BASICS
In 1703, an English physician, Dr. W. Musgrave, initially described neurogenic arthropathy in a luetic patient, described as a swollen and inflamed joint. French neurologist Jean Martin Charcot published the first observations of tabes dorsalis, due to tertiary syphilis, in the Archives de Neurologie in 1883. In 1936, Dr. W. R. Jordan established the association between foot/ankle neuropathic changes and diabetes mellitus (DM). á
DESCRIPTION
- A progressive destructive arthritis secondary to peripheral neuropathy and the associated loss of pain sensation. The affected joints are subjected to repeated stress that is unrecognized by the patient, causing damage to underlying bone and cartilage.
- Synonym(s): neuropathic joint disease/arthropathy; Charcot joint disease
- Two pathologic theories: neurovascular and neurotraumatic
- 60% of cases are in tarsal and tarsometatarsal joints, 30% in metatarsophalangeal and talotibial joints; may also be seen in knee, hip, spine
- Upper extremity joints are rarely involved (seen in syringomyelia).
- Affected systems: musculoskeletal, endocrine, and neurological
- DM is the most common cause in the United States.
- There are four stages of Charcot arthropathy
- Modified Eichenholtz classification:
- Stage 0-prodromal: joint edema, negative radiographs
- Stage I-development: joint fragmentation and destruction
- Stage II-coalescence
- Stage III-reconstruction: consolidation /resolution (1)[C]
- Refer neuropathic arthropathy patients promptly to an orthopedic surgeon or podiatrist.
EPIDEMIOLOGY
- Usually occurs 8 to 12 years after diagnosis of DM
- Seen mostly in the 5th and 6th decades but can be seen in patients as young as 20 years
- Men > females
- 30% bilateral incidence
- 77% prevalence in patients with DM
- Prevalence without DM 11.7% (2)
Incidence
- 3 to 11.7/1,000 patients per year
- 1/600 to 700 in the United States have diabetes.
Prevalence
- 0.1% in all patients
- 0.8-8% in with the general DM population
- Up to 13% in high-risk diabetic patients (3)
ETIOLOGY AND PATHOPHYSIOLOGY
- Exact cause is unknown
- Two pathologic theories:
- Neurotraumatic: Repeated minor trauma of pedal bones in patient unable to perceive pain leads to multiple fractures and collapse of normal architecture (2).
- Neurovascular: Loss of sympathetic function leads to destruction of bone secondary to hypervascular state. Increased blood flow causes leaking of bone minerals, osteopenia, and fracture (2).
- Causes of peripheral neuropathy:
- DM
- Multiple sclerosis
- Raynaud disease
- Connective tissue disease (i.e., RA, scleroderma)
- Syphilis/tabes dorsalis
- Syringomyelia, upper extremity disease
- Meningomyelocele
- Frequent intra-articular steroid injections
- Alcoholism, pernicious anemia
- Charcot-Marie-Tooth disease
- Leprosy
- Dialysis, amyloidosis
- Trauma, spinal or peripheral nerve injury
RISK FACTORS
- DM >10-year, especially if poorly controlled
- Poor foot hygiene
- Syphilis, leprosy
- Concomitant arthritis (osteoarthritis, rheumatoid arthritis)
DIAGNOSIS
Findings frequently confused with cellulitis á
PHYSICAL EXAM
- Skin erythema, edema, and increased warmth
- Usually occurs in midfoot
- Pain is not as severe as physical findings would suggest. Patients may report no pain or minimal discomfort.
- Erythema usually resolves with elevation (helps differentiate from infection).
- Loss of distal sensation, proprioception, vibration
- Effusion in joint
- Usually unilateral
- Limited motion
- Swelling: early large effusion, late often resolved
- Foot deformities:
- Collapse of arch
- Collapse of tarsal bones causing rocker-bottom foot
- Protruding osteophytes
- Plantar ulcer
- Peripheral circulation often normal
- Brodsky test: Patient supine with involved leg raised for 10 minutes. In neuropathic arthropathy, swelling and erythema dissipate (persist with infection)
- Neuropathic arthropathy types:
- Atrophic-localized to forefoot
- Hypertrophic-affects midfoot, rearfoot, and ankle. "6 D's"Ł of hypertrophic type: distended joint; density increase; debris production; dislocation; disorganization; destruction
DIFFERENTIAL DIAGNOSIS
- Cellulitis, osteomyelitis, septic arthritis
- Osteonecrosis
- Advanced osteoarthritis
- Gout; calcium pyrophosphate dihydrate (CPPD) crystal deposition disease
- Neoplasm
- Trauma or acute injury (i.e., sprain)
- Deep vein thrombosis
- Idiopathic inflammatory disease
DIAGNOSTIC TESTS & INTERPRETATION
Initial Tests (lab, imaging)
- HgA1C
- White blood cell (WBC) count and erythrocyte sedimentation rate (ESR) may be elevated in osteomyelitis.
- Vitamin B12/folate, mean corpuscular volume
- Rapid plasma reagin (RPR), fluorescent treponema antibody absorption test to rule out syphilis
- Calcium, parathyroid hormone, phosphate, BUN, Cr to evaluate presence of metabolic bone disease
- Radiographs
- At onset, no radiographic changes are observed.
- Early changes: slight fracture with joint subluxation, effusion, joint space narrowing, bone fragmentation, sclerosis of subchondral bone
- Late radiographic changes: marked articular destruction, fractures, periarticular new bone, osteophytes, osseous debris, bone resorption
- Intra-articular loose bodies, osteolysis, large osteophytes
- Atrophic changes: massive bone resorption, joint disintegration; may look like chronic infection
Follow-Up Tests & Special Considerations
- MRI: helps to rule out osteomyelitis, stress fracture, or intra-articular fragmentation. Joint will most likely have increased signal.
- Bone scan +/- tagged WBC scan to rule out osteomyelitis
- Indium-111 more specific than technetium-99. Combination of indium-111 and technetium-99 may improve sensitivity (93-100%) and specificity (~80%).
- Bone or synovial biopsy
Diagnostic Procedures/Other
- Arthrocentesis: fluid for culture, WBC, crystals
- Rule out malignancy and neurologic disease if suspected.
TREATMENT
GENERAL MEASURES
- The goal of treatment is to heal broken bones and prevent further deformity, dislocation, and joint destruction. The mainstay therapy is offloading the foot and immobilization to reduce edema (4)[B].
- Nonsurgical
- Casting
- Custom shoes
- Bone growth stimulation: Ultrasonic bone stimulation to promote healing of fresh fractures (supported as adjunct therapy during the postoperative period)
MEDICATION
- Bisphosphonates: There is currently no evidence base for the use of bisphosphonates (5)[A].
- Calcitonin: A small randomized study suggests intranasal calcitonin decreased bone turnover compared with controls (6)[B].
- Proinflammatory cytokines: Anti-inflammatory agents, including antagonists of TNF-╬▒ and RANKL, are under investigation (7).
ADDITIONAL THERAPIES
- Protective treatment with bracing and orthotics
- Radiotherapy does not appear to benefit healing of acute Charcot feet in people with diabetes.
SURGERY/OTHER PROCEDURES
Indications for surgery: pain not managed by nonoperative therapy, recurrent ulcers, failed nonoperative treatment, chronic instability not amenable to bracing or casting (4)[A] á
- Surgery is generally avoided in the acute phases because of the risk of wound infection and failure of fixation.
- In the chronic, stable phase, surgical intervention (e.g., by exostectomy, arthrodesis, tendon lengthening, and fixation) is used to improve function of the foot and reduce likelihood of ulceration (7).
INPATIENT CONSIDERATIONS
Admission Criteria/Initial Stabilization
Foot ulceration, suspicion for osteomyelitis, fractures á
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
Activity: typically non-weight-bearing initially; regular follow up with foot care professional á
Patient Monitoring
Repeat imaging (x-ray or MRI) in 4 to 6 weeks. á
PATIENT EDUCATION
- Educate diabetic patients about signs and symptoms of neuropathic joint disease.
- Daily foot exam: looking for swelling, erythema, or increased temperature of joints
PROGNOSIS
- Poor diabetic control can ultimately lead to amputation.
- Obesity and noncompliance are strong predictors for the recurrence of CN (8).
- Contralateral limb is affected within 2 years in ~50% of amputees (8).
COMPLICATIONS
- Unidentified fractures can lead to debilitating joint deformities and skin ulceration, increasing risk of infection.
- Collapse into clubfoot or rocker-bottom foot
- Amputation
REFERENCES
11 Rosenbaum áAJ, DiPreta áJA. Classifications in brief: Eichenholtz classification of Charcot arthropathy. Clin Orthop Relat Res. 2015;473(3):1168-1171.22 Blume áPA, Sumpio áB, Schmidt áB, et al. Charcot neuroarthropathy of the foot and ankle: diagnosis and management strategies. Clin Podiatr Med Surg. 2014;31(1): 151-172.33 Suder áNC, Wukich áDK. Prevalence of diabetic neuropathy in patients undergoing foot and ankle surgery. Foot Ankle Spec. 2012;5(2):97-101.44 Armstrong áDG, Lavery áLA, Wu áS, et al. Evaluation of removable and irremovable cast walkers in the healing of diabetic foot wounds a randomized controlled trial. Diabetes Care. 2005;28(3):551-554.55 Richard áJL, Almasri áM, Schuldiner áS. Treatment of acute Charcot foot with bisphosphonates: a systematic review of the literature. Diabetologia. 2012;55(5):1258-1264.66 Bem áR, Jirkovsk í áA, Fejfarov í áV, et al. Intranasal calcitonin in the treatment of acute Charcot neuroosteoarthropathy: a randomized controlled trial. Diabetes Care. 2006;29(6):1392-1394.77 Game áF, Jeffcoate áW. The Charcot foot: neuropathic osteoarthropathy. Adv Skin Wound Care. 2013;26(9):421-428.88 Varma áAK. Charcot neuroarthropathy of the foot and ankle: a review. J Foot Ankle Surg. 2013;52(6):740-749.
ADDITIONAL READING
- Frykberg áRG, Belczyk áR. Epidemiology of the Charcot foot. Clin Podiatr Med Surg. 2008;25(1):17-28.
- Gazis áA, Pound áN, Macfarlane áR, et al. Mortality in patients with diabetic neuropathic osteoarthropathy (Charcot foot). Diabet Med. 2004;21(11):1243-1246.
- Goldner áMG. The fate of the second leg in the diabetic amputee. Diabetes. 1960;9:100-103.
- Lowery áNJ, Woods áJB, Armstrong áDG, et al. Surgical management of Charcot neuroarthropathy of the foot and ankle: a systematic review. Foot Ankle Int. 2012;33(2):113-121.
- Osterhoff áG, B Âni áT, Berli áM. Recurrence of acute Charcot neuropathic osteoarthropathy after conservative treatment. Foot Ankle Int. 2013;34(3):359-364.
CODES
ICD10
- M14.60 Charcot's joint, unspecified site
- A52.16 Charcot's arthropathy (tabetic)
- M14.679 Charcot's joint, unspecified ankle and foot
- M14.671 Charcot's joint, right ankle and foot
- M14.672 Charcot's joint, left ankle and foot
ICD9
- 094.0 Tabes dorsalis
- 713.5 Arthropathy associated with neurological disorders
SNOMED
- Charcot's arthropathy (disorder)
- Charcot arthropathy of joint of ankle (disorder)
- Charcot's joint of foot
CLINICAL PEARLS
- Neuropathic arthropathy typically presents with swelling, warmth, and erythema in the feet following a history of trauma.
- Skin erythema classically resolves with foot elevation in cases of neuropathic arthropathy, whereas the erythema persists with infection.
- The key initial treatment for neuropathic arthropathy is offloading and/or immobilization the affected joint(s).