What is a trimalleolar fracture?

Trimalleolar fractures are complicated fractures involving 3 bony prominences of the ankle joint (formed from the tibia and the fibula meeting the foot). This involves the bone prominence inside the ankle (tibia), outside the ankle (fibula) and at the back of the ankle (tibia). This type of injury can be quite painful as the bone has twisted, splintered or been broken, typically because of significant trauma such as a car accident, sports injuries or a fall from a significant height.

How serious the broken ankle is will vary from individual to individual. In some cases, the small part of bone that breaks off may stay in place, whereas in other cases, it may shift away from its original position after breaking and end up elsewhere. The ligaments (connective tissue which holds the bone joints together) or tendons (connect muscles to bone) may be injured, sometimes more severely than others. 

Depending on how badly or how many structures in the ankle joint are injured, the ankle joint may become unstable, thus making it more difficult to carry out normal activities. More complex injuries will ordinarily require surgical intervention. Without surgical intervention, this may result in long-term pain, arthritis, deformity or disability. The following article will explore this type of fracture in more detail, as well as the possible reasons surgical intervention may be required. 

Why do some trimalleolar fractures require surgery?

Not every case will require surgery. Frequently, if the bone fragments have not been displaced from their original location, casting may be sufficient to encourage the bone to heal on its own without surgical intervention over 6 weeks.¹ The cast or boot would hold the joint steady, thus encouraging new bone to heal the cracks. However, many things, such as age, sex, the extent of the injury, and general health, can determine whether surgical intervention is required. 

Displaced bone fragments

The displacement of shattered bone fragments is one of the most frequent causes of surgery for trimalleolar fractures because if the bone fragments are not positioned properly, they will heal in the wrong position or will fail to heal entirely. This will affect the ligaments and tendons, affecting how the muscles and bones move. 

This can result in issues whilst attempting to walk, pain, and walking irregularly may also lead to joint wear from the misaligned bones. Screws, plates or wires can typically be used to fix the loose bone fragments back in their original positions. 

Instability of the ankle joint

Only when an ankle joint is stable can it function, supporting the weight of your entire body as you walk and push forward or backwards. The ankle may no longer be as stable as it once was if the fracture damages the ligaments or misaligns the bones. It may be difficult to walk, stand, or even stand for extended periods of time if your ankle joint is unstable.

Surgery is frequently recommended when instability is significant or continues. Properly repairing the fracture and re-establishing normal alignment can help avoid instability in the future and improve mobility when the healing process is over. Instability may increase the risk of arthritis by causing more harm to the cartilage and surrounding tissues if treatment is not received.

Damage to the joint surface

Depending on how the fracture was caused, the cartilage, smooth tissue which lines the surface of bones where they touch each other to minimise friction and bone wearing, may become injured. Failure to align the bones properly may also result in this. 

This can lead to chronic pain every time the bones move, stiffness of the joint and lead to arthritis if the damaged joint becomes inflamed repeatedly. Aligning bones correctly may only be possible with surgery, depending on the severity of the fracture. If the fracture carries on into the joint surface, surgery may be necessary as well to help prevent long-term joint issues. 

Open fractures

An injury which cracks or breaks the bone and is visible from the skin’s surface is called an open fracture, This is because the wound is visible from the outside of the body. These are quite dangerous because this means that the bacteria and other harmful pathogens can directly get into the wound, possibly causing infection, which at times can be life-threatening or require amputation. Due to the way the bones are angled in trimalleolar fractures, the risk of further damage to surrounding tissues is very high because of the sharp shards of the bones, which are pierced through the skin as well as the many structures (bones, tendons, muscles, and ligaments) involved.

In emergency cases where this has occurred, surgery may be necessary to clean out the wound and stabilise the joint. Ensuring the bones heal at the correct angle is vital. If they do not, the patient may not be able to turn their leg or walk properly. 

Using antibiotics before, during and after surgery, as well as managing contamination risks, would be necessary for this type of surgery in order to minimise infection risks. Depending on whether the blood supply to and from the foot has been damaged in this case, compartment syndrome may factor into how the surgery is performed to prevent the foot from dying (which could lead to amputation). 

Fractures involving multiple malalignments

In some cases, trimalleolar fractures result in the ligaments, tendons and bones getting stuck out of place. This type of injury requires complex surgical intervention to restore proper alignment and ensure the ankle joint is as stable as possible to ensure that the bones heal in the correct position, thus permitting adequate movement in the future. Irregular healing could lead to the bones not moving properly, leading to walking issues or issues with turning the leg or foot. 

Inability to heal with non-surgical treatment

While some trimalleolar fractures can heal well with conservative measures such as a cast or boot, not all fractures will resolve because of this alone. Non-healing fractures, also called "non-unions," can lead to chronic pain, deformity, and instability, which are altogether terrible for your quality of life. 

Many issues, such as bone quality, blood supply, nutritional intake, infection and the type of fracture, can contribute to the bone not healing without surgery, thus necessitating surgical intervention to help the wound heal. 

Severe soft tissue damage

The softer tissues surrounding the ankle joint, including tendons, muscles and ligaments, may be severely damaged and unable to heal in the correct place on their own. Therefore, surgery may be necessary to repair these structures correctly to ensure a properly functioning ankle for future use. Compartment syndrome can also  occur if the blood supply is impeded by the break 

Age and activity level considerations

Age and sex are crucial factors in determining the appropriate treatment for trimalleolar fractures. In adolescents, particularly those who are active or participate in physically demanding activities, surgery is often recommended to realign the bones and ensure proper healing.² This approach is vital for preventing long-term complications, maintaining mobility, and avoiding permanent dysfunction. Conversely, for older adults, especially those over 60, the treatment approach may differ.² If the fracture is stable and the bones are not significantly displaced, non-surgical management focusing on pain relief and preventing further injury may be considered more appropriate. 

Elderly women are especially at risk for trimalleolar fractures due to a higher incidence of falls, often resulting from low-energy trauma such as trips or stumbles while standing. This is because after menopause, their bones tend to weaken due to the hormonal changes their bodies undergo, with less oestrogen contributing to a lower bone density.³

Since older individuals generally have lower physical demands on their ankles, surgery may not always be necessary unless the fracture causes instability or impaired function. However, when the fracture is displaced or unstable, surgical intervention becomes essential to restore joint stability and function. Additionally, the presence of conditions like osteoporosis, which is more prevalent in older women, can complicate the healing process and affect the integrity of the bones, making surgery more challenging.³ In such cases, alternative surgical treatments like tibio-talo-calcaneal (TTC) nailing may be considered, especially for elderly patients with low functional demands.² 

Studies have shown that TTC nailing is associated with fewer postoperative complications, such as sepsis and nonunion, compared to traditional internal fixation methods. Nevertheless, TTC nailing may not be ideal for younger patients, where more anatomical restoration of the ankle joint through open reduction and internal fixation would provide better outcomes.²

Ultimately, the decision for surgery depends on the patient’s age, activity level, and overall health, with younger, more active patients generally being candidates for more invasive surgical options, while older patients may benefit from a more conservative approach unless complications arise.

Comorbidity

Illnesses which affect bone health also play a role in determining whether surgery is suitable for the individual. Osteoporosis has already been mentioned, but thyroid disorders can also play a role in weakening bones, as the parathyroid hormone directly impacts bone health.⁴ Both hypothyroidism and hyperthyroidism, as well as their medications, play a role in this, and surgical intervention in this state could increase the risk of complications.⁴

Diabetes mellitus (type 2) also plays a role in affecting bone health, and non-surgical treatment in these cases drastically increases the risk of complications.⁵ Therefore, trimalleolar fractures in these patients should generally involve surgical intervention (depending on other health factors) in order to minimise complication risks.⁵

Summary

A number of different reasons can lead to surgical intervention for trimalleolar fractures, including displaced bone fragments, very damaged soft tissues like tendons and ligaments, damage to the surface of the joints and open fractures. The individual health of the patient will also factor into how likely the patient’s body is to heal with conservative treatment, and without the need for surgical intervention.  

I have redone this a lot, and it still gives it a really high AI score, highlighting large parts of the text as AI, even though I have written them myself. I did use AI for the outline, but it’s still really high