New Zealand faces a ''tsunami of knee replacements'' in the
coming years, placing even more pressure on health services,
a Dunedin academic says.
Consultant orthopaedic surgeon David Gwynne-Jones, Associate
Professor of Orthopaedic Surgery at the Dunedin School of
Medicine, said demand for knee replacements was ''catching
up'' rapidly to hip replacements.
''We project that knees are potentially going to be double
hips [in the coming years],'' he said.
Figures showed an increase in the number of total hip
replacement (THR) procedures in New Zealand from 4114 in 1999
to 7481 in 2012, while total knee replacements had risen from
2429 in 1999 to 6345 in 2012. In Otago, there were 432 THR
and 227 TKR procedures done in 2012.
Most joint replacements were a result of osteoarthritis,
which came about through genetics and ageing, sports injuries
and, increasingly, obesity, Prof Gwynne-Jones said.
''There is a strong association between obesity and knee
arthritis, which relates to overload on the knee joints.
''A big person puts a lot of force through a small bone - in
certain movements, you put up to five times your body weight
through parts of your knee.''
While about 80% of joint replacements were done in people
over 60 years of age, the obesity epidemic meant the
population of people needing knee surgery would likely grow
younger, he said.
Otago showed an increased demand compared to the New Zealand
average, due to the region's ageing population and a backlog
of patients due to demand exceeding provision of services in
The ''joint initiative'', introduced by the Ministry of
Health in 2004 had raised Otago's contracted rate of joint
replacement surgeries from 315 to 475 per year, but this was
reduced in 2009 to 425 surgeries per year.
However, it appeared that the clinical need for surgery was
significantly greater than this, Prof Gwynne-Jones said.
''I feel quite strongly that musculo-skeletal disease is not
getting the attention it deserves, despite the high costs [of
Health Minister Tony Ryall said the latest data showed the
Southern DHB performed a record 10,470 elective surgeries
last year, more than 1900 of them orthopaedic operations.
The Government also had many initiatives aimed at promoting
healthy lifestyles and reducing obesity and would be
introducing a new Healthy Families NZ initiative later this
year, he said.