summary Neuropathic Charcot Joint of the Elbow is a chronic and progressive joint disease most commonly caused by syringomyelia leading to the destruction of the elbow joint and surrounding bony structures. Diagnosis is made with radiographs of the elbow and supplemented with cervical spine MRI to assess for a syrinx. Treatment should be individualized based on degree of functional limitation and underlying neurological condition. Neurosurgical decompression is indicated in the presence of a syrinx. Epidemiology Incidence rare condition in the upper extremity (~ 40 cases reported in literature) Anatomic location elbow (this topic) shoulder foot & ankle (see diabetic Charcot foot) Etiology Pathophysiology syrinx formation syrinx formation (fluid-filled cavity) in spinal cord causes damage to the decussating fibers of the lateral spinothalamic tract leading to loss of pain and temperature sensation loss of pain/temperature leads to dissociative anesthesia in which proprioception and motor function are preserved but pain and temperature are not as syrinx enlarges, damage to dorsal column and anterior horn of spinal cord lead to areflexia, loss of motor strength and muscle atrophy. joint destruction neurotrauma loss of peripheral sensation and proprioception leads to repetitive microtrauma to the joint poor fine motor control generates unnatural pressure on certain joints leading to additional microtrauma neurovascular neuropathic patients have dysregulated reflexes and desensitized joints that receive significantly greater blood flow the resulting hyperemia leads to increased osteoclastic resorption of bone Genetics molecular biology RANK/RANKL/OPG triad pathway is thought to be involved Associated conditions orthopedic conditions ulnar neuropathy medical conditions & comorbidities syringomyelia most common etiology of neuropathic arthropathy of the upper extremity 25% of Charcot joints are a result of syringomyelia monoarticular (shoulder > elbow) Arnold-Chiari malformation most common cause of syringomyelia Hansen's disease (leprosy) second most common cause of upper extremity neuropathic arthropathy neurosyphilis (tabes dorsalis) usually affects the knee can be polyarticular diabetes most common cause of foot and ankle neuropathic joints Presentation Symptoms swollen elbow 50% have pain, 50% are painless loss of function Physical exam inspection swollen, warm, erythematous joint mimics infection atrophy due to ulnar nerve entrapment interosseous atrophy hypothenar atrophy clawing motion loss of active motion is most common finding elbow flexion, extension, pronation and supination all affected elbow joint may be mechanically unstable loss of passive motion indicates mechanical block neurovascular a neurologic evaluation is essential ulnar nerve entrapment at the elbow very common paresthesias in ulnar nerve distribution interosseous weakness Imaging Radiographs recommended views standard views of affected joint AP and lateral of the elbow findings early changes degenerative changes may mimic osteoarthritis late changes obliteration of joint space fragmentation of both articular surfaces of a joint leading to subluxation or dislocation scattered "chunks" of bone in fibrous tissue joint distention by fluid surrounding soft tissue edema heterotopic ossification fracture MRI indications MRI of cervical spine to rule out syrinx when neuropathic elbow arthropathy is present Bone scan technetium bone scan findings may be positive (hot) for neuropathic joints and osteomyelitis indium WBC scan findings will be negative (cold) for neuropathic joints and positive (hot) for osteomyelitis useful to differentiate from osteomyelitis Studies Labs ESR and WBC can be elevated making it difficult to differentiate from osteomyelitis EMG/NCS helpful for confirming ulnar neuropathy associated with diagnosis Histology synovial hypertrophy detritic synovitis (cartilage and bone distributed in synovium) Differential Osteomyelitis/septic joint difficult to distinguish from osteomyelitis based on radiographs and physical exam common findings in both conditions swelling, warmth elevated WBC and ESR technetium bone scan is "hot" unique to Charcot joint disease indium leukocyte scan will be "cold" (negative) will be "hot" (positive) for osteomyelitis Treatment Nonoperative rest, NSAIDs, functional bracing, restriction of activity and treatment of underlying disease indications first line treatment for neuropathic elbow joint outcomes 50% of patients reported improvement after non-operative management intra-articular corticosteroid injection indications severe elbow pain Operative neurosurgical decompression indications presence of cervical syrinx outcomes decompression of syrinx has shown to slow disease progression, maximize joint function and improve bone quality studies have shown some elbow joint space restoration following syrinx decompression peripheral nerve neurolysis indications ulnar nerve palsies PIN palsies outcomes limited cases series have shown good recovery of nerve function but high recurrent rates elbow arthrodesis indications elbow pain and instability having failed conservative management outcomes limited case series have shown improvement of pain but with functional limitations total joint replacement indications Charcot joint is considered a contraindication to elbow total joint replacement due to poor bone stock, prosthetic loosening, instability, and soft-tissue compromise outcomes limited case reports exist on elbow arthroplasties for charcot elbow with mixed results Techniques Rest, NSAIDs, functional bracing, restriction of activity and treatment of underlying disease technique functional bracing allows flexion-extension, but neutralizes varus-valgus stresses Intra-articular corticosteroid injection technique ulnohumeral joint injection is considered most effective Neurosurgical decompression technique neurosurgical management has been reported to consist of 1 or more of the following posterior fossa decompression craniotomy syringoperitoneal shunt laminectomy Peripheral nerve neurolysis technique cubital tunnel release must be performed with careful soft tissue dissection due to severely altered anatomy noted in patients with charcot elbow Elbow arthrodesis technique optimal position optimal position for most activities is110 degrees flexion whereas 45-60 degrees flexion is optimal for work-related activities. contoured plate fixation most commonly used to achieve arthrodesis Complications Ulnar nerve entrapment most common complication of charcot elbow Infection risk factors high risk with surgical intervention without management of underlying condition Upper extremity DVT risk factors any surgical intervention