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Orthopaedic joint replacement surgery rates jump in developed nation as populations ageFri, 06 May 2016

The benefits speak for themselves 

By Nicki Bourlioufas

Orthopedic surgeries are experiencing some of the greatest growth rates in developed nations across the world, highlighting that as populations age, demand is growing for procedures which can dramatically improve the quality of a person’s life.

In Australia, high growth rates have been reported particularly for hip and knee surgeries, which also account for much surgical activity, reflecting trends in other developed nations. Procedures involving surgery for musculoskeletal conditions increased by 18% between 2006–07 and 2010–11, according to data from the Australian Institute of Health and Welfare (AIHW), Surgery in Australian hospitals 2010-11.

Almost 23% of all surgical procedures in 2010-11 were for procedures on the musculoskeletal system, with 81% of these occurring in private hospitals. The most common age group for hospital procedures involving musculoskeletal surgery was 55 to 64.

For elective hospital admissions in Australia, one of the most common reasons for hospitalisation was knee disorders. For emergency admissions, one of the top five common reasons for hospitalisation involving surgery was a hip fracture.

For people unresponsive to medication, several studies show that joint replacement surgery is a cost-effective intervention that restores joint function, helps relieve pain and improves quality of life. The ageing of the Australian population, and the osteoarthritis that comes with it, has been a big driver of demand for orthopedic procedures.

The hospitalisation rate for Australians with osteoarthritis increased in the 10 years to 2013–14 to 415 hospitalisations per 100,000 population from 362 hospitalisations per 100,000 population in 2004–05, AIHW data show. Moreover, the rate of knee replacement increased to 169 per 100,000 population from 128 over the same period. The rate of hip replacement increased from 83 to 104 per 100,000 population.

As joint replacements do not last forever, some people required revision surgery. Based on data from the Australian Orthopaedic Association National Joint Replacement Registry, there were 4,307 revision hip replacements and 4,104 revision knee replacements reported in 2014. There is about a 5% chance of revision surgery within 10 years of a hip or knee replacement, the AIHW says in this report, Hospitalisation for osteoarthritis.

Between 2003 and 2014, revision hip replacement increased by 19.2% in the private sector and 33.8% in the public sector. Over the same period, revision knee replacements increased 78.1% in the private sector and 75.3% in the public sector. Second revisions of knee and hip replacements occurred in more than 20% of people who had a first revision, according to the AIHW.

In Europe, also with a relatively wealthy and older population, very high growth rates have been reported for hip and knee replacement surgeries.

Between 2008 and 2013, the frequency of secondary hip replacements increased in 14 of the 17 EU Member States. By 2013, for every seven hip replacements carried out in the EU, there was approximately one secondary hip replacement. Rates for secondary replacements were as high as 54.5 times per 100 000 inhabitants in Italy, a country with one of the world's oldest populations, according to official EU statistics, Surgical operations and procedures statistics.

Total knee replacement posted one of the highest growth rates for procedures performed in the EU. Between 2008 and 2013, the frequency of total knee replacement increased in all of the EU Member States for which data are available, except for Germany, Cyprus, Latvia and Lithuania.

Total knee replacement was performed 215 times per 100 000 inhabitants in Austria, 210 times per 100 000 inhabitants in Switzerland, 160 times in Luxembourg in 2013 and 164 times in Malta, which also has one of the world’s oldest populations. This group notably includes some of the world's wealthiest nations, where the population is willing and able to pay for procedures that enhance quality of life.

Hip replacements themselves are very high in demand in the EU, being performed 280 times per 100 000 inhabitants in Germany, 276 times per 100 000 inhabitants in Austria and 301 times per 100 000 inhabitants in Switzerland in 2013 and 201 times in Luxembourg. In poorer EU countries, such as Turkey and Cyprus, the rates for hip replacement were much lower, below 50 per 100 000 inhabitants.

So the EU data shows that the wealthier the nation, and in some cases the older its population, the greater the rate of orthopedic surgery.

In the UK, the National Health Service says in this media note, Surgery and the NHS in numbers, with continuing innovation, an increasing number of medical conditions are being remedied or managed by surgery. In that country, the main specialty for surgeons is trauma and orthopedic surgery. The area with the greatest surgical activity is general surgery, followed by trauma and orthopedic surgery.

Out of the top five surgical procedures most commonly performed in England in 2013-14, hip replacement was the second most common procedure (115,758 surgeries) and knee replacement (81,590) was the third most common procedure.

The main procedures undertaken by English orthopedic surgeons are joint arthoscopy, fracture repair, arthroplasty or replacement of whole joints, general repair procedures on damaged muscle or tendon and corrective surgery.

In the US, orthopedic surgeries are similarly the most common surgeries performed in hospitals in that country with some very high growth rates. Rates of hospitalisation for knee replacement and spinal fusion approximately doubled between 1997 and 2010. The rate of hospitalisation with hip replacement (15 stays per 10,000 population) increased 38% over the same period, according to this US government report, Most Frequent Procedures Performed in U.S. Hospitals, 20101 published in 2013.

A separate study from 2014, Most Frequent Operating Room Procedures Performed in U.S. Hospitals, 2003-20122 found that the most common inpatient operating room procedure in the US in 2012 involved the musculoskeletal system. Knee arthroplasty, spinal fusion, and hip replacement were among the top five most frequently performed procedures for both men and women.

The most common US procedure was knee arthroplasty, which had a rate of 223 times per 100 000 population, well ahead of the next most common hospital procedure, percutaneous coronary angioplasty, with a rate of 170 times. Next was laminectomy (removal of part of a spinal vertebra) (149 times), the same rate also being reported for hip replacement (total and partial). Spinal fusion closely followed at 144 times.

Of the eight million total non-maternal and non-neonatal hospital stays with an operating room procedure in the US, five of the seven most common procedures involved the musculoskeletal system—these were knee arthroplasty (700,100 stays), laminectomy (468,200 stays), hip replacement (468,000 stays), spinal fusion (450,900 stays), and partial excision bone (338,000 stays). Two other common musculoskeletal procedures were trauma-related (treatment of hip fracture and treatment of other lower extremity fracture).

The US data show that comparing payer groups, knee arthroplasty was the most common operating room procedure for hospital stays paid by Medicare (10.8% of stays) and by private insurance (9.1%).

So orthopedic surgeries are not only accounting for a high number of surgeries in the US and other countries, but growth rates for hip and knee replacements are often very high due to ageing populations in developed nations.

And it is wealthier nations that account for relatively higher levels of surgical activity, as the EU data highlights. A separate study published in The Lancet in 2008, An estimation of the global volume of surgery3, backs this finding. That study found that per-head total expenditure on health by individual nations was strongly correlated with rates of major surgery. In other words, the more countries spent on healthcare, the more the population accessed surgery.

That study, which examined surgical data for 56 of 192 WHO member states, found that countries spending US$100 or less per head on health care had an estimated mean rate of major surgery of 295 procedures per 100 000 population per year, whereas those spending more than $1000 have a mean rate of 11,110.

Middle-expenditure ($401–1000) and high-expenditure (>$1000) countries, accounting for 30·2% of the world’s population, provided 73·6% of operations worldwide in 2004, whereas poor-expenditure (≤$100) countries accounting for 34·8% of the global population undertook only 3·5% of all surgical procedures in 2004.

Back in Australia, separate statistics from Private Healthcare Australia4 show that expenditure on hip and knee replacements outstrips most other surgical procedures in the private health sector due to high volumes. In 2012-13, private health insurance funds paid benefits for 16,680 hip replacements performed in Australian hospitals, a 19% increase from the previous year.

The total benefits paid by health funds for hip replacements increased by 21% from the previous financial year to $414 million in 2012-13 from $342 million in 2011-12.

The average benefits paid including cost of hip prosthesis was the highest in Victoria, being more than $25,000 for an episode without complications. In comparison, $22,000 was paid in benefits for the same procedure in the ACT. The average benefits paid for an episode with complications was highest in the ACT, being almost $28,000. Average benefits for a similar procedure in TAS were $22,500.

In 2012-13, the overall number of hospital episodes related to knee replacement that were funded by private health insurance was 25,132, increasing by 41%. The total benefits paid including knee prostheses were $522 million, an increase from $401 million in the previous year.

The highest benefits paid were for a procedure with complications, with an average payment of $22,233. For a procedure without complications, the average benefit per episode was lowest in the ACT at $17,888, and highest in Victoria at $20,423.

But several studies and patient surveys from Australia and abroad find that both hip and knee replacements are cost-effective interventions to improve people’s quality of life of people. In a 2011 study of Australians with osteoarthritis, Cost-Effectiveness of Total Hip and Knee Replacements for the Australian Population with Osteoarthritis5, the authors measured how the total replacement of hips and knees in men and women with osteoarthritis aged over 40 years reduced disability-adjusted life-years (DALYs). The study found that both hip and knee replacements are “highly cost effective to improve the quality of life of people with osteoarthritis” ($5,000 per DALY and $12,000 per DALY respectively). The exclusion of cost offsets, and inclusion of future unrelated health care costs in extended years of life, did not change the findings that the interventions are cost-effective ($17,000 per DALY and $26,000 per DALY respectively), the researchers found.

The incremental cost-effectiveness ratio (ICER) for knee replacements without cost offsets was $21,000, or $26,000 including unrelated health care costs, per DALY averted with time costs, and was about half that for hip replacements ($12,000, or $15,000 including unrelated health care costs, per DALY).

An earlier study in Australia from 2004, Priority setting in osteoarthritis6, also reported favourable cost-effectiveness, measured by ratios of $4,535 to $6,953 per quality-adjusted life-years (QALY) for hip replacement and $7,671 to $11,671 for knee replacement.

“Even if cost of surgery is somewhat underestimated, performance will still be favourable. It should also be noted that a recent study has indicated that there is substantially lower use of health-care resources by people who are post total hip replacement (THR) and total knee replacement (TKR) surgery compared with prior to surgery (March et al., 2002). This cost saving has not been included in these estimates, but will only increase the benefits from (THR)/TKR surgery,” the 2004 study noted.

Similarly, a 2007 European study, Effectiveness of hip or knee replacement surgery in terms of quality-adjusted life years and costs7 found that both hip and knee replacements improve health-related quality of life. The cost per QALY gained from knee replacement is twice that gained from hip replacement. Of 15 health dimensions, there were statistically significant improvements in moving, usual activities, discomfort and symptoms, distress, and vitality.

A later UK study from 2013, Predicting the cost-effectiveness of total hip and knee replacement: a health economic analysis8 , found that the cost per QALY for total hip replacement was £1372 compared with £2101 for total knee replacement. The number of QALYs gained was higher after total hip replacement (6.5 years) than after total knee replacement (4 years).

“Total hip replacement and total knee replacement are extremely effective both clinically and in terms of cost effectiveness, with costs that compare favourably to those of other medical interventions,” the study found.

So, the evidence is strong: common orthopedic procedures like hip and knee replacements are cost-effective surgical interventions to boost people’s quality of life. Demand for such procedure will only rise as populations in developed nations not only live longer, but are required to work for longer.




1 Most Frequent Procedures Performed in U.S. Hospitals, 2010, Statistical Brief #149, Anne Pfuntner, Lauren M Wier, MPH, and Carol Stocks, RN, MHSA.

2 Most Frequent Operating Room Procedures Performed in U.S. Hospitals, 2003-2012, Statistical Brief #186, Kathryn R. Fingar, Ph.D., M.P.H., Carol Stocks, Ph.D., R.N., Audrey J. Weiss, Ph.D., and Claudia A. Steiner, M.D., M.P.H.

3 An estimation of the global volume of surgery: a modelling strategy based on available data Thomas G Weiser, Scott E Regenbogen, Katherine D Thompson, Alex B Haynes, Stuart R Lipsitz, William R Berry, Atul A Gawande, Vol 372 July 12, 2008 4 Variations in Care – Hip and Knee Replacement, February 7, 2014

4 Variations in Care – Hip and Knee Replacement, February 7, 2014

5 Cost-Effectiveness of Total Hip and Knee Replacements for the Australian Population with Osteoarthritis, Hideki Higashi and Jan J. Barendregt, 0025403, September 23, 2011

6 Priority setting in osteoarthritis, Leonie Segal, Susan Day, Adam Chapman, Richard H Osborne, Monash University, Centre for Health Economics, Centre for Health Economics Research Papers 01/2004

7Effectiveness of hip or knee replacement surgery in terms of quality-adjusted life years and costs, Räsänen P1, Paavolainen P, Sintonen H, Koivisto AM, Blom M, Ryynänen OP, Roine RP, Acta Orthop. 2007 Feb;78(1):108-15.

8 Predicting the cost-effectiveness of total hip and knee replacement: a health economic analysis, Jenkins PJ1, Clement ND, Hamilton DF, Gaston P, Patton JT, Howie CR, Bone Joint J. 2013 Jan;95B(1):115-21

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