Stress Fractures

A stress fracture is a tiny crack in a bone caused by repeated impact rather than a single hard hit. Bone is constantly remodeling itself, breaking down and rebuilding stronger. When you load it faster than it can rebuild (think a runner ramping up mileage too quickly, or a soldier in a new training program), microscopic cracks accumulate until they form a real fracture. Stress fractures fall into two big buckets. Low-risk stress fractures (the inner side of the tibia, the metatarsals in the foot, the smaller leg bone, the rim of the pelvis) heal reliably with rest and activity changes. High-risk stress fractures (the front of the tibia, the navicular bone in the foot, the Jones zone of the fifth metatarsal, the neck of the femur, the inner ankle, the kneecap, the small bones under the big toe) are different: they often don't heal on their own and may need surgery, especially in athletes.

In women with recurring stress fractures, we screen for the Female Athlete Triad, a combination of disordered eating, missed periods, and reduced bone density. The triad substantially raises stress fracture risk and is treatable; missing it can mean years of repeat injuries.

• Pain in a specific spot on the bone that comes on during activity and eases with rest
• Pain that gets worse over days to weeks as you keep training through it
• Tenderness when you press directly on the bone at the painful spot
• Mild swelling over the area, sometimes barely visible
• Pain that starts later in a run or workout and now begins earlier and earlier each session
• Night pain or pain at rest in advanced cases, a sign the fracture is worsening

Plain X-rays often miss stress fractures in the first few weeks, because the bone changes lag behind the injury. An MRI is the most sensitive test and shows how far along the injury is. A bone scan is an alternative when MRI is not available. For high-risk sites, a CT scan checks whether the fracture has broken through the outer wall of the bone. For repeated or unusual stress fractures, we add a bone density scan (DEXA) to look for underlying weakness.

The single most important thing to know: most stress fractures heal with rest alone. The whole job is taking the load off the bone long enough for it to finish rebuilding. Low-risk stress fractures heal reliably this way; the high-risk sites need closer watching and sometimes more. The steps below build on each other: each one is added depending on where the fracture is and how far along it is, not swapped in for the last.

High-risk stress fractures are the surgical ones, especially the navicular bone in the foot, the upper-outer side of the thigh-bone neck, and a long-standing stress fracture on the front of the tibia that often refuses to heal on its own. Active patients with these fractures, or any stress fracture that has broken through the outer wall of the bone, are candidates for surgical fixation with a screw or plate.

External patient-education references and related OSI pages for additional background:

• AAOS OrthoInfo, patient education library
• OSI glossary, orthopedic terminology in plain language