summary Neuropathic (charcot) shoulder is a chronic and progressive joint disease most commonly caused by syringomyelia leading to the destruction of the shoulder joint and surrounding structures. Diagnosis is made with radiographs of the shoulder 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 very rare around 70 total cases reported in literature 25% of individuals with syrinxes develop neuropathic arthropathy, with 80% of cases occurring in upper extremity Demographics mean age at diagnosis is ~50 2:1 male:female ratio Anatomic location shoulder (this topic) elbow foot & ankle 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 login to view 1 more bullet 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 login to view 2 more bullets neurovascular login to view 2 more bullets Genetics molecular biology RANK/RANKL/OPG triad pathway is thought to be involved Associated conditions shoulder syringomyelia login to view 4 more bullets Hansen's disease (leprosy) login to view 1 more bullet neurosyphilis (tabes dorsalis) login to view 2 more bullets diabetes login to view 1 more bullet Arnold-Chiari malformation login to view 1 more bullet multiple sclerosis end-stage renal disease adhesive arachnoiditis and TB arachnoiditis meningomyelocele chronic alcoholism Presentation History 30% of patients report trauma to the shoulder as the inciting event Symptoms swollen shoulder 50% are painless loss of function joint instability Physical exam inspection swollen, warm, erythematous joint login to view 1 more bullet motion loss of motion is most common finding (90%) crepitus joint laxity with mechanically instability neurovascular decreased upper extermity muscle strength sensory and temperature changes along patient's back and arms in cape-like distribution asymmetric reflexes login to view 1 more bullet Imaging Radiographs recommended views standard views of affected joint login to view 1 more bullet findings gold-standard in diagnosis of Charcot shoulder login to view 9 more bullets CT scan indications if significant concern osteomyelitis/chronic infection findings helpful in evaluating for intraosseous gas, cortical destruction, and sequestra MRI indications MRI of cervical spine to rule out syrinx when neuropathic shoulder arthropathy is present findings syrinx has signal intensity equal to or higher than CSF on T1-weighted images Bone scan technetium bone scan findings login to view 1 more bullet indium WBC scan findings login to view 2 more bullets Studies Labs ESR and WBC can be elevated making it difficult to differentiate from osteomyelitis 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 login to view 3 more bullets unique to Charcot joint disease login to view 2 more bullets Synovial chondromatosis Soft tissue sarcoma Tumeral calcinosis Winchester syndrome Gorham's disease Milwaukee shoulder syndrome Treatment Nonoperative rest, NSAIDs, protected immobilization with a sling, restriction of activity and treatment of underlying disease indications login to view 1 more bullet outcomes login to view 1 more bullet intra-articular corticosteroid injection indications login to view 1 more bullet outcomes login to view 1 more bullet Operative neurosurgical decompression indications login to view 1 more bullet outcomes login to view 2 more bullets shoulder arthrodesis indications login to view 1 more bullet outcomes login to view 1 more bullet shoulder arthroplasty indications login to view 3 more bullets outcomes login to view 1 more bullet Techniques Rest, NSAIDs, protected immobilization with a sling, restriction of activity and treatment of underlying disease technique immobilization slows the progression of ligamentous and soft-tissue laxity gentle physical therapy, passive stretching, range-of-motion exercises allow for reduction of pain and swelling Intra-articular corticosteroid injection technique glenohumeral injection is considered most effective Neurosurgical decompression technique neurosurgical management has been reported to consist of 1 or more of the following login to view 4 more bullets Shoulder arthrodesis approach S-shaped skin incision beginning over scapular spine, traversing anteriorly over acromion, and extending down the anterolateral aspect of arm technique fusion position login to view 5 more bullets Shoulder arthroplasty technique hemiarthroplasty, anatomic TSA, reverse TSA and shoulder resurfacing have all been previously performed off-label for treatment of charcot shoulder with encouraging results. complications progressive glenoid erosion in hemiarthroplasty cases acromial stress fractures in rTSA Complications Infection risk factors high risk with surgical intervention without management of underlying condition Upper extremity DVT risk factors any surgical intervention Acromial stress fracture risk factors reverse TSA for treatment of charcot shoulder