King Charles poked fun at himself and the "endless plates and screws" in his arm.
While visiting Chatfield Health Care in Battersea, southwest London, on Wednesday, November 5, the monarch talked to veterans about the results of injuries he has sustained from polo and hunting over the years.
Speaking to a group of five former Army personnel, the 76-year-old king joked with David Wiggins, whose left arm was in a cast. Wiggins told the King he now had three plates in his arm.
The monarch replied, "I've got endless plates and screws in my arm as well. All that's left of you when you drop dead is 'made in Switzerland'."
Due to his fondness for polo, Charles had faced a number of injuries, including a broken right arm in a fall in 1990, which required several operations and was not healed for months.
In 2001, the King fell from his horse during a hunt in Derbyshire and broke a bone in his left shoulder, resulting in his arm being placed in a sling, reported The Telegraph.
Despite the setbacks, the king could never stay away from playing polo or hunting; however, he did eventually give up the sport in 2005, when he was 57.
The King, who is undergoing weekly treatment for an undisclosed form of cancer, surprised veterans waiting for a GP appointment in Battersea on Wednesday morning.
Chatfield Health Care was one of the first practices to join the Veteran Friendly programme, which is accredited by the Royal College of GPs and NHS England.
The visit came ahead of the Royal Family gathering this coming weekend to mark Remembrance Day, including attending the annual Royal British Legion Festival of Remembrance at the Royal Albert Hall on Saturday evening, as well as at the Cenotaph service on Sunday.