QuestionSBA
QuestionChoice
Arterial imaging would be of benefit if there was a concern about circulatory deficit preventing healing. The pathophysiology of diabetic foot ulcers is usually microvascular in nature and therefore arterial duplexes are not indicated
32535
c
Arterial lower limb duplex
QuestionChoice
Venous doppler scanning is predominantly used to look for venous thrombosis. Whilst haemostasis in the legs due to poor drainage can cause venous ulceration the vignette here indicates this is a diabetic foot ulcer and therefore dopplers are not indicated
32536
d
Lower limb venous doppler
QuestionChoice
Blood cultures would be indicated if this patient had presented acutely septic, however this is a chronic infection and therefore blood cultures are unlikely to be positive or helpful in this case
32534
b
Blood cultures
QuestionChoice
Given the chronicity of this infection and the relative immunosuppression of a patient with poorly controlled diabetes, it is important to rule out osteomyelitis which would require extended intravenous antibiotic therapy. The best modality for this is MRI
32533
a
Magnetic resonance imaging (MRI) of the foot
QuestionChoice
Serum HbA1C is useful in determining both the initial diagnosis and long term control of diabetes. Whilst in this case we know the patient has poorly controlled diabetes and tighter diabetic control will lead to better outcomes it does not deal with the acute issue at hand
32537
e
Serum haemoglobin A1C (HbA1C) measurement
Concept
Chapter
# Summary

Charcot arthropathy is a chronic, progressive condition characterised by destructive changes in the bones and joints of patients with neuropathy, most commonly from diabetes. It presents with the '6Ds': Destruction, Deformity, Degeneration, Dense bones, Debris, and Dislocation. Diagnosis often involves imaging, typically with radiographs, and distinguishing it from osteomyelitis. Management focuses on immobilisation, orthotics, medication to manage pain and bone loss, and surgical interventions in advanced or refractory cases.

# Definition

Charcot arthropathy, also known as Charcot joint or neuropathic arthropathy, is a chronic, progressive condition characterised by painful or painless bone and joint destruction in the limbs that have lost sensory innervation. The condition primarily affects patients with peripheral neuropathy.

# Epidemiology

Charcot arthropathy is most commonly seen in patients with long-standing diabetes mellitus, with the prevalence being estimated to be around 0.1-0.9% in this group. It can occur at any age but is more frequently observed in the middle-aged and elderly population.

# Aetiology

The underlying aetiology of Charcot arthropathy is primarily neuropathy. The most common cause of this is diabetes mellitus, which leads to microvascular disease, autonomic neuropathy, and peripheral neuropathy, resulting in cumulative damage to the joints. Other, rarer causes include conditions that cause neuropathy, such as syringomyelia, chronic alcohol abuse, and syphilis.

# Signs and Symptoms

Charcot arthropathy often presents with the '6Ds'(some of which are imaging features):

- Destruction of bone and joint
- Deformity
- Degeneration
- Dense bones
- Debris of bone fragments
- Dislocation

It classically affects the tarsometatarsal joints, but it can involve any joint in a limb that has lost sensation due to neuropathy.

# Differential Diagnosis

The main differential diagnosis to rule out in the context of Charcot arthropathy is osteomyelitis, which also causes bone destruction but is typically associated with systemic symptoms like fever, increased inflammatory markers, and often a preceding or concurrent soft tissue infection.

# Investigations

The diagnosis of Charcot arthropathy is primarily clinical but often involves imaging to assess the extent of the bone and joint involvement:

- X-rays are usually the first-line imaging study. They can demonstrate bone destruction, debris, sclerosis (dense bones), and dislocation.
- MRI can provide more detailed imaging, particularly in early disease or when osteomyelitis is suspected.
- Bone scans may be used in complex cases or when other imaging is inconclusive.

# Management

The management of Charcot arthropathy involves conservative and surgical strategies:

Conservative:
- Prolonged off-loading, often involving special footwear or plaster casts, to allow healing and prevent further damage.
- Use of orthotics for long-term management and prevention of recurrences.

Medications:
- Bisphosphonates can help slow down the process of bone destruction.
- Neuropathic pain agents, such as gabapentin or pregabalin, for pain management.
- Topical anesthetics can also be used to manage pain.

Surgical:
- Resection of bony prominences to prevent ulcers or improve fitting of footwear.
- Correction of severe deformities, usually after the acute phase has settled.
- Amputation may be required in severe cases or when there is a concurrent uncontrolled infection.



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Charcot Arthropathy
Topic
5
Endocrinology
6507
In diabetic patients with chronic foot ulcers, MRI is essential to rule out osteomyelitis when infection fails to improve with oral antibiotics.
A 73 year old female with poorly controlled type two diabetes mellitus has had a chronically infected foot ulcer for six weeks and it is not improving with oral antibiotics. She's become increasingly unable to weight bear over the past week.

Which investigation will be most useful to guide your management?
a