the 522,800 hip replacements is 16 percent more than the 451,600
predicted by 2020 in the JBJS. Even savvy statisticians miss the mark,
consistently underestimating the impact of even commonly performed
operations.
In patients sixty-five and over (almost 100 percent of whom have
Medicare insurance), there were 315,400 hip replacement operations in
2014, representing the second most common operating room procedure
among that age group.^8 Hip replacements in 2014 were the third most
costly inpatient stays in America, averaging over $17,000 per stay, which
is over 5 percent of all costs associated with admission to US hospitals. As
will be seen, pacemaker operations are twice as expensive, and heart valve
operations are three times as expensive as hip replacement, but because
they are less commonly performed are less costly overall than hip surgery.
The aggregate costs for hip replacement hospitalization (not counting
outpatient therapy and nursing) is over $8 billion dollars, which is, all by
itself, more than the entire 1967 Medicare budget for hospital care. What
started in a tiny workshop in Lancashire, northwest England, at the hands
of Sir John Charnley, has grown into one of mankind’s most effective
interventions, occurring almost one million times per year in America as
you read this book, if you combine its use for arthritis and fracture. The
old saying in orthopedics that “man enters life through the womb but
exists through the hip” is not nearly as true as it used to be, and we can
thank Charnley for that. It was cheaper to fold an afghan over the
incapacitated legs of an invalid with a fracture—but not very effective or
humane.
Total knee replacement numbers are more sobering. Arthroplasty of the
knee is the second most expensive procedure in America, costing almost
$12 billion in 2014.^9 In fact, the six most commonly performed
musculoskeletal operations account for one-quarter of aggregate costs of
all inpatient stays in America, totaling $41.2 billion in 2014.^10 In the year
2014, there were 723,100 total knee replacements performed in US
operating rooms.^11 The same 2007 JBJS article referenced above forecast
1,641,00 knee replacement operations by 2020 (7 percent of which are
predicted to be revision operations), and 3,749,00 total knees by 2030 (of
which 268,000 are estimated to be revision operations).^12 Based on 2014
AHRQ data, wherein the average cost of knee arthroplasty is $16,300,