Neuropathic joint disease
Encyclopedia
Neuropathic arthropathy (or neuropathic osteoarthropathy), also known as Charcot joint (often "Charcot foot"), refers to progressive degeneration of a weight bearing
joint
, a process marked by bony destruction, bone resorption
, and eventual deformity
. Onset is usually insidious.
If this pathological process continues unchecked, it could result in joint deformity, ulceration and/or superinfection
, loss of function, and in the worst case scenario: amputation
or death. Early identification of joint changes is the best way to limit morbidity.
, and fine motor control
:
In reality, both of these mechanisms probably play a role in the development of a Charcot joint.
(medial joints affected more than lateral), 30% Metatarsophalangeal joints
and 10% have ankle disease. Over half of diabetic patients with neuropathic joints can recall some kind of precipitating trauma, usually, minor.
Patients with neurosyphilis tend to have knee involvement, and patients with syringomyelia
of the spinal cord may demonstrate shoulder deformity.
Hip joint destruction is also seen in neuropathic patients.
, edema
and increased temperature in the affected joint. In neuropathic foot joints, plantar ulcers may be present. Note that it is often difficult to differentiate osteomyelitis
from a Charcot joint, as they may have similar tagged WBC scan and MRI features (joint destruction, dislocation, edema). Definitive diagnosis may require bone or synovial biopsy.
of the distal metatarsals in the forefoot. The more common form of destruction is hypertrophic joint disease, characterized by acute peri-articular fracture and joint dislocation. According to Yochum and Rowe, the "6 D's" of hypertrophy are:
The natural history of the joint destruction process has a classification scheme of its own, offered by Eichenholtz decades ago:
Stage 0: Clinically, there is joint edema, but radiographs are negative. Note that a bone scan may be positive before a radiograph is, making it a sensitive but not very specific modality.
Stage 1: Osseous fragmentation with joint dislocation seen on radiograph ("acute Charcot").
Stage 2: Decreased local edema, with coalescence of fragments and absorption of fine bone debris
Stage 3: No local edema, with consolidation and remodeling (albeit deformed) of fracture fragments. The foot is now stable.
Destroyed Tarsometatarsal joints in the medial left foot, with fracture and dislocation of fragments; these are classic findings. Also note loss of the foot arch and acquired flat foot
(pes planus) deformity.
Atrophic Features:
will help ward off further joint destruction. Pneumatic walking braces are also used. Surgical correction of a joint is rarely successful in the long-term in these patients.
It can take 6–9 months for the edema and erythema of the affected joint to recede.
Weight bearing
In orthopedics, weight-bearing is the amount of weight a patient puts on the leg on which surgery has been performed. In general, it is described as a percentage of the body weight, because each leg of a healthy person carries the full body weight when walking, in an alternating fashion.After...
joint
Joint
A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally.-Classification:...
, a process marked by bony destruction, bone resorption
Bone resorption
Bone resorption is the process by which osteoclasts break down bone and release the minerals, resulting in a transfer of calcium from bone fluid to the blood....
, and eventual deformity
Deformity
A deformity, dysmorphism, or dysmorphic feature is a major difference in the shape of body part or organ compared to the average shape of that part.Deformity may arise from numerous causes:*A Genetic mutation*Damage to the fetus or uterus...
. Onset is usually insidious.
If this pathological process continues unchecked, it could result in joint deformity, ulceration and/or superinfection
Superinfection
In virology, superinfection is the process by which a cell, that has previously been infected by one virus, gets coinfected with a different strain of the virus, or another virus at a later point in time. Viral superinfections of serious conditions can lead to resistant strains of the virus, which...
, loss of function, and in the worst case scenario: amputation
Amputation
Amputation is the removal of a body extremity by trauma, prolonged constriction, or surgery. As a surgical measure, it is used to control pain or a disease process in the affected limb, such as malignancy or gangrene. In some cases, it is carried out on individuals as a preventative surgery for...
or death. Early identification of joint changes is the best way to limit morbidity.
Pathogenesis
Any condition resulting in decreased peripheral sensation, proprioceptionProprioception
Proprioception , from Latin proprius, meaning "one's own" and perception, is the sense of the relative position of neighbouring parts of the body and strength of effort being employed in movement...
, and fine motor control
Motor control
Motor control are information processing related activities carried out by the central nervous system that organize the musculoskeletal system to create coordinated movements and skilled actions...
:
- Diabetes mellitusDiabetes mellitusDiabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
neuropathy (the most common in the U.S. today, resulting in destruction of foot and ankle joints), with Charcot joints in 1/600-700 diabetics. Related to long-term poor glucose control. - Alcoholic neuropathy
- Cerebral palsyCerebral palsyCerebral palsy is an umbrella term encompassing a group of non-progressive, non-contagious motor conditions that cause physical disability in human development, chiefly in the various areas of body movement....
- LeprosyLeprosyLeprosy or Hansen's disease is a chronic disease caused by the bacteria Mycobacterium leprae and Mycobacterium lepromatosis. Named after physician Gerhard Armauer Hansen, leprosy is primarily a granulomatous disease of the peripheral nerves and mucosa of the upper respiratory tract; skin lesions...
- SyphilisSyphilisSyphilis is a sexually transmitted infection caused by the spirochete bacterium Treponema pallidum subspecies pallidum. The primary route of transmission is through sexual contact; however, it may also be transmitted from mother to fetus during pregnancy or at birth, resulting in congenital syphilis...
(tabes dorsalis), caused by the organism Treponema pallidumTreponema pallidumTreponema pallidum is a species of spirochaete bacterium with subspecies that cause treponemal diseases such as syphilis, bejel, pinta and yaws. The treponemes have a cytoplasmic and outer membrane... - Spinal cord injurySpinal cord injuryA spinal cord injury refers to any injury to the spinal cord that is caused by trauma instead of disease. Depending on where the spinal cord and nerve roots are damaged, the symptoms can vary widely, from pain to paralysis to incontinence...
- Myelomeningocele
- SyringomyeliaSyringomyeliaSyringomyelia is a generic term referring to a disorder in which a cyst or cavity forms within the spinal cord. This cyst, called a syrinx, can expand and elongate over time, destroying the spinal cord. The damage may result in pain, paralysis, weakness, and stiffness in the back, shoulders, and...
- Intra-articular steroidSteroidA steroid is a type of organic compound that contains a characteristic arrangement of four cycloalkane rings that are joined to each other. Examples of steroids include the dietary fat cholesterol, the sex hormones estradiol and testosterone, and the anti-inflammatory drug dexamethasone.The core...
injections - Congenital insensitivity to painCongenital insensitivity to painCongenital insensitivity to pain , also known as congenital analgesia, is one or more rare conditions where a person cannot feel physical pain...
Underlying Mechanisms
- Two primary theories have been advanced:
- Neurotrauma: Loss of peripheral sensation and proprioception leads to repetitive microtraumaMicrotraumaMicrotrauma is the general term given to small injuries to the body.Microtrauma can include the microtearing of muscle fibres, the sheath around the muscle and the connective tissue. It can also include stress to the tendons, and to the bones . It is unknown whether or not the ligaments adapt like...
to the joint in question; this damage goes unnoticed by the neuropathic patient, and the resultant inflammatory resorption of traumatized bone renders that region weak and susceptible to further trauma. Indeed, it is a vicious cycle. In addition, poor fine motor control generates unnatural pressure on certain joints, leading to additional microtrauma. - Neurovascular: Neuropathic patients have dysregulated autonomic nervous systemAutonomic nervous systemThe autonomic nervous system is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils,...
reflexes, and de-sensitized joints receive significantly greater blood flow. The resulting hyperemia leads to increased osteoclastic resorption of bone, and this, in concert with mechanical stress, leads to bony destruction.
- Neurotrauma: Loss of peripheral sensation and proprioception leads to repetitive microtrauma
In reality, both of these mechanisms probably play a role in the development of a Charcot joint.
Joint Involvement
Diabetes is the foremost cause in America today for neuropathic joint disease, and the foot is the most affected region. In those with foot deformity, approximately 60% are in the tarsometatarsal jointsTarsometatarsal articulations
The tarsometatarsal articulations are arthrodial joints in the foot.It is also known as the "Lisfranc joint". It is named after 18th-19th century surgeon and gynecologist, Jacques Lisfranc de St...
(medial joints affected more than lateral), 30% Metatarsophalangeal joints
Metatarsophalangeal articulations
The metatarsophalangeal articulations are the joints between the metatarsal bones of the foot and the proximal bones of the toes...
and 10% have ankle disease. Over half of diabetic patients with neuropathic joints can recall some kind of precipitating trauma, usually, minor.
Patients with neurosyphilis tend to have knee involvement, and patients with syringomyelia
Syringomyelia
Syringomyelia is a generic term referring to a disorder in which a cyst or cavity forms within the spinal cord. This cyst, called a syrinx, can expand and elongate over time, destroying the spinal cord. The damage may result in pain, paralysis, weakness, and stiffness in the back, shoulders, and...
of the spinal cord may demonstrate shoulder deformity.
Hip joint destruction is also seen in neuropathic patients.
Clinical Findings
Clinical findings include erythemaErythema
Erythema is redness of the skin, caused by hyperemia of the capillaries in the lower layers of the skin. It occurs with any skin injury, infection, or inflammation...
, edema
Edema
Edema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...
and increased temperature in the affected joint. In neuropathic foot joints, plantar ulcers may be present. Note that it is often difficult to differentiate osteomyelitis
Osteomyelitis
Osteomyelitis simply means an infection of the bone or bone marrow...
from a Charcot joint, as they may have similar tagged WBC scan and MRI features (joint destruction, dislocation, edema). Definitive diagnosis may require bone or synovial biopsy.
Radiologic Findings
First, it is important to recognize that two types of abnormality may be detected. One is termed atrophic, in which there is osteolysisOsteolysis
Osteolysis refers to an active resorption of bone matrix by osteoclasts as part of an ongoing disease process.-Osteolysis in joint replacement:...
of the distal metatarsals in the forefoot. The more common form of destruction is hypertrophic joint disease, characterized by acute peri-articular fracture and joint dislocation. According to Yochum and Rowe, the "6 D's" of hypertrophy are:
- Distended joint
- Density increase
- Debris production
- Dislocation
- Disorganization
- Destruction
The natural history of the joint destruction process has a classification scheme of its own, offered by Eichenholtz decades ago:
Stage 0: Clinically, there is joint edema, but radiographs are negative. Note that a bone scan may be positive before a radiograph is, making it a sensitive but not very specific modality.
Stage 1: Osseous fragmentation with joint dislocation seen on radiograph ("acute Charcot").
Stage 2: Decreased local edema, with coalescence of fragments and absorption of fine bone debris
Stage 3: No local edema, with consolidation and remodeling (albeit deformed) of fracture fragments. The foot is now stable.
Destroyed Tarsometatarsal joints in the medial left foot, with fracture and dislocation of fragments; these are classic findings. Also note loss of the foot arch and acquired flat foot
Flat feet
Flat feet is a formal reference to a medical condition in which the arch of the foot collapses, with the entire sole of the foot coming into complete or near-complete contact with the ground...
(pes planus) deformity.
Atrophic Features:
- "Licked candy stick" appearance, commonly seen at the distal aspect of the metatarsals
- Diabetic osteolysis
- Bone resorption
Treatment
Once the process is recognized, immobilization with a total contact castOrthopedic cast
An orthopedic cast, body cast or surgical cast, is a shell, frequently made from plaster, encasing a limb to hold a broken bone in place until healing is confirmed...
will help ward off further joint destruction. Pneumatic walking braces are also used. Surgical correction of a joint is rarely successful in the long-term in these patients.
It can take 6–9 months for the edema and erythema of the affected joint to recede.