Non-Union Fracture Repair

Introduction

When a bone breaks, the body normally starts a healing process that knits the broken ends back together over weeks to months. In most people, this happens without difficulty. In a smaller number of cases, the bone does not heal as expected. When healing stalls for long enough that doctors no longer expect it to finish on its own, the fracture is called a non-union.

If you are reading this, you have most likely been told that a fracture you sustained months ago has not healed. You may be dealing with ongoing pain, a limb that does not feel stable, or repeat X-rays that look much the same as they did weeks ago. The next step is usually a procedure called non-union fracture repair — surgery designed to remove the tissue that is blocking healing, stabilise the bone properly, and give it the biological help it needs to finally unite.

This guide explains what non-union fracture repair is, why fractures sometimes fail to heal, the surgical and non-surgical options doctors consider, what happens during and after surgery, how recovery typically unfolds, and what to expect in the longer term. It is written for patients planning the next phase of their care, not for emergency situations.

What Is Non-Union Fracture Repair?

A non-union is a fracture that has not healed and is no longer showing progress toward healing on imaging. There is no single universally agreed time point, but orthopaedic surgeons commonly consider a fracture a non-union when there has been no clear healing progress on X-ray for at least three consecutive months, and at least six to nine months have passed since the injury. A related term, delayed union, is used when healing is slower than expected but still progressing.

Non-union fracture repair is the umbrella name for the surgical procedures used to treat a non-union. The aim of the surgery is not simply to fix the bone again. It is to address whatever stopped the bone from healing in the first place. That usually means a combination of:

• Removing dead bone, scar tissue, and any infected material at the fracture site
• Restoring good alignment of the bone ends
• Providing strong, stable fixation so the bone fragments cannot move
• Adding biological material — most often a bone graft — that encourages new bone to grow

Orthopaedic literature often describes successful bone healing as needing four things together: mechanical stability, living bone-forming cells, a scaffold for new bone to grow on, and the right biological signals. This is sometimes called the “diamond concept” of fracture healing. Non-union surgery is usually planned around restoring whichever of these elements was missing.

Why Fractures Fail to Heal

Understanding why a particular fracture has not healed shapes the choice of surgery. The cause is often a combination of factors rather than a single one.

Poor blood supply

Bone healing depends on a good blood supply bringing oxygen, nutrients, and healing cells to the fracture site. Some bones — including the scaphoid in the wrist, the femoral neck in the hip, the talus in the ankle, and the middle portion of the tibia (shin bone) — have naturally limited blood supply and are known to be at higher risk of non-union. High-energy injuries can also tear blood vessels around the bone and reduce the supply further.

Inadequate stability

For a fracture to heal, the bone ends need to be held still in relation to each other. If the original fixation was not strong enough, if a cast did not control movement well, or if hardware loosened or broke before healing was complete, the resulting micromotion can prevent proper bone union.

A gap between the bone ends

If too much bone was lost at the time of injury or removed during initial surgery, the gap may be too wide for the body to bridge on its own. This is common after high-energy open fractures and after surgery for bone infection or tumour.

Infection

An infection in or around the bone (osteomyelitis) interferes with the normal healing cascade. Infected non-unions are more complex and often need staged treatment — first to clear the infection, then to reconstruct the bone.

Patient-related risk factors

Several patient factors are well known to slow or block bone healing:

• Smoking and use of other tobacco products
• Poorly controlled diabetes
• Osteoporosis or other conditions that weaken bone
• Poor nutrition, including low protein, calcium, or vitamin D
• Long-term use of certain medications, particularly corticosteroids and some anti-inflammatory drugs
• Heavy alcohol use
• Some chemotherapy and immunosuppressive medications
• Peripheral vascular disease, which reduces blood flow to the limbs

If your fracture has been classified as a non-union, you may already be familiar with how it was identified. The typical picture includes:

• Pain at the original fracture site that has not settled with time
• Tenderness when the area is pressed
• A feeling of instability or abnormal movement at the fracture
• Swelling that persists or returns
• Difficulty putting full weight on a leg, or using an arm normally
• X-rays that show a persistent fracture line, a gap, or unchanged appearance over months

Orthopaedic surgeons also describe two broad patterns of non-union based on imaging. Hypertrophic non-unions show abundant bone formation around the fracture but no bridging across the gap — this usually points to a stability problem rather than a biological one. Atrophic non-unions show little or no new bone formation and suggest a biological problem, such as poor blood supply or infection. The pattern matters because it influences the surgical plan.

Diagnosis and Pre-Surgical Assessment

Before non-union surgery is planned, your orthopaedic team will usually gather a detailed picture of the fracture, the surrounding tissues, and your general health.

Imaging

• X-rays remain the primary tool, often compared with images taken weeks earlier to confirm there has been no progress.
• CT scan shows the bone in fine detail and can confirm whether any bridging bone is forming across the fracture — something X-rays sometimes miss.
• MRI assesses the soft tissues around the bone, the blood supply, and can help look for signs of infection.
• Bone scan is occasionally used to assess metabolic activity at the fracture site.

Tests for infection

If there is any suggestion of infection — previous open fracture, prior surgery, draining wound, fever, or raised inflammatory markers — blood tests such as ESR and CRP, and sometimes tissue samples taken during a separate procedure, may be done before definitive reconstruction.

General health review

Your surgeon will usually look at factors that affect healing: diabetes control, vitamin D and calcium levels, thyroid function, nutrition, smoking status, and current medications. Some of these will be optimised before surgery to give the bone the best possible chance of healing.

Non-Surgical Options

Surgery is the most common treatment for an established non-union, but there are situations where non-surgical methods are tried first or used alongside surgery, particularly for delayed unions or for non-unions where the bone is stable and well-aligned.

Bone stimulation devices

External devices that apply low-intensity pulsed ultrasound or pulsed electromagnetic fields to the fracture site are used in some cases to encourage healing. The evidence on their effectiveness is mixed, and they are generally considered an adjunct rather than a replacement for surgery in established non-unions.

Optimising healing factors

Before deciding on surgery, doctors may address factors that could be slowing healing: stopping smoking, correcting vitamin D deficiency, improving nutrition, tightening diabetes control, and reviewing medications that may interfere with bone repair.

Continued immobilisation

If imaging suggests healing is slow but still progressing, a longer period of protected weight-bearing or casting may be tried before declaring the fracture a true non-union.

Non-union surgery is not a single operation. Surgeons choose from a range of techniques, often combining several, based on the bone involved, the type of non-union, the presence of infection, the length of any bone gap, and the patient’s general health.

Revision of internal fixation

If the original fixation has loosened, broken, or was not strong enough, the surgery may involve removing the old hardware and replacing it with stronger or differently positioned implants. Common options include:

• Compression plates and screws — metal plates fixed to the bone with screws, designed to press the bone ends firmly together.
• Intramedullary nails or rods — long metal rods passed down the central canal of long bones such as the femur or tibia, providing stability along the length of the bone.
• Locking plates — plates with screws that lock into the plate itself, useful when the bone is weak or osteoporotic.

Bone grafting

Bone grafting is one of the most important parts of non-union surgery. The graft provides a scaffold for new bone, supplies bone-forming cells, and delivers signals that encourage healing. Several sources are used:

• Autograft — bone taken from the patient’s own body, most often from the iliac crest (the rim of the pelvis). Autograft is often considered the most biologically active option because it brings living cells and growth factors from the same person.
• Allograft — processed bone from a donor, used when larger volumes are needed or when taking autograft would cause additional problems.
• Synthetic bone substitutes — materials such as calcium phosphate or hydroxyapatite that act as scaffolds for new bone growth.
• Reamer-irrigator-aspirator (RIA) graft — a technique that harvests bone graft from the inside of a long bone, often the femur, providing a large volume of biologically active material with less pain at the donor site.

External fixation and bone transport

When there is a large bone gap, severe deformity, or active infection, external fixation may be used. An external fixator is a frame on the outside of the limb connected to the bone through pins or wires. It allows the surgeon to hold the bone stable while wounds heal, infection is treated, or the limb is gradually corrected.

A specialised form of external fixation is the Ilizarov technique and related circular frames, which can perform bone transport — slowly moving a segment of healthy bone across a gap to fill it in over weeks to months. This is often used for large defects, complex non-unions, and infected non-unions.

Biological adjuncts

To improve the biological environment at the fracture site, surgeons sometimes add:

• Bone marrow aspirate — concentrated bone marrow taken from the iliac crest, rich in stem cells.
• Bone morphogenetic proteins (BMPs) — growth factor preparations that stimulate bone formation. These are used in selected cases according to the surgeon’s judgement and local availability.
• Platelet-rich plasma (PRP) — a preparation made from the patient’s own blood, used as an adjunct in some centres, though evidence for routine use in non-union is still evolving.

Staged surgery for infected non-union

Infected non-unions usually require a staged approach. In the first stage, the surgeon removes infected and dead bone and tissue, takes samples to identify the organism, and places a temporary stabilisation device, often with an antibiotic-impregnated spacer. Antibiotics are given for several weeks. Once the infection is controlled, a second operation reconstructs the bone with grafting and definitive fixation. This process can take many months.

Who Is a Candidate for Non-Union Fracture Repair

Most patients with a confirmed non-union are candidates for surgical repair, but the timing, approach, and likely outcome depend on several factors that your orthopaedic surgeon will assess:

• The bone involved and the type of non-union (hypertrophic or atrophic)
• Whether infection is present or suspected
• The condition of the soft tissues and skin around the fracture
• The patient’s general health, including diabetes, vascular disease, and nutrition
• Smoking and tobacco use
• The patient’s activity goals and ability to follow rehabilitation
• Whether previous surgery has already been attempted

In some situations — for example, in a patient who is medically unfit for major surgery and whose non-union is stable and not painful — surgeons may suggest living with the non-union with bracing or activity modification rather than operating. This is a clinical decision made together with the patient.

Preparing for Non-Union Fracture Repair

Preparation for non-union surgery is often more involved than for a fresh fracture, because the goal is to give the bone the best biological and mechanical environment possible.

Medical optimisation

Your team will usually try to address modifiable factors before surgery, which may include:

• Stopping smoking, ideally several weeks before surgery
• Improving blood sugar control if you have diabetes
• Correcting vitamin D deficiency, calcium intake, and overall nutrition
• Reviewing medications that may affect healing, such as long-term steroids or certain anti-inflammatories
• Treating any other infections in the body

Pre-operative tests

Standard tests usually include blood work, an ECG, a chest X-ray for older patients, and detailed imaging of the fracture site. Additional tests are added based on your overall health and the complexity of the planned surgery.

Practical preparation

• Arrange for help at home after surgery, particularly if a leg is involved and weight-bearing will be limited.
• Prepare the home environment — clear pathways, consider a ground-floor sleeping arrangement, place frequently used items within reach.
• Plan how you will travel to follow-up appointments and physiotherapy.
• Discuss work and family responsibilities with your employer and household.

You will receive specific instructions about fasting, which regular medications to continue or stop, and when to arrive at the hospital.

What Happens During the Surgery

The exact steps depend on the surgical plan, but most non-union procedures share a similar sequence.

Anaesthesia

Most non-union surgeries are performed under general anaesthesia, sometimes combined with a regional nerve block to help with pain control after the operation. For some lower limb procedures, spinal anaesthesia may be used.

Exposure of the fracture site

The surgeon makes an incision over the non-union, working through the previous scar where possible. Old hardware, if present, is exposed and removed if it is loose, broken, or in the way of the new fixation.

Debridement

Realignment

The bone ends are brought back into the correct position. In cases with significant deformity or shortening, the surgeon may perform additional corrective cuts (osteotomies) to restore alignment.

Stabilisation

Strong, stable fixation is applied using plates and screws, an intramedullary nail, an external fixator, or a combination, depending on the bone and the situation.

Biological enhancement

Bone graft and any additional biological materials are placed at the fracture site to encourage healing. If autograft is used, it is harvested through a separate small incision, most commonly over the pelvis.

Closure

The wound is closed in layers and dressed. A drain may be left in place for a short period to remove fluid that collects after surgery.

Surgery duration varies widely — from around two hours for a straightforward revision with grafting to many hours for complex multi-stage reconstruction.

Recovery and Healing

Recovery after non-union surgery is longer and more carefully staged than recovery from a simple fracture, because the bone has already proven slow to heal. Your team will give you a plan tailored to your specific surgery, but the broad pattern is similar in most cases.

Hospital stay

Most patients stay in hospital for a few days, sometimes longer for complex procedures, infected cases, or when external fixators are used. Early focus is on pain control, wound care, blood thinners to prevent clots in the legs, and starting basic mobilisation under the physiotherapist’s guidance.

The first few weeks

During the early weeks at home, the priorities are protecting the surgical site, controlling pain, and starting gentle movement as advised by your surgeon. You will usually be given:

• Clear instructions about how much weight you can put through the limb
• Wound care advice and signs of infection to watch for
• Pain medication and instructions on how to take it
• Blood thinners for a period of time, especially after lower limb surgery
• A schedule of follow-up appointments and X-rays

Weight-bearing restrictions are particularly important. Putting too much load on the bone too soon can cause hardware to loosen and the non-union to recur. Putting too little load over a long period can lead to muscle wasting and stiffness. The right balance is decided by your surgeon based on your imaging.

Rehabilitation

Structured physiotherapy is a central part of recovery. The programme is usually staged:

• Early stage — gentle range-of-motion exercises for the joints above and below the fracture, swelling control, and protecting the surgical site.
• Middle stage — progressive weight-bearing as healing is confirmed on imaging, building muscle strength around the fracture, and improving joint movement.
• Late stage — full weight-bearing, balance and proprioception work, and gradual return to walking, climbing stairs, and work or sport.

Healing timeline

Bone healing after non-union surgery typically takes several months. For long bones such as the tibia or femur, healing on imaging may take four to six months or longer. Healing of small bones such as the scaphoid often takes a similar amount of time despite their smaller size, because of their poor blood supply. Healing in patients with diabetes, smokers, or those with infected non-unions is generally slower.

Return to work and activity

Return to work depends on the bone involved, the type of surgery, and the nature of the job:

• Desk-based work — many patients return within four to six weeks, sometimes sooner with adjustments such as working from a comfortable position with the limb elevated.
• Standing or walking work — usually two to four months, depending on the limb involved.
• Heavy manual work or work at heights — often three to six months, sometimes longer.
• Sport and recreational activity — staged return guided by your surgeon and physiotherapist, often starting with low-impact activity around three months and full sport later.

Risks and Complications

Non-union fracture repair is generally safe in experienced hands, but it is a more complex undertaking than initial fracture surgery, and the risks are correspondingly higher than for a fresh fracture. Your surgeon will discuss the specific risks for your situation. The most commonly discussed include:

• Recurrent non-union — in a minority of cases, the bone may still not heal after the first revision, and further surgery may be needed.
• Infection — either of the wound or deeper in the bone. Infection at the operative site can lead to prolonged treatment with antibiotics and sometimes further surgery.
• Hardware-related problems — loosening, breakage, or irritation from plates, screws, nails, or external fixator pins.
• Nerve or blood vessel injury — uncommon but possible, particularly in revision surgery where anatomy is distorted by scar tissue.
• Blood clots — in the deep veins of the legs (DVT) and, rarely, in the lungs (pulmonary embolism). Blood thinners and early mobilisation help reduce this risk.
• Pain at the bone graft donor site — if autograft is taken from the pelvis, some patients experience prolonged tenderness at the donor site.
• Stiffness and weakness — particularly in joints that have been immobilised for long periods.
• Limb-length difference or residual deformity — especially after complex reconstructions.
• Compartment syndrome — a rare but serious complication where pressure inside the limb rises dangerously after surgery, requiring urgent treatment.
• General anaesthesia risks — including cardiac and respiratory complications, particularly in older patients or those with significant health conditions.

You will be told what warning signs to watch for after surgery — spreading redness, increasing pain, fever, drainage from the wound, sudden severe limb pain, or new swelling and pain in the calf. These should prompt urgent contact with your team.

Life After Non-Union Fracture Repair

Most patients who undergo non-union fracture repair achieve healing of the bone and return to a good level of function. The longer-term picture depends on the bone involved, the cause of the original non-union, and any associated joint or soft-tissue injury.

Bone health and long-term care

After healing, looking after the bone is part of normal life. Doctors commonly advise:

• Maintaining a balanced diet with adequate protein, calcium, and vitamin D
• Regular weight-bearing exercise to keep bones strong
• Not smoking, and limiting alcohol
• Maintaining a healthy body weight
• Managing chronic conditions such as diabetes carefully
• Treating osteoporosis if it is present

Hardware after healing

Plates, screws, nails, and rods are usually designed to remain in the body permanently and do not need to be removed in most patients. Removal is considered if the hardware causes pain, irritation, infection, or interferes with future surgery — or in some younger patients with prominent hardware. External fixators are removed once the bone has healed enough to take load without them.

Joint and soft-tissue effects

If the non-union involved a bone close to a joint, the joint may show some long-term stiffness or, over time, develop wear-and-tear changes (post-traumatic arthritis). Continued physiotherapy and, in some cases, further treatment may be needed for these problems.

Follow-up

You will usually be seen at intervals after surgery for clinical review and X-rays. Once the bone is fully healed and function is stable, follow-up becomes less frequent. Your surgeon will tell you when you can return to specific activities and when you no longer need routine review.

Non-Union in Children

True non-union is far less common in children than in adults. Children’s bones generally heal quickly and reliably because of their excellent blood supply and active growth. When non-union does occur in a child, it is most often associated with specific situations — such as congenital pseudarthrosis of the tibia (a condition present from birth), high-energy injuries with bone loss, open fractures with infection, or fractures of the lateral humeral condyle in the elbow.

Management of paediatric non-union is specialised and often differs from adult care. It typically involves a paediatric orthopaedic surgeon, careful preservation of growth plates, and techniques chosen with the child’s future growth in mind. Bone grafting, internal fixation, and external fixators including circular frames are all used in selected cases. Outcomes are generally good when the underlying problem is addressed correctly.

Frequently Asked Questions

How long after a fracture is it considered a non-union?

There is no single fixed time, but orthopaedic surgeons commonly use a working definition of no healing progress for three consecutive months, with at least six to nine months since the original injury. Some bones with naturally slow healing, such as the scaphoid, may be given longer before the diagnosis is made.

Will I definitely need surgery?

Most established non-unions need surgery to heal, particularly if there is a gap, deformity, infection, or hardware failure. In selected cases — for example, a stable, well-aligned, painless non-union in a patient unfit for surgery — non-surgical management with bracing or activity modification may be considered. This is a decision made with your surgeon.

Is a bone graft always needed?

Not always, but bone grafting is used in many non-union surgeries because it adds both a scaffold and biological signals for new bone growth. Whether graft is needed, and what type, depends on the cause of the non-union and the size of any bone defect.

Where is bone graft taken from?

The most common autograft site is the iliac crest, the rim of the pelvis. The reamer-irrigator-aspirator technique can also harvest graft from inside a long bone such as the femur. In some cases, donor bone (allograft) or synthetic substitutes are used instead of or alongside autograft.

How long will it take for the bone to heal after surgery?

Healing usually takes several months and varies with the bone, the type of surgery, and individual healing factors. Long bones such as the tibia and femur often take four to six months or more. Infected non-unions and non-unions in patients with diabetes or who smoke generally take longer.

When can I put weight on my leg?

Weight-bearing instructions depend on the bone, the fixation used, and how healing is progressing on X-ray. Your surgeon will give you a specific plan, usually starting with limited or partial weight-bearing and progressing as healing is confirmed.

Can the non-union come back?

Recurrence is possible, particularly if underlying factors such as smoking, poor diabetes control, or infection are not addressed. With careful surgical technique, biological support, and patient cooperation with rehabilitation and lifestyle changes, the chance of healing after non-union surgery is generally high.

Does smoking really matter?

Yes. Nicotine reduces blood flow to the bone and is consistently associated with higher non-union and complication rates in orthopaedic studies. Stopping smoking before and after surgery is one of the most impactful steps a patient can take to support healing.

Will the metal hardware need to be removed later?

Most modern implants are designed to remain in the body permanently and do not need removal. Hardware is sometimes removed later if it causes pain, irritation, infection, or limits movement, or in younger patients with prominent hardware. External fixators are always removed once the bone is healed.

Will I be able to return to sport or heavy work?

Many patients return to their previous level of activity, including manual work and sport, after successful non-union surgery and full rehabilitation. The timeline depends on the bone, the type of surgery, and how healing progresses. Your surgeon and physiotherapist will guide the staged return.

Conclusion

A non-union is not a sign that healing is impossible — it is a sign that something specific needs to be addressed so that healing can resume. Non-union fracture repair surgery brings together several elements that work in combination: removing tissue that is blocking healing, providing strong and stable fixation, restoring good alignment, and adding biological material that encourages new bone to grow. Treating infection and improving general health factors are often just as important as the operation itself.

Recovery is slower than after a fresh fracture, and rehabilitation needs patience. With careful surgical planning, attention to the underlying causes, and a structured rehabilitation programme, most patients with non-union heal their bone, regain function, and return to the activities that matter to them.