What is the fifth metatarsal?
The metatarsal bones are the long bones in the middle of the foot. Each metatarsal bone has a base, a shaft, a neck and a head. The fifth metatarsal is the last bone at the outside of the foot, and most breaks of the fifth metatarsal occur at the base.
What is the goal of fifth metatarsal fracture surgery?
The majority of fifth metatarsal fractures are treated without surgery. However, certain situations may require surgical
treatment. Surgery can be performed to help the bone heal in a correct position and return the patient to full function. Surgery may reduce the time needed for immobilization and improve the chance of healing compared to nonsurgical treatment.
What signs indicate surgery may be needed?
The base of the fifth metatarsal is divided into three fracture zones. Zone 1 fractures are avulsion or “chip” fractures that occur at the tip of the base of the fifth metatarsal. These fractures are typically treated without surgery using a cast, boot or hard-soled shoe. These fractures tend to heal within six to eight weeks.
Zone 2 fractures are typically known as Jones fractures. They occur at the intersection between the base and the shaft of the fifth metatarsal (figure 1). These fractures are known to have a higher chance of not healing (nonunion). They are also at risk of refracture even after healing. Surgical treatment is commonly performed for these fractures.
Zone 3 fractures happen along the shaft of the fifth metatarsal. These are typically stress fractures in athletes. Lengthy healing times and risk of refracture may be reasons for surgical repair in these fractures.
When should I avoid surgery?
Surgery is not indicated in a fracture where there is an infection or severely damaged soft tissue. Sometimes the base of the metatarsal breaks into many small pieces, and when this happens, your surgeon may choose to fix the fracture with a plate rather than a screw. Your surgeon may also choose to remove part of the broken bone instead of trying to reattach it.
General Details of Procedure
There are many surgical options for fifth metatarsal fractures. One popular technique is a surgery where a screw is inserted
into the fifth metatarsal (intramedullary screw fixation). Fractures of the shaft of the metatarsal are typically fixed with a plate and screws. These procedures can be performed as an outpatient procedure under either general anesthetic or regional anesthesia.
The surgical incision for an intramedullary screw is typically no more than a stab incision at the base of the fifth metatarsal. An X-ray machine is used to guide the screw placement (figure 2). The screw threads cross the fracture site and allows for the fracture ends to be squeezed together. If bone grafting is needed, such as in a chronic fracture that has failed nonoperative treatment, then a separate incision may be needed over the fracture to insert the bone graft or bone graft substitute.
What happens after surgery?
For the first seven to 14 days after surgery, you may be allowed to weight bear through the heel, but some surgeons will not allow you to bear any weight on the injured foot. This could last as long as six weeks. Weight bearing in a removable walking boot is allowed after that. Patients can expect to return to full activity three to four months after a typical fracture. This includes returning to sports. Some fractures may require bone grafting and have longer recoveries. The screw is not usually removed unless it causes discomfort.
There are complications that relate to surgery in general. These include the risks associated with anesthesia, infection, damage to nerves and blood vessels, and bleeding or blood clots.
Some complications can result in the need for repeat surgery. The metatarsal fracture may not heal and can become a nonunion. Another rare but serious complication is a re-fracture after fixation. Some patients may be at greater risk for poor healing or re-fracture due to the shape of their foot. A high-arched foot or a heel that turns in can put extra pressure on the fifth metatarsal and affect healing.
Frequently Asked Questions
If I have a zone 2 fracture of the base of the fifth metatarsal, will I jeopardize my chance of bone healing if I try nonoperative treatment first?
Most of these breaks will go on to heal after 12 weeks with appropriate treatment. The nonunion rate of these fractures may still be as high as 15 to 20 percent. A fracture that fails to heal and is painful may require surgical repair. The surgery can be more difficult at that point and can require a bone graft.
If I have a fracture of the neck or shaft of the metatarsal, is there a need for surgery?
The need for surgery in these fracture types depends on the degree of deformity. Rotational deformity of the little toe, angulation of the shaft of the metatarsal with a change in the shape of the foot, and shortening as a result of the fracture are a few of the reasons for surgical repair.
If I choose not to have surgery and use a walker boot for six weeks, is there any other treatments that can help accelerate healing?
There is some evidence that electromagnetic bone stimulation may be useful in increasing healing rates and reducing time for healing in zone 2 fractures of the base of the fifth metatarsal. However, more evidence is needed before these therapies can be recommended to all patients with such fractures.
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