Hip resurfacing is often seen as a modern alternative to the more conventional
total hip replacement, but new data from a study led by Rush
University Medical Center in Chicago, USA, suggest that a patient’s
age and gender are key to the operation’s success. The study will be published
in the December issue of the Springer journal Clinical Orthopaedics and Related
In a review of over 500 surgeries performed in the United States using a hip
resurfacing device recently approved by the Food and Drug Administration (FDA),
the researchers found that the majority of serious complications occurred in
women of all ages and men over the age of 55. The most common complication,
and the most serious, was a fracture of the femoral neck, the slender area of
bone just beneath the head of the femur.
In hip resurfacing, the femoral head remains, but its surface is reshaped to
accept a rounded cap with a short stem that sits in the femur. A thin metal
cup is pressed into the hip socket. Both components are made entirely of cobalt
chrome, a metal.
“The ideal patients for hip resurfacing are males under the age of 55.
They have the fewest, and the least serious, complications,” said Dr.
Craig Della Valle, lead author and a specialist in joint reconstruction. “Patients
may be eager to take advantage of technological innovations, but for older individuals,
a conventional hip replacement is generally more appropriate.”
The researchers analyzed data for the first 537 hip resurfacing surgeries performed
in the United States after the Birmingham Hip Resurfacing implant, manufactured
by Smith & Nephew, was approved by the FDA in October 2006. The majority
of the patients suffered from severe osteoarthritis. All 89 orthopedic surgeons
involved in the procedures had undergone training required by the FDA before
conducting their first cases. Their level of experience with hip surgery varied.
Some were joint replacement specialists; others were general orthopedic surgeons.
Serious complications occurred in 32 of the 537 cases, including 10 cases in
which the femoral neck fractured after surgery, a problem not seen with conventional
hip replacements. Such fractures require additional surgery. Nine of the fractures
in the study occurred in patients who were either female or older than 55 at
the time of the implant. Eight of the fractures occurred when the surgeon was
relatively inexperienced with the procedure (within the surgeon’s first
“Patients who are older or who are female tend to have softer bone,”
Della Valle said. “Also, men on average have larger bone structures, with
a greater surface area for securing the implant.”
Hip resurfacing is generally recommended for younger, more active patients
out of concern that the traditional artificial hip might wear out during their
lifetime and require a second replacement, a far more complicated surgery.
“Hip resurfacing has certain advantages over the conventional total hip
replacement,” said Della Valle. “It preserves more bone because
the head of the femur is retained. But despite its benefits, risks remain. Our
findings suggest that we need to be cautious. This procedure is not ideal for