Interspinous process device versus standard conventional surgical decompression for lumbar spinal stenosis: randomized controlled trial.
OBJECTIVE
To assess whether interspinous process device implantation is more effective in the short term than conventional surgical decompression for patients with intermittent neurogenic claudication due to lumbar spinal stenosis.


METHODS
Randomized controlled trial.


METHODS
Five neurosurgical centers (including one academic and four secondary level care centers) in the Netherlands.


METHODS
203 participants were referred to the Leiden-The Hague Spine Prognostic Study Group between October 2008 and September 2011; 159 participants with intermittent neurogenic claudication due to lumbar spinal stenosis at one or two levels with an indication for surgery were randomized.


METHODS
80 participants received an interspinous process device and 79 participants underwent spinal bony decompression.


METHODS
The primary outcome at short term (eight weeks) and long term (one year) follow-up was the Zurich Claudication Questionnaire score. Repeated measurements were made to compare outcomes over time.


RESULTS
At eight weeks, the success rate according to the Zurich Claudication Questionnaire for the interspinous process device group (63%, 95% confidence interval 51% to 73%) was not superior to that for standard bony decompression (72%, 60% to 81%). No differences in disability (Zurich Claudication Questionnaire; P=0.44) or other outcomes were observed between groups during the first year. The repeat surgery rate in the interspinous implant group was substantially higher (n=21; 29%) than that in the conventional group (n=6; 8%) in the early post-surgical period (P<0.001).


CONCLUSIONS
This double blinded study could not confirm the hypothesized short term advantage of interspinous process device over conventional "simple" decompression and even showed a fairly high reoperation rate after interspinous process device implantation.


BACKGROUND
Dutch Trial Register NTR1307.
Department of Neurosurgery, Leiden University Medical Center, Leiden, Netherlands.
Wouter A
WA
Moojen
Mark P
MP
Arts
Wilco C H
WC
Jacobs
Erik W
EW
van Zwet
M Elske
ME
van den Akker-van Marle
Bart W
BW
Koes
Carmen L A M
CL
Vleggeert-Lankamp
Wilco C
WC
Peul
D000368:Aged; D000369:Aged, 80 and over; D019299:Decompression, Surgical / Q000295:instrumentation / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007383:Intermittent Claudication / Q000209:etiology / Q000601:surgery*; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D011446:Prospective Studies; D019736:Prostheses and Implants; D013130:Spinal Stenosis / Q000150:complications / Q000601:surgery*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome