Many patients having knee replacements have hidden hopes that their sexual activity will improve post-op, but don’t ask doctors about it, a new study finds.

A year after surgery, about 40% of patients say their expectations of sexual activity were not met, researchers report in Clinical Orthopaedics and Related Research.

“Patients generally have high expectations towards the results of a prosthesis and expect to remain active despite their age, which also includes sexual activity,” said lead author Dr Rita Harmsen, of Leiden University Medical Centre in the Netherlands.

“Sexual activity is important to quality of life for men and women alike; however, sexual issues are not easily discussed — not in daily life, not in the consultation room, not by specialists, not by patients,” she said.