Prevalence, impact and long-term consequences of lateral ankle sprains

Treating a sudden LAS can vary, and many people get back to their normal activities quickly. But surprisingly, about half of those who get injured never seek help at all. Unfortunately, LAS often comes back, leading to what we call chronic ankle instability (CAI). This means the ankle doesn’t feel stable, and it can lead to ongoing problems with movement and balance, making it hard to stay active and affecting your overall quality of life.

What’s worrying is that people who’ve had LAS and CAI are more likely to develop a type of arthritis called post-traumatic osteoarthritis (PTOA) in the ankle joint. This can eventually lead to needing surgery to fix the ankle joint. And what’s surprising is that this arthritis can start at a younger age than many people might think.

Although treating a single ankle sprain may not seem costly upfront, the expenses add up when considering follow-up care and time away from activities. Since ankle sprains are so common among active people, the overall societal costs are much higher than you might think. When you factor in the costs of managing decreased activity and treating potential long-term issues like ankle arthritis, it becomes clear how much of a burden even a seemingly minor injury can be on healthcare systems.

In a related statement, the International Ankle Consortium’s Executive Committee suggests using this information to guide future research and improve how we prevent and manage ankle sprains. By focusing on prevention and early treatment, we can reduce the risk of developing chronic ankle instability and related problems, ultimately promoting healthier lifestyles and encouraging more physical activity.

Understanding Ankle Sprains (LAS):

Understanding Lateral Ankle Sprains (LAS):

Lateral Ankle Sprains (LAS) are the most common type of injury affecting the lower limbs in people who are physically active. This means they occur frequently among those who engage in sports or other physical activities. An acute LAS is defined as a sudden injury to the ligaments on the outside of the ankle joint, typically caused by the ankle rolling inwards or a combination of downward and inward foot movement.

How Ankle Sprains Happen:

Ankle sprains are often seen in sports like soccer and basketball. Researchers have studied how these injuries occur to better understand their causes. They found that two common scenarios involve either direct contact with another player or a sudden movement while the foot is planted. Both situations can lead to the ankle twisting unnaturally.

Research Insights:

Recent studies have provided valuable insights into how ankle sprains happen. For example, researchers observed the movements leading to an ankle sprain during laboratory testing. They found that the ankle rapidly turned inward and rotated internally, even when there wasn’t direct contact with another object or person. This suggests that ankle sprains occur due to a sudden, forceful twisting and turning of the ankle joint, regardless of the foot’s position.

Understanding these mechanisms can help healthcare providers better diagnose and treat ankle sprains, as well as develop effective prevention strategies for patients involved in physical activities or sports.

Recently, researchers like Mok et al and Fong et al have been using advanced motion analysis techniques to study ankle sprains captured on video during live sports events. For example, Mok et al analyzed two ankle sprains that occurred during the 2008 Beijing Summer Olympic Games. One happened during the women’s high jump qualification round, where the ankle was severely turned inward, rotated internally, and slightly pointed downward when it first made contact with the ground. Then, there was a sudden, rapid increase in the inward twist and internal rotation of the ankle. In another instance during a field hockey match, a player accidentally stepped on another player’s foot, causing a similar twisting of the ankle.

Similarly, Fong et al studied ankle sprains from televised tennis matches. They found that in all cases, the ankle was turned inward when it first hit the ground, which is a position that makes the ankle more vulnerable to injury. The inward twist of the ankle happened very quickly after the initial contact, typically within a fraction of a second. Understanding these specific movements that lead to ankle sprains can help athletes and coaches recognize and potentially prevent these injuries during sports activities.

Understanding the Frequency of Ankle Sprains:

In this section, we’ll discuss how ankle sprains, specifically Lateral Ankle Sprains (LAS), are incredibly common among people who are physically active. While often associated with athletes, LAS affects a broad range of individuals engaging in various physical activities. To paint a clear picture of the impact of LAS on society, it’s essential to look at how prevalent these injuries are across different demographics, including data from emergency departments.

Research Insights:

Numerous studies have delved into the patterns of ankle sports. For instance, a comprehensive review by Fong and colleagues in 2007 examined over 200 epidemiological studies spanning 70 different sports, involving a total of more than 200,000 individuals. They found that in 34% of these sports, the ankle was the most commonly injured body part. A more recent systematic review by Doherty and others focused on prospective studies, providing pooled incidence rates for ankle sprains across various sports, age groups, and genders.

Key Findings:

Indoor and court sports, in particular, showed the highest incidence rates, with an estimated 7 ankle sprains per 1000 exposures. Moreover, the incidence rates varied based on gender and age, with women and younger athletes experiencing higher rates of ankle sprains compared to men and older individuals. Importantly, the majority of ankle injuries diagnosed were sprains, with LAS accounting for 80-90% of these cases.

Understanding the frequency and distribution of ankle sprains is crucial for healthcare professionals and individuals alike, as it informs prevention strategies and treatment approaches to reduce the burden of these injuries on public health.

Understanding Ankle Sprain Incidence:

Comparing data from various sports and regions can provide valuable insights into ankle sprain rates. However, pooled incidence figures, like those compiled by Doherty et al, may have limitations due to differences in study methods and definitions. Utilizing large regional datasets with consistent methodologies over time can offer more reliable insights.

For example, the National Collegiate Athletic Association (NCAA) Injury Surveillance System in the USA has tracked injuries across 16 collegiate sports over nearly three decades. According to Hootman et al, ankle ligament sprains are the most common injury among NCAA athletes, with basketball and soccer players experiencing the highest rates.

Additionally, ankle sprains are prevalent in other physically active groups, such as military personnel. Studies have reported comparable incidence rates to sports like softball and baseball. Moreover, ankle sprains also account for a significant portion of emergency department (ED) visits worldwide, with millions of cases annually.

In the UK, ankle sprains contribute to a substantial portion of ED presentations, particularly among young girls. Similarly, studies in the USA and the Netherlands have highlighted ankle sprains as a common reason for ED visits, with incidence rates remaining relatively consistent over time.

These findings emphasize the widespread occurrence of ankle sprains across various populations and underscore the importance of prevention and proper management strategies to reduce their impact.

Mid-Term and Long-Term Effects of Ankle Sprains:

Developing Chronic Ankle Instability (CAI):

While ankle sprains are often seen as minor injuries with quick recovery, many patients face ongoing challenges. These can include lingering symptoms like instability, decreased function, and limitations in activities even months or years after the initial injury. Some individuals may develop Chronic Ankle Instability (CAI), which involves recurrent ankle problems and a higher risk of reinjury. However, what exactly leads to CAI in some patients remains unclear, and several theories are being explored.

Post-Injury Deficits:

Although the initial inflammatory symptoms of an ankle sprain typically improve relatively quickly, recurrence rates are high, posing a significant concern. Studies have shown that ankle sprains have the highest rates of recurrence among lower limb injuries, with a doubled risk of reinjury within the first year after the initial incident. However, it’s important to note that certain factors, such as an individual’s role or function in a sport like volleyball, can influence their risk of recurrence.

It’s believed that an ankle sprain can disrupt neuromuscular function, leading to issues like impaired balance, weakened muscles, and delayed muscle reaction times. Even after returning to normal activities, these deficits may persist, increasing the likelihood of further injuries. For instance, individuals with a history of ankle sprains tend to experience more difficulty with balance control, especially when fatigued. This ongoing impairment in ankle function could contribute to the development of CAI over time.

Transitioning from Ankle Sprains to Chronic Ankle Instability (CAI):

For many patients, persistent pain, feelings of instability, and instances of their ankle “giving way” are ongoing issues, indicating the development of Chronic Ankle Instability (CAI). Hertel proposed a model of CAI, suggesting that repeated occurrences of ankle instability lead to multiple sprains. This model combines the ideas of mechanical instability (ligament damage causing laxity) and functional instability (recurrent instability due to proprioceptive and neuromuscular deficits).

Delahunt and colleagues expanded on this, defining CAI as a condition encompassing both mechanical and functional instability. They specified that for someone to be diagnosed with CAI, they must experience residual symptoms like “giving way” and feelings of instability for at least a year after their initial sprain.

To address inconsistencies in CAI research, Hiller and others revised the Hertel model, suggesting that CAI is not a single condition but rather a heterogeneous one with various subgroups. They proposed seven subgroups, considering factors such as perceived instability instead of solely focusing on functional limitations.

Recently, the International Ankle Consortium’s Executive Committee published a statement outlining criteria for selecting patients with CAI for research purposes. These criteria include assessing the patient’s history of ankle sprains and functional limitations, as well as self-reported episodes of “giving way” and validated outcome measures. This aims to provide clearer guidelines for studying and treating CAI effectively.

Prevalence of Chronic Ankle Instability (CAI):

Research indicates a concerning trend in the prevalence of CAI, with up to 70% of individuals who have experienced a previous ankle sprain developing CAI within a short timeframe. Recent studies have shown high prevalence rates of CAI (>25%) in sports like handball, basketball, soccer, and volleyball. Similar trends are observed among collegiate and high school athletes, with about a quarter of them reporting CAI after previous ankle injuries. Even in performing arts such as ballet, over half of dancers with a history of ankle sprains report experiencing CAI. This prevalence extends to the general population, where more than 20% of individuals with ankle injuries report chronic issues, particularly associated with sports activities.

Post-traumatic OA development

Despite the link between ankle sprain severity and CAI development, there seems to be insufficient awareness of CAI and its impact on physical activity. Many individuals, including athletes, may not seek proper medical care after an ankle sprain, potentially contributing to the development of CAI. This lack of medical assessment and appropriate care might be a significant factor in CAI development, although conclusive evidence is lacking due to challenges in recruiting appropriate study populations.

Another theory suggests that the management of ankle sprains, particularly in emergency departments (EDs), may not be optimal, leading to inadequate restoration of ankle function. Treatment often focuses on controlling acute symptoms without sufficient attention to restoring joint function and preventing reinjury. This lack of comprehensive care may contribute to ongoing ankle instability and decline in patient outcomes characteristic of CAI. Thus, there is a need for more proactive and tailored management strategies to address ankle sprains effectively and reduce the risk of CAI development.

One benefit of being part of a structured healthcare system is access to follow-up rehabilitation, which aims to restore function and reduce disability. However, in clinical care for athletes, there’s often a push for a speedy return to activity once pain decreases and weight-bearing becomes possible. This aggressive approach might overlook critical outcomes, allowing disability to persist. Athletes may resume activities before completing the necessary healing stages, potentially leading to inadequate structural integrity and inefficient neuromuscular control.

Thus, there’s a risk of both insufficient follow-up rehabilitation and overly aggressive care, which can result in negative consequences. Delahunt and colleagues propose a ‘road map’ to help assess the needs and deficits of patients with ankle sprains, guiding clinical care decisions. Prospective trials are essential to determine the optimal management and rehabilitation dosage for a safe return to activity timeline that minimizes instability and reinjury.

Another theory for Chronic Ankle Instability (CAI) development involves abnormal sensorimotor and neuromuscular patterns observed in this population. Studies have shown persistent alterations in balance, gait, and movement patterns in CAI patients. While these findings suggest a link between ankle injury and sensorimotor deficits, conclusive evidence is lacking. Longitudinal studies have demonstrated ongoing postural control issues and abnormal movement patterns in patients with ankle sprains, indicating a potential foundation for CAI development.

Genetic factors may also play a role in CAI development, although research in this area is still in its early stages. One study found that soldiers with a specific genotype had fewer ankle sprains, suggesting a possible genetic influence. Further research, including prospective studies, is needed to confirm these relationships and determine potential interventions.

There’s a clear connection between acute ankle sprains (LAS) and the development of Chronic Ankle Instability (CAI). What’s less commonly known is that LAS and CAI can also lead to ankle joint Post-Traumatic Osteoarthritis (PTOA). Ankle joint PTOA, regardless of its cause, can significantly limit physical function and quality of life. Studies show that patients with end-stage ankle joint PTOA often experience physical limitations similar to those with serious health conditions like kidney disease or heart failure.

Research indicates that between 70% and 80% of ankle joint PTOA cases are linked to previous ligamentous injuries, particularly LAS. This means that a significant portion of ankle joint OA cases are due to past ankle sprains. What’s concerning is that ankle joint PTOA tends to develop at a younger age compared to other joint degenerations like knee or hip OA. Ligamentous injuries and instability play a major role in this process.

Some studies suggest that even a single severe LAS can lead to ankle joint PTOA over time, with a latency period of around 26 years. Recurrent LASs may shorten this latency period. Furthermore, evidence shows that patients with chronic ankle instability often have arthritic changes in their ankles, even if their main complaint is chronic pain rather than instability.

These findings emphasize the importance of proper care and rehabilitation after an ankle sprain to prevent long-term complications like ankle joint PTOA. Early detection and management of ankle instability may also help reduce the risk of developing PTOA and its associated physical limitations.

Chronic Ankle Instability (CAI), varying rates of degenerative changes in the ankle joint have been observed. For instance, Sammarco and DiRaimondo found degenerative changes in only 21% of CAI patients during lateral ligament stabilization. Meanwhile, Hintermann et al discovered cartilage lesions in 55% of CAI patients through arthroscopic evaluation performed less than two years after their initial ankle sprain. Similarly, Takao et al reported degenerative changes in 50% of their patients, with 29% showing osteochondral lesions, within just seven months of injury.

On the other end of the spectrum, Taga et al found that 95% of chronically unstable ankles had chondral lesions, with an average age of 20 years. Other studies by Komenda and Ferkel and Ferkel and Chams noted degenerative changes in 91% of unstable ankle cases, with 25% having chondral lesions, and intra-articular problems in 95% of CAI patients, respectively.

However, it’s important to note that these findings are from patients requiring surgery for CAI-associated symptoms. Thus, the rates of ankle joint osteoarthritis (OA) reported in the literature might be higher in symptomatic patients seeking medical care than in those who sustain recurrent ankle sprains but do not seek treatment.

Some studies have suggested that even a single severe ankle sprain can lead to ankle joint OA over time, with a latency period of around 26 years. Additionally, Golditz et al found that young, physically active CAI patients and ankle sprain “copers” (those who sprained their ankle but did not develop CAI symptoms) had higher T2 relaxation times, indicating cartilage degeneration, within five years of their initial injury.

While these findings suggest a link between ankle sprains and degenerative changes, more research is needed to understand the underlying causes and effective interventions for mitigating cartilage degeneration following ankle injuries. This emphasizes the importance of early rehabilitation and appropriate biomechanical restoration after an ankle sprain to potentially prevent long-term complications like ankle joint OA.

Impact on physical activity, quality of life and comorbidity risk

Throughout this writing, we’ve explored how ankle sprains can have a significant impact on various aspects of life. Not only do they cause immediate disruptions in daily activities and sports, but they can also lead to long-term consequences affecting physical activity, quality of life, and overall health.

Physical activity is crucial for maintaining good physical and emotional well-being. Ankle sprains often lead to temporary limitations in movement due to pain and swelling. While many people believe that once the pain subsides, they can resume normal activities, patients with ankle sprains, especially those progressing to Chronic Ankle Instability (CAI), may continue to experience difficulties with physical activity over their lifetime.

Research using animal models has shown that ankle injuries can lead to a decline in physical activity levels, even after the acute phase of recovery. Similarly, studies involving human populations have found that a significant number of individuals with ankle sprains report persistent limitations in physical activity, impacting their ability to participate in sports, recreational activities, and even occupational tasks.

Interestingly, young adults with CAI have been found to engage in less physical activity compared to those without ankle injuries. This decline in physical activity may also contribute to an increase in body mass index (BMI), as obesity has been linked to ankle instability.

While the exact reasons for the decline in physical activity following ankle sprains are not fully understood, factors such as lingering ankle pain, instability, and psychosocial changes may play a role. Understanding these factors is essential for developing effective strategies to overcome limitations to physical activity and improve overall outcomes for individuals with ankle injuries.

Do you have more questions?