Shares in artificial joint specialist, Smith & Nephew, were off slightly after rumours of a takeover teased the market yesterday.Its shares moved 11.5p higher to 684p on Wednesday after talk of a 850p approach by United States's Stryker.However, any further details of the alleged cash offer were not forthcoming and the company's share price fell back 2p on Thursday morning.In May Smith & Nephew said first quarter revenue had been boosted by progress at its US knee franchise while net profit fell. During the first quarter ended 2 April 2011 revenue rose to $1.055bn from $995m the year before. Trading profit fell to $241m from $250m after it incurred higher administrative expenses. Group trading profit margin was 22.8% while net debt was reduced to $351m.