Biomechanical efficacy of four different dual screws fixations in treatment of talus neck fracture: a three-dimensional finite element analysis

A rare combination of talar neck fracture (Hawkins 3) and bimalleolar ankle fracture: A case report

INTRODUCTION

The combination of talar neck fractures with malleolar fractures is a rare. This rare association accounts for 0.3 % of all bone fractures. We describe a one-of-a-kind ankle dislocation with a talar neck fracture and a bimalleolar fracture.

CASE PRESENTATION

A 24-year-old male patient presented to the emergency department after a traffic accident. A physical examination revealed swelling and tenderness in the left ankle. The radiograph and the CT scan showed a Hawkins type III comminuted talar neck fracture, with an oblique fracture of the medial malleolus and an infra-syndesmotic fracture of the lateral malleolus. The patient underwent open reduction and internal fixation involving screw fixation for talar neck fracture and the medial malleolus and plating for the lateral malleolus. The treatment and post-operative follow-up showed successful healing and functional recovery, with a score of 85 on the American Orthopedic Foot and Ankle Society ankle-hindfoot at the last follow up.

DISCUSSION

The discussion includes insights on the rarity of this fracture combination, treatment challenges, and potential complications such as avascular necrosis. This article emphasizes the importance of achieving anatomical reduction and stable fixation for optimal outcomes in such complex fractures.

CONCLUSION

This case report highlights the successful treatment of a rare combination of talar neck and bimalleolar ankle fractures, emphasizing the importance of anatomical reduction and stable fixation for optimal outcomes in complex fractures.

Influence of Surgical Approach and Fixation on Complications in Talus Fractures: A Multicenter Review

Fractures of the talus are infrequent injuries often associated with substantial morbidity and imperfect outcomes. We undertook a retrospective review of talus fractures at multiple level 1 trauma centers in order to identify common treatment patterns and potential predictors of complications. All cases of talar fractures meeting inclusion criteria at our institution were reviewed. 54 of 103 talus fractures met inclusion criteria. 33 (61.1%) involved the talar neck, 13 (24.1%) the talar body, and 6 (9.2%) involved the lateral process. The most common etiology was motor vehicle accidents, accounting for 27 (50.0%). Mean follow up was 13.6 months (range 8-52 months). 37 (68.5%) fractures were fixated with screws, and 17 (31.5%) were fixated with a plate construct. Single and dual incisions were used in 63.0% and 25.9% of cases, respectively. Complications were seen in 46.3% of cases, with post-traumatic osteoarthritis being the most common complication (35.1%). Avascular necrosis occurred in 4 (7.4%) patients. No independent variables met the statistical threshold to be associated with complications. The present data alludes to possibility of over-reporting complications due to historical literature and the need for further studies.

Biomechanical study of different bone cement distribution on osteoporotic vertebral compression Fracture-A finite element analysis

Purpose

This study aimed to compare the biomechanical effects of different bone cement distribution methods on osteoporotic vertebral compression fractures (OVCF).

Patients and methods

Raw CT data from a healthy male volunteer was used to create a finite element model of the T12-L2 vertebra using finite element software. A compression fracture was simulated in the L1 vertebra, and two forms of bone cement dispersion (integration group, IG, and separation group, SG) were also simulated. Six types of loading (flexion, extension, left/right bending, and left/right rotation) were applied to the models, and the stress distribution in the vertebra and intervertebral discs was observed. Additionally, the maximum displacement of the L1 vertebra was evaluated.

Results

Bone cement injection significantly reduced stress following L1 vertebral fractures. In the L1 vertebral body, the maximum stress of SG was lower than that of IG during flexion, left/right bending, and left/right rotation. In the T12 vertebral body, compared with IG, the maximum stress of SG decreased during flexion and right rotation. In the L2 vertebral body, the maximum stress of SG was the lowest under all loading conditions. In the T12-L1 intervertebral disc, compared with IG, the maximum stress of SG decreased during flexion, extension, and left/right bending and was basically the same during left/right rotation. However, in the L1-L2 intervertebral discs, the maximum stress of SG increased during left/right rotation compared with that of IG. Furthermore, the maximum displacement of SG was smaller than that of IG in the L1 vertebral bodies under all loading conditions.

Conclusions

SG can reduce the maximum stress in the vertebra and intervertebral discs, offering better biomechanical performance and improved stability than IG.

Comparison of different internal fixation implants in the treatment of talar neck fractures: A finite element analysis

OBJECTIVES

This study aimed to analyze the biomechanics of cannulated screws (CS) with or without a lateral locking plate (LLP) in talar neck fractures through a finite element analysis.

PATIENTS AND METHODS

The computed tomography image of the talus from a healthy volunteer (adult male) was used to reconstruct a three-dimensional talar model. The method for fixing talar neck fractures with CS and an LLP was planned using computer-aided design software. Afterward, the three-dimensional models of comminuted talar neck fractures were used to simulate fixation with anteroposterior parallel dual CS, single CS+LLP, and dual CS+LLP. Finally, finite element analysis was carried out to compare the outcomes of dual CS+LLP to those of single CS+LLP and to those of using dual CS alone. The displacement and von Mises stress values of the three groups with different internal fixation were analyzed.

RESULTS

For a simple talar neck fracture, the lowest amount of displacement was obtained with CS+LLP (0.407 mm), while dual CS (0.459 mm) showed the highest amount of total displacement; the lowest amount of peak stresses was obtained with CS+LLP (5.38 MPa), while dual CS (8.749 MPa) showed the highest amount of total peak stresses. For a comminuted talar neck fracture, the lowest amount of displacement was obtained with CS+LLP (0.398 mm), while dual CS (0.408 mm) showed the highest amount of total displacement; the lowest amount of peak stresses was obtained with CS+LLP (129.9 MPa), while dual CS (205.9 MPa) showed the highest amount of peak stresses.

CONCLUSION

Compared to the other two groups, the dual CS+LLP group had better biomechanics properties in the displacement and stress peak of the talus and implant. Thus, the use of dual CS+LLP fixation is recommended for the surgical treatment of comminuted talar neck fractures.

[Effectiveness analysis of percutaneous parallel screw fixation via posterolateral "safe zone" for Hawkins type - talar neck fractures]

Objective

To explore the effectiveness of the percutaneous parallel screw fixation via the posterolateral "safe zone" for Hawkins type Ⅰ-Ⅲ talar neck fractures.

Methods

A retrospective analysis was conducted on the clinical data from 35 patients who met the selection criteria of talar neck fractures between January 2019 and June 2021. According to the surgical method, they were divided into a study group (14 cases, using percutaneous posterolateral "safe zone" parallel screw fixation) and a control group (21 cases, using traditional open reduction and anterior cross screw internal fixation). There was no significant difference in gender, age, affected side, Hawkins classification, and time from injury to operation between the two groups ( P>0.05). The operation time, bone healing time, complications, and Hawkins sign were recorded, and the improvement of pain and ankle-foot function were evaluated by visual analogue scale (VAS) score and American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score at last follow-up. The overall quality of life was assessed by the short form of 12-item health survey (SF-12), which was divided into physical and psychological scores; and the satisfaction of patients was evaluated by the 5-point Likert scale.

Results

The operation time in the study group was significantly shorter than that in the control group ( P<0.05). All patients werefollowed up 13-35 months, with an average of 20.6 months; there was no significant difference in the follow-up time between the two groups ( P>0.05). The time of bone healing in the study group was shorter than that in the control group, and the positive rate of Hawkins sign (83.33%) was higher than that in the control group (33.33%), and the differences were significant ( P<0.05). In the control group, there were 2 cases of incision delayed healing, 7 cases of avascular necrosis of bone, 3 cases of joint degeneration, 1 case of bone nonunion, and 3 cases of internal fixation irritation; while in the study group, there were only 2 cases of joint degeneration, and there was a significant difference in the incidence of complications between the two groups ( P<0.05). At last follow-up, there was no significant difference in VAS score between the two groups ( P>0.05), but the SF-12 physical and psychological scores, AOFAS ankle and hindfoot scores, and patients' satisfaction in the study group were significantly better than those in the control group ( P<0.05).

Conclusion

The treatment of Hawkins type Ⅰ-Ⅲ talar neck fractures with percutaneous parallel screw fixation via the posterolateral "safe zone" can achieve better effectiveness than traditional open surgery, with the advantages of less trauma, fewer complications, faster recovery, and higher patient satisfaction.

Fragility fracture of talar neck in an osteoporotic patient treated by posterior-to-anterior screw fixation under hindfoot endoscopy: a case report

Fragility fractures of the talar neck are extremely rare. Here, we describe a case of fragility fracture of the talar neck associated with osteoporosis in a 76-year-old female, who was treated by posterior-to-anterior screw fixation under hindfoot endoscopy. A 76-year-old female cleaner with a history of osteoporosis complained of pain in her right ankle when going downstairs. Radiological findings revealed a fragility fracture of the talar neck associated with osteoporosis. Because the patient was elderly and it was difficult to treat using a prolonged non-weight-bearing cast, we performed a posterior-to-anterior parallel dual screw fixation under hindfoot endoscopy for this case. As a result, the patient was able to return to work 8 weeks after surgery without pain, dysfunction or complication. Osteosynthesis with posterior-to-anterior screw fixation under hindfoot endoscopy successfully treated a rare case of fragility fracture of the talar neck in a 76-year-old female cleaner.

Anatomical observation, classification, fracture and finite element analysis of the posterior process of the Asian adult talus

BACKGROUND

Fractures of the posterior process of the talus are rarely seen and frequently overlooked. In our study, anatomical observation and classification of the posterior process of the talus were carried out, and related imaging and finite element methods were combined. The study aimed to observe and provide anatomical data related to posterior process of talus in Asian adults and explore the potential relationships between the different types with fracture of posterior process of talus.

METHODS

Combined with the anatomical morphology and imaging data, the posterior process of talus was divided into four types, and the incidence and fracture situation were statistically analyzed. The finite element models of four different types of talus processes were established and verified, and the stress and strain were simulated and analyzed.

RESULTS

The total incidence of the posterior process of the talus was 97.47%. The proportions of the four types were neck-like 10.13%, flat 36.29%, pointy 12.66% and round blunt 38.39%. The overall incidence of bone cracks of the posterior process of the talus was 4.98%; the most common type was neck-like type. Compared with the value on the other types, the maximum von Mises stress increased by 67.66%, 83.90% and 111.18% on the neck-like posterior process of talus respectively.

CONCLUSIONS

It is speculated that different types of the posterior process of the talus may be related to the probability of fracture, and it may be better to consider different treatment strategies for different types of fractures.

Surgical management of displaced talus neck fractures: single vs double approach, screw fixation alone vs screw and plating fixation-systematic review and meta-analysis

PURPOSE

To provide a direct comparison between two important aspects related to talar neck fractures management - surgical approaches and fixation strategies.

DATA SOURCES

A systematic review and meta-analysis was performed using PubMed, SciELO, and gray literature databases. The keyword "talus fracture" and the combined terms "talus neck fracture AND surgical approach" and "talus neck fracture AND fixation strategy" were used.

STUDY SELECTION

Study selection, data extraction, and the risk of bias assessment were performed following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Searches were limited to human studies and the English and Portuguese. Inclusion criteria were articles in full text that reported on any aspect of surgical approach and fixation strategy for talus neck fractures. Exclusion criteria were skeletally immature patients, mean follow-up of less than 12 months, studies that did not use the Hawkins classification system, primary treatment of arthrodesis, studies published before year 2000, and studies published in languages other than English and Portuguese.

DATA EXTRACTION

Basic information was collected including journal, author(s), year published, level of evidence, number of fractures, and follow-up. Specific information was collected including fracture classification, surgical approach, fixation strategy, complication rate, type of complication(s), and outcome measurement(s).

DATA SYNTHESIS

Fixed-effects model was used for meta-analysis. The choice for surgical approach(es) and fixation strategy was stratified based on fracture classification. Complication rate, type of complication(s), and outcome measurement(s) were calculated for all studies and delineated by fracture classification.

CONCLUSION

There is a significant correlation between poor scores and poor fracture reduction, but not with the modified Hawkins classification, surgical approach, and fixation strategy. The presence of an open talus neck fracture-dislocation jeopardizes the functional outcome, increasing the risk of complications. The overall avascular necrosis and post-traumatic osteoarthritis event rate was 0.279 and 0.400, respectively. Both complications were highly correlated to higher energy fracture patterns and to the use of combined approaches, but not to fixation strategy.

LEVEL OF EVIDENCE

I (systematic review and meta-analysis).