New research shows nearly 40 percent of patients who need hip and knee operations in at least two district health boards are not getting them because of budget restrictions.
The study, published in The New Zealand Medical Journal, which looked at Northland and Hawke's Bay, found the drive to cut wait times has left 36 percent of patients with moderate to severe pain and disability untreated.
Dr James Blackett , who led the study on the impact of waiting targets, said the Health Ministry has publicised the reduction in wait times to six months, now five, moving to four in January next year.
But he said not enough was known about the consequences.
"That's really great that we've reduced waiting times, but that does has resulted that 36 percent of people are missing out because they won't get their surgery done within that time-frame ... we just want patients and their treating physicians to be aware of that."
A recent high-level review of the elective waiting time goals was performed at the request of the Director General of Health.
It noted that wait times had reduced, but no data was collected on the outcomes for patients who did not reach the threshold for treatment.
Christchurch surgeon Philip Bagshaw, chairman of the Canterbury Charity Hospital Trust, said focusing on wait times rather than waiting lists was "a great way of hiding the scale of the problem".
"It's become smoke and mirrors. They've created a self-fulfilling prophecy, so they say the waiting list is only six or four months, but that's because they only allow that many people onto the waiting list."
Mr Bagshaw said other debilitating conditions, from cataracts to varicose veins, haemorrhoids and hernias, simply did not get done in the public system - at least until there are serious and costly complications.
The trust, which is entirely funded by donations, helps Canterbury residents who do not have health insurance and cannot afford to pay for private surgery.
"Investing in health early on is not only humane but also makes good economic sense because to do things in a timely way is the cheapest way.
"If you deny people treatment ... they come back later with bigger complications and cost more money."
The president of the Orthopaedic Association, Wellington surgeon Brett Krause, said half of those referred by their GPs never even get a specialist assessment and in some regions, it is more than 50 percent.
He said there was then a second cut-off point, when the wait-time limit is applied, "which is essentially an artificial measure".
Mr Krause said surgeons were reporting that they were not seeing people they should be seeing and not treating people they should be treating, "simply because the health boards would exceed their four-month time limit".
"So from that point of view, I don't think the four-month mark is a sensible mark."
Mr Krause said surgeons were keen to work with health boards and the Ministry to find better ways of managing those patients who were not getting operations, including more access to physiotherapy and pain management.
However, he said it was unavoidable that more orthopaedic resources were going to be needed to deal with the ageing population: more surgeons, nurses, physios, theatres and hospital beds.
The Health Ministry has recently begun collecting information on patients waiting for specialist referrals over a three-year period, but that data is not yet available.
However, the Ministry's manager of performance for electives, Clare Perry, said patients who were referred back to their GPs were "not hidden to the system or lost".
"They have been referred back so that there can be ongoing monitoring of their condition."
Ms Perry said the most effective way to deal with unmet demand was to do more operations.
"This has been occurring. In 2007/8, there were 117,863 elective surgical discharges. In 2013/14 there were 162,169.
"This is a 37 per cent rise over six years."