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Logo Julien Lopez

All about the operation of flat feet

Dr Julien Lopez, foot surgeon, explains the flatfoot operation and answers his patients' recurring questions : What is flatfoot ? How to treat flat foot without operating ? When and how to operate on a flat foot in adults or children ?


What is the flat foot ?

Flatfoot is a biomechanical problem characterized by the sagging of the internal arch of the foot and the decrease in the arch of the foot (loss of curvature or arch of the foot). The arch of the foot is formed by the architecture of the bone pieces, by ligament and muscle structures that fight against crushing under the weight of the body. It mainly affects women between 40 and 60 years old.

Usually, the foot has the shape of a propeller. The flat foot is the loss of the propeller and conversely in the hollow foot, the propeller is too twisted. We classically observe in the flat foot valgus : a valgus of the rear foot (heel which goes outwards), a collapse of the medial arch secondary to a failure of the posterior hamstring and the spring ligament as well as a supination compensating forefoot. Clinically, abnormalities of the hindfoot, midfoot and forefoot are observed in flexible flatfoot.

There are several clinical stages of flat feet. In the first stages of development, the flat foot is flexible : we speak of reducible or flexible foot (stage 1 and 2). It can be painful and disabling on a daily basis, both feet are often affected. In the more advanced clinical stages, the foot is deformed but it is no longer flexible : we speak of a fixed or non-reducible flat foot valgus. Finally, in the most advanced stage, we find ankle arthritis. This classification is important for the surgeon because it directly informs the surgeries and the procedures to be performed.

Where does it come from and what are the aggravating factors?

The causes of flat foot are different in children and adults.

In children, we speak of congenital foot and in adults of acquired or degenerative flat foot, that is to say that the flat foot appears over time. It is sometimes found in a history of trauma such as rupture of the posterior tibial tendon, fractures or osteoarthritis.

The common origin of the formation of the flat foot in adults is the insufficiency or weakness of the tendon of the posterior tibialis muscle as it actively struggles to hollow out the medial arch of the foot and to keep the heel in the correct axis. We can find contributing factors such as :

  • Chronic ankle instability
  • Overweight
  • Degenerative or inflammatory pathologies
  • Repeated pregnancies
The child's flat foot ?

The main cause of flat foot in children is the immaturity of the structures that hold the foot. Most children are born with a collapsed arch (up to 97%) which will correct with growth. Other factors are involved such as the shape of the legs (valgus), weak ligaments, overweight or reduced muscle strength (hypotonia). In rare cases, flatfoot is secondary to a genetic pathology (hereditary disease) such as Marfan syndrome or Ehlers Danlos disease.

Parents often worry about the presence of a flat foot in their children. Flatfoot is considered " normal " until the age of 6. As the child is a small growing human being, some muscle and ligament structures are maturing and not yet strong enough to properly walking the foot. In most cases, flat feet correct themselves over time and with growth. If the problem persists, it is important to check with a flat foot surgeon although most flat feet are asymptomatic and require no special treatment.

How to recognize a flat foot and make the diagnosis ?

The flat foot can be recognized by its shape of a crushed foot. If you wear your shoes on the inner side, it will also be necessary to evoke the flat foot.

The diagnosis is made in charge with a podoscope which will highlight the plantar imprint during the walking. Depending on the shape of the footprint, several types of flat feet can be defined, from the least severe to the most severe.

What are the symptoms ?

The main symptom of flatfoot is pain in the medial or plantar area, sometimes ankle pain or lameness. The pain is localized under the medial malleolus along the course of the posterior tibial tendon with sometimes swelling or squeezing of the retro-malleolar groove.

We can evoke other symptoms such as:

  • Low back pain or lumbar radiculalgia
  • Knees tucked in
  • Heels that deflect outward
  • Changing the shape of the foot
  • Instability or feeling of imbalance on uneven ground
  • Internal shoe wear
  • Pain in the calf

You may have complications if the flatfoot problem is not treated. You may have problems with inflammation of the membrane that covers the bones of the tibia, knees, hips, hallux valgus (bunion), hardening of the skin, ankle problems, plantar fasciitis, back problems, tendon pain (for this type of pain it is important to consider one), metatarsalgia as well as Morton's neuroma.

What is the evolution without treatment?

In the absence of suitable treatment, the spontaneous evolution of the foot is the aggravation of deformities and pain. An evolved flat foot can lead to complications and related pathologies such as:

  • Plantar fasciitis or fasciitis which may be associated with a heel spur
  • Morton syndrome
  • Pain under the forefoot or metatarsalgia
  • Hallux valgus or bunion of the big toe
  • Ankle joint instability or (cuneometatarsal)
  • Tendon pain and instability (fibular dislocation)
  • Achilles tendonitis, stiffness, joint limitations ...

We advise you to consult and treat the flat foot before the onset of complications. In the other cases, it will be necessary to discuss a surgery of the flat foot and posterior tibial tendon.

Adult degenerative flatfoot slowly gets worse. It is imperative to wear orthopedic insoles and renew them every year. In contrast, a child's congenital flatfoot corrects itself in most cases with growth.

Special case of the child : the persistent flat foot of the child is often secondary to a synostosis or synchondrosis of the hindfoot. The pain is in the foreground while the deformity progresses slowly : it is necessary to consider a surgical treatment of the flat foot of the child.

How to prevent a flat foot valgus for less heavy surgery

The prevention of flat foot valgus for less heavy surgery is based on simple measures:

  • Correction of excess weight (dietician management)
  • Adaptation of the footwear : favor a large arch and shoes that correctly wedge the heel
What treatment for flat foot (non-surgical) ?

Medical treatment is always offered as a first-line treatment. Its objective is to obtain a sedation of the pain and to prevent the aggravation of the deformity.

Here are the main measures for non-surgical treatment of flat foot valgus:

  • Adapt your footwear and favor shoes and orthopedic insoles that correctly walking the arch of the foot
  • Correction plantar orthotics: these are performed by the podiatrist on prescription after taking impressions of the feet. They are made to measure and allow the distribution of pressure, walking the arch of the flat foot and reduce pain while strengthening balance. In addition to the walking of the arch, the podiatrist often adds an extra thickness at the level of the heel (heel wedge) in order to correct the “heel valgus ”
  • Physical exercise focusing on strengthening leg muscles
  • Lose weight
  • Physiotherapy : it helps to strengthen the muscles and have a better musculo-tendon balance
  • Rest and immobilization are recommended during severe painful crises

Everything you need to know about flat foot surgery

We will discuss the different techniques for operating flat feet and valgus . When pain or deformity cause important discomfort, adult flatfoot surgery should be considered. It is a corrective surgery of the shape of the foot.

When prevention and medical measures are no longer sufficient, it is necessary to consult a specialist surgeon to discuss adult flat foot surgery.

The flat foot correction operations depend on the cause (it is important to look for its origin) and the type of flat feet: flexible or rigid and flexible.

If complications or persistent pain are present, valgus flatfoot surgery may be offered, which can be combined with ligamentoplasty . Each flat valgus foot is unique and only a specialist consultant can inform you about the procedures to be performed. To know the exact nature of the treatment to be performed, the surgeon will first have to specify certain elements in consultation. The choice of technique and the assessment of the actions to be performed is left to the surgeon depending on the severity of the damage and the complexity of the intervention.

The objective of the surgery is to restore the foot to its anatomical helix shape : flatfoot surgery is multi-stage : it concerns the rear foot, the midfoot and the forefoot. To achieve this result, different operating techniques are possible, such as conventional “open” surgery, percutaneous surgery or minimally invasive surgery. Modern surgical techniques reduce postoperative pain and allow faster rehabilitation gestures of everyday life.

How is the flatfoot operation performed?

Hospitalization : The intervention usually takes place in hospitalization for 2 to 3 nights. However, for various reasons, it is possible to extend the duration of hospitalization.

Anesthesia : You will have to perform the mandatory pre-anesthetic consultation with the anesthesiologist. During this consultation, the anesthesiologist will explain the possible modes of anesthesia to you according to your associated pathologies and the planned operative procedure. If necessary, he will adapt your treatment before and after the operation and may prescribe anticoagulants, painkillers, anti-inflammatory drugs or others.

Several types of anesthesia are possible : you may benefit from local or regional anesthesia meaning that only your leg will be desensitized : this is the most common. General anesthesia is also a solution if you prefer to sleep.

The intervention:

It is important to note that the surgeon may face an unforeseen or unusual situation requiring different acts than those initially planned. In this case, the surgeon will explain the difficulties encountered and the actions taken as soon as you wake up or return to your room.


The surgery is “conservative”, that is to say that the mobility of the joints is preserved.

  1. The rear foot : the first objective is to realign the rear foot. The procedure can be an osteotomy (surgical cutting of the bone to change its axis, size or shape) of the calcaneus to medialize (translate) and move it inward or the placement of a subtalar implant which will correct talocalcaneal divergence. In the case of an osteotomy, osteosynthesis is provided by a specific material (screw, plate or bone staples).
  2. The midfoot : the surgeon must then perform a gesture on the arch of the foot in order to put back in tension the defective elements (retention of the spring ligament, repair and / or tenodesis of the posterior hamstring tendon). The correction of the hindfoot and midfoot will reveal the compensatory supination of the front which should be corrected surgically. Several surgical techniques are possible to achieve this result.
  3. The forefoot : In most cases, the surgeon performs an opening osteotomy of the first cuneiform in order to lower the first metatarsal (Cotton osteotomy) or Lapidus arthrodesis (cuneo-metatarsal fusion 1). Flatfoot is often associated with a hallux valgus which can be corrected during the same operation.
  4. The Achilles tendon : in most flat feet, there is a tendon lengthening of the triceps in the calf.


In the case of fixed or non-reducible flat feet (clinical stage 3 and 4) which may be associated with ankle osteoarthritis, the surgical procedure is said to be non-conservative, i.e. the mobility of certain joints cannot be preserved. The goal is to correct the shape of the flat foot and to regroove the medial arch by fusing (arthrodesis) several joints. To perform an arthrodesis, we remove the articular cartilage down to the bone then the joints are positioned and fixed in a position that allows the plantar arch to be straightened and deviations to be reduced in order to regain the correct walking. In severe flat feet, a double arthrodesis or a triple arthrodesis is performed.

Surgery for rigid flat feet requires further medical attention. After this operation, the ankle is immobilized in a boot and walking is prohibited for 4 to 6 weeks while awaiting the fusion of the bone parts.

What are the postoperative consequences?


After undergoing adult flatfoot surgery, your foot will be immobilized in a boot for 3 to 6 weeks. Walking is prohibited for 21 days and movement is facilitated by crutches, a walker or a wheelchair.


Dressing treatments are necessary every 2 days until complete healing. A prescription will be given to you by the secretary.


Swelling is not a complication and is a common occurrence after flat foot surgery. To speed up its absorption, it is recommended to regularly ice the foot and put the foot up as soon as you feel the swelling. It takes about 2 months for the swelling to resolve 80% and 6 to 9 months for the foot to deflate completely.


Depending on your history, your existing medical conditions and your mobility, the anesthesiologist may prescribe anticoagulant treatment by injection (subcutaneously) or systemically (per os). This treatment helps prevent the onset of phlebitis, i.e. the formation of a clot in the veins.

It is strongly recommended to take the painkillers prescribed systematically during the 5 days following the surgery in order to reduce the risk of algodystrophy (complication).


Physiotherapy is systematic, its duration will be evaluated by the surgeon during your first postoperative consultation. In order to accelerate functional recovery and the melting of the swelling, self-rehabilitation is essential (moving the toes).


Driving a vehicle will be permitted after removal of the splint and after resuming full walking (unless you have had an operation on your left foot and you have an automatic car). Sick leave will be 2 to 6 months depending on the surgical technique and the patient's profession.


Sports can be resumed gradually after 3 to 6 months depending on the type of operation and surgery of the flat foot and your sports activity.


Two appointments are necessary postoperative : 21st day and then 60 days after the operation.


For any additional questions or in the event of a problem, you can contact his secretary.

In conclusion:

Flatfoot requires management from the moment it becomes painful. Treatment is medical and surgical first line in 2nd intention if the functional impairment persists. If you have any questions and need advice, please do not hesitate to contact us. You can also consult the FAQ, especially if you want to know the care and price of a flatfoot operation.

What are the complications of the surgery?

There is less than a 1% risk of complications for flatfoot surgery for adults. Among the most frequent are thrombosis, infection, dystrophy, nerve damage or non-union of arthrodesis (pseudarthrodesis).

Symptoms are, for example, pain in the calf or local signs of infection (redness, purulent discharge, scar disruption, fever). Certain complications such as non-union in the case of an arthrodesis operation for flat feet require a new intervention. We can also observe discomfort related to the implanted material (in this case it is common to remove it after 6 months).

The following list of complications is not exhaustive, but the most frequent complications are mentioned.

Any surgery can create complications that are both common and specific to the type of intervention performed. This risk varies from one individual to another depending on their age, existing medical conditions (hypertension, diabetes, poor skin condition, etc.) as well as depending on their lifestyle (tobacco, alcohol, practice of a sports activity).

Some complications can be prevented by simple measures such as:

Common Complications

Specific complications


Flat valgus feet
What is a flat valgus foot ?

Flat foot valgus is characterized by the collapse of the medial arch of the foot. It causes a decrease in the height of the arch of the foot and the heel goes outwards. Medial structures can decompensate and cause pain.

Which specialist to treat a flat valgus foot?

In the presence of a flat foot, you can consult the podiatrist, your attending physician or a specialist surgeon. Whichever specialist you consult, medical and non-surgical treatment is always indicated as the first line. If this is unsuccessful, you can consult Dr Lopez who will examine you and possibly suggest a flatfoot operation in Nice or a flatfoot operation in Cap d’Ail.

For patients who live on the Ile de Beauté, making an appointment with a flatfoot surgeon in Corsica is sometimes difficult. If you cannot get an appointment, Dr Lopez can see you in Nice.

How to treat a flat valgus foot?

In beginners painful flat feet (stage 1), the treatment is the wearing of adapted orthopedic insoles. In painful soft and reducible flat feet (stage 2), conservative surgery should be considered. In the advanced and non-reducible stages of painful flatfoot (so-called " fixed "), the surgical procedure is non-conservative (arthrodesis).

How to operate on a flat valgus foot?

The operating techniques are numerous and adapted to each type of foot and patient. The objective of the surgery remains to regroove the medial arch of the foot by acting on all parts of the foot : rear foot, midfoot and forefoot.

How long does the operation of a flat foot valgus take?

The duration of flatfoot surgery varies with the surgical technique and the type of gesture performed. It takes 1 to 3 hours on average.

What anesthesia is used during the operation of a flat foot valgus ?

You will have to carry out the obligatory pre-anesthetic consultation with the anesthesiologist. During this consultation, the anesthesiologist will explain the possible modes of anesthesia to you according to your associated pathologies and the planned operative procedure. If necessary, he will adapt your treatment before and after the operation and may prescribe anticoagulants, painkillers, anti-inflammatory drugs or others.

Several types of anesthesia are possible : you may benefit from local or regional anesthesia meaning that only your leg will be desensitized : this is the most common. General anesthesia is also a solution if you prefer to sleep.

What pain do you feel during the operation of a flat foot valgus?

The pain is significant for 3 days after the operation. Immediately after the operation, the pain is not felt because the foot remains asleep for several hours. Then the painkillers prescribed by the anesthetist provide adequate relief. To reduce painful phenomena, it is essential to take painkillers systematically for 72 hours.

You should also regularly ice the operated foot using a prescribed pharmacy splint. It is also possible to put in place a peri-nervous catheter which ensures complete analgesia for several days.

What is the period of immobility after an operation for a flat foot valgus?

The period of immobility, that is to say the time when walking is not allowed, is 3 to 8 weeks on average.

Am I allowed to drive after an operation for a flat foot valgus?

Driving is possible after 3 to 6 weeks. Even if your surgeon allows you to drive, consider contacting your car insurer to verify that you are covered in the event of an accident.

Can we operate on both feet at the same time ?

No, it is not possible to operate both feet at the same time. If you have 2 flat feet to operate, it is advisable to respect an interval of 6 months between 2 operations.

What is the cost of an operation for a flat valgus foot?

Flat foot surgery and its prices depend on the type of flat feet, the origin of the causes and the stage of development. The price of an intervention for flat feet depends on the duration of the intervention and the difficulty of the surgical procedures. Social security covers the costs of the operation. The reimbursement of additional fees depends on your insurance contract. The average remaining charge after reimbursement by your insurance company is €500.

Do you need flat foot surgery?

Contact Dr. Julien Lopez.