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Charcot arthropathy of shoulder: a case report

2011; Wiley; Volume: 3; Issue: 4 Linguagem: Inglês

10.1111/j.1757-7861.2011.00152.x

1757-7861

Roger B. Gaskins, Benjamin J. Miller, Mark T. Scarborough,

Diabetic Foot Ulcer Assessment and Management

Neuropathic (Charcot) arthropathy is a degenerative disorder caused by decreased sensory and proprioceptive innervation of the involved joint1. It was first described by Jean-Marie Charcot in patients with tabes dorsalis2. This type of arthropathy has many different underlying etiologies, including diabetes mellitus, tabes dorsalis, multiple sclerosis and syringomyelia3,4. The commonest presentation of neuropathic joint is secondary to diabetes mellitus, usually affecting the ankle1. Cases in the upper extremity are more likely to be due to syringomyelia1,4, where neurologic compromise leads to rapidly progressive joint destruction5. Syringomyelia is a progressively degenerative disorder of the spinal cord resulting in formation of an enlarging central cavity or syrinx6. The syrinx initially damages the pain and temperature fibers because they cross the midline; later it damages adjacent gray and white matter6,7. The patient often maintains motor function and proprioception6,8. Neuropathic arthropathy reportedly develops in up to one quarter of patients with syringomyelia, involving the upper extremity, usually the shoulder or elbow, in the vast majority of those cases9–12. Syringomyelia is commonly associated with Type I Arnold-Chiari malformation. This malformation is caused by migration of the tentorium cerebelli inferiorly from the foramen magnum, thus enlarging the fourth ventricle6,13. Syringomyelia develops in 75%–85% of patients with the Type I Chiari malformation6. A 52-year-old, right-hand dominant, African American woman presented with complaints of swelling, minimal pain and loss of mobility in her right shoulder. Her symptoms had begun suddenly three weeks previously and had been progressive since then. She was not able to lift her right arm above her head. She denied any traumatic event and did not have any significant rest or night pain. The patient denied any recent illnesses, fevers, or chills. There was no history of neurologic disease or endocrine disorders. Upon further questioning, she revealed a history of repeated burns to her hands while cooking, as well as burns to her neck from a hair-dryer. These burns had not been recognized by the patient until they were seen by her daughter. Her physical examination revealed some fullness of her right shoulder compared to the left. She was able to flex to 50° and abduct to 60°. Her passive range of motion was also limited, but did not cause significant discomfort. She could not actively rotate her right arm either internally or externally, but had 5/5 strength of her biceps, triceps, wrist extensors, finger flexors, and intrinsic muscles. She had full range of motion in her elbow and wrist. She demonstrated decreased coordination of fine motor movements in each of her hands. There was also decreased sensation to light touch along her arms bilaterally. Her upper and lower extremity reflexes were intact without hyperreflexia and she had a normal gait. Radiographs of her right shoulder and MR images of her right shoulder and cervical spine are shown in Figure 1a–e. The patient's radiographs and MR images. (a) X-ray of the right shoulder demonstrating humeral head resorption and heterotopic calcification. (b) MRI of the right shoulder demonstrating destruction of the humeral head without intramedullary extension. (c) MRI of the right shoulder showing an extensive soft tissue mass originating from the glenohumeral joint. (d) Sagittal view of the cervical spine demonstrating longitudinal extension of a syrinx from C2-T1. (e) Axillary view of the cervical spine demonstrating a syrinx. Based on the combination of the patient's history of lack of pain relative to the radiographic findings and the clinical findings of subtle neurological abnormalities, a presumptive diagnosis of syringomyelia as the cause of the joint destruction was made. This was later confirmed by an MRI, which revealed a syrinx in the patient's cervical spine. The imaging findings were consistent with severe late stage joint degeneration with an accompanying soft tissue mass. No abnormal blood glucose concentrations were noted and the patient was not diabetic, thus ruling out peripheral neuropathy secondary to diabetes mellitus as a cause. Tabes dorsalis was ruled out by a negative rapid plasma reagin. The patient did not have a history or clinical findings suspicious of an inflammatory arthropathy and there was no evidence of infection on laboratory tests. Primary or metastatic neoplasms were eliminated by the absence of tumors on imaging. Neuropathic osteoarthpathy is a chronic destructive joint disease caused by decreased sensory innervation of the involved joint, leading to repeated trauma. Neuropathic (Charcot) arthropathy can involve any joint, but in our case was isolated to the shoulder. Causes of decreased innervation include diabetes mellitus, tabes dorsalis due to tertiary syphilis, cerebral palsy, spinal cord injury, repeated corticosteroid injections, chronic alcoholism, and syringomyelia12,14–16. In this patient, a syrinx had formed and was damaging the pain and temperature nerve fibers of the spinothalamic tract as they crossed in the spinal cord. An early clue to her diagnosis was that her pain was decidedly less than would have been expected by the findings on her imaging studies. Furthermore, syringomyelia often leads to a neuropathic upper extremity12,17. Up to one quarter of patients with syringomyelia will develop a Charcot joint17. Syringomyelia is a disorder in which an enlarging cavity forms within the spinal cord6. The syrinx can expand over time and lead to increasing damage to the spinal cord6,7. Patients often experience pain and weakness in the spine, shoulders, elbows and wrist. Syringomyelia generally leads to loss of pain and temperature sensation along the back and arms in a classic cape-like distribution6,12. Syringomyelia may also cause a loss of the ability to feel extremes of hot or cold, especially in the hands. There are two theories regarding the mechanism by which syringomyelia leads to joint destruction. The neurovascular theory of neuropathic osteoarthropathy states that blood flow and periarticular bone resorption are increased in the damaged joint due to an autonomically stimulated vascular reflex18. The neurotrauma theory states that the decreased innervation and proprioception results in minor injury to the involved joint14. Over time, these injuries weaken the joint and lead to inflammatory bone resorption. Both mechanisms are likely involved in this type of joint destruction. The treatment for a neuropathic joint is initially symptomatic. Appropriate referrals should be made to address whatever pathological process has been identified as the cause of the arthropathy. Therapy usually involves both slowing progression of the underlying disease process and preserving maximum functionality of the joint11. Immobilization and joint protection are crucial therapies for the treatment of Charcot joints6,7. Splinting and aspiration may prevent the progression of ligamentous laxity11. Non-steroidal anti-inflammatory medications also may help mitigate synovial inflammation15. Joint arthroplasty is contraindicated in most cases12. Shoulder arthroplasties in patients with syringomyelia have unacceptable failure rates because the poor bone structure leads to early prosthetic loosening. This problem usually stems from the glenoid component19. Physical therapy, passive stretching exercises, and functional orthosis are the preferred therapies7. Our neurological surgery colleagues performed a suboccipital decompression for the Chiari I malformation and a T1-2 laminectomy. However, the patient continued to have right shoulder pain and a limited range of motion. She was given a subacromial steroid injection in our clinic, after which she reported an 80% improvement in her degree of pain. She continues to be followed up in our clinic. The plan is to defer any surgical intervention for a minimum of two years post-decompression provided her neurological condition remains stable. No benefits in any form have been, or will be, received from a commercial party related directly or indirectly to the subject of this manuscript.