Graham A Neale BCC        Dipa Shah Bsc (Hons) Mchs

Queens University Hospital

Romford Essex

charcot

Jean Martin Charcot 1825-1893

Neurologist and professor of Anatomical Pathology

Jean Martin Charcot Born 29th   November 1825 Nationality French.

 

 

Charcot was a Neurologist and Professor of Anatomical Pathology and known for studying and discovering Neurological Diseases, He is known as the founder of modern Neurology and his name has been associated with at least 15 Medical Eponyms, including Charcot-Marie Tooth Disease and Charcot Disease better known as Amyotrophic Lateral Sclerosis, Motor Neuron Disease.

Charcot has been referred to as the Father of French Neurology and one of the Worlds Pioneers of Neurology, his work greatly influenced the developing fields of Neurology and Psychology, Modern Psychiatry owes much to the work of Charcot and his direct followers.

Charcot Osteoarthropathy

Charcot joint, also known as Neuropathic joint, is an acute inflammatory condition affecting the foot. The cause of this condition is not known, but it is usually associated with peripheral neuropathy and osteopenia.

This condition usually occurs following some minor injury, preceding ulcer or other cause of inflammation to the foot or ankle. The injury usually goes undetected due to the lack of sensation; as a result the person will continue with their daily activities as normal, causing further fractures and/or dislocation of the joints and bones.

Due to the loss of sensation in the joint, the joint becomes severely damaged and deformed. The joint damage/deformity is usually gross making it easy to diagnose both clinically and on x-ray. The level of destruction within the joint would cause severe un-tolerable pain, but due to the underlying neuropathy goes undetected.

We usually associate a Charcot joint with Diabetic neuropathy, but this condition can also occur in non-diabetics with peripheral neuropathy: (Diabetes is the most common cause of Charcot Osteoarthropathy)

  • Physical damage to the nerves such as a road traffic accident or post-surgery
  • Alcoholism
  • Beriberi (vitamin B1 deficiency)
  • Vitamin B12 deficiency

Stages of Charcot Arthropathy

The most common anatomical location of Charcot Osteoarthropathy is at Lisfranc’s (tarsometatarsal) and Chopart’s (talonavicular/calcaneocuboid) joints.

The disease process can be divided into 3 stages based on the radiographic reports:

  1. The Developmental Stage – characterised by joint laxity, subluxation, osteochondral fragmentation and debris formation.
  2. The Coalescence Stage – marked by the absorption of fine debris and fusion of larger fragments of bone.
  3. Reconstruction – this is the final stage of the process. It is marked by remodelling of the joints architecture, revascularisation and remodelling of the bone fragments.

Presentation

Clinical presentation is dependent on the stage at which the process is at. A patient could present with any of the following or all of them:

  • Swelling
  • Deformity
  • Subluxation (misalignment of the bones that form a joint)
  • Loss of function
  • Pain – 75% of people will have some level of pain considering the level of joint destruction (but there would be considerably more pain if the person was not neuropathy)
  • Redness and heat
  • Associated foot ulcers
  • Osteomyelitis (which would further complicate things)
  • Instability in the joints
  • Strong pedal pulses
  • Discolouration of the joint

initial-presentation

Initial presentation of a Charcot Foot

Charcot arthropathy may affect any part of the foot and ankle, including (in decreasing order of frequency) the midfoot, hindfoot, ankle, heel and forefoot.

If an acute Charcot Arthropathy is suspected, the patient should be seen by an MDT (Multi-Disciplinary Team) within 24 hours.

What is a Multi-Disciplinary Team (MDT)

A Multi-Disciplinary team is a group of health care professionals who are members of different disciplines, each providing specific services to the patient. Each professional independently treats various issues a patient may have, based on their speciality.

The activity of each member is brought together to produce a care plan for each individual patient. This enables co-ordination of services and enables them to work together towards a specific set of goals.

In the case of treating someone with Charcot Arthropathy, the following specialities would be involved:

* Podiatrists
* General Practitioners/Practice Nurses
* Orthopaedic consultants
* Orthopaedic technicians
* Vascular consultants/Vascular Specialist Nurses
* Endocrinologists
* Diabetes Specialist Nurses
* Microbiologists
* Tissue Viability Nurses
* District Nurses
* Keyworkers/Carers/Family

To provide a fully comprehensive service for these patients it is essential that all these departments and professionals work together.

 

 

 

Differential Diagnostic

Infection, Gout, Soft Tissue Injury Fracture or any cause of foot inflammation such as arthritis.

Activity modification

Patients must be informed that they need to modify their daily activity to avoid repetitive trauma. They are at increased risk of developing a Charcot joint in the other foot, or even re-activating after the foot has consolidated. They must take precaution and measures to prevent and protect both feet.

Recovery

The total healing time can take as long as 1-2 years, and the patient will remain in a TCC for a long time during this process. This is why it is essential for the Podiatrist to work closely with the Orthopaedic technicians, to gain the best possible knowledge and treatment plan for each individual. We rely on Orthopaedic technicians and their experience to help guide us, so that each plaster cast applied is tailored to each individual.

Outcome

Often patients undergo reactivation of the Charcot joint, and will require going through the whole process again. Furthermore, there may be bilateral involvement, which is common. This is why it is imperative that the patient has bespoke footwear and orthotics made and continues to be monitored on a regular basis.

Patients may require reconstructive surgery or lengthening of the Achilles tendon once the process has finished.

Complications 

Due to the nature of the process, severe deformities may include:

  • Collapse of the midfoot arch – forming a rocker bottom sole, this can then be associated with plantar midfoot ulceration.
  • Navicular drop – which can lead to a bony prominence on the medial side, again can be associated with ulceration.
  • Digital deformity – over riding digits
  • Instability – often difficult to manage with braces
  • Infections – can lead to amputation, or could be life threatening
  • Calluses
  • Blood vessel and/or nerve compression
  • Loss of function in the foot

 

Examination/Initial treatment of the foot

Surprising, examining the foot will cause minimal or no discomfort at all. There are several things that should be checked:

  • Neurological testing – to identify the extent of sensory loss and whether there is any motor loss
  • Vascular testing: to identify any circulatory problems that the person may have. If any are detected, it would be advisable to involve the Vascular consultants to carry out further testing.
  • Blood tests – to check for raised inflammatory markers, HbA1c – to check the glycaemic control
  • X-ray – check level of joint destruction, a weight-bearing x-ray should be taken of the affected foot and ankle. If the x-ray is normal but Charcot Arthropathy is still suspected, then an MRI scan should be considered.
  • Temperatures – literature states that there will generally be a difference of greater than 2 degrees in the affected foot. (NB temperature checked cannot be carried out if the person has any ulcers on their feet)
  • Thorough medical history and medication list. We must also know of any trauma that may have occurred, as well as any past operation (especially to the foot), fractures (especially to the foot), and allergies.
  • Review of current footwear
  • Previous history of any foot ulceration – when they occurred and duration of healing.
  • Patients must be educated and informed about the risk of joint damage and long term complications that may arise.
  • Treat any underlying diseases – infected wounds/osteomyelitis
  • Educate the patient about the importance of good glycaemic control – involve Diabetes Specialist Nurses/Endocrinologist, Dieticians
  • Alcoholism or deficiencies may require attention/treatment.

Skin temperature reading

Skin temperature assessment is a promising modality for early detection of diabetic foot problems. Inflammation proceeds diabetic foot complications, and thus results in increased temperatures in the affected foot. A difference in temperature can be noted when measuring specific points on the affected foot and then the same points in the contralateral limb. This is done using an infrared thermometer.

Infrared thermometer is a non-contact tool that detects the surface temperature at a particular point. These temperature differences are useful when quantifying sensitive changes in skin temperature that occur due to pathological processes such as inflammation.

Skin temperature readings enable us to detect the urgency of the diabetic foot complication, and hopefully enable us to detect problems in the early stages so that we can provide the best possible care to minimise or even reverse the problem.

However, in order to define “increased temperatures”, a standardised reference temperature is required. Foot temperatures can vary from patient to patient, and depend on ambient temperature and level of activity. Temperatures of corresponding areas on both feet do not usually differ by more than 1°C; a temperature difference of more than 2.2°C is considered abnormal.

Temperatures are measured after allowing the feet to acclimatise for a minimum of 20 minutes. The temperatures are then measured at corresponding sites on both feet. If a temperature difference of more than 2.2°C is noted, then the patient should be advised to reduce activity, obtain a blood test checking for raised inflammatory markers and HbA1c, and an x-ray should be taken. All these would aid in the diagnosis of a Charcot Arthropathy. Once the Charcot Arthropathy has been diagnosed the patient should be immobilised (and this is usually done in the form of non-weight-bearing total contact casting) and temperatures should be checked every 2 two weeks.

 

infared

 

Infrared Thermometer measuring temperatures on the feet

Total Contact Casting

This is an advanced casting technique and should only be undertaken by experienced Orthopaedic Technician with good casting skills.

The Technique we use at Queens Hospital is shown here, when applying the under cast padding and felt over bony prominences, great attention to detail must be taken to prevent any rucking up of the stockinette and felt is essential to prevent blisters or sores developing under the cast.

The same attention to detail must be shown when applying the plaster bandage, with good moulding and smoothing to achieve a good contoured and well-fitting cast which will immobilise and support the foot and ankle to reduce the risk of further joint destruction and deformity.

In patients with foot/leg ulceration the cast needs to be changed on a weekly basis, so that the wound can be monitored and managed. Windows can also be added to make the wound care management more effected if the wound requires to be dresses more than once a week. In patients without wounds the cast can be changed every 1-2 weeks.

This casting method means that the patient will be non-weight baring while the process is active.

Many consider this as the gold standard of treatment for Charcot Foot.

 

Removable walker cast

This method is usually issued to patients once they have reached the third stage of the Charcot process. This method can also be used in patients with PAD.

This can be in the form of a removable weight-bearing cast, walker boot or air cast boot. Which walker cast is used is dependent on the patient and the MDT. A lot of patients like to use the casted method as if they feel the foot seems more stable and it can be worn in bed.
The walker boot is also favoured as it can be removed and applied easily by the patient. The walker boots must be warn at all times when weight-bearing, and therefore the non-inflated boot is favoured as it doesn’t require accurate pumping of the valves every time it is worn. Wearing the boot increases the responsibility of the patient to monitor the foot between appointments and check for any sores.

Walker boot (non-inflated)

The boot provides basic support for the foot and ankle, and is lined with foam. This boot is ideal for anyone with little or no oedema. Some also come with memory foam which can contour to the foot, providing pressure relief. They fasten using Velcro straps that can be easily adjusted and are easy to apply. The sole is thicker than a shoe, which means that the affected leg will be slightly higher than the other; so It is advisable to use crutches until you are used to walking in the boot.
fixed-walker-boot-1

Air cast boot (inflated)

This boot is very effective for healing fractures and the management of oedema. The airbags around the foot and ankle allow compression of the area. IT IS IMPORTANT THAT THE AIR BAGS ARE NOT OVER-INFLATED – this will cause irritation of the skin; if over inflated over a wound it can cause a breakdown or cause pressure sores. The patient would need to check the foot more frequently for pressure sores. The sole is thicker than a shoe, which means that the affected leg will be slightly higher than the other; so it is advisable to use crutches until you are used to walking in the boot.
This boot is not suitable for patients with peripheral neuropathy (affecting the feet and hands), ischaemia, and poor eye sight.

Bespoke footwear

Once the joint has consolidated and the patient is able to partial weight-bare, a referral would be sent to Orthotics. They would then measure the patient for bespoke shoes as well as bespoke orthotics. Once the shoes are made and fit correctly, the patient can start to wear the shoes slowly as advised by the Orthoptist/Podiatrist.

In our practice it is common place to make a FRC Bellow Knee Walking Cast to use in-conjunction with the bespoke shoes. Once the patient is comfortable and able to wear the shoes daily, they will no longer have a need for the removable cast.

 

 

 

References

  1. Charcot Arthropathy: Background, Proble, Epidemiology
  2. The Charcot Foot in Diabetes
  3. Neuropathic Arthropathy
  4. An overview of the Charcot Foot Pathophysiology
  5. Diabetic Foot Problems: Prevention and Management
  6. Jean Martin Charcot