…..The jury is still out!….
First, the problem:
Affected patients complain of back pain, leg pain and weakness, worse with prolonged standing and walking, better with sitting or flexing the spin forward (such as pushing a supermarket trolley).
Next, the solution(s):
This stenosis (or narrowing) is caused by degenerative bone spurs, disc disease and ligamental hypetrophy. While many patients try conservative measures including physical therapy and epidural injections, spinal stenosis is a mechanical problem, and usually necessitates a mechanical (surgical) solution to alleviate symptoms. Consider the analogy of a blocked sewer pipe – you can try pouring chemicals down the sink, but ultimately you know you are going to need to call a plumber (Rota-Rooter)!
Traditional surgical management calls for a lumbar laminectomy to decompress the spinal canal and alleviate symptoms.
In some cases, laminectomy can leave the spine unstable necessitating a spinal fusion using bone garft, rods and screws (“hardware”) done at the same time, and this major surgery can lead to an extended recovery period of months to a year.
Implantation of a interspinous spacer has been proposed as a less-invasive alternative surgical option than spinal fusion:
Which is better?
A recent study compared the outcomes of these techniques in 99,000 Medicare patients who underwent surgery for spinal stenosis from 2006 to 2009.
6,000 patients who underwent implantation of new interspinous spacers were compared with 76,000 who underwent laminectomy, and 17,000 patients who underwent laminectomy with spinal fusion.
The results showed that patients treated with spacers had the lowest rate of major medical complications: 1.2%, compared to 1.8%with laminectomy and 3.3% with spinal fusion. Patients receiving spacers also spent less time in the hospital: average 1.4 days versus 2.7 days in the decompression group.
However, patients receiving spacers had the highest rate of revision surgery – about 17% of patients receiving spacers needed a second operation on the lumbar spine, compared to only 8.5% in the laminectomy group and about 10% in the fusion group.
Patients receiving spacers tended to be older and to have other medical problems. With adjustment for these and other factors, patients in the spacer group were more than twice as likely to require repeat surgery.
Hospital payments for spacer surgery were greater for decompression alone, but less than for fusion procedures
Other than the need for repeat surgery (presumably because initial surgery was ineffective), the study did not look at pain control or functional outcome between the groups. More data is needed.
Nevertheless, so far it looks as if the higher cost and higher re-operation rate with spacers may argue in favor of conventional decompression surgery, except in higher risk older patients with medical problems.