Fifth Metatarsal Fracture
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.
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 non-surgical treatment.
Diagnosis
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 typically are treated without surgery using a cast, boot, or hard-soled shoe and tend to heal within 6-8 weeks.
- Zone 2 fractures are known as Jones fractures. They occur at the intersection between the base and the shaft of the fifth metatarsal. These fractures are known to have a higher chance of not healing (nonunion). They also are at risk of refracture even after healing. Surgery is common for these fractures due to the risk for delayed healing or reinjury.
- Zone 3 fractures happen at the junction of the wide portion of the bone with the shaft of the fifth metatarsal. These typically are stress fractures, and may be associated with symptoms prior to the fracture, or with minimal trauma that still results in a fracture. Lengthy healing times and risk of refracture may be reasons for surgical repair in these fractures.
Surgery is not indicated in a fracture where there is an infection or severely damaged soft tissue. Zone 1 fractures that are not displaced do not require surgery, and most fifth metatarsal shaft fractures without significant displacement do not require surgery.
Treatments
There are many surgical options for fifth metatarsal fractures. One popular technique (for zone 2 and 3 fractures) is a surgery where a screw is placed lengthwise within the bone (intramedullary screw fixation). Fractures of the shaft of the metatarsal are fixed with a plate and screws. These procedures can be performed under general or regional anesthesia with the patient going home the same day.
Specific Techniques
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. The screw threads cross the fracture site and allow for the fracture ends to be squeezed together. If bone grafting is needed, such as in a chronic fracture that has failed non-operative treatment, then a separate incision may be needed over the fracture to insert the bone graft or bone graft substitute.
Screw fixation of a fifth metatarsal base fracture
Recovery
For the first 7-14 days after surgery, you may be allowed to weight bear through the heel but typically not through the front of the foot. This could last as long as six weeks (sometimes longer based on healing and other factors such as diabetes). Weight bearing in a removable walking boot is allowed after that. Patients can expect to return to full activity 3-4 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.
Risks and Complications
All surgeries come with possible complications, including 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 may require other surgical procedures to change the architecture of the foot.
FAQs
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 non-operative 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 may 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, are 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.
Is there any role for PRP or stem cell injections?
This is a relatively new and not well researched area currently. No recommendation for these injections can currently be made; they are not typically covered by insurance and can be quite expensive without data to suggest that they improve results. However, you should be aware that even if the biology can be improved with injections, these will not alter the mechanics of the foot. An increasing number of orthopedic practices are providing these injections. You should speak with your foot and ankle orthopedic specialist who is best educated to evaluate the full spectrum of care including non-surgical and surgical options.