Assessing Charcot Foot in the Diabetic Patient with

Assessing Charcot Foot in the Diabetic Patient with Peripheral Neuropathy Louise Wade MSN, RN

Type 2 Diabetes According to the American Diabetes Association [ADA] (2013), Type 2 diabetes involves severe systemic complications, which occur due to uncontrolled elevated glycemic levels such as nephropathy, neuropathy, retinopathy, foot complications, heart disease, stroke and many other devastating health problems.

Type 2 Diabetes Facts Key facts (World Health Organization) • • • 347 million people worldwide have diabetes In 2004, an estimated 3. 4 million people died from consequences of high fasting blood sugar More than 80% of diabetes deaths occur in low- and middleincome countries WHO projects that diabetes will be the 7 th leading cause of death in 2030 (4). Healthy diet, regular physical activity, maintaining a normal body weight and avoiding tobacco use can prevent or delay the onset of type 2 diabetes. (who. org, 2013)

Common Complications of Type 2 Diabetes What are common consequences of diabetes? Over time, diabetes can damage the heart, blood vessels, eyes, kidneys, and nerves. Diabetes increases the risk of heart disease and stroke. 50% of people with diabetes die of cardiovascular disease (primarily heart disease and stroke). Combined with reduced blood flow, neuropathy (nerve damage) in the feet increases the chance of foot ulcers, infection and eventual need for limb amputation. Diabetic retinopathy is an important cause of blindness, and occurs as a result of long-term accumulated damage to the small blood vessels in the retina. One percent of global blindness can be attributed to diabetes. Diabetes is among the leading causes of kidney failure. The overall risk of dying among people with diabetes is at least double the risk of their peers without diabetes.

Uncontrolled Glucose Levels High blood sugar (glucose) that circulates in the bloodstream instead of being absorbed into cells damages nerves and blood vessels throughout the body and, ultimately, the major organs such as the kidneys and heart. It has been said that there isn’t a system in the body that isn’t affected by diabetes.

Peripheral Neuropathy Peripheral neuropathy is the result of nerve damage from uncontrolled blood glucose levels and often involves weakness, numbness and pain of the affected extremity (mayoclinic. org, 2013). Neuropathy can also lead to a condition known as Charcot foot, which is a condition affecting the bones, joints, and soft tissue of the foot and ankle. If not diagnosed correctly during the acute phase, Charcot may result in amputation of the affected limb; therefore, it is essential for health care providers to be familiar with the signs and symptoms and refer to the appropriate specialist (Rogers et al, 2013).

Etiology of Neuropathy The etiology of neuropathy is the destructive or dysfunction of peripheral nerves, which are damaged by uncontrolled elevated blood glucose levels. Peripheral neuropathy causes significant issues such as nonhealing wounds, major infections, amputations, and a condition known as Charcot foot that involves the soft tissue and bones of the foot and ankle and leads to permanent deformities.

Types of Neuropathy In general, there are three types of neuropathy: sensory, autonomic and motor. Sensory neuropathy is the most common, affecting how we perceive temperature, texture and pain. Autonomic neuropathy affects nerves involved in involuntary actions in the body such as emptying of the stomach, intestines and bladder. Motor neuropathy, affecting the nerves involved in movement, is rare in diabetes. (virginiamason. org, 2014).

Distal Neuropathy • Distal neuropathy affects the hands and feet and is the most common form of diabetic neuropathy. It usually affects both hands or both feet, but may affect only one hand or foot.

Foot Complications Foot problems Nerve and blood vessel damage – causing a lack of pain sensation and decreased blood flow – can result in serious foot problems. People with diabetes are particularly at risk for foot ulcers and infections: they may not know, for example, that an injury has occurred to the foot. And a lack of blood flow may slow the healing process. In severe cases, sores may never heal, leading to gangrene and amputation. For people with diabetes, it is important always to wear shoes and to inspect your feet every day, including the bottoms of your feet, for sores and infections.

Charcot Marie-Tooth (CMT) CMT is just one kind of neuropathy (also called peripheral neuropathy). These names simply mean that the peripheral nerves are damaged. There are many other causes of neuropathy besides CMT, including the most common cause— diabetes. Charcot-Marie-Tooth is named after three physicians who were the first to describe it in 1886: Jean-Martin Charcot, Pierre Marie, and Howard Henry Tooth (cmtausa. org, 2010).

“Charcot Foot” Charcot foot is a serious and potentially life-threatening complication associated with diabetes and continues to challenge the most experienced practitioner. Charcot is characterized by various degrees of bone, joint, soft tissue, foot and often ankle involvement and is secondary to underlying neuropathy, trauma, and perturbations of bone metabolism and involves inflammation during the acute phase (Rogers et al, 2011). While the exact etiology of Charcot foot is unknown, the primary causative issue is believed to be the result of diabetic neuropathy.

Charcot Cont’d • Charcot joint may occur if the bones in the feet develop fractures and the foot becomes misaligned. The condition can be painless because nerves were damaged from diabetes before the fracture developed. The foot or feet may then lose muscle support, eventually becoming deformed.

Progression of Charcot

Pathophysiology Charcot arthropathy most likely results as a combination of the following two theories: Neurotraumatic Theory The process begins with an unperceived trauma or injury to an insensate joint. The sensory neuropathy renders the patient unaware of the osseous destruction that occurs with ambulation. This microtrauma leads to progressive destruction and damage to bone and joints. Neurovascular Theory The underlying condition leads to the development of autonomic neuropathy, causing the extremity to receive increased blood flow. This results in a mismatch in bone destruction and synthesis, leading to osteopenia.

Neurotraumatic Theory Because of the decrease in sensation, the patient usually does not realize they have the condition. They continue walking on the untreated foot, ultimately causing the condition to worsen. Neuropathic patients who have a tight Achilles tendon are also prone to developing Charcot foot.

Jones Fracture (5 th Metatarsal Stress Fracture)

Obesity �Obesity is a strong risk factor for peripheral neuropathy Charcot arthropathy of weight-bearing joints.

Risk Factors Cont’d �The trigger for Charcot foot can be a sprain or twisted ankle that goes unnoticed because of reduced feeling from nerve damage. �If the person continues to place pressure on the foot through walking, the injury can worsen and could lead to dislocation or fractures in one or more bones of the foot or ankle.

Types of Charcot There may be several types of injury associated with this complication including subluxation, dislocation and other deformities but the classic sign is the midfoot collapse, described as a “rocker-bottom” foot, which is a permanent deformity unless surgically repaired.

Incidence and Prevalence "Charcot foot occurs in less than one percent of the entire diabetes population and in only about one-third of those with neuropathy” (Frykberg, 2010). According to the American Diabetes Association, 60– 70% of people with diabetes develop peripheral nerve damage that can lead to Charcot foot and about 0. 5% of these patients develop the condition. In most cases, onset occurs after the age of 50, and after the patient has had diabetes for 15 to 20 years (Peng & Swierzerswki, 2011).

Signs & Symptoms of Charcot In the most common kinds of CMT, symptoms usually begin before the age of 20 years. They may include: • Foot deformity (very high arched feet); May be severe • Foot drop (inability to hold foot horizontal); • “Slapping" gait (feet slap on the floor when walking because of foot drop); • Loss of muscle in the lower legs, leading to skinny calves; • Numbness in the feet; • Difficulty with balance; • Later, similar symptoms also may appear in the arms and hands.

Signs & Symptoms Cont’d Symptoms of Charcot foot include the following: • Dislocation of the joint • Heat • Insensitivity in the foot • Instability of the joint • Redness • Strong pulse • Swelling of the foot and ankle (caused by synovial fluid that leaks out of the joint capsule) • Subluxation (misalignment of the bones that form a joint)

Stages of Charcot Arthropathy 1. Development (Acute Phase) - Inflammation and radiographic visibility of changes. Possible debris formation, fragmentation, subluxation, dislocation, and distention. 2. Coalescence - Decreased inflammation. Absorption of debris and fusion of fragments. Progression slows and transitions into remodeling. 3. Remodeling - Remodeling and consolidation. Structural deformity is likely present and can lead to skin breakdown, infection, and amputation.

Acute Phase

Coalescence Stage

Remodeling Stage

Challenges of Charcot According to Rogers et al (2011), “the Charcot foot in diabetes poses many clinical challenges in its diagnosis and management. Despite the time that has passed since the first publication on pedal osteoarthropathy in 1883, we have much to learn about the pathophysiology, and little evidence exists on treatments of this disorder. ”

Complications Charcot foot can cause various complications, including: • Calluses • Foot ulcers, especially if the foot is deformed or if the condition is not caught in its early stages • Bony protrusions (these have potential to become infected if rubbed on the inside of the shoe for an extended period) • Osteomyelitis (bone infection) • Inflammation of the joint membranes • Blood vessel and/or nerve compression • Loss of sensation in the foot • Loss of function in the foot

Associated Injuries Other potential complications include the following: • Progressive inability to walk from weakness, balance problems, and/or orthopedic problems; • Progressive inability to use hands effectively; • Injury to areas of the body that have decreased sensation (i. e. Achilles tendon tear or rupture).

Foot Ulcerations

Calluses

Bony Protrusions

Diagnosis of Charcot Identifying this condition in its early stages is critical to successful treatment. Patients should see a podiatrist at the first sign of symptoms. Diagnosis can sometimes be difficult because this condition can mimic other conditions like cellulitis or deep venous thrombosis, and because diagnosis of a Charcot fracture cannot be made definitively until bone changes occur. “The initial manifestations of the Charcot foot are frequently mild in nature, but can become much more pronounced with unperceived repetitive trauma. Diagnostic clinical findings include components of neurological, vascular, musculoskeletal, and radiographic abnormalities” (Rogers et al, 2011).

Clinical Findings Typical clinical findings include a markedly swollen, warm, and often erythematous foot with only mild to modest pain or discomfort. Acute local inflammation is often the earliest sign of underlying bone and joint injury

Diagnostics Diagnostic recommendations for active Charcot The diagnosis of active Charcot foot is primarily based on history and clinical findings but should be confirmed by imaging. Inflammation plays a key role in the pathophysiology of the Charcot foot and is the earliest clinical finding.

Diagnostics Cont’d The occurrence of acute foot/ankle fractures or dislocations in neuropathic individuals is considered active CN because of the inflammatory process of bone healing, even in the absence of deformity. X-rays should be the initial imaging performed, and one should look for subtle fractures or subluxations if no obvious pathology is visible. MRI or nuclear imaging can confirm clinical suspicions in the presence of normal-appearing radiographs.

Prognosis (Expectations) CMT usually gets worse, slowly, with age; rapid progression is rare, and should motivate a prompt re-evaluation. The problems with weakness, numbness, difficulty with balance, and orthopedic problems can progress to the point of causing disability. Pain can be an issue, as a direct result of the neuropathy (neuropathic pain) and as consequence of orthopedic problems.

Prognosis Cont’d Affected joints may be fully healed within 1 -2 years of treatment, however lifelong care should be taken to prevent recurrence. This includes preventing injury, noting temperature changes, checking feet regularly, reporting trauma, and receiving professional foot care as necessary. Patients should check feet daily for any changes including injuries, cracks or dryness, warmth, infections, decreased sensation, etc.

Treatment There are several ways to treat Charcot foot. The main goal is to stabilize the joints. Although there are no known treatments that will stop or slow down the progression of CMT, but the CMTA is funding research to find these treatments. Recovery times can be up to eight weeks or longer in the acute stage, during which time patients will be required to be nonweight bearing. Non-surgical treatment options include: • Immobilization • Custom shoes and bracing • Use of crutches, casts, wheelchair used to protect foot • Limiting activities that cause the condition

Treatment Cont’d Although surgical treatment is an option, treatment is primarily nonoperative. Conservative treatment of Charcot arthropathy relies on halting the destructive phase of progression, and then protecting and supporting the joints throughout the healing process. Physical therapy, occupational therapy, and physical activity may help maintain muscle strength and improve independent functioning. Treatment plans can be broken into two phases, acute and postacute

Acute Treatment Phase (Onset until Charcot is inactive, 36 months after onset) Immobilization to prevent further destruction. The medical treatment of CN is aimed at offloading the foot, treating bone disease, and preventing further foot fractures. **Offloading at the acute active stage of the Charcot foot is the most important management strategy and could prevent the progression to deformity**

Immobility Immobilization usually is accomplished by casting. Total contact casts have been shown to allow patients to ambulate while preventing the progression of deformity.

CROW (Charcot Restraint Orthotic Walker) CROW is an acronym for Charcot Restraint Orthotic Walker. This orthosis is prescribed for patients who have foot ulcers or insensate feet (can’t feel). This is an orthosis that is clamshell in design and covers the entire foot and calf of the leg, resembling a ski boot (See Figure 1). While it is somewhat big and bulky, the CROW gives tremendous support by preventing foot and ankle movement. It is fully padded on the inside. A shoe is not worn with this orthosis.

Surgical Treatment Options Surgical treatment of Charcot arthropathy of the foot and ankle is based primarily on expert opinion. Surgery has generally been advised for resecting infected bone (osteomyelitis), removing bony prominences that could not be accommodated with therapeutic footwear or custom orthoses, or correcting deformities that could not be successfully accommodated with therapeutic footwear, custom ankle-foot orthoses, or a Charcot Restraint Orthotic Walker Surgery has generally been avoided during the active inflammatory stage because of the perceived risk of wound infection or mechanical failure of fixation.

Surgical Repair of Charcot

Postacute Treatment Phase (End of acute phase through 1 -2 years after onset) Following acute treatment phase, it is necessary to protect the foot throughout the remainder of the healing process. Protection methods include: Accommodative footwear with rigid soles and shanks Rocker bottoms to relieve stress on plantar ulcers Accommodative foot orthoses to protect insensate feet Orthopedic equipment (such as braces, inserts, or orthopedic shoes) may make it easier to walk.

Custom Fit Orthotics

Long Term Effects of Charcot Although Charcot is a devastating complication of diabetic peripheral neuropathy and may affect a person’s physical appearance and their ability to work, it does not have an affect on their mental capabilities. Patients are often left with feelings of depression, guilt from financial strains, and isolation. Referrals for counseling and other resources are to be considered. Patients may qualify for social security disability benefits and should consider applying as soon as they have been diagnosed.

Questions?

References American diabetes association: Living with diabetes; complications. (2013). Retrieved from http: //www. diabetes. org/living-with-diabetes/complications/ Charcot-marie-tooth-association: What is charcot-marie-tooth (cmt)? . (2010, December 10). Retrieved from http: //www. cmtausa. org/index. php? option=com_content&view=article&id= 70&Itemid=159 Diabetes complications. (2014). Retrieved from https: //www. virginiamason. org/Complications Frykberg, R. (2010). Understanding the etiology of the. Retrieved from http: //www. presentdiabetes. com/ezines/index. php? action=view. Publication &nopopout=true&confirm. Off=true&Search. Text=&id=324&keep. This=true&T B_iframe=true&height=700&width=768&full=true&thickbox. On=true Peng, H. , Swierzewski, S. , & (2011, May 23). Charcot foot overview. Retrieved from http: //www. healthcommunities. com/charcot-footoverview. shtml Rogers, L. , Frykberg, R. , Armstrong, D. , Boulton, A. , Edmonds, M. , Ha Van, G. , & Hartemann, A. (2011). The Charcot foot in diabetes. Diabetes Care, 34(9), 2123 -2129. doi: 10. 2337/dc 11 -0844 World health organization: Diabetes fact sheet. (2013, October). Retrieved from http: //www. who. int/mediacentre/factsheets/fs 312/en/