Overview

Definition of talus fractures

The anatomy and function of the talus

The talus is a small bone that creates a link between the leg and the foot.¹ Along with the leg bones (tibia and fibula) and another foot bone called the calcaneus, it makes up the ankle.¹ The talus is composed of three parts: the head, the neck and the body.¹ It is a small bone with many articular facets, and it is essential to the process of transmitting body weight to the foot. Its existence also allows the foot to flex, making it pivotal for walking.¹ The talus is the only foot bone (also known as a tarsal bone) that is not attached to any muscles. Instead, it is held in place by large ligaments, offering a great range of movements.¹ The lack of direct muscle attachment to the talus, coupled with its large articular function, leaves little room for blood supply, which occurs through non-articular areas.¹ The bone’s blood supply is therefore fragile and can easily be cut off, particularly in cases of neck fractures or displacement of any part of the bone.¹ In these cases, the bone cannot heal because it has lost its blood supply, which can even lead to the death of the tissue (known as avascular necrosis).¹

Talus fractures

Fractures of the talus represent 3% to 6% of fractures involving the foot, and less than 2% of fractures overall.² Talus fractures usually happen because of a fall (either simple or from a height) or a transport accident (for instance, a car accident).³ They can occur on the neck of the talus, its body or its lateral process (a prominence on the side of the talar body). The most common is the neck fracture (over 50% of all talar fractures), followed by body fractures (15% to 23%), lateral process fractures (10.4%) and head fractures (3% to 10%), although these figures can vary depending on the definition of anatomical boundaries across different studies.² All these fractures have a considerable impact on a person’s ability to walk.³ Early and adequate treatment is particularly crucial as the unique function of the talus in the human body, and its limited blood supply, make talar fractures difficult to recover from and long-term complications and disability are likely.^1,2,3 

The symptoms of talus fractures include:⁴

• Pain
• Swelling
• Difficulty walking

The complications from a talus fracture include:⁴

• Osteoarthritis
• Infection
• Avascular necrosis (death of bone tissue because of a lack of blood supply to the area)

Definition of osteoporosis 

What is osteoporosis?

Osteoporosis has been referred to as “the silent disease of the 21st century”. It is a chronic condition that affects the microarchitecture of the bone tissue, resulting in a progressive decrease in bone mass. It makes the skeleton more fragile,  increasing its likelihood of fracture.^5,6 Despite affecting the entire skeleton, the disease is most often identified through the occurrence of hip and spine fractures, as fractures in these areas have been found to be particularly linked to decreasing bone mass density.⁷

Causes of osteoporosis

Although osteoporosis can also be found in children and young adults for various reasons (genetic for example), it is most commonly found in older adults because bone mass naturally decreases with age.⁶ It is particularly found in men over 65 years old and females over 55 years old.^6,7 For the latter, it is usually triggered by symptoms associated with menopause.⁶

The skeleton constantly remodels itself through life to ensure its functions can be performed. This process involves small parts of the bone being removed by bone cells called osteoclasts and new bone being formed by other cells called osteoblasts.⁷ Osteoporosis occurs when there is an imbalance between the amount of bone resorption and bone formation.⁷ In most cases, such an imbalance and subsequent bone loss are caused by age-related processes. For instance, in older people assigned female at birth (AFAB), the rate of bone modelling increases with age, but bone resorption occurs more than bone formation, and the microarchitecture of the skeleton is greatly disturbed, therefore making the skeleton more fragile.⁷ In contrast, bone loss occurs in ageing people assigned male at birth (AMAB) who go through a general reduction of bone formation and a decrease in bone turnover (rate of bone remodelling).⁷

The strong link between ageing and osteoporosis is partly due to hormonal changes. Indeed, several hormones, including the sex hormones (oestrogen and testosterone) and the thyroid hormones (T3 and T4), for instance, have been found to affect osteoblast and osteoclast metabolism.⁸ The production of these hormones changes in later life, affecting the bone remodelling process and potentially leading to osteoporosis.⁸ Therefore, studies found that the rise of thyroid-stimulating hormones, coupled with the decline in sex hormones, leads to bone loss associated with ageing.⁸

Other risk factors for osteoporosis include:⁹

• Being female
• Family history of the disease (in first-degree relatives)
• Small body size
• Body weight disorders (such as anorexia nervosa and malabsorptive bariatric surgery)
• Sustained diet low in calcium and vitamin D
• An inactive lifestyle
• Smoking
• Alcohol
• Comorbid illnesses (including hypercalciuria, osteogenesis imperfecta, Inflammatory Bowel Disease, diabetes mellitus, etc.)

Incidence of osteoporosis

Studies have found osteoporosis to be a commonly occurring disease with approximately 10 million people being diagnosed in the US in 2004 as well as 10% to 30% of  people AFAB over 40 and up to 10% of people AMAB being recorded to have the disease in the Asia Pacific region (data from Australia, China, Hong Kong, Japan, Singapore, South Korea, and Taiwan).¹⁰

Link between osteoporosis and talus fractures in elderly people

Osteoporosis causes bone mass to decrease, which makes every part of the skeleton more likely to break, increasing the odds of a fracture when falls or injuries occur.^5,6 Considering its load-bearing function, the talus is therefore particularly at risk in elderly populations with osteoporosis. Indeed, ankle fractures are one of the most common fractures in people over the age of 50, and their incidence continues to increase.^11,12 A review study found a significant association between a reduction in bone mass density and the incidence of ankle fractures in the elderly population.¹¹

Treatment and management of talus  fractures in osteoporotic patients

The aim of treatments for talus fractures in osteoporotic patients is to ensure that as much mobility and weight-bearing ability is retained as possible. However, in elderly and osteoporotic patients, the management methods chosen need to be carefully considered according to bone mass density.¹³ For example, weak bones might present a high risk and/or a low success rate for surgical intervention.

In order to limit displacement following a talus fracture and subsequent complications, ankle immobilisation is needed. This can be achieved using a plaster or a fixed ankle boot (also known as an orthosis).¹³ The use of medical imaging, such as radiographs, allows a better understanding of the fracture and consequently decides the immobilisation method and position to optimise chances of healing.¹³ 

In the cases where immobilisation was not a successful or adequate treatment, surgery might be considered. Possible interventions include ankle open reduction and internal fixation (ORIF) and intramedullary tibiotalocalcaneal (TTC) nailing, for instance.^12,13 All surgeries for talus fractures involve some type of metalwork (screws, plates or nails), which can be particularly challenging in elderly and osteoporotic populations.¹³ Indeed, the weakness and porosity of the bone tissue can lead to metalwork failure and screw/nail pull-out.¹³ Consequently, these patients require special considerations, and surgical options and strategies should be considered on a case-by-case basis.

Regardless of the treatment strategy chosen, it is essential for elderly osteoporotic patients to undergo rehabilitation and return to full weight-bearing as soon as possible to avoid tissue mass and muscle strength being negatively impacted.^12,13 

Prevention strategies

To reduce the chances of osteoporotic talus fractures in later life, some prevention strategies can be put into place. For instance, reducing risk factors for osteoporosis by improving bone density through sustaining a diet rich in calcium and vitamin D, as well as exercising regularly. 

Additionally, despite osteoporosis being a silent disease (as it is unnoticeable until fractures occur), being able to detect it early can allow patients to access medications and supplements which could reduce the progression of the condition, boost bone turnover and slow the reduction in body mass density.¹⁴ Knowledge of family history, hormonal changes (such as menopause), as well as early signs of hip and spinal fractures, can help identify the condition early.

Summary

Osteoporosis is an increasingly common condition which causes the entire skeleton to become more fragile and vulnerable to fractures throughout life. As it is greatly linked to ageing and hormonal changes, it is most often seen in elderly patients. This disease is commonly associated with fractures of the talus in elderly populations, as the location and function of this bone make it particularly vulnerable to falls and injuries. Whenever possible, it is best to avoid surgical treatment for talus fractures in elderly osteoporotic populations because the weak bone tissue might not be able to hold the metal work (screws and nails) in position. Regardless of treatment, it is essential for elderly patients to return to weight-bearing status as soon as it is feasible to avoid further impact on tissue and muscular masses. Preventing osteoporosis by sustaining a lifestyle and a diet that promotes bone density and getting an early diagnosis (and subsequent medication) appears to greatly reduce the chances of osteoporotic talus fractures in elderly populations.