Huge increase in spinal-fusion surgery: is it overused?

[Guest guest]

Rheumawire

Feb 18, 2004

Huge increase in spinal-fusion surgery: is it overused?

Seattle, WA - Spinal-fusion surgery has increased rapidly over the last

few years, but is it being overused? While it is undoubtedly effective

for some conditions in some patients, there is little evidence to

support its use for spinal stenosis without spondylolisthesis or for

most cases of disk herniation, say the authors of a " sounding-board "

article in the February 12, 2004 issue of the New England Journal of

Medicine [1]. They urge restraint in the use of spinal-fusion surgery

and call for controlled trials to more clearly define the associated

benefits and indications.

During a spinal-fusion procedure, the opposing bone surfaces of 2

vertebrae are roughened and packed with bone graft material, which

induces new bone formation; this bridges the gap and fuses the 2

vertebrae into a single unit. The procedure is invasive, complex, and

expensive. Instead of focusing on how best to perform this surgery,

research emphasis should shift to examining who should undergo this

procedure, say Dr Deyo and Dr Sohail Mirza (University of

Washington, Seattle) and Dr Alf Naachemson (University of Gothenburg,

Sweden).

This sentiment is echoed in an accompanying Perspective [2], which

reviews recent advances in spinal-fusion surgery. These advances are

" exciting, but they continue to provoke questions about the appropriate

clinical place for this complex surgery, " writes Dr Lipson

(Harvard Medical School, Boston, MA).

US statistics show a 77% growth in the annual number of spinal fusion

procedures from 1996 to 2001. In contrast, over the same period, the

rates for hip replacement and knee arthroplasty increased by only 13%

and 14%, the authors point out. Deyo et al suggest that this leap was

driven in part by financial incentives. They write, " Reimbursement for

spinal procedures is more favorable than reimbursement for most other

procedures performed by orthopedic surgeons and neurosurgeons. "

One reason for this rapid rise has been the introduction of many new

devices and implants. These include spinal fixation devices involving

plates and rods, the most popular of which are pedicle screws, and also

intervertebral fusion cages, perforated metal devices that are inserted

between the 2 vertebrae and filled with bone graft.

Both spurred an increase in spinal-fusion surgery rates despite the lack

of conclusive evidence from randomized trials or prospective cohort

studies that they improve clinical outcomes. Deyo et al note that these

devices are expensive, adding thousands or tens of thousands of dollars

to the cost of each operation. Clinical trials have consistently shown

no clinical advantage for fixation with pedicle screws, they point out.

In fact, some studies have shown a greater rate of complications and

rates of reoperation for fusions performed with pedicle screws compared

with those without.

" The FDA should provide closer scrutiny of spinal implants and their use

for unapproved indications, " they say. All new implants and new

indications should undergo randomized clinical trials, and rigorous

postmarketing surveillance should become mandatory.

Another reason for the increase in spinal-fusion rates has been a

widening of indications for which this procedure is used. It was

originally developed for the treatment of severe scoliosis, spinal

tuberculosis, and fractures, but these indications now account for only

a small fraction of spinal-fusion procedures, Deyo et al comment.

Approximately 75% of this surgery is carried out for spondylosis (spinal

degenerative changes), disk disorders, and spinal stenosis exclusive of

deformities. However, wide geographical variations in the use of spinal

fusion, and also in whether it is performed in conjunction with

diskectomy or laminectomy, suggest a poor level of professional

consensus on the indications.

One of the most common new indications for spinal fusion, and perhaps

the most controversial, is so-called diskogenic pain, or low back pain

without sciatica in patients with degenerative disks. This diagnosis is

typically made by provocative diskography, which involves injecting

contrast material into the possible culprit disk in an effort to

reproduce the patient's pain. As back pain and disk degeneration are

both nearly universal with aging, the number of potential candidates for

such procedures is enormous. Benefits of spinal fusion in these cases

are likely to be small, at best. At least 1 randomized trial found that

pain relief and functional improvement were no better after spinal

fusion than after a rehabilitation program focused on returning patients

to normal activities, reducing anxiety, and promoting exercise [3].

Deyo et al also caution against considering spinal fusion the gold

standard against which the ever-growing list of new devices such as

artificial disks should be measured. " If ongoing trials suggest results

equivalent to those of spinal fusion, it may be faint praise, given the

paucity of evidence that spinal fusion is safe and effective for common

indications, " they note.

Zosia Chustecka

Sources

1. Deyo RA, Nachemson A, Mirza SK. Spinal-fusion surgery - the case for

restraint. N Engl J Med 2004 Feb 12; 350(7):722-6.

2. Lipson SJ. Spinal-fusion surgery - advances and concerns. N Engl J

Med 2004 Feb 12; 350(7):643-4.

3. Moller H, Hedlund R. Surgery versus conservative management in adult

isthmic spondylolisthesis--a prospective randomized study: part 1. Spine

2000 Jul 1; 25(13):1711-5.

I'll tell you where to go!

Mayo Clinic in Rochester

http://www.mayoclinic.org/rochester

s Hopkins Medicine

http://www.hopkinsmedicine.org