The Royal College of Surgeons has hit out at cost-cutting plans to ration who can receive hip and knee replacements.
Three Clinical Commissioning Groups (CCGs) in the West Midlands have proposed slashing the number of people who qualify for hip replacements by 12% and introducing a 19% cut over who is eligible for knee replacements.
Board papers reported by the Health Service Journal (HSJ) suggest an "opportunity to reduce expenditure on hip and knee replacement surgery" by £2m a year.
This would include only treating "severe to the upper end of moderate" cases, and people who are obese with a body mass index of 35 or over needing to lose 10% of their weight unless their problems were very severe.
Patients in pain would now need to have such severe levels of pain that they cannot sleep or carry out daily tasks.
Documents said a "patient's pain and disability should be sufficiently severe that it interferes with the patient's daily life and/or ability to sleep".
Redditch and Bromsgrove, South Worcestershire, and Wyre Forest are the CCGs that intend to change their scoring system for eligibility, hoping to prevent about 350 operations needing to be carried out each year.
But the Royal College of Surgeons has said there is "no clinical justification" for their plans.
The move is the latest in a round of cost-cutting by CCGs - with some slashing access to treatments, expensive drugs and IIVF despite guidelines from the National Institute for Health and Care Excellence (Nice).
Stephen Cannon, vice president of the Royal College of Surgeons, said: "We appreciate that the CCGs face significant financial challenges which now mean they are looking at which groups of patients they can target to save money.
"While the CCGs have stated they hope this policy will save them £2 million a year, it is unclear whether they have considered the costs of not treating a patient.
"This could include the cost of pain relief medication and a later operation when the patient does meet the required pain and weight thresholds.
"Delaying access to surgery also adversely affects a patient's quality of life and surgical outcomes, meaning the operation may not be as beneficial as if it had been carried out earlier."
He said the scoring system used by the CCGs - known as the Oxford scoring system - were designed to measure outcomes of care "and should not be used to create barriers to care".
He added: "Such criteria are in explicit contravention of Nice and surgical commissioning guidance, and have no clinical justification in being applied to a general population to determine who gets NHS treatment.
"This policy is the latest demonstration of how NHS financial pressures are directly affecting patients."