A knee replacement typically costs between £12,000 and £15,000. A new hip costs between £9,000 and £16,500, and cataract removal between £2,000 and £4,000, according to figures from the health data provider LaingBuisson. Despite the steep average annual cost of £2,252, more people have been forking out for individual medical insurance. Some say this trend, coupled with higher medical costs, is driving up insurance premiums.