A ruling from the National Institute for Clinical Excellence on which hipreplacement devices the NHS should use has been delayed by a manufacturer's advance appeal.
The decision was set to be the third from NICE, which earlier this week banned the routine extraction of wisdom teeth and told dentists and surgeons to take patients off their waiting lists.
A ruling on the NHS use of drugs for ovarian cancer - taxanes - is due later this month.
More than 60 different artificial hip joints are in common use in the NHS and the choice of device rests with individual surgeons.
David Adams, chief executive of the British Orthopaedic Association, said he was expecting the decision to say 'the number of prostheses on the market may be too large'.
The guidance will spell out how long each joint lasts before it needs to be replaced.
Manufacturers can appeal against NICE decisions, on the grounds that the ruling is 'perverse' or that the appraisal process was not properly followed.
Mike Kreuzer, technical director of the Association of British Healthcare Industries, submitted evidence on hip replacements and said: 'We would like to see the faster acceptance of new technologies.'
But some orthopaedic surgeons warned that a NICE judgement could leave patients having to pay for new joints.
Richard Rawlins of Bedford Hospital trust said there was little evidence to show whether one prosthesis was better than another. 'It is a complex area.
To imagine that it can be boiled down to advice on one or two or a number of hips is simplistic. It will end up with patients having to go private.'
Hugh Phillips, president of the British Orthopaedic Association, said: 'The best outcome will be a better surveillance system for existing implants that have been put in place over a number of years and those that are new to the marketplace.'