What is Metatarsal Fractures?
Metatarsal fractures, or breaks in the bones of the foot, are quite common. The main aim of treatment is to correctly line up all the metatarsal bones, preserving the foot’s arches and ensuring an even distribution of body weight on the foot. When handled correctly, these injuries are generally straightforward to treat and most people recover well. However, if the injury doesn’t heal properly or the bones don’t realign, it can lead to ongoing disability. One such complication is metatarsalgia, a painful foot condition often seen when treatment doesn’t achieve its aim.
What Causes Metatarsal Fractures?
Metatarsal fractures are often caused by direct or indirect trauma. These injuries can range from just a single fracture in the metatarsal bone to severe crush injuries that involve multiple fractures and extensive soft tissue damage. Direct trauma can happen if a heavy object falls on the foot – usually this happens to people who work with heavy machinery. Indirect trauma can happen if the foot is twisted while it’s stuck in place. This type of injury can cause the fifth metatarsal bone in the foot to fracture because of tension in the peroneus brevis tendon and the plantar aponeurosis.
The Lisfranc joint complex joins the tarsal and metatarsal bones. A Lisfranc fracture-dislocation may occur from a fall from a height or down the stairs. The foot either experiences a longitudinal compression or twists around a fixed front part. For the compression injury, the front end of the metatarsal bone is fixed while the body weight puts pressure on the back part of the foot and the metatarsal’s base.
Stress fractures in the metatarsal bones are also common, resulting from repetitive low-level force. This type of fracture is common among ballet dancers, athletes and soldiers, and is often called a “march fracture”. Several risk factors contribute to stress fractures such as overloading the foot, Morton’s foot, severe weight loss disorders like anorexia nervosa, a lack of menstruation, and prolonged low estrogen levels.
Insufficiency fractures can happen in the metatarsal bones when normal stress is placed on a weakened bone. These fractures are typically seen in people with bone weakening conditions like osteoporosis and in postmenopausal women.
Risk Factors and Frequency for Metatarsal Fractures
Metatarsal fractures, or breaks in the bones of the foot, are very common. In fact, they occur about ten times more frequently than a specific kind of foot injury known as Lisfranc fracture-dislocations. In children, over half of all foot fractures are of the metatarsals.
- The most common locations for metatarsal fractures in children are on the fifth (41%) and first (19%) rays, areas of the foot.
- For industrial injuries, the fifth metatarsal is the most commonly fractured (23%), followed by the third metatarsal.
Signs and Symptoms of Metatarsal Fractures
People with foot injuries often experience harsh pain and trouble walking or standing. It is vital to ask these patients about how they received their injuries. Symptoms of these injuries may include pain, a crunching feeling, bruising, bending of the foot, and swelling over the top-front part of the foot. More severe injuries, involving various fractures and dislocations, usually show clear deformities.
Distinguishing between an injury to the soft tissue and a fracture at the base of the fifth toe bone can be tricky. This is because the pain and swelling for both of these injuries are located just below the outer ankle. Therefore, a careful examination and proper evaluation are crucial for diagnosing toe bone injuries.
Testing for Metatarsal Fractures
To make sure your foot is okay, a doctor will take standard pictures from three different angles: straight on, 45 degrees, and from the side. If they suspect that the one of the small bones in your foot (metatarsals) might be damaged from too much pressure or load, they may take some additional x-rays while you are standing up.
However, fresh stress fractures, which are tiny cracks in the bone from overuse, are often not spotted with a regular x-ray. So, if the doctor suspects a stress fracture, you might need to have another x-ray after the pain has been around for about 10 to 14 days. That’s because, by then, the bone around the fracture may start to wear away, making it easier to see on an x-ray.
In some cases, the doctor may order an MRI or a Technetium scan because these tests are particularly good at finding small fractures. If the doctor thinks you might have more than one break at the base of your metatarsals, they will likely use a CT scan to check for a very specific type of injury known as a Lisfranc fracture-dislocation. If a Lisfranc injury is suspected, the doctor might take some special x-rays while gently moving your foot side to side, which can show instability in the Lisfranc joint.
In children, the doctor will also look for signs of growth, which can appear on the x-ray as a small spur of bone near the base of the foot’s fifth metatarsal. This is common in boys between 11 and 14 years, and girls between 9 and 11 years.
There are different types of metatarsal fractures, which can happen in different parts of the bone: near the toe, in the middle of the bone, or near the base. The fifth metatarsal, specifically, can have fractures in three zones, each with its own classification.
Lisfranc fracture-dislocation is a specific type of injury that disrupts the connection between one of the metatarsals and another bone in the foot called the medial cuneiform. There are two types: one where all the metatarsals shift in the same direction, and one where the metatarsals shift in opposite directions.
This type of injury often happens with other foot fractures, and it’s very important to catch it because it can be missed about 20% of the time. If the doctor sees a gap of more than 5mm between certain bones in your x-ray, they might suspect a Lisfranc fracture-dislocation. In any of these situations, it’s important to get the right diagnosis for the best treatment approach.
Metatarsal neck
Treatment Options for Metatarsal Fractures
In the case of metatarsal fractures that haven’t shifted out of place, non-surgical methods like adhesive strapping, wearing a walking cast for about a month, or not bearing weight on the foot could be opted for, except in the case of professional athletes who need to avoid long periods of immobility. On the other hand, fractures of the first and fifth metatarsals that have shifted out of place will usually require surgery to avoid further deformities.
If open metatarsal fractures occur, the procedure to be followed includes thoroughly cleaning and washing the wound, stabilizing the fracture using temporary or minimal internal structures, and taking antibiotics post-surgery. Subsequent follow-up surgeries may also be planned. Several implants, including K-wires, mini fragment plates, and screws, can be used to assist in the process.
The first metatarsal is crucial in maintaining foot balance. In case it is fractured, internal fixation or surgical immobilization is typical. The surgical treatment for a fracture in the shaft of the first metatarsal often involves using two crossed K-wires for stable fixation. If the bone fracture is complex, plates can be used and should ideally be placed over the medical-plantar aspect. Extensive fractures may sometimes need external fixation rather than internal due to potential postoperative infection risks.
The second to the fourth metatarsals are relatively more stable due to strong ligament connections and minimal movement, allowing for a high degree of intrinsic stability. In case of displacement due to severe trauma, these metatarsals usually displace together. The aim of treatment for these fractures is to restore the length in the sagittal plane. In most cases, the treatment of choice is percutaneous pinning, a procedure performed under X-ray guidance where wires are inserted through the skin into the bone to hold the fracture together.
The fifth metatarsal should be managed surgically, especially if the bone has moved out of place. While initial management can be conservative, surgery becomes necessary if the healing process is slow, such as in athletes or in cases where healing hasn’t taken place even after ten weeks. As for all metatarsal fractures, it’s important to distinguish between non-union, delayed union, stress fractures, and acute injuries to make accurate diagnoses and proceed with the most appropriate treatment plan.
What else can Metatarsal Fractures be?
When a doctor suspects a person has a fracture in their foot bones (metatarsals), they have to rule out some other conditions that might cause similar discomfort. These may include:
- Ankle sprains – when the ligaments that support the ankle stretch beyond their limits and tear.
- Plantar fascia ruptures – a tear in the tissue that connects your heel to your toes, often causing severe heel pain.
- Peroneal tendon injuries – damage to the tendons that run along the outer edge of your foot and help stabilize your ankle.
- Sesamoiditis – inflammation of the small bones under the big toe.
- Freiberg infraction – a condition that causes pain and stiffness in the second or third toes due to lack of blood flow.
- Osteomyelitis – a bone infection often caused by bacteria.
- Neuropathic osteoarthropathy – also known as Charcot foot, it’s a condition that can cause fractures and dislocations of bones and joints in the foot.
- Tenosynovitis – inflammation of the protective sheath that surrounds a tendon.
- Bursitis – inflammation of the cushioning pads around joints.
- Calluses – hardened areas of skin that have become relatively thick and tough in response to repeated friction or pressure.
- Morton’s neuromas – a painful condition affecting the ball of the foot, most commonly the area between the third and fourth toes.
The doctor can differentiate between these conditions through a detailed physical examination and necessary x-rays or other imaging studies.
What to expect with Metatarsal Fractures
If you have a minor fracture in your metatarsal bone in your foot that doesn’t move much from its original position, you can usually expect a good outcome if you rest and stabilize your foot adequately. This is particularly true for fractures at the base of the metatarsals, as this area is made of a type of bone known as cancellous bone, which typically heals well.
Similarly, fractures in the first metatarsal bone tend to heal well due to the beneficial properties of the cancellous bone. Central metatarsal fractures also usually recover quickly, thanks to the natural stability of this area and the ample blood supply from the surrounding muscles.
However, a specific type of fracture known as a Jones fracture, may not heal well because there isn’t much blood supply in this area and it’s subject to many forces that can move the fracture out of place. But on a positive note, other types of fractures in the same area, like those where a small chunk of bone gets pulled away from the ‘tuberosity’ of the fifth metatarsal, usually heal well.
Possible Complications When Diagnosed with Metatarsal Fractures
After a metatarsal fracture, where surgery was not performed, there can be several complications. The most typical issue is metatarsalgia, which is foot pain often due to imperfect healing or persisting deformity. Additionally, there can be several other complications such as delayed healing, failure to heal, post-injury deformations such as misalignment of the fifth toe, and joint disease. Though less common, other complications can include failure to heal, hardware failures in case of supportive device use, irritation caused by these devices, and injuries to the sural nerve, a nerve running down the leg to the foot.
Common Complications:
- Metatarsalgia (foot pain)
- Delayed healing
- Failure to heal
- Post-injury deformations
- Joint disease
- Hardware failures (for supportive devices)
- Device-caused irritation
- Sural nerve injuries
Preventing Metatarsal Fractures
If you’ve been experiencing foot pain for a while, it’s crucial to get your foot checked. Even without a prior injury, you could have stress fractures in the bones of your foot, specifically the metatarsals, and these fractures might go unnoticed. They often don’t appear on standard x-rays and might require more detailed imaging examinations to be spotted.
Those diagnosed with these metatarsal fractures should get proper treatment and physical rehabilitation. Ignoring these fractures could lead to further painful conditions such as Morton’s neuroma, which can cause ongoing disability.
