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Health condition

Atypical femoral fractures

Atypical femoral fractures are stress-type fractures of the thigh bone’s shaft associated with long-term antiresorptive therapy (bisphosphonates, denosumab); weeks of prodromal thigh ache precede many of them, making awareness genuinely protective for the millions on these drugs.

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against current NHS and UK specialist society guidance at the time of review.

  • 03

    Current for 2026

    Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.

Key facts

The essentials at a glance.

The symptoms to recognise, when to seek help, which specialist to see, and what treatment usually involves.

  • Warning symptom: dull, aching thigh or groin pain in someone on long-term bisphosphonate or denosumab therapy - this "prodrome" precedes many complete fractures

  • The fracture is transverse, in the shaft or subtrochanteric region, often after minimal or no trauma, with characteristic cortical thickening ("beaking") on X-ray

  • Both femurs are imaged when one is affected - a substantial minority have changes on the other side

  • Management: stop the antiresorptive, ensure calcium and vitamin D, surgical fixation (intramedullary nail) for complete or painful incomplete fractures; teriparatide is often used to promote healing

  • Perspective matters: these fractures are rare, and for high-risk patients bisphosphonates prevent many times more fractures than they cause

Understanding the condition

What it is and what happens next.

What causes it, how it is diagnosed, and the treatment routes available in the UK.

What it is and how it feels

Years of suppressed bone remodelling can allow microdamage to accumulate at the femur’s point of maximal bending stress, where a stress fracture slowly develops - announced, in over half of cases, by weeks or months of thigh ache that is easily dismissed. An X-ray showing lateral cortical beaking at the painful site changes everything; missed, the bone can snap completely during ordinary walking.

Diagnosis and treatment routes

Any persistent thigh or groin pain on long-term antiresorptive treatment warrants imaging - X-ray first, MRI or isotope scan if normal but suspicion remains - plus imaging of the opposite femur. Confirmed cases are managed jointly: prophylactic nailing for incomplete fractures with pain or a visible lucent line, drug holiday and bone-formation support for the rest, and a structured re-think of long-term osteoporosis strategy, which for most high-risk patients still includes antiresorptive therapy after recovery, given the far larger number of hip and spine fractures these drugs prevent. In much of the UK, a routine NHS referral to the relevant specialist clinic can take several months, whereas an initial appointment with a private consultant is typically available within around two weeks.

Seeing a specialist

Who to see, and how quickly you can be seen.

The specialist for this condition is usually a metabolic bone specialist and orthopaedic surgeon. Your GP can refer you on the NHS, or you can arrange a private consultation directly.

A quiet reminder

This guide is for information, not medical advice.

Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any of the emergency symptoms described above.

Frequently asked

Common questions about Atypical femoral fractures.

Quick, plain-English answers to what people ask us most.

  • What is atypical femoral fractures?

    Atypical femoral fractures is a type of injury to the affected structure, which can be partial or complete, and mild, moderate or severe. It typically follows a specific incident such as a fall, twist, impact or overuse, although some cases build up gradually. The severity of the injury largely determines the symptoms, the treatment needed and the recovery time.

  • What causes atypical femoral fractures?

    Atypical femoral fractures is usually caused by a specific traumatic event, such as a fall, a sudden twisting movement, a direct blow, or repetitive overuse of the affected area. Certain sports, occupations and pre-existing weakness in the surrounding tissue can increase the risk. In some cases the exact moment of injury is not obvious, and symptoms build up over days.

  • What are the symptoms of atypical femoral fractures?

    Symptoms of atypical femoral fractures vary from person to person and depend on how severe the condition is and which structures are affected. Some people notice symptoms gradually over weeks or months, while others experience a more sudden onset. Because symptoms can overlap with other conditions, a proper assessment is important to reach an accurate diagnosis rather than relying on symptoms alone.

  • Is atypical femoral fractures serious or dangerous?

    Most cases of atypical femoral fractures are manageable, especially when identified and treated early, but severity varies from mild and self-limiting to more significant, depending on individual circumstances. Left unassessed, some cases can lead to complications or a longer-term impact on daily life. If you are worried about your symptoms, it is always worth getting them checked rather than waiting.

  • How long does atypical femoral fractures take to heal?

    Healing time for atypical femoral fractures depends on the severity of the injury, the specific tissue involved, and how well any treatment or rehabilitation plan is followed. Mild cases may settle within a few weeks, while more significant injuries can take several months to heal fully. Returning to normal activity too soon can slow recovery or increase the risk of re-injury, so it is worth following professional guidance on pacing your return.

  • Can atypical femoral fractures be cured, reversed or prevented?

    Outlook varies with atypical femoral fractures: some cases resolve completely with treatment, others improve significantly but need ongoing management, and a smaller number become a long-term condition to be controlled rather than cured. Prevention strategies, such as addressing modifiable risk factors, can reduce your chances of developing it or of it recurring, but cannot guarantee against it in every case.

  • How is atypical femoral fractures treated?

    Treatment for atypical femoral fractures is tailored to the individual and depends on severity, underlying cause and personal circumstances. Options can range from simple lifestyle measures, monitoring and conservative treatment through to medication, specialist procedures or surgery in more significant cases. A specialist assessment helps identify which combination of treatments is most appropriate for you.

  • Will atypical femoral fractures affect me long term?

    Most people recover well from atypical femoral fractures and return to their normal activities, particularly with appropriate treatment and rehabilitation. A minority of more severe cases can leave some residual stiffness, weakness or reduced function, especially if treatment is delayed. Following a structured recovery plan gives the best chance of a full return to function.

  • When is surgery needed for atypical femoral fractures?

    Surgery is not usually the first option for atypical femoral fractures and is generally reserved for cases where conservative treatment has not worked, symptoms are severe, or there is a significant structural problem that needs to be corrected directly. The decision depends on your specific findings, symptoms and how they are affecting your life. A specialist consultation is the best way to establish whether surgery is being considered too early, or should be considered sooner rather than later.

  • When should I see a doctor about atypical femoral fractures, and how quickly can I be seen privately?

    It is worth seeing a doctor about atypical femoral fractures if symptoms are persistent, getting worse, or affecting your daily life, rather than waiting to see if they settle on their own. NHS routine referrals to a specialist can currently take anywhere from around 20 to 45 weeks or more depending on your area, whereas a private consultant can typically see you within about 2 weeks. Getting an earlier assessment can help clarify the diagnosis and start the right treatment sooner.