It takes waste many people are thrilled to be rid of, stores it safely and then uses it to improve others' lives.
Orthopaedic surgeon Bruce Hodgson, happy to be referred to as one of the service's best customers, says it is one of the health sector's unsung success stories which "quietly ticks away".
Mr Hodgson uses donated bone in 150 to 200 procedures each year.
The service, run by the New Zealand Blood Service tissue bank, would not be possible without the generosity of patients having hip replacements, he said.
It is their donations of the bone (femoral heads) removed before the prosthesis is inserted which can later be used in other orthopaedic surgery.
The transfusion medicine specialist for southern New Zealand, Dr Jim Faed, said the bone bank had been collecting bone since the late 1980s.
The bone, which was crushed into chips before being reused, could be used in reconstruction work on patients having repeat hip replacements, people undergoing other surgery for major bone defects, including bone cancers, and young patients with spinal curvature having straightening or stabilising surgery.
The donated bone cells sent signals to the patient's own bone in the healing process, causing them to function more efficiently and to produce new bone.
"It's a temporary scaffold to get the healing process under way."
Eventually, the donated bone would be reabsorbed by the body and disappear.
Mr Hodgson said while in some cases the person's own bone, from the hip or pelvis, could be used in surgery, use of donor bone meant they could avoid this extra surgery and the pain associated with it.
There was a small risk of rejection, but tissue matching or immune suppressing drugs were not needed.
Mr Hodgson said the use of a person's own bone was slightly more successful than donor bone, about 95% compared with 90%.
South Island scoliosis surgery, for people with curvature of the spine, is conducted in Dunedin and Dr Faed said that at times, extra bone had to be brought in from Christchurch.
While the bone could be stored for up to five years, usually there was only about a month or two's supply ready to use.
Mr Hodgson said it was unusual for patients to refuse donor bone and he could only recall one patient in about the last 15 years to do this.
Bone bank
- Donor bone is from patients having hip replacements.
- Donors must consent and provide medical information to ensure bone is safe to use.
- Aids or HIV patients, carriers of hepatitis B or C, drug addicts, haemophiliacs are not suitable donors.
- Bone is cleaned and stored in sterile conditions at -80degC for at least six months before being used.
-It can be stored for about five years.
- Blood samples checked for illnesses which would preclude donation are taken at the time of the donor's surgery and repeated 6-12 months later as a safety measure.
