Charcot arthropathy of the shoulder joint following Arnold-Chiari malformation: A case report.

Introduction: Charcot arthropathy of the shoulder is a rare, progressive joint disorder associated with neurosensory deficits, most commonly syringomyelia. It is infrequently linked to Arnold-Chiari malformation, making diagnosis and treatment particularly challenging.

Case Presentation: A 51-year-old man presented with chronic, painless swelling and limited range of motion in the right shoulder. He had a history of Arnold-Chiari malformation, treated surgically eight months prior. Imaging revealed extensive humeral head destruction consistent with Charcot shoulder. Reverse shoulder arthroplasty (RSA) was performed due to the advanced stage of joint damage. At one-year follow-up, the patient had an excellent functional recovery, with no postoperative complications or radiographic signs of implant failure.

Clinical Discussion: Although rare, Charcot shoulder should be considered in patients with progressive shoulder dysfunction, especially with underlying neurologic conditions. Interestingly, in this case, disease progression continued despite surgical correction of the Arnold-Chiari malformation, suggesting a self-sustaining degenerative process. While RSA is generally used cautiously in Charcot joints due to concerns of instability and bone loss, it proved effective here.

Conclusion: Charcot arthropathy of the shoulder can progress even after resolution of the primary neurologic cause. Early recognition is crucial. In advanced cases, reverse shoulder arthroplasty may offer good functional outcomes when applied in selected patients.