The description of Charcot joints dates back to 1703 when neuropathic osteoarthropathy was first described by W. Musgrave. Charcot is credited for his work in 1868 for describing gait anomalies of patients with syphilis (tabes dorsalis). Jordan, in 1936, was the first to describe a relationship of diabetes to neuropathic arthropathy.

The most common area of the foot to be effected by a Charcot joint is the mid arch. Charcot joints can also develop at the rearfoot and ankle but are much less common. The most common cause of Charcot joints of the foot is peripheral neuropathy due to diabetes mellitus.

The progress of a Charcot joint can be rapid and depends upon several variables. Any ability to perceive pain may lead to a more prompt diagnosis due to a patient's concern regarding their abilities to complete an average day. Complete loss of deep pain sensation may delay early diagnosis. Charcot joints are easily confused with osteoarthritis, which is treated much less aggressively than a Charcot joint.

In 1966 Eichenholz proposed a classification of Charcot joints which is broken down into three distinctive stages. Stage one, or the development stage, shows debris surrounding the joints on xray. Stage one can develop over a period of days to weeks and is radiographic change that occurs in response to unperceived trauma. Stage two is the coalescence stage. In stage two, the bone begins to heal with absorption of debris and healing of large fracture fragments. Stage three, often called the reconstruction or reconstitution stage, note a reduction in bone turn over and reformation of stable bone structure. Stage 0 was added in 1999 by Sella and Barrette to include patients who exhibit clinical symptoms of Charcot arthropathy but have yet to show radiographic changes.

The classification proposed by Brodsky in 1992 includes the location of the Charcot joint and is commonly used in clinical practice today. Brodsky's classification is as follows;

Type 1 - Lisfrank's joint - 27-60% of all Charcot joint deformities of the feet.

Type 2 - Chopart's joints and subtalar joints - 30-35%.

Type 3A - Ankle joint - 9% of all Charcot deformities.

Type 3B - The posterior calcaneus.

Type 4 - Multiple regions of the foot and/or ankle.

Type 5 - The forefoot.

Charcot joints are often not diagnosed until they create another problem that affects a patients normal activities. These may be as simple as an inability to fit into shoes, or as severe as an infected ulceration of the foot. By this stage, the Charcot deformity has in all likelihood progressed to a point where there is massive displacement of the bones and joints along with multiple displaced fractures.

Any condition that contributes to the loss of sensation of the foot may be considered a cause for a Charcot joint. Some of those conditions include;

Diabetes mellitus Tabes dorsalis (neuropathy caused by syphilis Hansen's Disease (Leprosy) Tumors of the spinal cord Degenerative change of the spinal cord or peripheral nerve Amyloid Familial-hereditary neuropathies including Charcot-Marie Toothe Disease, Hereditary sensory neuropathy and Dejerine-Sottas Disease Pernicious Anemia

Medications that may be a contributing cause of Charcot joints include;

Injectable and systemic use of steroids Phenylbutazone Indomethacin Vincristine

Other factors that may contribute to causing neuropathy, and subsequently, Charcot joints include;

Alcoholic neuropathy Congenital insensitivity to pain Pott's Disease (tuberculosis of the spine)

The most common complicating factor of a Charcot joint of the foot is the prominence that develops on the bottom of the foot, referred to as a 'rocker bottom' foot. This condition occurs as the bones of the arch collapse. In an advanced rocker bottom foot, the inability to sense pain becomes a complicating factor for the skin. As the bone places more pressure on the skin, the skin begins to ulcerate and becomes infected.

X-rays are the single most useful tool in diagnosing Charcot joints. Bone scans are helpful in the early phases of Charcot joints and are sensitive indicators of hyperemia (increased blood flow to the area of the fracture). Surface skin temperature is the most reliable indicator of the activity of the fractures. Most doctors do not keep the necessary equipment to measure skin temperature but merely measure with direct touch to sense the presence or lack of

Treatment of Charcot joints

The hallmark of treatment of Charcot joints is early diagnosis and prevention. The symptoms and findings of Charcot joints vary so that each case requires careful evaluation. Treatment of Charcot joints of the feet may include rest, casting and non-weight bearing to allow adequate time for fracture healing. Total contact casting or the use of a Charcot Restraint Orthotic Walker (CROW) are popular in stages one and two. The goal is to limit weight bearing to enable progression to stage three. This progression can take from several weeks up to 6 months. Electrical stimulation, or bone stimulation, is a popular adjunct to non-weight bearing or casting.

Surgical procedures for Charcot joints are often challenging not only due to the complexity of this condition but also due to the fact that these patients are usually poor surgical candidates due to other health problems (co-morbidity). Surgical procedure may include reconstruction of the arch and/or joint fusion. Often, surgical procedures are used to return the foot to a shape that can be accommodated by normal foot wear. Stage three Charcot deformities often result in lumps, bump and unusually shaped feet due to bone changes. Reshaping the foot may be used to eliminate a boney prominence on the top or bottom of the foot.

Nomenclature:

reflex vasodilitation - increased flow of blood to an area in response to inflammation

Rocker bottom foot - a prominence that forms on the sole or bottom of the foot as a result of the collapse of the arch

Symptoms:

The symptoms of Charcot joints vary based upon the location and severity of the condition. The initial sign is localized edema (swelling) of the joint or joints. The edematous area may exhibit increased temperature change. Often, the first noticeable symptom that a patient with advanced peripheral neuropathy will notice is the fact that their shoes have become tighter or they have difficulty fitting into a pair of shoes that have fit well for some time.

The challenge in diagnosing this condition is the lack of symptoms that are due to peripheral neuropathy. Peripheral neuropathy makes it impossible for the patient to be able to speak in terms that would be understood by the general population such as 'my feet hurt'. As a result, the physician needs to rely more on testing and less on the history and physical exam.

Differential Diagnosis:

The differential diagnosis for this condition should include;

Arthritis rheumatoid and osteoarthritis

Bone tumor

Diabetic osteolysis

Fracture

Gout

Idiopathic edema

Lymphedema

Pseudogout

Septic arthritis (infected joint)

Soft tissue tumor

Additional references include;

Grady, J.F., et al: The use of electrostimulation in the treatment of diabetic neuroarthropathy J. Am. Podiatric Med. Assoc. 90(6): 287-294, 2000

Sinha, S., Munichoodappa, C.S., Kozak, G.P: Neuroarthropathy (Charcot Joints) in diabetes mellitus. Medicine (Baltimore) 51:191, 1972

Saltzman, CL, Johnson KA, Goldstein RH, et al: The patellar tendon-bearing brace as treatment for neuropathic arthropathy: a dynamic force monitoring study. Foot Ankle 13: 14, 1992

Sticha RS, Frascone ST, Werthheimer SJ: Major arthrodesis in patients with neuropathic arthropathy. J Foot Ankle Surg 35: 560, 1996

Frykberg RG, Osteoarthropathy. Clin Podiatric Med Surg 4:351, 1987

Eichenholtz SN: Charcot Joints, Charles C. Thomas, Springfield, Il 1966

Giurini JM: Applications and use of in-shoe orthoses in the conservative management of Charcot foot deformity. Clin Podiatric Med Surg 11: 271, 1994

Banks AS, McGlamry ED: Charcot Fott. JAPMA 79:213, 1989

Pinzur MS, Sage R, Stuck R, et al: A treatment algorithm for neuropathic (Charcot) midfoot deformity. Foot Ankle 14: 189, 1993

Lavery LA, Armstrong DG, Walker SC: Healing rates of diabetic foot ulcers associated with midfoot fracture due to Charcot's arthropathy. Diabet Med 14:46, 1996

Cleveland M: Surgical fusion of unstable joints due to neuropathic disturbance. Am J Surg 43: 580, 1939

Wilson M : Charcot foot osteoarthropathy in diabetes mellitus. Mil Med 156: 563, 1991

Reinherz RP, Cheleuitte ER, Fleischle JG: Identification and treatment of the diabetic neuropathic foot. J Foot ankle Surg 34: 74, 1995

Pap J, Myerson M, GirardP, et al: Salvage with arthrodesis in intractable diabetic neuropathic arthropathy of the foot and ankle. J Bone Joint Surg Am 75:1056, 1993

Lavine LS, Grodinsky AJ: Current concepts review: electrical stimulation of repair of bone. J Bone Joint Surg Am 69: 626, 1987

Bassett CA, Mitchell SN, Norton L, et al: Repair of non-unions by pulsing electromagnetic fields. Acta Orthop Belg 44: 706, 1978
About the Author

Jeffrey A. Oster, DPM, C.Ped is a board certified foot and ankle surgeon. Dr. Oster is also board certified in pedorthics. Dr. Oster is medical director of Myfootshop.com and is in active practice in Granville, Ohio.