Patients affected will be those allocated about 70 points on the surgical waiting list who had been recommended by specialists for surgery.
Usually, 90 points are required for joint replacements and 80 for other orthopaedic surgery, but clinicians can override the points system if they believe there are special reasons for patients to get surgery.
Board emergency medicine and surgery group manager Colleen Coop said 27 patients would be sent back to their general practitioners' care next week.
These would include people needing shoulder, hand, knee and foot procedures such as bunions. Knee and hip replacements are not affected.
A similar number of people may be referred back in May, but it will depend on the staffing situation and the pressure on services from acute admissions in the meantime.
Dr Coop said the board regretted having to return patients in this way, and it was trying to do as many procedures as possible with local anaesthetic, such as carpal tunnel surgery.
If referred patients and their doctors felt their condition was deteriorating they could return to the list.
Otago District Health Board chief operating officer Vivian Blake told the hospital advisory committee this week that while the number of trauma patients had been high over about four months, the hospital was short of six anaesthetists and beds had also been restricted by up to 24 because of staffing shortages.
Some trauma patients had been occupying beds while they waited for access to theatre and extra theatre time had to be scheduled to deal with this.
Mrs Blake said general wards were experiencing winter demand, which was "very unusual'' at the end of summer. There was no rationale to it, but it appeared to be happening in other centres too.
In total, the board has carried out more surgery on Otago patients than planned, but because the acute demand has been high, the amount of scheduled surgery has been below expectations.
At the meeting, Mrs Blake confirmed reports that the hospital would be unable to carry out as many cataract operations as planned because of the shortage of specialists.
The eye service has fewer than half the specialists it should have, although one is due to start in June. The board expects to fall short of the planned number of cataract operations by 126 by the end of June, which will mean it will miss out on about $270,000 in funding.
Board chairman Richard Thomson asked if there would be any chance of getting the operations done by having one specialist doing a "run'' on them in July, when the new specialist arrived, until the backlog was cleared. He accepted this would mean the rest of the team would still be under pressure.
Mrs Blake said while she believed the Ministry of Health would look favourably on any solutions, the availability of anaesthetists and theatres could prevent that from working.
