A new study shows hip and knee operations aren't keeping up with demand.
New research reveals a surge in unmet demand for hip and knee replacements in Otago - up 19 percent since 2012.
Author of the study, orthopaedic surgeon David Gwynne-Jones, says they have "significant problems".
"[The] drive for shorter wait times for elective surgery has not been matched by any significant increase in joint replacement numbers in our region," he says.
Patients who previously would have met the threshold for joint replacement surgeries are often being referred back to their GP for for ongoing conservative management - which means patients are now suffering for longer.
The research, published in the New Zealand Medical Journal, shows patients undergoing hip and knee replacement in Otago in 2014 were more severely disabled than between 2006-2010.
University of Otago Professor Gary Hooper says that can also lead to further complications and more expense.
"Operating on 'end-stage' osteoarthritis can be surgically demanding, resulting in the use of more expensive implants, more extensive rehabilitation and intensive nursing -- all of which require added resources," says Mr Hooper.
With an ageing population the problem is likely to become increasingly widespread across the country.
Health Minister Jonathan Coleman says the Government's increased the number of elective surgeries but admits it has to continue to do more.
"Public funding for hip and knee replacement will soon only be for the most severely affected," says Dr Gwynne-Jones.
Others may have to consider private insurance or self-funding their surgery.
Dr Coleman says the Government isn't looking at alternative schemes and is focusing on providing operations through the public system.