Surgeons at Middlemore operate on 120 spinal injuries each year, and 25 of those deal specifically with spinal cord issues.
Consultant orthopaedic spine surgeon Alpesh Patel said the $1 million machine gives surgeons greater confidence, particularly where the anatomy is complicated.
"The main benefit is the accuracy when we're putting metalware into the spine.
The navigation system linked with the O-Arm allows us to place the screws in the optimal position to avoid damage to nerves or the spinal cord or to major vessels.
"We can also then place screws in places like the upper cervical spine, which is below where the neck attaches to the skull.
"It gives us a bigger scope to put screws in the spine that you wouldn't have without the machine."
Patel said there have been no returns to surgery to correct mistakes since using the O-Arm.
People with severe spinal cord injuries at smaller hospitals from Taupo northwards will be referred to Middlemore to be treated.
A recent case where the use of the O-Arm allowed a young woman who had sustained critical injuries in a car crash to walk again has special significance for Patel.
The 21-year-old woman was walking the next day, and a week later she flew back to Australia.
According to ACC, the average cost of rehabilitation following a spinal injury is $6.2m, more than doubling to $13.2m if the injury happens before the age of 20.
Patel said it was too early to know exactly how much using the O-Arm system will affect the cost of recovery.
"It's difficult to put a number value on that, but it has definitely been a worthwhile investment."
About 130 people suffer from spinal cord injuries each year.
Of those injuries, 39 per cent are caused by motor vehicle accidents, 24 per cent from sport and recreation, and 20 per cent are a result from falls.
