The fifth metatarsal bone is the long bone on the outside of the foot that connects to the little toe, while the first metatarsal bone connects to the big toe.
The two most common types of fractures of the fifth metatarsal bone are:
- Demolition fractures. In a demolition fracture, a small part of the bone is torn out by a tendon or ligament. This type of fracture is often the result of an ankle distortion.
Similarly, a fracture of the outer ankle can occur.
A demolition fracture is often neglected (not treated), especially in children, if it occurs in conjunction with an ankle distortion.
- Jones fracture. Jones fractures occur in a small area of the fifth metatarsal bone that is less supplied with blood and therefore heals more slowly.
A Jones fracture can be a stress injury (many repeated microfractures) or an acute fracture (trauma). These fractures are caused by overuse, repetitive stress, or trauma. They are less common and harder to treat than a demolition fracture.
Other types of fractures can also occur on the fifth metatarsal bone, such as “central” fractures, usually caused by trauma or distortions, and fractures to the head or neck of the metatarsal bone.
Causes of a fracture of the fifth metatarsal bone
A fracture of the fifth metatarsal bone usually occurs in conjunction with an ankle distortion, especially if the ankle has twisted inwards.
The fracture can also occur due to an unfortunate landing after a jump (especially on uneven surfaces) or caused by a fall or a direct blow to the outside of the foot. Fractures of the fifth metatarsal bone often occur while running or jumping, especially in sports that often change direction, such as football, rugby, basketball or dancing.
Symptoms of fracture of the fifth metatarsal bone
The most common symptoms of a fracture of the fifth metatarsal bone are foot pain on the outside and surrounding stiffness.
Normally, a hematoma forms and the foot swells. In addition, you can not occur with the affected foot.
The mobility of the foot may also be limited.
Stress fractures mostly occur in young patients and athletes, especially at the beginning of the sports season. Patients complain of pain at the base of the fifth metatarsal bone and may have a patchy hemorrhage (ecchymosis) or edema at the site of the fracture.
Also, patients often report that they had already felt discomfort and pain at the base of the fifth metatarsal bone a month earlier.
Warning signs may occur weeks or months before the fracture event.
Diagnosis of a fracture of the fifth metatarsal bone
It is important to recognize whether it is a stress or acute Jones fracture, as treatment and prognosis are very different.
The type of fracture can be determined from the patient’s description.
If the pain has existed for a long time, it is probably a stress fracture.
The patient’s medical history is the most important part, because on the X-ray a distinction is almost impossible.
Although some authors argue that a stress fracture occurs in a different anatomical area than an acute fracture, there is no evidence to support this claim.
Diagnostic examinations for fractures of the fifth metatarsal bone
First of all, the doctor orders radiography. Since a Jones fracture is often not apparent from the X-ray in the first few days, further diagnostic examinations may be necessary.
X-ray image of a stress fracture of the fifth metatarsal X-rays
are important for the diagnosis of traumatic fractures. An acute fracture appears as a dark line and as an interruption of the cortical surface. Dislocated fractures as a result of an impact may appear as a dull line; these fractures can be confirmed by shooting from another projection plane.
Fractures can affect any metatarsal bone, but usually occur on the fifth. A fracture can be transverse, oblique or shattered.
Linear longitudinal fractures are extremely rare.
The radiological findings of a stress fracture depend on the bone involved and the stage of injury. At the first stages of injury, the X-rays appear normal; in fact, stress fractures appear as a dark defined line only after 7-10 days.
The heads of the second and, extremely rarely, the third metatarsal bone can also suffer fractures. The first metatarsal bone breaks in 10% of stress fractures; this type of fracture shows a different reaction, on the images you can only see a linear lesion.
The base of the second metatarsal bone often breaks in dancers.
The area near the ankle of the fourth and fifth metatarsal bones is affected, a dark line can be seen in the X-ray and the fracture heals very slowly.
Fractures of the sesamoid bone are also common in dancers.
In the first stages of these injuries, X-rays do not reveal a stress fracture in 50% of patients.
In addition, an undisplaced fracture can be difficult to detect.
The associated injuries of ligaments and changes in soft tissue are not visible on the X-ray.
CT is not strictly necessary for the diagnosis of a metatarsus fracture; however, if it is provided, CT must be performed in at least 2 planes: on the coronal plane (perpendicular to the sole of the foot) and on the axial plane (parallel to the sole).
Magnetic resonance tomography
Although magnetic resonance imaging is useful for the diagnosis of fractures, it is not necessary in this case, since radiography alone provides sufficient specific findings. Magnetic resonance imaging is still helpful for evaluating fractures and dislocations, soft tissue, sole of the foot, joint capsule structures, exact number of bones affected, and fragments of small fractures.
Treatment of a fracture of the fifth metatarsal bone
Because the blood supply in this area is low, healing these types of fractures is often difficult.
Even though metatarsal fractures can be treated without surgery, there is a significant risk of incomplete bone healing and a valuable loss of time before one can return to one’s daily activities. A non-surgical treatment consists of a prolonged immobilization of the joint with a boot that prevents you from stepping on with the foot. An operation performed in the orthopedics department can accelerate the “speed of bone callus formation” and shorten the recovery time so that rapid rehabilitation is possible.
Four different fracture patterns were observed.
- Type I: occurs at the junction between the extra-articular and intra-articular part of the protrusion of the fifth metatarsal bone;
- Type II: at the proximal joint (the area closer to the ankle) of the fifth metatarsal bone;
- Type III: occurs at the distal joint (the area farther from the ankle) of the fifth metatarsal bone;
- Type IV: occurs in the diaphysis (central area).
Before the development of the Torg classification, many pseudarthroses in patients were interpreted as Jones fractures.
It was found that these pseudarthroses were due to an interruption in the blood supply to the bone.
However, if the fracture has been correctly classified as type I or type II, conservative treatment is not used, unless it concerns professional athletes, advanced amateur athletes or patients who prefer surgical treatment.
Type I fractures are treated with immobilization (without stress), a short plaster cast or a brace for six to eight weeks with gradual rehabilitation after removal of the plaster cast.
Type II fractures can also be treated with a plaster cast without stress, but complete healing may take longer.
A bandage is not sufficient.
In professional athletes, these fractures are usually treated surgically with a bone graft or with a screw connection of the bones. Type III fractures should be treated surgically. Complications associated with surgical fixation may be associated with persistent pain at the base of the fifth metatarsal bone, requiring removal of the screws and adjustment of the shoe.
Additionally, surgical treatment of acute Jones fractures may lead to a delay in consolidation, pseuarthritis, and new fractures.
Treatment of stress fracture
Stress fractures are treated like acute proximal fractures of the fifth metatarsal bone.
It is important to note that stress-free immobilization over 20 weeks may be necessary and that magnetic therapy can reduce the period for bone callus formation.
The treatment options as well as possible complications due to prolonged immobilization (such as sympathetic reflex dystrophy and muscle atrophy) should be fully explained to the patient in advance when discussing the treatment.
The treatment of type II and type III stress fractures is equivalent to the treatment of acute fractures described above.
Sometimes the bone is not cast because the fracture is undisplaced and the patient has little pain. Nevertheless, consolidation also takes a very long time here.
The surgical procedure is the same for stress fractures and acute Jones fractures. It is a small incision on the outside of the foot that allows the insertion of a screw along the fifth metatarsal bone.
Numerous scientific studies show that the screw should be as long and wide as possible, with a diameter of at least 4 millimeters.
After surgery, the foot is protected with a splint and bandage until the wound heals. The gradual load can begin as early as two weeks after surgery and can be slowly increased depending on pain tolerance.
In some studies, the median recovery time is between six and eight weeks. However, one should follow the instructions of the orthopedist who performed the operation to know when to load with the full body weight.
Patients are often able to resume exercise as early as three months after surgery.
If the patient develops symptoms related to the screw head after healing, its removal may be necessary.
Some patients require physical therapy and rehabilitation to regain strength and mobility.
Stress fractures usually heal without complications.
Over time, patients can fully resume their previous activities.
One can return to normal activity if one can perform it without feeling pain.
The foot swelling decreases after a few months. There are some natural remedies that can speed up healing, such as saltwater baths or arnica ointments.
It can take anywhere from 3 months to up to a year to achieve this goal. It is important to gradually resume sports and work after a stress fracture.
There are several ways to prevent stress fractures:
- The intensity and duration of training must be increased slowly and gradually.
- The times for rest and recovery must be gradually increased in each training program.
- One should be aware of the symptoms of stress fractures, because if they are treated quickly, one can shorten downtime.
- You should make sure that the footwear is of high quality and used correctly.