 15.5%, and type A4 for 2.0%, respectively. 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 cortical expansion of the posterior coronal fragment 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

The novel comprehensive classification of femoral intertrochanteric fractures can describe the morphological characteristics of fractures in more detail, include more rare and complex types, provide more personalized subtype selection, and adapt to the clinical needs of both fractures and surgeries.

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.

What’s new in artificially intelligent joint surgery in China? The minutes of the 2021 IEEE ICRA and literature review

Objective

To outline the main results of the 2021 International Conference on Robotics and Automation (ICRA 2021) of the Institute of Electrical and Electronics Engineers (IEEE) and review the advances in artificially intelligent joint surgery in China.

Methods

The keynote speeches of the 2021 ICRA were summarized in detail, and publications indexed by five core electronic databases (PubMed, Cochrane, Medline, Embase and CNKI) were systematically surveyed (cutoff date: July 30, 2021) in terms of the main topics of the conference. Publications directly related to artificially intelligent joint surgery in China were identified by using the search strategies of (robotic AND arthroplasty OR replacement), (navigation AND arthroplasty OR replacement), (artificial intelligent AND arthroplasty OR replacement), and (mixed reality AND arthroplasty OR replacement) and systemically reviewed.

Results

While robot-assisted arthroplasty in China is mainly performed using robots made in other countries (e.g., Mako from Stryker, USA), China’s domestic R&D of robots and clinical studies of robotic joint surgery have made some achievements. Although reports on the safety, effectiveness and clinical efficacy of China’s domestic robot-assisted joint surgery were presented at conferences, they have rarely been published in journals. Existing data indicate that, after the learning curve is overcome, robot-assisted hip and knee replacement surgery can fully achieve the established goals of precision and individualization and can significantly improve the accuracy of prosthesis placement angle and the recovery of the mechanical axis as compared with conventional surgery. The downside is that the low level of intelligentization and individualization means that existing designs are not conducive to personalization during surgery, resulting in low cost-effectiveness.

Conclusion

The safety and efficacy of domestic robot-assisted arthroplasty in China are well documented, and its accuracy and short-term clinical efficacy have been reported. However, the long-term clinical efficacy and the cost-effectiveness of large-scale clinical application of this technique warrants further study. The inadequacies of robot-assisted surgery should be remedied through the deep integration of medicine, engineering and the network.

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.

[Patterns and research progress on the concomitant ipsilateral fractures of intracapsular femoral neck and extracapsular trochanter]

OBJECTIVE

To summarize the patterns and research progress of the concomitant ipsilateral fractures of intracapsular femoral neck and extracapsular trochanter, and to provide a common language among orthopedic surgeons for scientific exchange.

METHODS

According to related literature and authors own experiences concerning the anatomic border between femoral neck and trochanter region, the intertrochanteric line (or intertrochanteric belt) and its capsularligament attachment footprint, fracture patterns, and treatment strategies were reviewed and analyzed.

RESULTS

With the rapid growing of geriatric hip fractures, an increased incidence was noted in recent years regarding the proximal femoral comminuted fractures that involving ipsilateral intracapsular neck and extracapsular trochanter regions simultaneously. But the concept of femoral neck combined with trochanter fractures was ambiguous. Based on the anatomic type of femoral neck fracture, the location of fracture center, and the ability to achieve direct inferior calcar or anteromedial cortex-to-cortex apposition and buttress, we classified these complex fractures into 3 sub-types: ① Segmental femoral neck fractures (two separate fracture centers at subcapital and trochanteric region respectively); ② Femoral neck fracture (trans-cervical) with extension to the supero-lateral trochanteric region (fracture center in femoral neck); ③ Trochanteric fracture with extension to the medio-inferior femoral neck region (fracture center in trochanter, comminuted basicervical fracture, or variant type of comminuted trochanter fracture). For treatment strategy, surgeons should consider the unique characteristics of femoral neck and trochanter, usually with combined fixation techniques, or arthroplasty supplemented with fixation.

CONCLUSION

Currently there is no consensus on diagnosis and terminology regarding the concomitant ipsilateral fractures of femoral neck and trochanter. Further studies are needed.

The effect of orthopedic screw profiles on the healing time of femoral neck fracture

One possible treatment for femoral neck fractures, especially in young people, is the use of bone screws or Lug screws. The design of these implants requires taking into account the biocompatibility of materials, mechanical properties plus surface properties, and thread's geometric, as well as chemical properties, etc. Various profiles are designed for fracture fixation. The most famous of these profiles, which are introduced by the ISO standard, are HB, HC, and HD type profiles. This article investigates the performance of these profiles in reducing or increasing the healing time. This study is based on the rule of bone remodeling and using a set of three-dimensional computational (finite element) models. The study revealed that the HB profile outperformed the other two profiles. Meanwhile, HD profile was also better than HC profile.

The Effect of Integrity of Lateral Wall on the Quality of Reduction and Outcomes in Elderly Patients with Intertrochanteric Fracture: A Controlled Study

Objective

The study is aimed at evaluating the effect of the integrity of lateral wall on the quality of reduction and outcome in intertrochanteric fracture treated with proximal femoral nail antirotation (PFNA).

Methods

Medical record systems for elderly patients with intertrochanteric fracture treated with PFNA were included. The patients were divided into incompetent and intact lateral wall groups. Patients' baseline characteristics, quality of reduction, and Harris Hip scores (HHS) were collected.

Results

The study included 115 patients with intertrochanteric fractures, with 59 in the incompetent lateral wall group and 56 in the intact group. Lateral wall thickness was 16.47 ± 2.46 mm and 23.68 ± 1.59 mm in the incompetent group and intact group (t = -18.766, P < 0.001), respectively. There was no significant difference in the quality of reduction (P = 0.646) between intact and incompetent groups. Mean HHS at final follow-up were 83.02 ± 13.89 in the incompetent group and 86.04 ± 3.39 in the intact group, with no significant difference (P = 0.123). In addition, there was no significant difference in weight-bearing or clinical healing between intact and incompetent groups. The partial weight-bearing with crutches was allowed at 2.71 ± 0.93 and 2.66 ± 1.01 weeks after the operation in the incompetent and intact groups. Time to clinical healing was 5.83 ± 0.99 and 6.00 ± 0.92 months in the incompetent and intact groups, respectively. However, the operative time in the incompetent group (58.54 ± 18.14 mins) were longer than that in the intact group (51.79 ± 17.77 mins).

Conclusions

In conclusion, it seems that lateral wall thickness does not affect the quality of reduction and outcome in patients with intertrochanteric fracture receiving PFNA.

Classification of femur trochanteric fracture: Evaluating the reliability of Tang classification

INTRODUCTION

Given the drawbacks of a femoral intertrochanteric fracture classification based on 2-dimensional radiographic imaging, an artificial intelligence-based classification system- the Tang classification system-which uses 3-dimensional image analysis, has previously been developed. This study explored the reliability of the Tang classification by comparing the consistency of this classification with the conventional 2-dimensional femoral intertrochanteric fracture classification systems.

METHODS

X-ray and computed tomography (CT) data of 258 patients with femoral intertrochanteric fractures were classified by 6 orthopedic surgeons using the Evans, Jensen, AO/OTA, and Tang classification systems on 2 separate occasions, 1 month apart. Kappa statistics were used to evaluate the inter- and intraobserver differences in classifications.

RESULTS

When the interobserver reliability was based on X-ray image analysis, the Kappa values for the Evans, Jensen, AO/OTA, and Tang classifications were 0.54 ± 0.03 (moderate agreement), 0.53 ± 0.02 (moderate agreement), 0.46 ± 0.02 (moderate agreement), and 0.63 ± 0.02 (substantial agreement), respectively. When the interobserver reliability was based on CT images, the Kappa values of the Evans, Jensen, AO/OTA, and Tang classifications were 0.49 ± 0.03 (moderate agreement), 0.49 ± 0.03 (moderate agreement), 0.44 ± 0.03 (moderate agreement), 0.64 ± 0.02 (substantial agreement), respectively. For X-ray images, the intraobserver Kappa values for the Evans, Jensen, AO/OTA, and Tang classification were 0.53 ± 0.02 (moderate agreement), 0.54 ± 0.03 (moderate agreement), 0.45 ± 0.03 (moderate agreement), and 0.65 ± 0.03 (substantial agreement), respectively. When intraobserver reliability was based on CT images, the Kappa values for the Evans, Jensen, AO/OTA, and Tang classification were 0.52 ± 0.03 (moderate agreement), 0.52 ± 0.02 (moderate agreement), 0.41 ± 0.02 (moderate agreement), and 0.63 ± 0.03(substantial agreement), respectively.

CONCLUSIONS

The current study suggests that the Tang classification system is more reliable than the Evans, Jensen, and AO/OTA classification systems for measuring intertrochanteric fractures of the proximal femur.

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.

3D object reassembly using region-pair-relation and balanced cluster tree

BACKGROUND AND OBJECTIVE

Object reassembly is a key technology in scenarios such as surgical planning and broken object restoration. Based on previous research, this work intends to explore the general tasks of 3D object reassembly, including conventional object reconstruction and bone fracture reduction.

METHODS

We introduce an efficient and robust region-pair-relation descriptor, which incorporates strong geometric constraints and remains invariant to rotation and translation. We segment the fractured objects using balanced cluster tree, and develop a coarse-to-fine method for object reassembly. The matching quality of potential region contact pairs at different depths is estimated recursively from the root of the tree. Once the best contact pairs are determined, the least squares method is implemented to obtain the matching results. In addition, we also provide a semi-interactive manipulation to deal with the complex objects.

RESULTS

For most types of broken objects, our approach can generate high accuracy matching results within 10 s, with the cluster tree depth equals to 11. It allows the automatic reassembly of different-sized fragments. For bone fracture blocks with cancellous structures, a semi-interactive operation is integrated so that the precise matching can also be achieved in 30 s.

CONCLUSION

The proposed framework can be expanded to various object reassembly tasks in either automated or semi-automated manner, including the fracture reduction problem which used to be an intensive manual process. Therefore, our work shows significant advantages in medical applications.

Simple guidelines for evaluating intraoperative alignment after the reduction of intertrochanteric fractures

The incidence of intertrochanteric femoral fractures has rapidly increased with the extended lifespan of the elderly population. Surgery enables early ambulation by achieving anatomic reduction and stable internal fixation. However, reduction usually involves postoperative evaluation. Here, we present reliable parameters obtained from analyses of three-dimensional computed tomography images from cadavers to serve as guidelines during the reduction of intertrochanteric fractures. We included 184 three-dimensional modeling samples from cadavers placed in two standardized positions, similar to C-arm imaging. We recorded the level of the orthogonal line from the greater trochanter (GT) tip to the femoral head (GT orthogonal line [GTOL]) in the anteroposterior view and the line along the anterior femoral cortex passing through the femoral head (anterior cortical line) in the axial view. Correlations between these lines and angular alignments were statistically determined. The GTOL passed above the femoral head center at mean 2.36 mm in all patients; 77.17% of such instances were in the upper second quadrant of the femoral head. The anterior cortical line passed under the femoral head center at mean 10.82 mm; 73.37% of such instances were in the inferior one-third of the femoral head. Consistent correlations were found between the GTOL and neck-shaft angle and between the anterior cortical line and anteversion. The GTOL and anterior cortical line passed through a constant level of the femoral head in most samples and were correlated with angular alignments. The intraoperative use of these simple imaginary lines improves the intertrochanteric fracture reduction quality.

Evaluation of three-dimensional acromiohumeral distance in the standing position and comparison with its conventional measuring methods

Background

Narrowing of the acromiohumeral distance (AHD) implies a rotator cuff tear. However, conventional AHD measurements using two-dimensional (2D) imaging or with the patient in the supine position might differ from that while standing during daily activity. This study aimed to evaluate the three-dimensional (3D) actual distance between the acromion and humeral head in the standing position and compare the AHD values with those obtained using conventional measuring methods.

Methods

Computed tomography (CT) images of 166 shoulders from 83 healthy volunteers (31 male and 52 female; mean age 40.1 ± 5.8 years; age range, 30–49 years) were prospectively acquired in the supine and standing positions using conventional and upright CT scanners, respectively. The minimum distance between the acromion and humeral head on the 3D surface models was considered as the 3D AHD. We measured the 2D AHD on anteroposterior digitally reconstructed radiographs. The AHD values were compared between the supine and standing positions and between the 2D and 3D measurements.

Results

The mean values of 2D AHD were 8.8 ± 1.3 mm (range, 5.9–15.4 mm) in the standing position and 8.1 ± 1.2 mm (range, 5.3–14.3 mm) in the supine position. The mean values of 3D AHD were 7.3 ± 1.4 mm (range, 4.7–14.0 mm) in the standing position and 6.6 ± 1.2 mm (range, 4.4–13.7 mm) in the supine position. The values of 3D AHD were significantly lower than those of 2D AHDs in both the standing and supine positions (P < 0.001). The values of 2D and 3D AHDs were significantly lower in the supine position than in the standing position (P < 0.001).

Conclusions

This study evaluated the 3D AHD of normal shoulders in the standing position using an upright CT scanner. The present results indicated that assessments in the supine position can underestimate the value of the AHD compared with those made in the standing position and that assessments using 2D analysis can overestimate the value.

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.