Overview of Ankle Splinting
Splinting is a method used in several medical fields such as emergency care, bone treatments (orthopedics), general health care (primary care), and foot care (podiatry). Its main purpose is to keep a joint or limb still. This helps manage pain, secures the injured area, and aids in the healing of the tissue. When used short-term, splinting can treat things like pulled or torn muscles (strains and sprains), dislocated joints, and broken bones (fractures). For chronic, or persistent conditions, it’s predominantly beneficial for conditions which involve inflammation or gradual wear and tear.
For an injured ankle, the aim of splinting is to restrict movement in several directions, such as upward or downward foot movement (dorsiflexion and plantar flexion) or sideways movement of the foot (inversion and eversion) from the ankle joint. It comes in handy especially when injuries occur to the lower part of the tibia or fibula (the two main bones in the lower leg), the ankle joint, or the back part of the foot (hindfoot).
Anatomy and Physiology of Ankle Splinting
The ankle is made up of various parts including bones, muscle groups, and structures responsible for nerve and blood supply.
The ankle joint is comprised of three bones: the bottom parts of the tibia and fibula (the two bones below your knee), and a bone called the talus. The bottom portion of the tibia connects with the fibula and the talus to form the ankle joint. When we talk about the ‘ankle’ we usually don’t include the joint between the talus and a bone at the heel known as the calcaneus. This joint is a part of the hindfoot, not the ankle.
The lower part of the tibia has three sections. One segment bears our body weight as we walk or stand, while the sides of the tibia connect with two important ligaments, similar to strong ropes, providing support. Over time, the bone segments mature and fuse together, usually around the age of 18 to 20 years.
The bottom portion of the fibula also has important ligament attachments, and it restrains sideways movement of the talus, increasing ankle stability. The bone segments in the fibula usually mature and fuse together around the age of 18 to 20 years.
The talus is another crucial bone in the ankle. It matures early on approximately around seven months and usually fuses together around the age of 13 to 15 years. The talus connects with several other foot bones and plays a critical role in bearing body weight.
The muscles around the ankle are mostly tendon-like as they traverse from the leg and attach to foot bones. These muscles belong to four compartments, namely the anterior (front), lateral (side), superficial posterior (back), and deep posterior compartments.
There are also essential nervous structures around the ankle. Some of these nerves provide sensation to the ankle, while others are responsible for movement.
The blood supply to the ankle also plays a critical role, provided by the anterior (front-facing) and posterior (rear-facing) tibial arteries. These blood vessels branch out from a larger artery behind the knee, and course through the front and rear of the ankle respectively.
Why do People Need Ankle Splinting
Ankle splinting, or putting a brace on your ankle, is typically done to stabilize the ankle and prevent movement. It’s particularly important if you’ve injured your lower leg or foot. The main situations where an ankle might need to be immobilized with a splint are if you’ve fractured (or broken) your ankle or if you’ve dislocated it (when the ankle bone moves out of its usual position).
Your ankle has several different parts that could potentially become fractured, including the lateral malleolus, medial malleolus, and posterior malleolus. Sometimes, different combinations of these parts can be fractured all at once. Another bone called the talus can also be fractured in the ankle.
The malleoli are important because they help to keep the talus bone centered within part of your ankle known as the mortise. If you fracture your malleoli, it’s common that your tibiotalar joint (where the bones of your lower leg meet the bones of your foot) may move out of place or become partly dislocated. If your joint becomes dislocated or partly dislocated and then moved back into position, a splint can help keep it in position and stop it from moving out of place again while you receive further treatment.
If you’re experiencing any of the following injuries, you’ll likely need an ankle splint:
- Fracture of the lateral malleolus (the outer part of the ankle)
- Fracture of the medial malleolus (the inner part of the ankle)
- Fracture of the posterior malleolus (the back part of the ankle)
- Bimalleolar fracture (a fracture that involves two malleoli)
- Trimalleolar fracture (a fracture that involves all three malleoli)
- Dislocation or subluxation of the tibiotalar joint (the joint where the leg and foot bones meet)
- Ankle fracture-dislocation (an injury where the ankle is both fractured and dislocated)
When a Person Should Avoid Ankle Splinting
While there aren’t any hard and fast rules against using splints, doctors need to make careful decisions on when and where to use them, especially in urgent situations. They need to be extra careful if the patient has burns, open fractures (where the bone has pierced the skin), dirt-filled wounds, or severe tissue swelling.
Generally, it is safe to use a splint as long as any other injuries the patient has are taken care of first. For instance, in cases of open fractures with dirt-filled wounds, the wound should be cleaned and any dead tissue removed first. After that, a type of bandage that moves from wet to dry should be placed over the wound before the splint is applied.
In cases with severe tissue swelling, a splint is a better option than a cast since a splint isn’t tightly wrapped around the entire body part and can be loosened or taken off easily. The splint’s stability is beneficial in cases of ankle fractures or dislocations, as it helps to prevent further injury and helps reduce swelling.
However, using a splint may not always be the best choice. For example, in the case of sprained ankles, it’s usually better to use a simple elastic wrap instead of a splint, as the main goal is to keep swelling to a minimum. Moving the ankle as soon as possible actually helps recovery in sprained ankles. If there’s a need for the ankle to be kept still for a little while, a controlled motion boot (a special type of boot that allows for some movement while keeping weight off the ankle) is the better choice. A splint isn’t suitable in these cases.
Equipment used for Ankle Splinting
A few materials are needed to create a cast:
- A stockinette: This is a stretchy, knitted tube that goes over the part of your body that’s being put in a cast. It helps protect your skin from getting irritated by the cast material.
- Cast padding: This is a soft material that goes over the stockinette. It protects your skin and prevents the hard outer layer from pressing on spots that could be painful or uncomfortable.
- Plaster splinting material: This is the hard outer layer that keeps the injured part of your body from moving. It’s usually what people think of when they imagine a “cast.”
- Water: Cold water allows doctors more time to shape the plaster material, while warmer water makes it harden faster. This is important because the doctor needs to make sure the cast fits correctly and is comfortable for you.
- Elastic bandages: These bandages hold the padding and plaster material in place while the cast dries.
Who is needed to perform Ankle Splinting?
An ankle splint can sometimes be applied by a healthcare professional alone, but sometimes they might need an another person’s help. If there’s nothing out of place in the ankle joint and the patient can follow instructions, a second person may not need to be there. However, if the ankle needs to be put back in place or ‘reduced,’ another person will need to be there to help hold the ankle steady while the splint is put on. Also, if the patient can’t follow instructions well or is drowsy from a medicine that helps them relax, a second person will need to be there to help hold the leg.
Preparing for Ankle Splinting
If you’ve injured your ankle, the doctor may decide to use a splint to help keep it stable while it heals. There are three main kinds of ankle splints. The most secure kind is known as a stirrup plus posterior slap splint. This particular splint is best for certain types of broken ankles or when the ankle bone is out of place. The other options are a stirrup splint or a posterior slab splint. However, these last two splints are only sufficient for a break in a single part of the ankle. The posterior slab splint restricts movement in certain directions and prevents the ankle from bending too far forward or backward. In contrast, the stirrup splint wraps around the inside (medial) and outside (lateral) parts of the ankle to provide stability.
Before applying a splint, it’s important to measure the plaster’s length to avoid any discomfort. The length is measured from a point just below your toes to below the back of your knee (the popliteal fossa). It should be ensured that the plaster is not too long else it could potentially cause skin irritation. It’s equally important to adjust the size of the splint so that it’s not too thick – this could lead to a heat-related injury as plaster can generate heat while it sets.
Before the splint is set, any dislocation or misalignment in the ankle is corrected. A soft, flexible material called stockinette is used to cover your leg, providing an extra layer for comfort. Padding is then applied over this layer, from the base of your toes up to the bump on your shinbone (the tibial tubercle). Extra care is needed to ensure sufficient padding is applied to the ankle bone and heel to avoid pressure sores.
The ankle must be in a neutral position while the splint sets – else there could be an issue of muscle contraction over time. Meanwhile, molding against any dislocations helps keep the joint in place. The splinting process is a delicate one that is designed not only to support your ankle while it heals, but also to help alleviate discomfort and prevent further injury.
How is Ankle Splinting performed
If you’ve hurt your ankle, one way we can help it heal is by putting it in a plaster cast. Here’s how we typically do it:
1. We get the right length of plaster ready. It’s usually about 8 to 12 sheets thick for the back part of your cast and the “stirrup”, which is a piece that goes under your foot and up the sides of your ankle.
2. We cut a kind of soft mesh tube called a “stockinet” to fit your leg.
3. If your ankle is out of place from the injury, we carefully move it back to where it should be. We hold your leg and ankle steady during the casting process so it stays in the right position.
4. We slide the stockinet onto your leg to provide an initial layer of protection.
5. We wrap your leg in cotton from the base of your toes to the bony bump just below your knee. We make sure the bony parts on both sides of your ankle and your heel have extra padding. We also try to avoid any bunching or wrinkles in the cotton layer.
6. We soak the plaster in water so it gets fully wet. Then, we squeeze out the extra water and stick the sheets together with our fingers.
7. We put the back part of the cast onto your leg over the cotton. We make sure it starts under your toes and ends just below the back of your knee.
8. We also apply the stirrup part of the cast. This wraps from one side of your leg, under your heel, and up the other side. It starts at the upper part of your lower leg on the inside, wraps around your heel, and ends at the upper part of your lower leg on the outside.
We wrap the plaster in a layer of cotton to keep it from sticking to the wrap that will hold it in place. We fold the extra stockinet over the edges of the plaster to create a soft cuff. Next, we loosely wrap the whole cast in an elastic bandage to hold everything together. We shape the plaster while it’s drying. We make sure your ankle is not bent up or down. We avoid putting the cast on a pillow or blanket because that can make it warm and affect how the cast hardens.
Once the cast is hard and dry, we check again to make sure the blood is flowing well to your foot and toes. We also make sure you can move your them without any problems.
Possible Complications of Ankle Splinting
Sometimes after applying a splint, a patient may experience complications. Pressure necrosis, or the death of skin and other bodily tissue, can occur as early as two hours after the splint is put on. This can often be due to a lack of padding on prominent bones.
Another complication that can arise is compartment syndrome, this is a painful condition caused if the splint is wrapped too tight and puts pressure on the muscles, nerves and blood vessels.
Thermal injury is another possible issue, which can be caused if the plaster of the splint is too thick or if there isn’t enough padding. This can lead to skin burn and blisters.
Lastly, equinus contracture may occur, which is a condition where the ankle becomes permanently bent due to the positioning of the ankle in plantarflexion (downward flexing movement) while the splint is being applied. Such wrong angles can cause muscle contraction and restrict movements.
What Else Should I Know About Ankle Splinting?
Ankle splinting is a helpful method for keeping your ankle from moving if you’ve fractured or dislocated it. By limiting movement, it lessens the chance of further injuring your bones, cartilage (the flexible tissue at the ends of bones), or neighboring nerves and blood vessels. On top of that, splints allow for swelling, and a doctor can easily take them off to check any injuries hiding underneath. It’s a great way to manage ankle injuries until permanent treatment can be given.
After getting a splint, you should be told how to take care of it properly. The splint has to stay clean and not get wet. If it does, the hard material will lose its strength, and the padding underneath won’t dry. This could result in softening and breakdown of the skin. Moreover, if there’s an open wound under the splint, it could end up infected. If your splint gets wet, you should go back to where it was put on. It’s crucial not to take off your splint, especially if it has been put on for a dislocation. Taking it off might make the joint slip out of place again. The most crucial thing is that if you start feeling new numbness or tingling in your foot or toes, you should first try to elevate your leg. If these sensations don’t go away, you should go back to the place where the splint was applied, or to the emergency department for an additional check-up.
