A non union fracture of the 5th metatarsal is a condition in which a broken bone in the outer part of the foot does not heal properly over time. The 5th metatarsal is the long bone located on the outside of the foot, connecting the midfoot to the little toe. Fractures in this area are common, especially among athletes, runners, dancers, and people who twist their foot during walking or sports activities. While many 5th metatarsal fractures heal with rest and proper treatment, some develop into a non union fracture, meaning the broken bone fails to heal completely.
This condition can lead to long-term pain, swelling, weakness, and difficulty walking. A non union fracture of the 5th metatarsal often requires more advanced treatment than a simple foot fracture. Understanding the causes, symptoms, diagnosis, and treatment options can help patients recover more effectively and reduce the risk of long-term complications.
What Is a Non Union Fracture of the 5th Metatarsal?
A non union fracture occurs when the broken pieces of bone do not grow back together after several months. Normally, a fractured bone starts healing soon after the injury. Blood flow increases to the area, new bone tissue forms, and the fracture gradually closes. In a non union fracture, this healing process slows down or stops completely.
The 5th metatarsal is especially vulnerable to non union because some parts of the bone have limited blood supply. This is particularly true in fractures that occur near the base of the bone, such as a Jones fracture. When blood flow is poor, healing becomes more difficult, increasing the risk of delayed union or non union.
Types of 5th Metatarsal Fractures
- Avulsion fracture
- Jones fracture
- Stress fracture
- Shaft fracture
- Comminuted fracture
Among these fracture types, Jones fractures are most commonly associated with non union because they occur in an area with reduced blood circulation.
Common Causes of Non Union Fracture
Several factors can contribute to a non union fracture of the 5th metatarsal. In some cases, the original injury may have been severe enough to prevent normal healing. In other situations, the patient may return to walking, running, or sports too soon before the bone has fully recovered.
Poor blood flow is one of the biggest reasons why non union develops in this part of the foot. The outer section of the 5th metatarsal has fewer blood vessels compared to other bones, making it slower to heal. Smoking, diabetes, poor nutrition, and certain medications can also interfere with bone healing.
Risk Factors for Non Union
- Poor blood supply to the fracture site
- Smoking or tobacco use
- Diabetes
- Vitamin D deficiency
- Returning to activity too early
- Improper immobilization
- Repeated stress on the foot
People who participate in high-impact sports may also face a higher risk because repeated movement and pressure can prevent the fracture from healing properly.
Symptoms of a Non Union Fracture
The symptoms of a non union fracture of the 5th metatarsal may continue for months after the original injury. Instead of gradually improving, the pain often stays the same or becomes worse with activity. Swelling on the outside of the foot is also common, especially after standing or walking for long periods.
Patients may notice that they still cannot put full weight on the foot without discomfort. Some people feel sharp pain during walking, while others experience a dull ache that never completely goes away. In severe cases, there may be visible deformity or instability in the foot.
Common Symptoms
- Persistent pain on the outside of the foot
- Swelling near the fracture site
- Difficulty walking
- Tenderness when touching the bone
- Pain that increases with activity
- Weakness or instability in the foot
How Doctors Diagnose the Condition
Diagnosing a non union fracture usually begins with a physical examination. A doctor will ask about the original injury, symptoms, activity level, and how long the pain has been present. They may press on the outer side of the foot to check for tenderness and swelling.
Imaging tests are often necessary to confirm the diagnosis. X-rays are commonly used to see whether the bone has healed. If the fracture is difficult to evaluate, a CT scan or MRI may provide a more detailed view of the bone and surrounding tissues.
Doctors usually consider a fracture to be a non union if it has not healed after several months and there is no clear sign of progress on imaging studies.
Treatment Options for Non Union Fracture
Treatment for a non union fracture of the 5th metatarsal depends on the severity of the condition, the patient’s activity level, and how long the fracture has been present. Mild cases may improve with rest, immobilization, and avoiding weight-bearing activities. More severe cases may require surgery.
Non-Surgical Treatment
Non-surgical treatment often includes wearing a walking boot, cast, or brace to protect the foot. Patients may need crutches to avoid putting weight on the injured side. Bone stimulation devices may also be used to encourage healing by improving blood flow and bone growth.
- Rest and activity modification
- Protective walking boot or cast
- Crutches to reduce pressure on the foot
- Bone stimulation therapy
- Nutritional support and vitamin supplements
Surgical Treatment
Surgery is often recommended when the fracture has failed to heal despite conservative treatment. The most common procedure involves placing a screw inside the 5th metatarsal to stabilize the bone. In some cases, bone grafting may also be necessary to help the fracture heal.
Bone grafts may come from another part of the patient’s body or from a donor source. These grafts help stimulate bone growth and improve the chances of healing.
Recovery and Rehabilitation
Recovery from a non union fracture of the 5th metatarsal can take several months. Even after surgery, patients may need to avoid putting full weight on the foot for several weeks. Physical therapy is often recommended to restore strength, balance, and flexibility.
Rehabilitation exercises may focus on improving foot movement, rebuilding calf strength, and restoring a normal walking pattern. Patients should follow medical advice carefully because returning to sports or heavy activity too early can increase the risk of another fracture.
Tips for Recovery
- Follow weight-bearing restrictions
- Attend physical therapy sessions
- Wear supportive footwear
- Avoid high-impact activities during healing
- Maintain good nutrition for bone health
How to Prevent Future Fractures
Preventing another 5th metatarsal fracture often involves making changes to activity levels, footwear, and overall bone health. People who participate in sports should wear shoes that provide proper support and cushioning. Stretching before exercise and increasing training intensity gradually may also help reduce injury risk.
Healthy bones are less likely to fracture, so maintaining good nutrition is important. Calcium, vitamin D, and protein all support bone strength. Avoiding smoking and managing medical conditions such as diabetes can also improve bone healing and reduce future risk.
People who have already experienced a non union fracture should be especially careful about returning to sports too quickly. Giving the foot enough time to heal fully is one of the most important ways to prevent another injury.
A non union fracture of the 5th metatarsal is a serious foot condition that occurs when a broken bone does not heal properly. It can cause ongoing pain, swelling, and difficulty walking, especially if left untreated. Because the 5th metatarsal has limited blood supply, certain fractures in this area are more likely to become non unions. Early diagnosis, proper treatment, and careful rehabilitation are essential for recovery. Whether treatment involves rest, immobilization, or surgery, following medical advice closely can improve healing and help patients return to normal activities safely.