Stress Fracture

How stress fractures happen

Bone constantly remodels: small areas of damage from normal loading are removed and replaced. When training increases too quickly, or bone quality is poor, damage outpaces repair, and the bone develops a stress reaction that can progress to a crack.

Two types:

• fatigue fractures: normal bone under abnormal, repetitive stress (typical athletes)
• insufficiency fractures: weakened bone, such as with osteoporosis, under normal stress

Common and high-risk sites

High-risk fractures need prompt diagnosis, strict non-weight-bearing and sometimes surgery.

Stress fracture vs shin splints

Symptoms

• pain that develops gradually, worse with weight-bearing activity
• pain that eases with rest at first, later present at rest or at night
• a pinpoint, tender spot on the bone
• swelling on top of the foot or around the ankle
• pain when hopping on the affected leg

Risk factors

• training errors: rapid increases in mileage or intensity, hard surfaces, inadequate rest
• relative energy deficiency in sport (REDs): too little energy intake for training, which in women often causes missed periods and lower bone density; it also affects men
• low vitamin D and calcium, see vitamin D deficiency
• eating disorders, including anorexia nervosa
• previous stress fracture
• biomechanics: high or flat arches, leg length differences
• worn-out or unsupportive shoes
• osteoporosis, smoking, steroid use

Diagnosis

• history and examination: training changes, diet, menstrual history, and tenderness at a specific spot
• X-rays: often normal in the first 2 to 3 weeks; healing bone may show later
• MRI: the most sensitive test; shows bone stress injury early and grades severity
• CT for some sites such as the navicular
• blood tests and bone density scan for recurrent fractures or risk factors

Treatment

Low-risk stress fractures

• rest from the painful activity, typically 6 to 8 weeks
• a walking boot or stiff-soled shoe, and crutches if walking hurts
• ice and acetaminophen (paracetamol) for pain. Some clinicians prefer to limit NSAIDs during bone healing; ask your doctor
• cross-training that does not hurt, such as swimming, cycling or pool running, to maintain fitness
• gradual return to running once you are pain-free with walking and hopping, increasing distance by about 10% a week

High-risk stress fractures

• strict non-weight-bearing for several weeks
• close follow-up with imaging
• surgery (screw fixation) for some femoral neck, anterior tibia, navicular and fifth metatarsal fractures, or those that do not heal

Address the cause

• adjust training with a coach
• ensure adequate calories, calcium and vitamin D
• evaluate and treat REDs or eating disorders
• correct footwear and biomechanics

Prevention

• increase training load gradually
• include rest days and vary surfaces
• strength training for legs and core
• replace running shoes regularly
• eat enough to fuel training

Frequently asked questions

How can I tell if I have a stress fracture?

Typical signs are pain that builds during activity and eases with rest, a tender spot you can press on the bone, swelling, and pain when hopping. X-rays are often normal early, so an MRI may be needed to confirm it.

What are the most common stress fractures?

The most common are in the shin bone (tibia), the long bones of the foot (metatarsals), the heel and the fibula. Hip, navicular and fifth metatarsal stress fractures are less common but higher risk.

How long does a stress fracture take to heal?

Most low-risk stress fractures heal in about 6 to 8 weeks of rest from impact. High-risk fractures can take 3 months or more and may need surgery. Returning gradually reduces the chance of re-injury.

Can you walk on a stress fracture?

For many low-risk fractures, walking in a supportive boot or shoe is allowed if it is pain-free. Running and jumping must stop until healed. High-risk fractures, such as the hip or navicular, often require crutches and no weight on the leg.