Functional Outcomes of Isolated Infrasyndesmotic Fibula Fractures

Analysis of stress response distribution in patients with lateral ankle ligament injuries: a study of neural control strategies utilizing predictive computing models

Background

Ankle sprains are prevalent in sports, often causing complex injuries to the lateral ligaments. Among these, anterior talofibular ligament (ATFL) injuries constitute 85%, and calcaneofibular ligament (CFL) injuries comprise 35%. Despite conservative treatment, some ankle sprain patients develop chronic lateral ankle instability (CLAI). Thus, this study aimed to investigate stress response and neural control alterations during landing in lateral ankle ligament injury patients.

Method

This study recruited twenty individuals from a Healthy group and twenty CLAI patients performed a landing task using relevant instruments to collect biomechanical data. The study constructed a finite element (FE) foot model to examine stress responses in the presence of laxity of the lateral ankle ligaments. The lateral ankle ligament was modeled as a hyperelastic composite structure with a refined representation of collagen bundles and ligament laxity was simulated by adjusting material parameters. Finally, the validity of the finite element model is verified by a high-speed dual fluoroscopic imaging system (DFIS).

Result

CLAI patients exhibited earlier Vastus medialis (p < 0.001) and tibialis anterior (p < 0.001) muscle activation during landing. The FE analysis revealed that with laxity in the ATFL, the peak von Mises stress in the fifth metatarsal was 20.74 MPa, while with laxity in the CFL, it was 17.52 MPa. However, when both ligaments were relaxed simultaneously, the peak von Mises stress surged to 21.93 MPa. When the ATFL exhibits laxity, the CFL is subjected to a higher stress of 3.84 MPa. Conversely, when the CFL displays laxity, the ATFL experiences a peak von Mises stress of 2.34 MPa.

Conclusion

This study found that changes in the laxity of the ATFL and the CFL are linked to shifts in metatarsal stress levels, potentially affecting ankle joint stability. These alterations may contribute to the progression towards CLAI in individuals with posterolateral ankle ligament injuries. Additionally, significant muscle activation pattern changes were observed in CLAI patients, suggesting altered neural control strategies post-ankle ligament injury.

The association between person and fracture characteristics with patient reported outcome after ankle fractures in adults: A systematic review

BACKGROUND

The incidence of ankle fractures is increasing and the clinical outcome is highly variable.

QUESTION

What person and fracture characteristics are associated with patient reported outcomes after surgically or conservatively managed ankle fractures in adults?

DATA SOURCES

Medline, EMBASE, and Allied and Complimentary Health Medical Database (AMED) databases were searched from the earliest available date until 16th July 2020.

STUDY SELECTION

Prognostic factors studies recruiting adults of age 18 years or older with a radiologically confirmed ankle fracture, and evaluating function, symptoms and quality of life by patient reported outcome measures, were included.

STUDY APPRAISAL/SYNTHESIS METHODS

Risk of bias of individual studies was assessed by the Quality in Prognostic Factors Studies tool. Correlation coefficients were calculated and data were analysed using narrative synthesis.

RESULTS

Fifty-one phase 1 explanatory studies with 6177 participants met the inclusion criteria. Thirty-one studies were rated as high risk of bias using the Quality in Prognostic Factors Studies tool. There was low quality evidence that age, body mass index, American Society of Anesthesiologists classification and pre-injury mobility were associated with function, and low to moderate quality evidence that age, smoking and American Society of Anesthesiologists classification were associated with quality of life. No person characteristics were associated with symptoms and no fracture characteristics were associated with any outcomes.

CONCLUSION

There was low to moderate quality evidence that person characteristics may be associated with patient reported function and quality of life following ankle fracture.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42020184830.

Transverse Weber A fracture atrophic non-union. A single centre case series

INTRODUCTION

Weber A ankle fractures are isolated fibula fractures distal to the level of the ankle joint line. They are regarded as stable injuries that usually heal successfully without intervention. We have identified several patients that have developed symptomatic atrophic non-union of transverse Weber A fractures that are not simple avulsion fractures of the anterior talo-fibular ligament. We explored variations to the blood supply of the distal fibula as a potential cause of this rare complication.

CASES

Five patients presented with ongoing ankle pain following a period of non-operative management. All shared a similar transverse atrophic non-union fracture pattern.Surgical management with open reduction and internal fixation with or without the use of bone graft achieved successful union and resolution of symptoms in all cases.

CONCLUSIONS

Atrophic fracture non-unions usually result from a disruption to the blood supply at the site of injury. The arterial supply to the distal fibula consists of a complex of arterial loops which usually enable fracture healing. However, there are anatomical variations to the blood supply that potentially could account for the rare outcome of non-union of Weber A fracture patterns. Weber A fractures are generally benign ankle fractures that heal well with non-operative treatment. No alterations should be made to the management of such injuries, but patients should be counselled about the risk of a symptomatic non-union outcome.

Fibula fractures management

Isolated distal fibula fractures represent the majority of ankle fractures. These fractures are often the result of a low-energy trauma with external rotation and supination mechanism. Diagnosis is based on clinical signs and radiographic exam. Stress X-rays have a role in detecting associated mortise instability. Management depends on fracture type, displacement and associated ankle instability. For simple, minimally displaced fractures without ankle instability, conservative treatment leads to excellent results. Conservative treatment must also be considered in overaged unhealthy patients, even in unstable fractures. Surgical treatment is indicated when fracture or ankle instability are present, with several techniques described. Outcome is excellent in most cases. Complications regarding wound healing are frequent, especially with plate fixation, whereas other complications are uncommon.