Posterior interosseous nerve palsy secondary to rheumatoid cyst of the elbow joint: case report

A 73-year-old woman with rheumatoid arthritis had lost the ability to extend the digits on her right hand. A rheumatoid cyst in the elbow caused the posterior interosseous nerve palsy. Decompression was performed, and she recovered extension of the thumb and fingers completely within 3 weeks after the operation.